Food Engineering
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Item A Study on The Flour Properties and Qualities of Wheat-Based Biscuits Supplemented with Faba-Bean and Cassava Flour(Addis Ababa University, 2023-09) Gebremedhn Brhane; Shmeles Shumi (PhD)Faba beans and other legumes are significant due to their high nutritional value. The goal of this study is to investigate on the flour properties and qualities of wheat-based biscuits supplemented with faba-bean and cassava flour. The study examined the proximate composition of both (composite flour and biscuit flour), rheological, and functional properties. Besides mineral content, total energy, gluten content, texture, color attribute, and sensory evaluation have been studied. The formulation for composite flour was developed using a D-optimal mixture design ratio applying Design-Expert®, version 13. Accordingly, 16 composite flour samples were developed (T1, T2……. T16 and control sample) and evaluated using the standard method. The gluten content of wheat flour was significantly different from the whole formulated composite flour and also the samples were significantly different from each other at (p<0.05). The proximate composition shows that the crude protein content of faba-bean flour (23.13±0.00%) is two times more than that of wheat flour (11.75±0.00%) and eight times more than that of cassava flour (2.9±0.02%), respectively. Whereas, composite flours show lower water absorption capacity and higher oil absorption capacity and water solubility than wheat flour. The result showed that the pasting temperature range was 72.55 to 76.70 °C compared with the pasting temperature of the control sample (89.65 °C). Moreover, biscuit developed from 40.5% wheat flour, 40% cassava flour and 19.5% faba-bean flour biscuit looked almost similar to the wheat flour biscuit in all aspect with overall acceptability of 8.05±0.64. In this study the 40.5% wheat flour, 40% cassava flour and 19.5% faba-bean flour biscuit was found to be the most acceptable biscuit and had high crude protein, crude fiber and low gluten content. On the other hand, adding faba-bean flour to wheat-cassava flour positively affects the physical, chemical, color attribute, texture, alkaline water retention capacity, staling rate and sensory characteristics of the biscuits.Item Accelerated Shelf-life Prediction and Quality Characterization of Edible Cotton, Peanut and Soybean Seed Oils Produced in Ethiopia(Addis Ababa University, 2017-10-23) Addisu, Alemayhu; Shimelis, Admassu (Assoc.Prof.)Edible oils are regarded as an important component of the diet because they are source of energy, essential fatty acids, and also provide characteristic flavors and textures to foods. The purpose of this research study was to determine the qualities of edible cottonseed, peanut and soybean oils processed in Ethiopia and predict their shelf-life using ASTM. The AOAC method of Analysis was employed in the determination of the physical and chemical characteristics of the oils. The result obtained for edible soybean, peanut and cottonseed oils, respectively were; specific gravity at 20/20OC: 0.929, 0.943 and 0.922, refractive index at 20OC: 1.48850, 1.48508, and 1.48565, photometric color index: 5.262, 15.908 and 216.316, insoluble impurities: 0.001, 0.004, and 0.013% (w/w), moisture content: 0.210, 0.219 and 0.220% (w/w), peroxide value: 1.299, 2.398, and 3.396meq O2/kg of oil, iodine value: 136.740, 97.536 and 101.112grams of iodine absorbed/100g oil, Saponification value: 210.345, 210.779 and 208.411mgKOH/g, unsaponifiable matters: 0.169, 0.069 and 0.383% (w/w), and acid value: 0.420, 0.630 and 0.561mgKOH/g. Fatty acid profiles were also determined by GC-MS as methyl esters. The results showed that the predominant fatty acid in edible soybean and cottonseed oils was linoleic acid 42.807 and 41.587%, respectively while oleic acid (46.252%) was major fatty acid in edible peanut oil. The shelf-life of edible oils was tested applying ASTM. The oils were subjected to three different elevated temperatures: 35, 45 and 55OC in acceleration chamber and hydrogen peroxides formation were monitored for six successive weeks. The evaluation was performed graphically (fitting of experimental data to a linear equation) after completion of the experiments. Accordingly, the model that best fitted the experimental data corresponds to a zero order kinetic model for all edible oil investigated. Arrhenius relation was applied to model that effect of temperature on the rate constant of peroxide formation. Combining the kinetic model identified and the rate constant model equation, a general shelf-life model equation that could help to predict the shelf-life of oils studied at any temperature was developed. Employing predictive model developed, the shelf-life of the domestic edible oils was determined at room temperature (25OC) and amounts 36.9 weeks for soybean oil, 42.1 weeks for peanut oil and 37.8 weeks for cottonseed oil. The result obtained for most physicochemical quality parameters of the edible oils considered were within the standard range indicated by Ethiopia Standard Agency. From fatty acid profile analysis it can be concluded that edible soybean, peanut and cottonseed oils are an excellent source of essential fatty acid omega-6 (linoleic acid) and omega-9 (oleic acid). Comparatively edible peanut oil had longer shelf-life than edible soybean and cottonseed oils. The shelf-life of properly refined edible oils is typically 12 – 18 months at ambient temperature. From shelf-life assessment, all edible oils investigated scored lower shelf-life. So, to minimize the oxidation of edible oils and maximize the shelf-life, it is recommended to use: antioxidants, sequestering agents and selection of appropriate packaging material (colored glass bottle). Besides, FFAs are more susceptible to oxidation than the glycerol esters of these fatty acids. Therefore, any increase in the acidity of the oil must be absolutely avoided during refining of the oil.Item AComparative Study on Selected Tomato Varieties for Manufacturing Paste(Addis Ababa University, 2016-06) Abdu, Jemal; Edecha, MekonenThe favorable climatic condition, vast irrigation sources, abundant labor and other factors in Ethiopia are viable for the production and processing of tomato fruits, generally for fruits and vegetables. Tomato and tomato-based products are important sources of many established nutrients that have health benefits. This study aimed to compare the performance of selected local and foreign tomato varieties for manufacturing paste. The pastes were produced from three raw tomato varieties namely; Galilea (GL), Galilema (GLM), and Melkasalsa (MS). The Merti tomato paste in cans was used as a control sample which is commercially available in the market. The raw tomato and pastes proximate contents were determined using standard methods of analysis. Moreover, fruit weight, firmness, viscosity, and pH analyzed by instruments whereas Vitamin C and titratable acidity were determined using titration method. The samples were analyzed in triplicate. The data were analyzed using SPSS statistical software to compare the mean values of tomato varieties at the probability level of P < 0.05. The results of raw tomato varieties proximate analysis showed in the range: moisture (94.1 - 96.3%), ash (0.58 - 0.63%), protein (4.94 – 5.25%), fat (0.01 - 0.49%) and fiber (1.7 - 1.78%) whereas pastes result shows moisture (73.4-83.9%), ash (2.9 - 3%), protein (11.46 – 15.14%), fat (0 - 0.5%), and fiber (2.36 - 4.09%). Raw tomato varieties physicochemical analysis results showed in the range: fruit weight (47.86 – 63g), firmness (4.09 – 4.13Kg), titrable acidity (0.541 – 0.462%), pH (4.32 – 4.51), viscosity (6.5 – 10.7mPa.s), natural total soluble solids (4.3 - 4.8°Brix), and vitamin C (16 – 17.6mg/100g) and color rating scale 6 whereas pastes natural total soluble solids (16 - 24°Brix), titrable acidity (0.73 – 1.0%), sugar-acid ratio (21.92 – 29.63), pH(4.3 – 4.5),viscosity (0.8 – 2.12Pa.s) and vitamin C (11 – 14.11mg/100g) and the color(13 – 17SRM). From all the above quality parameters, the most criteria for tomato paste varieties selection are total soluble solids, firmness, color, and moisture contents. Results showed that Galilea and Galilema have high total soluble solids (24°Brix) while Melkasalsa has low (16°Brix). Therefore, the study identified that local Galilema varieties are the best performance of paste at industry level. Key words: Tomato, Paste, Physicochemical Properties, Variety, Manufacturing, Proximate AnalysisItem Activation of Peanut Shell Using Phosphoric Acid for The Bleaching Process of Niger Seed Oil(Addis Ababa University, 2019-06) Shikur, Wudu; Kumsa, DIn this study, a two-stage process was conducted. The first stage was carrying out for the activation process of Peanut shell powder at different temperatures and concentrations to select the optimum parameters. The second stage was bleaching of Niger seed oil using the chosen activated peanut shell powder adsorbent. The peanut shell collected from Sululta, Ethiopia was activated by phosphoric acid, and further bleaching experiments were conducted to assess the activated powders effect on the bleaching capacity of Niger seed oil. The Two key parameters of the acid activation process were acid concentration and activation temperature. The highest bleaching capacity was obtained around 3M acid concentration and at 350 o C of activation temperature as optimal activation. The PSP and PAAPSP at optimal condition were characterized by XRD, FTIR and SEM with EDS. The results of the XRD showed that the PSP is composed of cellulose, hemicellulose and lignin polysaccharide. The XRD analysis of PAAPSP illustrated the presence of crystalline carbonaceous structure and different alumino silicate minerals. X-ray and FTIR data confirmed that acid activation degrades cellulose. The results of the analysis by Energy Dispersive Spectroscopy (EDS) showed that, presence of carbon, oxygen, silica, alumina and phosphorous. Full factorial Box Behnken design (BBD) experimental design was employed to correlate the bleaching parameters (temperature, time and dosage of PAAPSP) to the percentage color reduction for Niger seed. The result showed that the optimum condition for the bleaching process was a temperature of 110 o C, a period of 20 minutes and 3% PAAPSP dosage which resulted in 88.02% bleaching performance of the Niger seed oil. The experimental result was in agreement with the model prediction. Generally, the study has shown that the phosphoric acid activated peanut shell powder is a good adsorbent for the bleaching of the Niger seed oil. This research has further established that acid activated peanut shell powder has the capacity to remove not only pigments but also reduce the free fatty acid and peroxide value of unbleached oil.Item Aflatoxin Content of Peanut (Arachis hypogaea) in Relation to Shelling and Storage Practice of Ethiopian Farmers(Addis Ababa University, 2010-06) Legesse, Eshetu; Abate, Dawit (PhD)The threat of aflatoxin contamination in food commodities and its association with health risks in both animals and humans continues to raise increasing concern over years. In this research, A. flavus species found in association with peanuts in storage and their potential to produce aflatoxin in collected samples was determined. About 11 to 87% of collected peanut samples were infected with various moulds including Rhizopus sp., Fusarium sp., Aspergilus flavus, A. niger, other Aspergillus sp., Penicillium sp., and other undefined sp. Aspergillus flavus is known to be the most patent aflatoxigenic strains infects 80.69 % of the total samples analyzed. Eighty five percent of the tested isolates of A. flavus were capable for the production of aflatoxins. From the total of 52 peanut (Arachis hypogaea) samples analyzed, 38 (73.06 %) were positive for aflatoxin. The average levels of aflatoxins detected in the seed samples were between 0.57(from Babile new harvest sample) to 447.02 ppb (from Babile three month stored in pp bag). The higher level of toxicity is more than twenty times greater than the acceptable dosage (20 ppb: US Standards) in peanuts of three month stored after wet shelling. This research pointed out that the storage and shelling practice of farmers have effects in aflatoxin contamination in peanut despite enormous efforts to control this mycotoxin. Keywords: Peanuts (Arachis hypogaea), A. flavus, aflatoxins, shelling and storage practiceItem Anchote (Coccinia abyssinica (Lam.) Cogn) Starch and Flour Modification Using Hydrothermal Treatments and Valorization as Functional Ingredients in the Development of Food Products(Addis Ababa University, 2024-06) Yohannes Toles; Shimelis Admassu (Prof.)Anchote (Coccinia abyssinica (Lam.) Cogn) is an underutilized root and tuber crop indigenous to Ethiopia and potentially an important source of starch. The native users cultivate anchote for its medicinal, economic, nutritional, and socio-cultural benefits. The anchote tuber has a significant number of beneficial nutrients, such as carbohydrates, protein, fat, fiber, and different minerals. Compared to other root and tuber crops, this crop is renowned for its vital protein and calcium content. Anchote tubers have a high starch content (75–79%), making them a suitable alternative source of starch for use in several industrial applications. However, understanding the physicochemical properties of starch generated from such underutilized roots and tubers is critical in order to develop unique value-added products. The quality of starch is determined by its physicochemical properties, which include its morphology, particle size, amylose content, crystallinity, thermal properties, and swelling powers. However, there is still a dearth of studies on important anchote starch properties from different genotypes: the rheological properties of anchote starch gels, intrinsic characteristics like storage texture kinetics, and the effect of starch concentration on the gel rheological properties of anchote starch gels, which are so important for their food applications. Thus, this study examines the properties of native and hydrothermally modified starches from four anchote tuber cultivars and compares them to potato and cassava starches. It also investigates the effects of hydrothermal modifications on the pasting, morphological, and thermal properties of anchote flour-starch mix. The study also examines the impact of partial replacement of gluten-free teff flour with modified anchote flour-starch mixes on gluten-free biscuits. The granule sizes of the anchote cultivars varied, but they all exhibited a B-type crystalline structure similar to that of potato starch. The amylose content of anchote starches ranged from 15.8–22.3%. The phosphorus in anchote starches ranged from 82 to 93 mg/100 g, which is much higher than that of potatoes and cassava (60.3 and 5.8 mg/100 g, respectively). This high phosphorus content influences the functional properties of anchote starches, making them well-suited for use in various types of noodles, glucose syrups, and viscous products. Anchote starches had a significantly different gelatinization temperature and enthalpy than potato and cassava starches, ranging from 60.97 to 69.33 °C and 16.87 to 18.38 J/g. Significant differences were also noticed in the pasting properties of anchote cultivar starches. In comparison to potato and cassava, they demonstrated greater stability to heating and shearing, with higher trough viscosity (TV) (2046 to 2280 mPa·s), lower breakdown viscosity (BV) (248 to 487 mPa·s), and a higher final viscosity (FV) (3409 to 3686 mPa·s). These properties are significant in the food processing industry and when high gel viscosity is needed after cooling. In comparison to cassava and potato gels, anchote starch gels displayed considerably greater viscoelastic moduli and much lower (tan δ)1 values. These rheological features are typical of true gels. According to the present findings, anchote starch had acceptable color characteristics that were similar to those of potato and cassava starches. The anchote starch exhibited lightness (L*) and whiteness values above 95 across different cultivars. As the cooking temperature increased from 40 - 90 °C, the swelling power (SP) and water solubility index (WSI) of anchote starches demonstrated a clear rise. It's important to note that the rate of increase differed significantly from that of the control starches, with anchote starches showing a lower increase compared to potato starches and cassava starch in the following order: anchote starches < potato starches < cassava starch. Compared to potato (PS) and cassava (CS) starch gels, anchote starch gels had lower (tan δ)1 values and demonstrated better elasticity, withstanding higher stresses before breaking their structure. In addition, they were more stable at higher concentrations and exhibited higher viscoelastic moduli even at lower concentrations than the PS and CS gels. The study of the textural evolution of the gels over storage revealed that anchote starch gels were less adhesive than PS gel and had initial and final hardness that was significantly higher (≥40%) after 192 hours. The hydrothermal treatments (ANN and HMT) significantly altered the pasting characteristics of anchote starches. The pasting properties (PV, TV, and BV) were decreased significantly after HMT and ANN treatment. HMT significantly reduced the PV of anchote starches compared to ANN treatment. The lower BV values obtained in all studied cultivars show the higher stability of modified anchote starches to thermal treatment and mechanical shearing. The ANN treatment significantly (p < 0.05) increased the final viscosity (FV) compared to HMT and native anchote starches. The rheological property shows the dominance of the elastic over the viscous behavior, having higher G′ values than G″ in the entire frequency range for all studied starch gels. The G′, G′′, and (tan δ)1 values were significantly decreased upon HMT treatment, while ANN treatment significantly increased the G′ and G′′ of anchote starches related to the native starches. Both HMT and ANN increased gelatinization temperatures and decreased enthalpy in all cultivars studied. The study found that the B-type structure of anchote starches remained unchanged after hydrothermal treatments. However, ANN and HMT treated anchote starches had higher relative crystallinity compared to native starches. These results showed that ANN and HMT treatments efficiently modified the rheological, pasting, and thermal properties of anchote starches isolated from four cultivars. The hydrothermal treatments significantly (p < 0.05) affected the pasting properties of anchote flour (DF) and anchote flour-starch mix (DFS). The PV and BV of DF and DFS anchote samples were decreased upon ANN and HMT treatment. The addition of anchote starch to anchote flour significantly improved color characteristics, and carbohydrate contents in both native and hydrothermally modified samples. The study showed that HMT and ANN treatment significantly (p < 0.05) reduced the phytate, tannin, and total phenol contents in both DF and DFS, while the HMT treated samples had the lowest phytate contents compared to ANN and native samples. Likewise, the study showed that the hydrothermal treatments significantly affected the hydration properties (WAC, OAC, SP, and WSI) of studied DF and DFS. The HMT and ANN treatments did not affect the FTIR spectra of studied anchote samples. However, hydrothermal treatments raised the gelatinization temperatures (TO, TP, and TC) of DF and DFS. The results revealed that hydrothermal treatments enhanced the thermal stability of DF and DFS samples. As a result, it appears that the HMT and ANN anchote flours would be appropriate for applications requiring heat stability. The growing consumer demand for gluten-free food products has led to an increased need for innovative gluten-free ingredients that offer improved nutritional benefits. Thus, this study examines the impact of the partial replacement of gluten-free teff flour (TF) by modified anchote flour-starch mixes (HMT-DFS and ANN-DFS) on the physical, nutritional and sensory characteristics of gluten-free biscuits. The result showed that the color, proximate compositions, pasting, and functional characteristics of the gluten-free flours used in this study varied significantly (p < 0.05). HMT-DFS and ANN-DFS flours had higher L*, a*, b*, and whiteness values compared to TF flour. The protein contents of gluten-free HMT-DFS and ANN-DFS flours were almost similar, while those of TF flour had a slightly higher protein content. But HMT-DFS and ANN-DFS had significantly higher ash contents and lower fat and fiber contents compared to TF. The pasting properties of the studied flour samples varied significantly (p < 0.05). The lowest BV value of the ANN-DFS and HMT-DFS samples shows that they have the highest stability to thermal treatment and mechanical shearing; thus, these samples are ideal functional ingredients in formulations of food products that require higher thermal treatments. The study showed that substituting gluten-free HMT-DFS and ANN-DFS flours for teff flour did not affect biscuit thickness, but slightly increased spread ratio. However, the inclusion of HMT-DFS and ANN-DFS significantly influenced color features. The study also found that incorporating anchote flour-starch mix into teff flour significantly affected color characteristics at higher substitution levels. The study found that gluten-free biscuits AB10, AB20, HB10, and HB20 had superior physical and sensory properties compared to control biscuits. These biscuits had higher ash, fat, and fiber contents than the control WB biscuits and comparable values with the control TB biscuits. The study also found that incorporating a modified anchote flour-starch mix in gluten-free teff flour biscuits enhanced proteins, carbohydrates, energy values, and mineral contents, making it a useful functional ingredient for gluten-free formulations. Therefore, the present findings showed that the hopeful potential utilizations of modified anchote flour and starches as functional ingredients in food processing, product development, novel food product formulations, and additional industrial applications.Item Byproducts Utilization from Wheat Milling Industries for Development of Value Added Products(Addis Ababa University, 2014-03) Yishak, Yemsrach; Admassu, Shimelis(Professor)The main byproducts of wheat milling industries, wheat germ and bran, have been known as an outstanding sources of protein, dietary fiber, trace minerals, antioxidants, phytochemicals and allied micronutrients. This research was conducted to evaluate utilization of wheat germ (WG) and wheat bran (WB) for the development of value added cookies and tea substitute products; respectively. Supercritical fluid extractor (SFE) was used to extract oil from wheat germ and the defatted wheat germ flour (DWGF) was used as a supplement for wheat flour at 10%, 15% and 20% blending ratios (BR1, BR2 &BR3) and baking temperatures of 150, 180 and 210 oC (T1, T2 &T3).Wheat bran (WB), the other byproduct of wheat milling industries, used to made tea substitute by milling, screening, and heating before utilized as final product. Chemical composition of raw materials, physico-chemical and rheological characteristics of flours were investigated prior to cookies preparation. Proximate analysis for wheat flour (WF)(0.83,11.92,0.52,0.45,9.33) and defatted wheat germ flour (DWGF) (4.72, 12.98,1.01,5.17,28.11); for ash, moisture, fat, fiber and protein were resulted respectively; as a result nutrient dense DWGF used as a substitute for development of cookies . It was found that protein, fiber, ash and minerals (Ca, K, P, and Mg) contents in the blends increased significantly (P<0.05) with an increase in DWGF substitution. The effect of BR2 and T2 on proximate composition resulted with (protein (14.29), fiber (2.84), and ash (1.31)) resulted better together with sensory quality evaluation. Rheological and functional properties of flours, physical properties for cookies and organoleptic properties for both products were analyzed. Total phenolic content (TPC) and antioxidant activity were determined by using Folin-Ciocalteu and DPPH scavenging activity assays respectively. Extraction procedure went out using methanol at three different temperatures (40, 60 and 80)0C. Higher total phenolic content ranged from 1.037 to 3.68mg of gallic acid equivalent (GAE)/gm of dried extract obtained at 60 0C using methanol. While antioxidant activity with lower half maximal inhibitory concentration (IC50) (mg/ml) value of (1.4, 1.75, 2.13) scavenging activity for ascorbic acid, methanol solvent extract of wheat bran and by absolute methanol respectively. Finally, cookies baked at 180oC using blend ratio 15 % resulted better sensory qualification and wheat bran extracted using solvent methanol at 60oC showed potential antioxidant activity and TPC. Keywords: defatted wheat germ, cookies, antioxidant, folin-Ciocalteu assay, DPPH scavenging capacity assayItem Characterization and Optimization of Casimiroa (Casimiroa edulis L) Fruit Juice(2018-06-05) Tesfaye, Zeru; Adamu, Zegeye (Ass. Prof.)Casimiroa (Casimiroa edulis L.) is a climacteric fruit with potential for commercialization due to its organoleptical quality. The fruit is native to the Mexican and the Central American highlands. This fruit is found in different parts of Ethiopia and it is underutilized. The objective of this study was to characterize casimiroa fruit pulp and to optimize the level of ingredients (Casimiroa fruit pulp, water, citric, acid and sugar) and process variables (incubation temperature, incubation time and enzyme concentration) optimization for juice production. The raw materials, Casimiroa fruits, were collected from Areka Agricultural Research Center, Dire Dawa and Kombolcha. Physico-chemical and sensory properties of the fruit pulp were analyzed. Based on the analysis results, fruits collected from Dire Dawa were selected for ingredients and process variables optimization. For ingredients formulation and optimization Mixture de-optimal design was employed and 15 combined randomized runs were generated and optimized. Response Surface Method was employed for process variables optimization. After selecting the optimized ingredients, process variables were employed to treat the optimized ingredients produced. A total of 20 randomized runs of process variables were generated and 15 of them were exposed to analysis. The results generated were subjected to one-way analysis of variance (ANOVA) model using the SPSS software program (version 20) and analyzed using a second order polynomial equation. The result revealed that 75 % fruit pulp, 21.25 % water, 2.63 % sugar and 1.13% citric acid were the best combination of optimized ingredients. Furthermore, the optimized process variables were 42.50 Characterization and Optimization of Casimiroa Fruit Juices Using RSM Page iv o C, 65 minutes and 0.11 % of incubation temperature, incubation time and enzyme concentrations, respectively. The sensory scores ranged between 6.000– 8.907, 6.852– 8.856, 6.517– 8.790, 6.632- 6.566- 8.184 and 6.008– 8.769 for colour, taste, flavor, appearance, mouth fill and an overall acceptability, respectively. The moisture, protein, fat, fiber, ash, energy, pH, titratable acidity, total soluble solid, clarity, viscosity, Sodium, Potassium, calcium, iron, Zink, Phosphorous, Tannin, phytate, total phenolics, total flavonoids, vitamin-c, B-carotene, and overall preference taste results in the optimized product were 83.235%, 0.785%, 0.491%, 0.988%, 0.977%, 61.655Cal, 4.720, 0.079 mg/100 ml,17.708 o Brix, 1.613 Abs, 210.350 mPa.s, 26.251mg/100g, 194.437mg/100g, 23.634mg/100g, 2.964 mg/100g 0.732mg/100g, 25.383mg/100g, 7.991mg/100g, 8.118 mg/100g, 47.431 mg GAE/g, 21.491mgQE/g, 21.071 mg/100g, 11.814 µg/g, 8.769, respectively. In conclusion, Optimized casimiroa fruit juice can be produced using 75 % fruit pulp, 21.25 % water, 2.63 % sugar and 1.13 % citric acid) with process variables of 42.5 o C, 65 minutes, and 0.11 % of incubation temperature, incubation time and enzyme concentrations respectively. In so doing, Casimiroa fruits can be utilized in Ethiopia and becomes more commercialized. Hence besides to its nutritional benefits, it will create job opportunities.Item Characterization of Hass and Fuerte Avocado (Persea americana) Varieties Grown in Wondogenet and Optimization of Some Oil Extraction Parameters(Addis Ababa University, 2017-11) Kenbon, Beyene; Shimelis, Admassu (Assoc.Prof.)The purpose of this research was to determine the physicochemical characteristics, proximate, mineral and the phytochemical composition of pulp and seed of two avocado cultivars, namely Fuerte and Hass, produced in Wondogenet, Ethiopia with respect to the unripe and ripe. Furthermore, extraction of oil from Hass avocado pulp using soxhlet and ultrasonic extraction and some process parameter optimization were carried out. The percentage oil yield, analysis of chemical properties and fatty acid profile of extracted oil were done. The basic characteristics evaluated were weight (of the fruit, pulp, seed, peel and seed coat), Dry matter (DM), Total soluble solid (TSS), pH, Titratable acidity (TA), Moisture content (MC), ash, total lipid, fatty acid composition, protein and minerals. The concentrations of phytochemicals (total phenolics, flavonoids, tannin, and phytate) were also analysed. Hass avocado cultivar showed greater flesh to seed ratio (13.57±10.43) and had lower fruit weight (183.92±47.58g) than Fuerte cultivar. The highest pulp MC (77.82±0.19%), protein (2.92±0.04%), ash (0.42±0.01%), fat (22.80±0.00%) and crude fiber (4.50±0.09%) corresponds to UHP except MC which is to UFP. The analyses of the nutritional compositions demonstrated that the pulp of the Hass proved to be rich in ash, fiber, total lipid, protein and potassium content than fuerte pulp. The seed, in turn, had higher DM (48.4±1.02%), TA (2.88±0.02%), Mg (2.01 ±0.02%), Na (12.67±0.01%), and Ca (24.77±0.02) mg/100g, wet basis contents than its pulp. With regard to the contents of phytochemicals, the seed was superior to the pulp. The effects of three factors (particle size, solvent to sample ratio and extraction time) on the oil yield were considered. The optimum extraction conditions for soxhlet extraction were found to be at 8 h reaction time, particle size of 1.4mm and solvent to solid ratio of 20:1 with a maximum yield of 69.7%, while the optimum extraction conditions for ultrasonic extraction were found at 1.5 h reaction time, particle size of 2mm and solvent to solid ratio of 15:1 with a maximum percentage yield of 67.2%. The analyses of the oil characteristics demonstrated that the oil extracted by soxhlet extraction shows lower PV, FFA, MVM and Alkalinity than oil extracted using Ultrasonic extraction. The results of fatty acid profile displayed that the oleic and linoleic acid contents of the soxhlet extracted oil were higher than that of the Ultrasonic extracted oil while palmitic and butanoic acid were higher in ultrasound extracted oil. Generally, Hass avocado variety was found to be better interms of pulp to seed ratio, proximate composition and minerals. Ultrasound assisted extraction showed a promising oil yield regarding short extraction time and low solvent consumption; but its oil quality is lower than that of soxhlet extracted oil.Item Characterization of Heat-Moisture Treared Starch from Locally Produced V. Faba for The Improvement of Freeze-Thaw stability of “Siljo” Paste(Addis Ababa University, 2011-06) Abebe Moges; Shimelis Admassu (PhD)Functional properties of granular and heat moisture treated (HMT) starches isolated from locally grown V. faba CS-20-DK variety were studied for their effect on the freeze-thaw stability of Siljo paste. Faba bean grain was dehulled, milled, sieved and fractionated into, course (>125μm), medium (80-125μm), and fine (< 80μm) size flour particles. Flour fractionates were slurred in a tap water and separated into supernatant and primary starch residue (PSR) using batch centrifuge. Sieving into fine flour particle resulted in higher carbohydrate (79.36%), lower protein, fat, ash, and fiber distribution, and highest starch yield (52.76%) and least nitrogen (0.08%) and ash (0.05%) contents in the total solids of PSR. Starch yield is comparable with 37% yield from horsebean flour obtained by Kawamura et al (1955) method. The starch obtained from fine flour fractionate was subjected into HMT at 19%; 23%; and 27% (d.b) moisture levels, treated in a hot air oven at 1000C for 16hr, and then dried and milled. The effect of temperature on hydration properties and least gellation concentration (LGC) were determined as a measure of water retention capacity of retrograded starch of granular and HMT starch was investigated. Hydrothermal conditioning led to restricted swelling power (SP) and significant increase in water solubility (WS) and water absorption index (WAI) with the level of conditioning moisture. In all investigations highest SP, WS, and WAI of starches in the temperature range of 85-950C suggests that water penetration into the granules can be achieved at elevated temperature. HMT resulted in increase hydrophilic tendency and conversely decreased the hydrophobic tendency. Except HMT19%; LGC of all HMT starches progressively decreased with the increase in conditioning moisture level. Percentage of retrogradation was decreased after HMT. Degree of retrogradation between the 1st and the 4th days starch gels storage was investigated in the range 100-100% (granular); 85-100% (HMT19%); 52-89% (HMT23%); and 48-84% (HMT27%). The effect of partial substitution of HMT starch at various concentrations (9%, 23%, and 38%) on the freeze-thaw stability (% syneresis) of Siljo paste was evaluated. The highest and the least percentage of syneresis were 167% for normal flour and 73% for the 37.5% HMT27% substituted flour. The incorporation of HMT starch resulted in improved resistance of Siljo paste against the re-crystallization process upon cooling. Application of HMT starch is recommended for the production of sauces and soups with a better stability at ambient or refrigerated storage conditionsItem Characterization of Local Honey and Development of Honey Based Extrudate(Addis Ababa University, 2014) Milkias, Misikir; Zegeye, Adamu(Professor)Ethiopia ranks first in Africa and tenth in the world in honey production. This study aimed at developing honey-based extruded ready-to-eat products and determining the physico-chemical parameters of honey from three distinct areas of Ethiopia. Accordingly, honey samples obtained from Oromiya (yellow), Tigray (white) and Gonder (red) areas were analyzed. A blend of rice with wheat (60:40%) flour was first formulated, and thereafter, 5%, 10% and 15% of this composite flour was replaced by the same amount of honey for the preparation of extruded snack. The design experiment produced 20 different combinations using Response Surface Methodology to investigate the effect of the response variables, lateral expansion, bulk density, color, water absorption and solubility index characteristics. The effect of each honey sample was studied separately and multiple regression equations were obtained to describe the effects of each variable on product responses. The results of the yellow honey analysis showed that it has 22%moisture, 0.273%ash, 4.1pH, 31.5%fructose, 33.9%glucose, 0.7%sucrose, 2.7%maltose, 7meq/kg free acidity, 0.52%water insoluble matters and 0.61μS/cm electrical conductivity; White honey contained 19%moisture, 0.155%ash, 4.1pH, 35.9%fructose, 31.5%glucose, 1.4%sucrose, 0.0%maltose, 5meq/kg free acidity, 0.56%water insoluble matters and 0.41μS/cm electrical conductivity. Red honey contained 19%moisture, 0.039%ash, 4.2pH, 35.4%fructose, 31.4%glucose, 3.3%sucrose, 4.6%maltose, 6meq/kg free acidity, 0.62%water insoluble matters and 0.22μS/cm electrical conductivity. For the purpose of optimization, the process parameters of 115 to 135oC BT, 270 to 350rpm SS and 5 to 15% honey were selected as independent variables. Results showed that increasing the barrel temperature resulted in extrudate with higher expansion, water absorption index, a* value and lower bulk density and L* and b* values. Increasing screw speed resulted in higher expansion, water solubility index, L value and lower bulk density whereas, increasing honey proportion of feed composition resulted in higher a* value, bulk density, water solubility index and lower expansion, water absorption index and L*value. The graphical optimization studies resulted in temperatures of 124.68, 125.12, 124.19oC, screw speed of 310.35, 309.88, 309.79rpm and amount of honey 9.69, 9.89, 9.66% as optimum variables for yellow, white and red honeys respectively. This is similar with the value 125oC BT, 310rpmSS and 10%honey obtained by panelists during sensory analysis for all types of samples. Accordingly white honey-based extrudate was found to be the best and addition of this honey upto 10% was selected as ideal for snack making. Key word: Extrusion, Extrudate, Honey, Response surface methodologyItem Chemical Composition and The Effects of Traditional Processing on Nutritional Composition of Gibto (Lupinus Albus. L) Grown in, Gojam Area(Addis Ababa University, 2009-06) Getachew, Paulos; Umeta, Melaku(PhD)Lupin seeds (Lupinus albus), grown in Ethiopia (Gojam area) were nutritionally investigated. This study was conducted in order to evaluate the effects of some commonly applied traditional processing methods on the nutritional and chemical composition of Lupinus albus. Traditional processing methods are observed to be effective in reducing anti-nutritional factors, meanwhile their effects on the nutritional composition is not wel investigated. Accordingly, the current study focused on the effects of traditional processing methods on the nutritional and chemical composition of Lupinus albus. Three traditional processing methods (i.e. soaking after roasting for 5 days, soaking after boiling for 5days, and germination for 48 hrs) were taken under investigation. The parameters analysed were proximate composition, anti-nutritional factors, mineral composition and fatty acid profile. The official methods used were AOAC (2000), Osborne and Voogot (1978), Haborne (1973) and Latta and Eskin (1980) for Proximate composition and fatty acid profile analyses, mineral analysis, total alkaloid determination, and phytate content analysis respectively. The hull size of the two cultivars from Dangla and Tilili were 16.22% and 19.30% respectively. Moisture, protein, fat, crude fiber, ash, utilizable carbohydrates and gross energy for the Dangla sample were 6.94, 37.87, 9.34, 11.08, 2.80, 38.92% and 391.19 (KCal/100 gm) respectively. Similarly, for the Tilili sample the values were 8.04, 39.71, 8.79, 11.07, 2.90, 37.56% and 388.12 (KCal/100 gm). The anti-nutritional factors studied were total alkaloids and phytate. The results for the Dangla sample were 2.46% and 144.33 mg/100 gm for total alkaloids and phytate respectively. Similarly, for the Tilili sample the values were 2.26% and 143.96 mg/100 gm. The mineral composition of the two cultivars was also investigated. Accordingly, the Dangla sample has 6.00, 2.11, 58.43, 8.93 mg/100 gm contents of Fe, Zn, Mn and Mg respectively. The values of the same types of minerals for the Tilili sample were 6.72, 1.81, 63.54, 59.14 and 9.46 mg/100 gm respectively. In the two cultivars an average value of 24.5% saturated and 74.5% unsaturated fatty acid levels were recorded. The un-saturated fatty acids found in the oil are predominantly, Oleic and Linoleic acid, while the saturated ones include Palmitic, Stearic and Eikosanic acids. Traditional processing methods have shown both an increasing and decreasing effects on the various chemical and nutritional compositions of the raw seed. Among the treatments the commonly used soaking after roasting method was found to reduce the alkaloid content effectively, at same time showing improvement in the nutritional composition. Nutritional compositions like protein and oil have shown an improvement on soaking after roasting treatment. The mineral composition of the raw seed was also affected by the various treatments applied. Except for Zn content all the minerals analyzed have shown a reduction in the treatments. Mn content was found to exceed the safety limit for daily intake. The effects of soaking after roasting and boiling on the fatty acid profile of the oil were insignificant. But germination has reduced the contents of some of the fatty acids significantly. In all the cases the predominant un-saturated fatty acid found on both sample types was oleic acid. It can be concluded that Lupinus albus was an excellent food source with high nutritional value. The total alkaloid content can be reduced effectively after the various traditional processing methods such as soaking after roasting and boiling. These processes including germination also have a potential to enhance the nutritional composition of the raw seed. After some of the treatments (i.e. except germination) the oil content has increased. And having high amounts of un-saturated fatty acids and oil content, it could be a potential oil crop. Key words: Lupinus albus, soaking, roasting, boiling, and germinationItem A Comparative Study on Physicochemical Properties of Starch Isolated from Varieties of Cassava Grown in Ethiopia and its Evaluation as Bio-edible Packaging Film(Addis Ababa University, 2021-09) Desta, Geta; Shimeles, Shumi (PhD)Starch extracted from different sources and varieties show various physicochemical properties which affect its applications. Considering this, the aim of this research was to study the physicochemical properties of starches extracted from Qulle (Q) and Kello (K) cassava varieties and their evaluation for making bio edible packaging film. Starch was extracted by wet extraction method using distilled water. The study showed that the proximate compositions of Kello starch were: moisture content (11.4%), ash content (1.1%), crude fat content (0.11%), protein content (0.52%), crude fiber content (0.01%) and total carbohydrate (86.85%). Whereas for Qulle starch: moisture content (10.6%), ash content (0.13%), crude fat content (0.13%), protein content (0.35%), crude fiber content (0.09%) and total carbohydrate (88.7%). Furthermore, the content of amylose and amylopectin of each varieties of starch were calculated and found to be 26.29 %( Q), 73.7 % (Q) while, 19.16 % (K) and 80.83% (K) respectively. It was observed that the high peak and breakdown viscosity values found for Kello starches is due to low amylose content. Films were prepared by casting method and the results showed that for Kello film: moisture content (13.25%), transparency (11.625%), thickness (0.13mm), tensile strength (13.554MPa), water absorption (33.08%) and solubility (26.37%).While for Qulle film: moisture content (11.62%), transparency (12.30%), thickness (0.12mm), tensile strength (14.983MPa), water absorption (29.39%) and solubility (28.85%). Generally, Qulle starch was better for the development of bio-edible packaging film due to its low moisture content, low ash content, low protein content, and contain high amount of amylose.Item Comprehensive Study on Oil Extraction from Papaya (Carica) Seed and Analysis of its Characteristics, Bioactive Components and Antimicrobial Properties(Addis Ababa University, 2024-03) Mekdes Amare; Shimelis Admassu (Prof.)The utilization of whole fruits and vegetables, including the typically discarded parts during food processing, presents an opportunity to reduce agro-industrial waste. This study focused on evaluating the proximate and nutritional potential of Carica papaya seeds and its oil. The oil from papaya seeds was characterized, and the effects of operating parameters (moisture content, temperature and heating time) on oil yield were investigated using a screw expeller. The Box-Behnken design was utilized for the experimental design, and response surface methodology was used to assess the effects and significance of the models on the response variable (oil yield). The maximum extraction efficiency 24.248%. achieved with a moisture content of 6.32 %, heating time of 9.82 minutes, and temperature of 69.54℃. Furthermore, the byproducts obtained from the screw press meal and cake underwent oil recovery through Soxhlet extraction, and the effects of moisture content, particle size, and extraction time were evaluated. Moreover, Physical and chemical properties of the oil also evaluated. Despite the growing interest in papaya seed oil, there is a lack of comprehensive research on its bioactive components and antimicrobial properties. Gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) analysis were employed to identify these components and functional groups for different extraction methods and also Total Phenolic content and Flavonoid content, were determined using standard methods. The results showed an average total Phenolic content of 19.41 ± 1.33 mg GAE/ml of sample and 2.25 ± 0.787 mg QE/g Total Flavonoid content. Antimicrobial properties were assessed using the agar diffusion method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through broth dilution methods. The oils exhibited effectiveness against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli. MIC values ranged from 3.125 to 12.5 μl/ml, while MBCs varied from 6.25 to 50 μl/ml.Item Cowpea-wheat Value Added Products Development and Quality Evaluation(Addis Ababa University, 2017-10) Moges, Yilma; Shimelis, Admassu (Assoc.Prof.)The study was conducted in order to develop products with bole type-cowpea flour incorporation in to wheat flour (Mangudo) to achieve nutritional quality product and to reduce celiac problem which is arise from gluten content of wheat flour. The blended flour of wheat (mangudo variety ) and bole type cowpea flour were prepared in ratio of B1(90,10), B2 (40,60), B3 (65,35), B4 (78,22), B5(53,47),B6(100,0)(control), respectively with D-optimal design software. In this study; grain quality analysis, blended flour (physical, functional and proximate composition) analysis, physical and functional properties, proximate composition, mineral analysis, microbial load determination, bioactive component and sensory evaluation of biscuit and flake extrudet products were investigated. The biscuit samples were prepared with each blended flours dough at 205 0C oven temperature for 10 minutes. The bulk density, water absorption and water solubility index, fracture strength, proximate and microbial load were determined. Bulk density ( 0.701g/cm3),water absorption and water solubility index(203.26 &23.383%), fracture strength (10.58N), proximate composition( moisture:5.392%, wb, crude fiber:2.2%, Fat:11.632%, crude protein:15.972%, ash:1.93%, carbohydrate:62.872%),microbial load (aerobic bacteria:44* 10-5 cfu, yeast and mold: un-detected) of biscuit sample B3 (65% wheat and 35% cowpea flour). The highest overall sensory evaluation score of biscuit sample was 7.6 comparable with like very much (B3) next to the control sample B6. The extrudet also prepared with twins screw extruder parameter on barrel temperature (100, 110 and 120°c), feed moisture (18 and 21%) and screw speed (175 and 220 rpm) after determined the flour flow screw speed rpm and water pump stoke level. Proximate composition and microbial load of flake extrudet sample (Ex-3) were determined. Proximate composition (moisture: 6.35%, wb, crude fiber: 2.22%, fat: 0.67%, crude protein: 15.915%, and carbohydrate: 72.34%) and microbial load (aerobic bacteria: 42*10-5, yeast and mold: un-detected). The highest overall sensory evaluation of extrudet score was 7.14 (Ex-3) which was above like moderately next to the control Ex-6. Based on the sensory result and further analysis, cowpea flour could substitute 35% of wheat flour in biscuit and flake extrudet product development with better nutritional quality.Item Decolorization of Raw Cane Sugar Syrup by using Activated Carbon Made from Sugarcane Bagasse(Addis Ababa University, 2019-06) Mebt, Kibret; Beteley, Tekola (PhD)Activated carbon is used in sugar industries for the removal of colorants from sugar liquor. It is also used for treatment of potable water as well as industrial wastewater. Coal is a commercially used activated carbon, which is a limited non-renewable resource. However, there are different renewable resources such as sugarcane bagasse, peanut shells, rice husk, rice straw, coconut shells, which could be used as alternatives. The aims of this study were to decolorize raw cane sugar by using activated carbons prepared from renewable low cost sugarcane bagasse (SCB) and to investigate the effects of reagent to precursor ratio and activation temperature on decolorization efficiency. SCB was ground to the desired particle size, screened and characterized for powdered activated carbons (PAC) preparation. Sodium hydroxide (NaOH) at 0.25:1.0 and 0.5:1.0 impregnation ratio (IR-reagent to precursor) was used as an activating agent. The carbons were prepared in a carbonization process in an inert environment with a nitrogen gas flow rate of 0.2 l/min at temperatures of 500°C and 600°C for three hours. Using the same temperature and activation time but without reagent, bio-chars were also prepared for control and reference purpose to compare and contrast effects of reagent on prepared carbons properties and adsorption efficiency. The prepared carbons were characterized for their proximate and surface properties. Carbon yield, amount of burn off and bulk density were also determined for each sample of prepared carbons. Decolorization efficiency of each carbon was batch tested using ICUMSA method. The effects of carbon dose, raw sugar solution (syrup) concentration, solution temperature, and adsorption time on decolorization efficiency were studied in this experiment. The adsorbent prepared at a temperature of 600°C and 0.5:1.0 IR gave the best quality with respect to carbon yield (25.5204 %), bulk density (0.4022g/ml) and decolorization efficiency (56 %). The second best quality adsorbent, in terms of these parameters, was the carbon prepared at 5000C with the same IR having the results of 29.9081 %, 0.4028 g/ml and 40 % respectively.Item Determinations of Optimum Maturity Indices and Storage life for Selected Avocado Cultivars Grown in Wendo-genet (Southern Ethiopia)(Addis Ababa University, 2017-07) Hailu, Tsegay; Worku, Teshome( Asst Perofesser)This study was conducted to determine the optimum maturity indices and storage life for selected avocado cultivars grown in Wendo-Genet: South Ethiopia. Maturity has a pronounced effect on the physical, nutritional and chemical compositions, and post-harvesting quality attributes of avocado fruit. Avocado fruit quality parameters such as, physico-chemical properties, dry matter and oil content of the mesocarp, and oil characteristics, of Hass and Fuerte avocado cultivars were conducted to determine the optimum maturity indices and acceptable fruit quality. Besides of that the effect of storage temperature on the shelf life, weight loss, and chilling injury of Hass avocado cultivar harvested which stored at 2, 5, 8 and 20 oC for 7, 14, 21 and 28 days was investigated. Fuerte and Hass avocado cultivars were harvested at their early, middle and late harvesting period in 2017 from Wendo-Genet Agricultural Research Center (March to May at one-month intervals). Statistically, significant differences between the avocado cultivars were observed in terms of fruit weight, percent of pulp to whole fruit weight ratio, pulp and seed weight during the harvesting season (March to May). Both dry matter and oil content of both cultivars increased significantly (p < 0:05) with harvesting time of the fruits. Dry matter of Hass and Fuerte avocado fruits gradually increased from 17.89 ± 2.36 to 29.11 ± 2.27% and 18.22 ± 1.811 to 28.73 ± 1.88%, respectively, from March to May. Similarly, oil content of Hass and Fuerte avocado fruits gradually increased from 6.66± 0.1 to 19.21±1.00 respectively. Avocado oil characteristics: oil content, acid value, peroxide value, and free fatty acid value of the two avocado cultivars at different harvesting time were examined. The oil characteristics result showed that both avocado cultivars harvested in March, April and May were within the range for acceptable condition for consumers as reported by different authors except for the free fatty acid which was slightly higher. Inter-cultivar differences of total soluble solids, and weight loss were found to be significantly different as the harvesting period goes from March to May while pH value showed insignificant difference among the cultivars. The storage experiment revealed that storage temperature affected the shelf life and quality of Hass avocados. Hass avocado fruit stored at 5 oC for 4 weeks had longer shelf life with medium chilling injury than the fruit stored at 2 oC which showed high chilling injury within 3 weeks storage time. The fruit stored at 8 oC and 20 oC had shorter shelf life, developed browning mesocarp, and rapidly ripened in short time. Storage at ambient temperature (20°C) resulted in high weight loss as compared to 2 and 5 °C storage temperatures due to increasing respiration rate and transportations of water from the fruit to the environment at higher temperature. As a result of this study; the optimum harvesting period of Hass and Fuerte cultivar were determined to be in April in terms of fruit dry matter 22.827%and 22.7.0 % and oil content 11.43% and 14.53% respectively for the cultivars. The storage of Hass avocado at 5°C for 4 weeks was the optimum storage condition causing less chilling injury and weight loss and maintaining better fruit quality. Keywords: Avocado (persea americana Mill.), Maturity indices, fruit quality, oil characteristics, storage, harvesting period.Item Development and Characterization of Bread from Mushroom and Wheat Composite Flour(Addis Ababa University, 2015-06) Alemu, Genenu; Zegeye, Adamu(Professor)This study was focused on substituting a part of whole wheat flour (WWF) with mushroom flour (MF) to develop mushroom bread for children, as an attempt to solve the problem in protein energy malnutrition of children from 1-5 years. The effect of mushroom supplementation on some physico-chemical and sensory properties of wheat bread was determined, as well as the dough rheological properties(farinograph) of the whole wheat flour with various proportions of the protein- rich mushroom flour were investigated. Examination of the functional properties of two different flours and breads were carried out. Analyses were made for different formulated bread and compared with the recommended daily allowance (RDA). The crude protein, crude fat, crude fibre ,ash and energy of the composite bread loaves increased significantly (p < 0.05) from 10.21% to 23.92%, 1.72% to 1.92%, 1.59% to 2.57% ,0.88% to 2.69% and 275.4kcal to 276.45kcal, respectively ; while the moisture content and carbohydrate decreased with increased level of supplementation from 30.84% to 28.02%, and 54.76% to 40.89% respectively. There was also a decrease in bulk density and bread volume by 22.22% and 44.86% respectively, with progressive inclusion of the mushroom flour. The sensory analysis showed that there was no significant difference (p < 0.05) in texture, taste, flavour and overall acceptability up to 12.5% substitution with mushroom flour. In this study, it was attempted to optimize the ingredient formulation and processing parameters of MF incorporated bread such as nutrient and sensory score responses. D – Optimal design was used which consists of WWF and MF, with 13 formulations for the nutrient and sensory score of the MF incorporated bread. The result showed that the optimized acceptability of the MF incorporated bread containing WWF 80.86%, MF 19.14%, protein 34g, energy 455.78kcal and overall acceptability of 6.2 was suitable for children between the age groups of 1-5 years being not lower than the recommended dietary allowance for this group of children . It was concluded that a substitution of 12.5% mushroom flour into wheat flour gave the bread with the best overall quality indices. Therefore Mixture Design was used to investigate the effects of Whole Wheat Flour (WWF) and Oyster Mushroom flour (MF)) on the bread. Keywords: Bread, characterization, mixture design, mushroom, optimization, protein, wheat.Item Development and Characterization of Papaya Based Fruit Leather Supplemented with Orange-Fleshed Sweet Potato and Haricoat Bean Flour(Addis Ababa University, 2023-02) Eftu Tesfaye; Solomon Kiros (PhD)The goal of this study was to investigate the production of nutritional fruit leather using haricot bean and orange fleshed sweet potato flours to partially substitute papaya pulp. The study examined β-Carotene content, functional property, anti-nutrient composition, and physicochemical properties, proximate composition of the raw materials and composite pulps, additional to this mineral and microbiological analysis, texture and color analysis, and finally sensory characteristics of the fruit leather were analyzed using standard methods. The formulation for composite flour was developed using a D-optimal mixture design ratio applying Design-Expert®, version 13. Accordingly, 11 composite pulp samples were developed (R1, R2……. R16) and the data analyzed using mini-tab software, the result was evaluated by used one-way analysis of variance (ANOVA) and test of significant (p<0.05).The composite puree samples are significantly different each other at (p<0.05) with increasing haricot bean and orange fleshed sweet potato flour ratios on papaya puree. the optimum fruit leather at run(sample) 11 was made with 60.02% papaya pulp, 19.98% haricot bean, and 20.00% orange-fleshed sweet potato flour showed significantly higher values of β-carotene (746 μg/g), protein (12.05%), fiber (5.32%), and fat (4.09%), and a moisture content (15%) than the control fruit leather(100%papaya pulp),Moreover the texture analysis result of the fruit leather indicated that the hardness, chewiness, and fracturability decreased with the increased amount of haricot bean and orange-fleshed sweet potato flours. The mineral contents of the fruit leathers ranged from Ca 5.37 to 21.49, Mg 11.49 to 22.49, Na 7.88 to 24.20, K 29 to 24.50 mg, Fe 0.13 to 1.72 (mg/100 kg), and Cu, Mn, and Zn were also detected in the zero range In terms of all the sensory parameters except taste and mouth-feel, the optimum fruit leather showed significantly higher scores than the control fruit leather. Generally the results showed that the supplementing of haricot bean and orange fleshed sweet potato flour to papaya puree improved the nutritional quality of the fruit leather.Item Development and Characterization of Pineapple Jam and Utilization of its Peel for Vinegar Production(Addis Ababa University, 2018-12) Teklu, Chalchisa; Adamu, Zegeye (Assoc. Prof.)Fruit extract, sugar (S), pectin(P) and citric acid are the four ingredients needed for jam production. The quality of the jam is highly dependent on the choice of concentrations of each ingredient and processing parameters. The physicochemical composition of pineapple (smooth cayenne variety) fruit pulp, and jam were studied and the results were recorded. Processing of pineapple fruit pulp into jam resulted in a significant increase in physico chemical properties like TSS and TA but a significant decrease in pH, Vitamin C and mineral composition were observed. Subsequently sensory and microbial evaluation were conducted to identify highly acceptable pineapple jam. Processing of pineapple fruit pulp into jam show slightly decrease the nutritional composition of the products. This study investigated good quality pineapple jam formulation using general factorial design (Minitab 17 modeling). Out of 12 pineapple jam samples that were formulated with different ratio of sugar, pectin, and processing temperature samples J10(T:90 o c, S:45%, P:3%), formulation proved as best products in terms of its nutritional composition; sensory and microbial analysis. Production of vinegar by fermentation of pineapple peel using three selected strains of acetic acid bacteria’s (propionic bacterium acid propionic, panteo agglomerans, and pantea disperse) was assessed. Fermentation times of 24h., 48h, and 72h at three levels with two factor full factorial was applied for experimental design and statistical analysis using Minitab 17.1. Aeration rate, temperature, and carbon source were set as constant factors. A total of 10 experiments were conducted at conditions as stated previously with three strains of acetic acid bacteria and fermentation time. Total acetic acid concentration was analyzed using acid base titration method. This experiment shows that propionic bacterium acid-propionic, acetic acid bacterial strain, produce 6.15g/l of acetic acid at fermentation time of 72h.which was higher yield when compared with the other strains used for this research wok. In general, bacterial strain and fermentation time were the most important factors affecting vinegar production.