Influence of Processing Methods on the Reduction of Bioactive Compounds of Quinoa (Chenopodium quinoa, Wild) Seeds
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Date
2019-12
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Addis Ababa University
Abstract
In this study, the influence of some processing techniques such as hydration, cooking, germination,
fermentation and integrated process on nutritional and mineral composition, and some level of bioactive
(saponin, phytate, tannins, oxalate, flavonoid and alkaloid) compounds of quinoa (Chenopodium
quinoa, Wild) flour was conducted. The physicochemical and functional properties, mineral
bioavailability, water absorption kinetics and phytate and non phytate phosphorus contents of quinoa
seeds were also investigated. The mean value on dry weight basis of raw quinoa seeds moisture content
was 9.47%, crude protein 15.58%, crude fat 7.53%, crude, fiber 9.50%, total ash 6.50%, total
carbohydrates 51.60% and gross energy 336.15 kcal/100g. The major mineral constituents of quinoa
seeds were Ca (114.40 mg/100g), P (290.39mg/100g), K (730.70 mg/100g), Mg (195.64 mg/100g) Fe
(13.50 mg/100g) and Zn (4.25 mg/100g). The saponins and alkaloids contents of raw quinoa seeds were
1.77%, and 8.25%; respectively. Whereas, phytate, tannins, oxalate, and flavonoid content of raw
quinoa seeds were 756.16 mg/100g, 529.50 mg/100g, 29.61mg/100g, and 31.44 mg/100g; respectively.
Crude protein, fiber, moisture, mineral bioavailability and non phytate phosphorus compositions were
improved during processing methods. Significant reduction of bioactive compounds was achieved by the
processing methods. Germination process at 48 and 72h enhance the value of alkaloids by 16.36 and
21.45% and flavonoids by 7.91 and 16.03% respectively compared to raw quinoa seeds. However,
germination process reduces phytates, saponin, oxalate and tannins by 75, 72.32, 49.68 and 38 %
respectively. And other processing methods like hydration, cooking, fermentation and integrated process
were significantly reduce bioactive compounds in quinoa seeds. Furthermore, complete removal of all
bioactive compounds was achieved by the fermentation process at 48 and 72hr, for phytate and
flavonoid; respectively, Hydration and fermentation at 24 h, for flavonoid and alkaloid respectively,
Germination followed by hydration for alkaloid and Fermentation of the germinated quinoa flour for
saponin, phytate, flavonoid and alkaloid. Nutritionally dense cookies were prepared from the
formulation of 30% fermented quinoa flour and combined process of fermentation and germination of
quinoa flour with 70% wheat flour. The microbiological results showed the cookies produced were safe
for consumption according to Codex Alimentarius. The cookies prepared from fermentation of the
germinated quinoa flour were the most selected cookies by the panelist.
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Keywords
bioactive compounds, cookies, processing methods, pasting property, quinoa seeds, saponins