Bioaccessibility
of Polyphenols from Wheat (<i>Triticum aestivum</i>), Sorghum
(<i>Sorghum bicolor</i>), Green Gram (<i>Vigna radiata</i>), and Chickpea (<i>Cicer arietinum</i>) as Influenced
by Domestic Food Processing
- Publication date
- Publisher
Abstract
Cereals
(wheat and sorghum) and legumes (green gram and chickpea)
commonly consumed in Asia and Africa were evaluated for polyphenolic
content. Bioaccessibility of polyphenols from these grains as influenced
by domestic processing was also estimated. Total polyphenol content
of wheat and sorghum was 1.20 and 1.12 mg/g respectively, which was
increased by 49% and 20% respectively, on roasting. In contrast, a
significant reduction of the same was observed in both the cereals
after pressure-cooking, open-pan boiling, and microwave heating. Total
flavonoids, which was 0.89 mg/g in native sorghum, reduced drastically
after processing. Tannin content of both the cereals significantly
increased on sprouting as well as roasting. Total polyphenol content
reduced by 31% on sprouting but increased to 24% on roasting in green
gram. Pressure-cooking (53%), open-pan boiling (64%), and microwave
heating (>2-fold increase) significantly increased total polyphenol
content in chickpea, while drastic reduction was observed in the total
flavonoid content. Bioaccessible total polyphenols from these grains
were in the following order: green gram > chickpea > wheat >
sorghum.
Domestic processing of these grains had minimal/no effect on the bioaccessible
total flavonoid content. Not all the phenolic compounds present in
them were bioaccessible. Concentration of bioaccessible phenolic compounds
increased especially on sprouting and roasting of these grains, except
chickpea, where sprouting significantly reduced the same (476 to 264
μg/g). Microwave heating significantly enhanced the concentration
of bioaccessible polyphenols especially from chickpea. Thus, sprouting
and roasting provided more bioaccessible polyphenols from the cereals
and legumes studied