A review on the status of the phenolic compounds and antioxidant capacity of the flour: Effects of cereal processing

Abstract

Cereals are important grains that are largely used for food and source of bioactive compounds such as starch, dietary fibre, amino acids, minerals, vitamins, and phenolic compounds. However, the use of cereals in the food industry subjects these cereals to different processes that can alter the phenolic content and cause degradation of their antioxidant properties. Understanding the influence of processing operations such as germination, fermentation, and thermal processing on the phytochemicals of cereals grains is important in retaining the health benefiting properties of these antioxidative compounds in processed food products. Most of the previous investigations in the literature review on cereal grains have shown that food processing operations reduced the antioxidants of the processed foods. However, in the last decade, some articles in literature reported improvement in antioxidants properties of processed cereals grains. In this review, more than 60 articles from indexed scientific journals were reviewed in order to understudy the effect of diverse pre-and post-processing methods on the phenolic and antioxidant status of cereals grains.

Changes in phenolic content, antioxidant activity, and volatile compounds during processing of fermented sorghum grain tea

“…Enzymes such as amylases and proteases produced by starter culture could hydrolyze phenolic conjugates with one or more bounded sugar into free polyphenols (Shrestha, Dahal, & Ndungutse, 2013). Kadiri (2017) reported that Saccharomyces cerevisiae could synthesize some enzymes, including β‐glucosidase, cellulase, and xylanase, which have the capability to hydrolyze the β‐glycosidic bonds of certain polyphenols. Therefore, the significant decrease in TFC and CTC but limited change of TPC was the result of the combined effects of enzymatic, physical, and biochemical activities during the fermenting process.…”

Can plant phenolic compounds reduceFusariumgrowth and mycotoxin production in cereals?

“…For the experiment, it was necessary to autoclave oat grains before the treatments, hence, the initial content in each variety was not known because thermal processing can lead to a degradation of flavonoids (Buchner et al 2006). Both, decreasing and increasing effects, were observed for phenolic acids as recently reviewed by Kadiri (2017). Nevertheless, it is likely that the fungus metabolised an extensive amount of the endogenous phenolic compounds leading to the observed differences between the control and the inoculated treatment, which was also reported by Bilska et al (2018).…”

Pasting alters glycemic index, antioxidant activities, and starch‐hydrolyzing enzyme inhibitory properties of whole wheat flour

“…Processing techniques may affect the phenolic content and antioxidant properties of vegetables, fruits, whole grains, and legumes (Adefegha & Oboh, ; Oboh, Ademosun, Olasehinde, Oyeleye, & Ehiakhamen, ). Although some processing techniques such as cooking, boiling, and roasting have been reported to reduce the phenolic content and antioxidant properties of some foods (Kadiri, ; Lemos, Siqueira, Arruda, & Zambiazi, ), these same processing methods have been reported to increase the phenolic content, antioxidant, and antidiabetic properties of other foods (Sharma & Gujral, ; Oboh, Ademosun, et al., ). Pasting is a traditional processing method that is common in West Africa.…”