Impact of Fermentation on the Phenolic Compounds and Antioxidant Activity of Whole Cereal Grains: A Mini Review

Abstract

Urbanization, emergence, and prominence of diseases and ailments have led to conscious and deliberate consumption of health beneficial foods. Whole grain (WG) cereals are one type of food with an array of nutritionally important and healthy constituents, including carotenoids, inulin, β-glucan, lignans, vitamin E-related compounds, tocols, phytosterols, and phenolic compounds, which are beneficial for human consumption. They not only provide nutrition, but also confer health promoting effects in food, such as anti-carcinogenic, anti-microbial, and antioxidant properties. Fermentation is a viable processing technique to transform whole grains in edible foods since it is an affordable, less complicated technique, which not only transforms whole grains but also increases nutrient bioavailability and positively alters the levels of health-promoting components (particularly antioxidants) in derived whole grain products. This review addresses the impact of fermentation on phenolic compounds and antioxidant activities with most available studies indicating an increase in these health beneficial constituents. Such increases are mostly due to breakdown of the cereal cell wall and subsequent activities of enzymes that lead to the liberation of bound phenolic compounds, which increase antioxidant activities. In addition to the improvement of these valuable constituents, increasing the consumption of fermented whole grain cereals would be vital for the world’s ever-growing population. Concerted efforts and adequate strategic synergy between concerned stakeholders (researchers, food industry, and government/policy makers) are still required in this regard to encourage consumption and dispel negative presumptions about whole grain foods.

African Sorghum-Based Fermented Foods: Past, Current and Future Prospects

“…While tannin decreases starch and protein digestibility, cause dysfunction of cellular membranes and cause dysfunction of cellular membranes [29,70,72,73], dhurrin could cause cyanide poisoning (respiratory difficulty, nausea, abdominal distension [71,74]. Several processing methods, including fermentation, have, however, been reported to reduce these ANFs, improve digestibility and release bound nutrients and health beneficial components [11,29,70,[75][76][77][78][79].…”

“…As with other fermentation processes, sorghum fermentation is generally classified into three categories viz. : spontaneous (also referred to as wild or natural), backslopping and controlled fermentation [11,90]. Spontaneous fermentation has been done for many years and basically involves the addition of water to sorghum and incubation of the mixture under suitable conditions of temperature and desired time.…”

“…Amongst all the available food processing techniques, fermentation is an age-long process, known to improve nutritional qualities, palatability and consumer appeal [8][9][10][11]. Derived fermented food products continue to constitute an important part of our daily diet and are estimated to provide about a third of world food supplies [12].…”

“…Derived fermented food products continue to constitute an important part of our daily diet and are estimated to provide about a third of world food supplies [12]. These foods are known to confer beneficial effects, including therapeutic and functional properties, in addition to possessing antimicrobial, antioxidant, probiotic and cholesterol-lowering attributes, and are a source of some other important bioactive compounds [11,[13][14][15][16][17]. Accordingly, fermented sorghum-based foods have a long history and strong cultural ties to the African people in particular.…”

Changes Occurring in Spontaneous Maize Fermentation: An Overview

“…During fermentation, other metabolic pathways are involved in the production of several interesting bioactive molecules. For example, phenolic compounds such as phenolic acids, flavonoids, and tannins, deriving from whole grain cereals, could be metabolized by microorganisms and modified into higher bioactive compounds (i.e., catechin, quercetin, and gallic acid) [144]; these and other microbial-based transformations are worthy of investigation.…”