Distribution of Phenolic Acids and Antioxidant Activities of Different Bran Fractions from Three Pigmented Wheat Varieties

Abstract

Phenolic acid profiles and antioxidant activities of outer bran, coarse bran, and shorts from blue, black, and purple wheat were analyzed. Phenolic acids were mainly in the bound form in pigmented wheat bran fractions. Phenolic acid content decreased in the order of outer bran, coarse bran, and shorts for the three pigmented wheat varieties. HPLC analysis of phenolic extracts demonstrated that the bound form of phenolic acids contained more ferulic, isoferulic, and p-coumaric acids compared to their free counterparts. Among the three pigmented wheat varieties, the bran fractions from blue wheat contained higher bound phenolic acids than the other two pigmented wheat bran fractions, except for purple coarse bran. The blue wheat outer bran had the highest total bound phenolic acid of 3458.71 g/g while the purple wheat shorts had the lowest of 1730.71 g/g. The contribution of bound phenolic acids to the total phenolic content and antioxidant activity was significantly higher than that of free phenolic acids. Blue wheat bran fractions had the highest radical scavenging activity against DPPH• while those of purple wheat gained the highest ABTS•+ scavenging activity. High correlations were observed between TPC and radical scavenging capacities for DPPH and ABTS ( 2 > 0.85, < 0.05).

Enzyme Selection and Hydrolysis under Optimal Conditions Improved Phenolic Acid Solubility, and Antioxidant and Anti-Inflammatory Activities of Wheat Bran

“…WB antioxidant activity as determined by the four in vitro methods was within the range of previous studies [ 29 , 40 ]. Ultraflo XL increased the antioxidant activity of WB hydrolysates ( Table 4 ) in consistency with previous works showing increased antioxidant activity after treatment of rice and wheat bran with different glycosidases [ 30 , 41 ].…”

“…Regarding phenolic composition, TSPC and free FA contents of WB ( Table 2 ) were in the range reported for brans from Triticum spp. (0.5-2 mg GAE/g of bran and 2.9-9.5 μg/g of bran, respectively) [ 28 , 29 ]. Most enzyme treatments used in the present study significantly increased TSPC and individual content of FA derivatives in WB ( Table 2 ).…”

Wild Edible Plant Nutritional Contribution and Consumer Perception in Ethiopia

“…Research has shown that many of the wild edible plants have been found to be rich sources of one or more of the nutritionally important substances, such as proteins, carbohydrates, vitamins, and minerals. Besides the dietary substances, some of them also contain considerable amounts of a variety of health-promoting compounds, such as phenolic compounds [ 37 – 39 ].…”

Thermal Processing for the Release of Phenolic Compounds from Wheat and Oat Bran

“…Avenanthramides are naturally-derived oat phenolic compounds with very good antioxidant activity [18]. Phenolic compounds present in wheat and oat bran are insoluble, being bound to the cellulose and hemicellulose structures [19][20][21], making the conventional extraction processes very difficult. Expensive, time-consuming, and unecological procedures like chemical and enzymatic hydrolysis or mechanical crash have been applied over time as pretreatment methods for the release of the phenolic compounds from bran [16,22,23].…”