Bioactive Components and Antioxidant Activity Distribution in Pearling Fractions of Different Greek Barley Cultivars

Abstract

In this study, three pearling fractions, namely bran, dehulled grains and pearled grains, derived from fourteen hulled and one hull-less Greek barley cultivars (Hordeum vulgare L.), were analyzed for the protein, ash, β-glucan, phenolic compounds and tocols contents. High variations appeared in the bioactive contents across the barley cultivars and fractions as well. The protein and ash contents decreased from the outer to the inner layers, whereas β-glucans presented an inverse trend. The highest protein and β-glucan contents were in the hull-less cultivar; however, one hulled cultivar (Sirios) exhibited similar β-glucan content, while another (Constantinos) had even higher protein content. The results also revealed that functional compounds were mainly located in bran fraction. Similar trends were also noted for the antioxidant activity. Ferulic acid was the primary phenolic acid in all fractions, followed by sinapic and p-coumaric acids that were dominant in bound form. However, oligomeric flavonoids, such as prodelphinidin B3, catechin, and procyanidin B2, were more abundant in free form. Overall, this study highlights that different barley cultivars can provide pearling flour fractions of varying composition (nutrients and bioactives), which have the potential to serve as nutritionally valuable ingredients in formulations of cereal-based functional food products.

Bioactive Compounds and Antioxidant Capacity in Pearling Fractions of Hulled, Partially Hull-Less and Hull-Less Food Barley Genotypes

“…In our study, there were detectable concentrations of the eight tocol isomers in all whole barley flours ( Table 2 ). Total tocols ranged from 38 to 44 μg/g in good accordance with values found in other barley cultivars [ 12 , 16 , 17 , 18 ]. Tocotrienols accounted for 79% of the total tocols while the tocopherols were 21%.…”

“…Most studies into the spatial distribution of PCs in barley have focused on either the total PCs by colorimetric methods [ 21 , 22 ] or just the major phenolic acids [ 38 , 39 ], or have analyzed representative phenolic acids and free flavan-3-ols in a few fractions of previously dehulled cultivars [ 18 , 40 ]. The results obtained in the present study show for the first time the specific distribution of a great variety of phenolic compounds determined by HPLC-MS/MS.…”

“…Thus, physical processes like pearling, an abrasive technique that gradually removes grain layers to obtain polished grain and by-products, allow favorable separation of fractions enriched in specific compounds and these can be used as functional ingredients. Several fold enrichment of antioxidant compounds has been described in barley pearled fractions [ 17 , 18 ] that have been used to improve the nutritional value of such wheat-based products as cookies, pasta and bread [ 19 , 20 , 21 , 22 ].…”

Biotransformation of Flavonoids Improves Antimicrobial and Anti-Breast Cancer Activities In Vitro

“…Flavonoids are a type of plant secondary metabolite that are widely present in many minor grains, such as Tartary buckwheat, quinoa, and barley [1][2][3]. In addition to being diverse in variety, flavonoids also possess complex structure types, and they perform many bioactive functions, including antioxidation effects [4,5], antiproliferative effects [6], and antibacterial effects [7,8].…”

Vitamin E in foodstuff: Nutritional, analytical, and food technology aspects

“…This process consists of the partial or total removal of the bran layer. The elimination of the cereal coating contributes to the massive loss of many essential phytochemicals, such as vitamin E, especially tocotrienols (Giordano et al., 2016; Irakli et al., 2020). Irakli et al.…”