Effect of chemical, thermal, and enzymatic processing of wheat bran on the solubilization, technological and biological properties of non-starch polysaccharides.

Wheat bran is a low-cost by-product with significant nutritional value, but it is primarily utilized in animal feed applications. This study sought to investigate chemical methodologies for modifying the wheat bran's structure, enhancing non-starch polysaccharides solubility in water, and assessing alterations in functional and biological attributes. Chemical modifications were conducted under aqueous, alkaline, acid, and oxidizing conditions. Parameters such as yield, monosaccharides, arabinoxylans, ß-glucan and phenolic content, molecular weight, functional properties, and prebiotic in vitro capacity were examined. The samples exhibited higher yields than the control, particularly in alkaline and acidic extractions. Notably, all soluble polysaccharide fractions (SPF) displayed a reduced molecular weight (<25KDa). ß-glucan contents were raised in alkaline and acid extractions compared to the control, despite only in alkaline extraction were observed increase in arabinoxylans, confirmed by enzymatic-driven linkage analyses. Phenolic compounds and their antioxidant activities were low across all SPF. The samples showed heightened solubility, minimal foaming, and reduced water absorption properties. An alkaline extraction demonstrated a potential high prebiotic effect. Most samples showed positive relative growth and prebiotic activity for Lactobacillus and Bifidobacterium. This study suggests that an alkaline extraction of wheat by-product could enhance its value by increasing ß-glucan content, arabinoxylans release, and prebiotic potential.

Enzymatic modification of arabinoxylans from soft and hard Argentinian wheat inhibits the viability of HCT-116 cells.

Dietary fiber plays an important role in the prevention of colorectal cancer, and arabinoxylans are an important source of this in grains, with some studies reporting the inhibition of cancer cell growth. However, very few studies have been conducted on this, and most previous studies have used oligosaccharides derived from arabinoxylans of specific molecular weight. The aim of this work is to extract, isolate, and analyze arabinoxylans from two different Argentinian genotypes of wheat (hard and soft) and study if they have the capacity to decrease the cellular viability of a colon cancer line (HCT-116). To determine whether the molecular size influences the inhibition of HCT-116 cell viability, specific hydrolysis was performed with endoxylanase, and the cells were exposed to the hydrolyzed arabinoxylans. The arabinoxylans treatment resulted in HCT-116 cell viability of 74% for the soft genotype and 64% for the hard genotype in comparison to nontreated cells. Hydrolyzed-arabinoxylans result in HCT-116 cell viability of 68% for soft and 36% for hard genotypes (the lowest IC50 values) compared to nontreated cells. More importantly, no decrease after the arabinoxylans treatment was observed in the viability of murine noncancer cells known to rapidly respond to polysaccharide presence. The arabinoxylans from hard wheat showed more disubstituted xylose and α-1,2/α-1,3 linkages than the arabinoxylans from soft wheat, the possible cause for showing the best in vitro biological effect. The results showed other beneficial effects than the prebiotic ones and support the use of enzymatic treatment to increase the biological impacts of arabinoxylans.

Whole-flours from hard and soft wheat genotypes: study of the ability of prediction test to estimate whole flour end-use.

The aims of this work were to assess the influence of the physicochemical composition of whole flour from soft and hard wheat genotypes on cookie and bread properties, as well as the ability of the prediction tests to estimate the whole meal flour end-use. Flours from hard and soft wheat genotypes proved to have different chemical composition and particle size distribution. Flours from hard wheat had lower particle average size and dietary fiber content, and higher lipid and wet gluten contents than flours from soft wheat. Particle size distribution, water absorption capacity and chemical composition of whole flours strongly influenced bread and cookie making performance. Considering prediction tests, flours from different wheat types were successfully discriminated using SDS-SI, SRC lac, and GI. However, rather weak correlations were found between the prediction test and the cookie and bread quality parameters. The prediction test, standardized for refined flours, showed a poor performance when whole flours were used. Nevertheless, grain texture and whole flour physicochemical properties did affect bread and cookie quality parameters, thus classical prediction tests should be modified in order to estimate the end-use performance of whole flours. Moreover, a standardization of the milling process should be considered.

Flour and starch characteristics of soft wheat cultivars and their effect on cookie quality.

Studies on Argentinian soft wheat cultivars are scarce, although the flours obtained from these wheats are the most suitable for cookie making. This work studies the behavior of the flours obtained from 44 adapted soft wheat lines harvested in two consecutive years for cookie making, focusing on starch properties. Starch granule size distribution, and thermal and pasting properties of flour samples were studied. Large variations in flour and starch characteristics were found between all experimental lines, indicating a wide variability among wheat genotypes and a noticeable effect of crop year conditions. Starch granule size distribution showed the typical bimodal distribution observed for wheat. Flours with higher proportion of large A-type granules were associated with lower damaged starch (DS). As expected, the lower the DS content, the lower the solvent retention capacity, gelatinization temperature and enthalpy, with a positive impact on cookie diameter. Flours from soft wheat genotypes with higher proportion of large A-type granules were associated with lower DS content and reduced water absorption capacity. Both genotype and environment exert an effect on soft wheat flour characteristics.