Effects of semidry milling on the properties of highland barley flour and the quality of highland barley bread.

BACKGROUND: This study aimed to investigate the effects of semidry milling on the quality attributes of highland barley flour and highland barley bread. Highland barley flours were prepared by dry (DBF), semidry (SBF), and wet (WBF) milling methods. The properties of different highland barley flours were analyzed, and highland barley breads made from different highland barley flours were evaluated. RESULTS: The results showed that WBF had the lowest damaged starch content (15.2 g kg-1 ), and the contents of damaged starch in SBF-35 and SBF-40 (43.5 g kg-1 and 24.1 g kg-1 respectively) were lower than that of DBF (87.6 g kg-1 ). And SBF-35 and SBF-40 with large particles exhibited low hydration performance. In addition, SBF-35 and SBF-40 had higher pasting viscosity, pasting temperature, ΔH, and relative crystallinity, consequently resulting in better gel properties than other highland barley flours. These properties could help SBF-35 and SBF-40 develop high-quality bread with large specific volume and superior crumb structure and texture that is similar to the bread with WBF. CONCLUSION: Overall, semidry milling not only could improve the characteristics of HBF, but also avoid high starch damage by dry milling and water wasting by wet milling. What is more, highland barley breads with SBF-35 and SBF-40 had preferable appearance and crumb texture. Therefore, semidry milling could be regarded as a feasible way to produce highland barley flour. © 2023 Society of Chemical Industry.

The structural and functional properties of dietary fibre extracts obtained from highland barley bran through different steam explosion-assisted treatments.

The effects of steam explosion (SE)-assisted ultrasound (SEU), citric acid (SEC), sodium hydroxide (SEA), and cellulase (SEE) treatment on the properties of soluble dietary fibre (SDFP) extracted from highland barley bran were analysed. The results showed that SE pretreatment combined with other methods effectively improves the SDFP yield. The highest yield of SDF (20.01%) was obtained through SEA treatment. SEU-SDFP had a loose and porous structure, whereas the surface of SEC-SDFP and SEA-SDFP presented a complicated and dense texture. Although SE pretreatment reduced the thermal stability of SDFP, SEC and SEE treatment maintained its thermal stability. Furthermore, SEU-SDFP exhibited the highest water and oil holding capacities, and cholesterol and nitrite ion adsorption capacities. SEE-SDFP exhibited the best DPPH and ABTS radical scavenging abilities. In summary, four SE-assisted extraction methods had different advantages, and highland barley bran SDF can be considered as a potential functional additive in the food industry.

Ultrasound Treatment Enhanced Semidry-Milled Rice Flour Properties and Gluten-Free Rice Bread Quality.

The structural and functional properties of physical modified rice flour, including ultrasound treated rice flour (US), microwave treated rice flour (MW) and hydrothermal treated rice flour (HT) were investigated with wet-milled rice flour (WF) used as a positive control. The results showed the presence of small dents and pores on the rice flour granules of US and MW while more fragments and cracks were showed in HT. XRD and FTIR revealed that moderate ultrasonic treatment promoted the orderly arrangement of starch while hydrothermal treatment destroyed the crystalline structure of rice flour. In addition, the significant decrease of gelatinization enthalpy and the narrowing gelatinization temperature were observed in US. Compared to that of SF, adding physical modified rice flour led to a batter with higher viscoelasticity and lower tan δ. However, the batter added HT exhibited highest G' and G″ values and lowest tan δ, which led to a harder texture of bread. Texture analysis demonstrated that physical modified rice flour (except HT) reduced the hardness, cohesion, and gumminess of rice bread. Especially, the specific volume of bread with US increased by 15.6% and the hardness decreased by 17.6%. This study suggested that ultrasound treatment of rice flour could improve texture properties and appearance of rice bread.

Edible qualities, microbial compositions and volatile compounds in fresh fermented rice noodles fermented with different starter cultures.

To shorten the fermentation time and reduce the heterozygous bacteria contamination during fresh fermented rice noodles (FFRNs) fermentation, four starter cultures that consist of Limosilactobacillus fermentum, Lactoplantibacillus plantarum and Saccharomyces cerevisiae were used to produce FFRN. The cooking qualities and texture profiles of FFRNs, the dynamics of microbial diversities and volatile compounds at different fermentation stages were explored. Results showed that the fermentation time of the adding starter culture groups required 12 h, while that the natural fermentation (NF) group required 36 h. Significant differences were observed in the texture profiles and cooking qualities of these five groups FFRNs (P ＜ 0.05). In addition, compared with NF group, the microbial diversity of four adding starter culture groups was significantly lower, which meant that the edible safety of FFRNs could be enhanced. Meanwhile, a total of 115 volatile compounds were detected by Gas chromatography-ion Mobility Spectrometry and Gas chromatography-mass spectrometry, the aldehydes, alcohols, acids and esters were increased while aldehydes were decreased in FFRNs during fermentation. Among these, the relative odor activity value of 50 volatile compounds was greater than 0.1, contributing unique flavors to FFRNs. Notably, the flavor of Lactoplantibacillus plantarum + Saccharomyces cerevisiae (L.p + S.c) and Lactoplantibacillus plantarum + Limosilactobacillus fermentum + Saccharomyces cerevisiae (L.pf + S.c) groups was richer than that of other groups.

Plant protein reduces serum cholesterol levels in hypercholesterolemia hamsters by modulating the compositions of gut microbiota and metabolites.

Plant proteins exert effects of reducing cardio-cerebrovascular disease-related mortality partly via cholesterol-lowering, which was associated with gut microbiota. Here, we verify that there are significant differences in cholesterol levels among hamsters consuming different proteins. The decisive roles of gut microbiota in regulating host cholesterol are illustrated by the fact that the difference in serum cholesterol levels between hamsters feeding with pea protein and pork protein disappeared when treated with antibiotics. The results of cross-over intervention of pea and pork protein show that serum cholesterol levels are reversed with dietary exchange. The corresponding changes in microbiota suggest that Muribaculaceae are responsible for the inhibitory effect of pea protein on serum cholesterol level, whereas the opposite effect of pork protein is due to Erysipelotrichaceae. Moreover, pea protein supplement alters cecal metabolites including arginine/histidine pathway, primary bile acid biosynthesis, short-chain fatty acids, and other lipid-like molecules involved in cholesterol metabolism.

Volatile compounds, bacteria compositions and physicochemical properties of 10 fresh fermented rice noodles from southern China.

To clarify the discrepancy in characteristic flavor and bacteria composition of 10 fresh fermented rice noodles from southern China, the volatile and bacteria composition were determined by headspace-gas chromatography ion mobility spectrometry and 16SrRNA sequencing methods. The potential relationship between volatile compounds and bacterial composition has also been further revealed using spearman's correlation analysis. The contents of proximate composition, cooking properties and texture properties of 10 fresh fermented rice noodles exhibited significant different among them (p ＜ 0.05). The flavor analysis showed that a total of 54 compounds were detected. 1-Octen-one, ethyl 3-methylbutanoate, 3-methylbutanal, n-nonanal, hexanal, amyl acetate, ethanol and 2-pentyl furan were the key volatiles among them. The bacterial analysis showed that Leuconostoc and Lactococcus were the core bacteria at the genu level of all samples. Amyl acetate, 2-butanone and methyl-2-methylpropanoate were positively related to Lactococcus while ethanol was negatively correlated with Lactococcus. And Leuconostoc was positively related to 3-methylbutanal and acetone, while was negatively correlated with hexanal. Results indicated that key volatiles and textural properties of different fresh fermented rice noodle samples were associated with bacterial composition.

Effects of damaged starch on glutinous rice flour properties and sweet dumpling qualities.

This study focused on exploring the effects of damaged starch on glutinous rice flour properties and sweet dumpling qualities. Glutinous rice flours with different damaged starch contents (2-8%) and the same particle size were prepared through sifting and blending of semidry-milled and dry-milled rice flour. The increase of damaged starch content led to an increase in elastic modulus (G'), viscous modulus (G″) and agglomeration of starch granules, and a decrease in peak viscosity, breakdown value and enthalpy change (ΔH). Among all the samples, the rice flour batters with damaged starch content 3% and 4% were more stable and structured, and rice flours with damaged starch content 2% and 3% showed better pasting properties. As for the sweet dumpling qualities, compact structure, weak water mobility, less water loss, slight cracking and desirable cooking and texture properties were observed in the sweet dumplings made from rice flour with damaged starch content of less than 5%. All the results demonstrated that glutinous rice flour with damaged starch content of less than 5% had good flour properties and was suitable for the production of sweet dumplings.