Effect of starch categories and mass ratio of TA/starch on the emulsifying performance and stability of emulsions stabilized by tannic acid-starch complexes.

This study compounded natural corn starch (CS), mung bean starch (MBS) and potato starch (PS) with tannic acid (TA) to stabilize O/W Pickering emulsion. The effect of TA/starch mass ratio (0-0.25) and three starch categories on particle properties, emulsifying properties, lipid oxidation, freeze-thaw stability, emulsion powder and digestive properties were comprehensibly investigated. In detail, the TA/starch complexes size increased gradually (91.14 nm-200.87 nm) and the hydrophobicity first increased and then decreased (TA/CS > TA/MBS > TA/PS) with increasing TA/starch mass ratio. In addition, the emulsifying ability of TA/starch complexes also increased first and then decreased with increasing mass ratio, especially TA/CS system was the best, which was the same as the hydrophobicity conclusion (θow = 80.46°). Moreover, four starch-based emulsion application characteristics were further evaluated to reveal interface structure. Compared to CS and PS system, TA/MBS emulsion had stronger ability to resist the oil oxidation (TBA = 2.54 µg/mL), destruction of ice crystal (whiter emulsion powder) and digestive enzymes (FFAs = 75.33 %). It mainly attributed to the crosslinking network structure and the highest surface load of TA/MBS complexes. This study would provide new ideas for the design and application of emulsifying properties and emulsion stability.

Exploring the remarkable effects of microwave treatment on starch modification: From structural evolution to changed physicochemical and digestive properties.

As one of the crucial components of the food system, starch can be hydrolyzed into glucose after gastrointestinal digestion, so regulating its digestive properties is vital for maintaining health. Microwaves can promote the rearrangement of intramolecular structure of starch, thus improving its physicochemical properties, enhancing its slowly digestible features, and expanding its scope of application. This review zooms in describing recent research results concerning the effects of microwave treatment on the multi-scale structure and physicochemical properties of starch and summarizing the patterns of these changes. Furthermore, the changes in starch structure, resistant starch content, and glycemic index after digestion are pointed out to gain an insight into the enhancement of starch slowly digestible properties by microwave treatment. The resistance of starch to enzymatic digestion may largely hinge on the specific structures formed during microwave treatment. The multi-level structural evolutions of starch during digestion endow it with the power to resist digestion and lower the glycemic index. The properties of starch dictate its application, and these properties are highly associated with its structure. Consequently, understanding the structural changes of microwave-modified starch helps to prepare modified starch with diversified varieties and functional composites.

Encapsulation of lycopene in Pickering emulsion stabilized by complexes of whey protein isolate fibrils and sodium alginate: Physicochemical property, structural characterization and in vitro digestion property.

In present study, whey protein isolate fibrils and sodium alginate complexes (WPIFs-SA) were prepared and further used to stabilize Pickering emulsions for lycopene delivery. The optimal interaction between WPIFs and SA occurred at pH 3.0, with a mass ratio of 2:1. Increasing the oil fractions and the content of WPIFs-SA complexes significantly improved Pickering emulsions' stability, concurrently reducing droplet size and increasing viscoelasticity. Meanwhile, it facilitated the formation of a thicker protective layer and a compact network structure around the oil droplets, offering better protection for lycopene against thermal and photo degradation. In vitro digestion studies revealed that as the oil fractions and complex contents increased, the lipolysis degree decreased. The engineered WPIFs-SA Pickering emulsion could be used as an innovative delivery system for the protection and delivery of lycopene.

Structural, physicochemical, and digestive properties of enzymatic debranched rice starch modified by phenolic compounds with varying structures.

The physicochemical properties of starch and phenolic acid (PA) complexes largely depend on the effect of non-covalent interactions on the microstructure of starch. However, whether there are differences and commonalities in the interactions between various types of PAs and starch remains unclear. The physicochemical properties and digestive characteristics of the complexes were investigated by pre-gelatinization of 16 structurally different PAs and pullulanase-modified rice starches screened. FT-IR and XRD results revealed that PA complexed with debranched rice starch (DRS) through hydrogen bonding and hydrophobic interaction. Benzoic/phenylacetic acid with polyhydroxy groups could enter the helical cavities of the starch chains to promote the formation of V-shaped crystals, and cinnamic acid with p-hydroxyl structure acted between starch chains in a bridging manner, both of which increased the relative crystallinity of DRS, with DRS-ellagic acid increasing to 20.03 %. The digestion and hydrolysis results indicated that the acidification and methoxylation of PA synergistically decreased the enzyme activity leading to a decrease in the digestibility of the complexes, and the resistant starch content of the DRS-vanillic acid complexes increased from 28.27 % to 71.67 %. Therefore, the selection of structurally appropriate PAs can be used for the targeted preparation of starch-based foods and materials.

Partial enzymolysis affects the digestion of tamarind seed polysaccharides in vitro: Degradation accelerates and gut microbiota regulates.

Two hydrolyzed fractions of tamarind seed polysaccharide (TSP), denoted ETSP1 (176.68 kDa) and ETSP2 (34.34 kDa), were prepared by partial degradation via endo-xyloglucanase, and then characterized and evaluated by simulated gastrointestinal digestion in vitro. The results showed that the hydrolyzed TSPs remained indigestible in gastric and small intestinal media, and were fermented by gut microbiota, similar to the native TSP (Mw = 481.52 kDa). Although the degradation of hydrolyzed TSPs was accelerated during fermentation with a decreasing degree of polymerization, the content of produced total short-chain fatty acids (SCFAs) decreased. After fermentation, the gut microbiota composition was modified, esp. the Firmicutes/Bacteroidetes ratio decreased (1.06 vs. 0.96 vs. 0.80) with a decreasing degree of polymerization, which implied that the potential anti-obesity prebiotic effect was enhanced. At the genus level, hydrolyzed TSPs maintained similar roles as native TSP, including promoting beneficial bacteria (Bifidobacterium, Parabacteroides, and Faecalibacterium) and inhibiting enteropathogenic bacteria (Escherichia-Shigella and Dorea). Moreover, ETSP1 had additional potential due to abundant Bacteroides vulgatus (LDA = 4.68), and ETSP2 might perform better as related to Bacteroides xylanisolvens (LDA = 4.40). All these results indicated the prebiotic potential of hydrolyzed TSP with detailed information about changes in degradation and gut microbiota based on enzyme-hydrolysis.

Physicochemical and functional properties of Pleurotus geesteranus proteins.

Edible mushroom protein has been regarded as a promising protein source due to its nutritional value and sustainability. In the present study, Pleurotus geesteranus proteins were extracted with alkaline solution and then precipitated with salting out (PPS) and isoelectric point precipitation (PPI), respectively. The influences of precipitation method on the physicochemical and functional properties of these two kinds of proteins were studied. The results showed that both PPS and PPI had a good balance of essential amino acids. These two proteins were mainly consisted of polypeptides with a molecular weight lower than 70 kDa. Using proteome analysis, a number of 772 and 459 protein compositions were identified in PPS and PPI, respectively. Compared to PPS, PPI showed a higher zeta potential, higher surface hydrophobicity, lower content of ß-sheet and ß-turn secondary structure, as well as lower denaturation temperature (Td) and enthalpy change of the denaturation (ΔH). These differences in the physicochemical properties between PPS and PPI resulted in the occurrence of differences in their functional and digestive properties. For example, PPS showed obviously higher protein solubility in water than PPI, especially at natural pH, PPS solution was clear, while PPI showed precipitates. PPI had higher foam capability (FC), lower foaming stability (FS), and lower emulsion stability index (ESI) as compared to PPS. PPI was easier to digest in the pepsin digestion period, while PPS showed a higher nitrogen release after trypsin digestion. These findings on the physicochemical and functional properties of P. geesteranus proteins will help to broaden their applications as protein ingredient in food industry.

Effect of White Kidney Bean Flour on the Rheological Properties and Starch Digestion Characteristics of Noodle Dough.

The aim of this study was to investigate the effect of adding white kidney bean flour on the quality of noodles. We selected four different proportions of white kidney bean flour (10−40%) in wheat flour to make the noodles, after which the noodles were analysed for their physical and chemical properties. The statistical method of correlation analysis was used in this study. The results showed that the noodles' sensory and textural characteristics significantly improved after adding white kidney bean flour (p < 0.05). Compared with the control, the noodles' surface with white kidney bean flour was denser and smoother. Moreover, microstructural observations indicated that the noodles with white kidney bean flour showed a more continuous protein network. The in vitro digestion results showed that the addition of white kidney bean flour reduced the digestibility of the noodles. Low addition of the flour (10−20%) improved the quality of the noodles, whereas high amounts (30−40%) showed the opposite effect. In this study, the optimal amount of white kidney bean powder was found to be 20%.

Processing, digestion property and structure characterization of slowly digestible gorgon nut starch.

Slowly digestible gorgon nut starch (GN-SDS) was prepared by heating-cooling treatment (HCT), meanwhile its morphological and structural features were characterized in detail by SEM, DSC, XRD and IR detection. The optimized parameters of GN-SDS processing were as following: starch milk (20%) was heated at 100 °C for 20 min, and then cooled under 4 °C for 24 h. Under the optimized parameters, the SDS content increased from 20.49 to 61.74%. GN-SDS showed typical SDS characteristics in in vivo digestion with a low postprandial blood glucose. SEM images suggested that GN-S particles changed from uniform regular polyhedron with smooth surface to irregular gravel-like particles with coarse surface and obvious layered structure inside after HCT. The results of SEM, DSC, XRD and IR determination indicated that HCT changed the granule morphology, interior structure, gelatinization temperature and crystal type (A to B-type) of GN-S, and therefore made it hard to be digested accordingly. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-01007-6.

The Quality Characteristics Comparison of Stone-Milled Dried Whole Wheat Noodles, Dried Wheat Noodles, and Commercially Dried Whole Wheat Noodles.

To explore the quality differences between dried wheat noodles (DWNs), stone-milled dried whole wheat noodles (SDWWNs), and commercially dried whole wheat noodles (CDWWNs), the cooking quality, texture properties, microstructure, protein secondary structure, short-range order of starch, antioxidant activity, in vitro digestive properties, and estimated glycemic index (eGI) of the noodles were investigated. The results showed that the cooking loss of SDWWNs was significantly lower than that of CDWWNs. The springiness, cohesiveness, gumminess, chewiness, and resilience of SDWWNs reached the maximum, and the tensile strength was significantly increased. The continuity of the gluten network of SDWWNs was reduced, and more holes appeared. The protein secondary structure of the SDWWNs and CDWWNs was mainly dominated by the ß-sheet and ß-turn, and the differences in the starch short-range order were not significant. Prior to and after the in vitro simulated digestion, the DPPH radical scavenging activity, the hydroxyl radical scavenging activity, and the total reducing power of the SDWWNs were the highest. Although the digested starch content of SDWWNs did not differ significantly from that of CDWWNs, the eGI was significantly lower than that of the CDWWNs and DWNs. Overall, the SDWWNs had certain advantages, in terms of quality characteristics.

Digestive properties of half-fin anchovy hydrolysates/glucose Maillard reaction products and modulation effects on intestinal microbiota.

BACKGROUND: The consumption of dietary Maillard reaction products (MRPs) might lead to positive or negative effects on health. The digestibility of half-fin anchovy hydrolysates/glucose MRPs (HAHp(9.0)-G MRPs) was therefore determined. The intestinal microbiota modulation of HAHp(9.0)-G MRPs in mice was also evaluated after administration for 14 days (1 g kg-1 •bodyweight). RESULTS: Different levels of digestibility of MRPs of fructosamine and advanced glycation products of Nε -carboxymethyllysine were detected in HAHp(9.0)-G MRPs during simulated gastrointestinal digestion. An increased relative proportion of soluble fluorescent melanoidins (SFMs) was observed during gastric digestion as compared to that in the original HAHp(9.0)-G MRPs, followed by decreases in SFMs in intestinal digestion. After feeding with HAHp(9.0)-G MRPs for 14 days, increased goblet cells were observed in the ileum regions of female and male mice. High-throughput 16S ribosomal RNA gene sequencing of fecal samples revealed that HAHp(9.0)-G MRPs administration increased the density of the phylum Bacteriodetes and reduced the density of the phylum Firmicutes in male mice. By comparison, a relatively higher density of members of the phylum Saccharibacteria was observed in female mice. A consistent increase in the abundance of Bacteroidales_S24-7_group_norank was found in female and male groups fed with HAHp(9.0)-G MRPs. Female and male mice treated with HAHp(9.0)-G MRPs also showed higher levels of propionic and butyric acids in feces than their corresponding controls. CONCLUSION: Half-fin anchovy hydrolysates/glucose MRPs can be partly hydrolyzed in the simulated gastrointestinal digestion system. Treatment with HAHp(9.0)-G MRPs induced sex-related differences in bacterial abundance and diversity in mice; however, the up-regulation of anti-inflammatory activity was predicted in both female and male mice. © 2021 Society of Chemical Industry.

Development of a cooked rice model for bibimbap and resulting physico-digestive properties.

A cooked rice model for bibimbap was developed using response surface methodology (RSM). The ratio of brown rice (X 1), high amylose rice (X 2) based on a white rice ratio of 1.0, and the ratio of water to total rice weight (X 3), were independent variables. Stickiness (Y 1), elasticity (Y 2), and overall acceptability by sensory testing (Y 3) of cooked rice were dependent variables. Optimal RSM conditions were white rice:brown rice:high amylose rice=1:1.07:0.56, and the ratio of water to total rice weight was 1.6. Coefficient of determination (R 2) values of response surface equations were 0.909, 0.930, and 0.956 for Y 1, Y 2, and Y 3, respectively (p<0.05). Experimental values measured under optimal conditions coincided with predicted values. Rapidly digestive starch (RDS) and expected glycemic index (eGI) values determined using the optimized rice model were much lower than for control white rice only.