Heat-moisture treatment can modulate all-purpose wheat flour for short dough biscuit making: Evidences and mechanism.

In view of the merits of all-purpose wheat flour (APWF) to soft wheat flour (SWF) in cost and protein supply, the feasibility of heat-moisture treatment (HMT, 19% moisture for 1 h at 60, 80 and 100 °C, respectively) to modify APWF as a substitute SWF in making short dough biscuits was explored. For underlying mechanisms, on the one hand, HMT reduced the hydration capacity of damaged starch particles by coating them with denatured proteins. On the other hand, HMT at 80 °C and 100 °C significantly denatured gluten proteins to form protein aggregates, highly weakening the gluten network in dough. These two aspects jointly conferred APWF dough with higher deformability and therefore significantly improved the qualities of biscuits. Moreover, the qualities of biscuits from APWF upon HMT-100 °C were largely comparable to that from SWF, even higher values were concluded in spread ratio, volume, specific volume and consumer acceptance.

In vitro digestion and fecal fermentation of selenocompounds: impact on gut microbiota, antioxidant activity, and short-chain fatty acids.

Selenium bioavailability is critically influenced by gut microbiota, yet the interaction dynamics with selenocompounds remain unexplored. Our study found that L-Selenomethionine (SeMet) and Se-(Methyl)seleno-L-cysteine (MeSeCys) maintained stability during in vitro gastrointestinal digestion. In contrast, Selenite and L-Selenocystine (SeCys2) were degraded by approximately 13% and 35%. Intriguingly, gut microflora transformed MeSeCys, SeCys2, and Selenite into SeMet. Moreover, when SeCys2 and Selenite incubated with gut microbiota, they produced red selenium nanoparticles with diameters ranging between 100 and 400 nm and boosted glutathione peroxidase activity. These changes were positively associated with an increased relative abundance of unclassified_g__Blautia (Family Lachnospiraceae), Erysipelotrichaceae_UCG-003 (Family Erysipelatoclostridiaceae), and uncultured_bacterium_g__Subdoligranulum (Family Ruminococcaceae). Our findings implied that differential microbial sensitivities to selenocompounds, potentially attributable to their distinct mechanisms governing selenium uptake, storage, utilization, and excretion.

Tailoring the composition, antioxidant activity, and prebiotic potential of apple peel by Aspergillus oryzae fermentation.

Apple peel is a typical lignocellulosic food by-product rich in functional components. In this work, apple peel was solid-state fermented with Aspergillus oryzae with an aim to modulate its composition and bioactivity. The results showed that A. oryzae fermentation substantially tailored the composition, improved the antioxidant activity and prebiotic potential of apple peel. Upon the fermentation, 1) free phenolics increased and antioxidant activity improved; 2) the pectin substances degraded significantly, along with a decrease in soluble dietary fiber while an increase in insoluble dietary fiber; 3) the in vitro fermentability increased as indicated by the increase in total acid production. The gut microbiota was shaped with more health-promoting potentials, such as higher abundances of Lactobacillus, Bifidobacterium, Megamonas and Prevotella-9 as well as lower abundances of Enterobacter and Echerichia-Shigella. This work is conducive to the modification of apple peel as a potential ingredient in food formulations.

Characterization of a low-methoxyl pectin extracted from red radish (Raphanus sativus L.) pomace and its gelation induced by NaCl.

There is an increasing demand for obtaining pectin from new sources. Red radish (Raphanus sativus L.) pomace pectin extracted by alkali was low-methoxyl pectin with esterification degree of 10.17 %, galacturonic acid content of 69.71 % (wt), and average molar weight of 78.59 kDa. The pectin primarily consisted of rhamnogalacturonan I and homogalacturonan domains. The predominant monosaccharides of the pectin were galacturonic acid (46.32 mol%), arabinose (16.03 mol%), galactose (10.46 mol%), and rhamnose (10.28 mol%), respectively. The red radish pomace pectin solution exhibited a shear-thinning behavior. NaCl could induce gelation of red radish pomace pectin, and the gel properties of red radish pomace pectin were considerably affected by the NaCl concentration. As the NaCl concentration (0.25-0.50 mol/L) increased, the rate of gelation accelerated, and the time to gelation point appeared earlier. There was an optimal NaCl concentration (0.50 mol/L) for the pectin to form a gel with the greatest solid-like properties, gel hardness (33.84 g) and water-holding capacity (62.41 %). Gelation force analysis indicated gel formation mainly caused by electrostatic shielding effect of Na+ and hydrogen bonding. This research could facilitate the applications of the red radish pomace pectin in the realm of edible hydrocolloids.

Mung Bean Starch and Mung Bean Starch Sheet Jelly: NaCl-Based Characteristics Variation.

Empirical evidence indicates that NaCl can improve the quality of mung bean starch sheet jelly (MBSS) when properly incorporated. In this study, by comparison with a sample without NaCl, the influences of NaCl (1.5-8%, w/w) on the physicochemical and structural properties of mung bean starch (MBS) and the quality of MBSS were investigated. MBS with added NaCl had greater gelatinization temperature and pasting parameters but lower gelatinization enthalpy than native MBS. With the addition of NaCl, the drying rate of MBSS first accelerated and then declined in the oven-drying process. The addition of NaCl improved the cooking properties of MBSS but decreased the hardness of cooked MBSS. Rheological results implied that the linear viscoelastic region of cooked MBSS decreased with the NaCl addition, and the storage modulus and tan δ were more frequency-dependent than the loss modulus of cooked MBSS. The addition of NaCl gradually increased the toughness of dried MBSS and the overall acceptability of cooked MBSS. Furthermore, NaCl decreased the structure order degree of starch in MBSS. Correlation analysis demonstrated that the quality of MBSS had a significant correlation with the molecular and lamellar order of starch. Overall, NaCl could improve the quality of MBSS by regulating the thermal, gelatinizing, and structural properties of MBS.

Replacement of fat with highland barley ß-glucan in zein-based cheese: Structural, rheological, and textual properties.

Nowadays, few plant-based cheese provides satisfactory viscoelastic property like conventional cheese, promoting the application of zein. Our study prepared zein-based cheese containing different concentrations (0-30 %) of highland barley ß-glucan (HBG) as a fat replacer. Increased HBG caused smaller and more uniform oil droplets in zein network. SAXS pattern implied Rg decreased from 0.936 nm to 0.567 nm with increased HBG concentration. The stretchability of Cheddar and Violife cheese was 23.69 cm and 6.72 cm, respectively, while that of zein-based cheese added with HBG was 7.76-16.47 cm. The melting behavior of zein-based cheese did not fully mimic Cheddar cheese, but those of HBG5 and HBG10 were more comparable than Violife cheese. Violife cheese lacked hardness and gumminess compared to Cheddar cheese, while more similarities in textural properties were observed between Cheddar and zein-based cheese added with 10 % HBG. Our results provide opportunities in creating meltable low-fat plant-based cheese.

Comparison of milling methods on the properties of common buckwheat flour and the quality of wantuan, a traditional Chinese buckwheat food.

The microstructural and techno-functional properties of buckwheat flour and its processability for making wantuan, as affected by different milling methods, were investigated. Results showed that the particle sizes (d(0.5)) of the flours made by stone-milling (SM), hammer-milling (HM), laboratory grinding with steaming pretreatment for 5 min (LG-5) and 10 min (LG-10) were 95.5, 111.5, 35.4 and 41.1 µm, respectively. Moreover, SM and HM flours had less liberated starch granules and 20.84%-24.32% higher relative crystallinity than LG-10 flour. Slurries of laboratory-grinded flours showed excellent suspension stability. LG-10 flour had lowest pasting viscosities but greatest storage modulus and loss modulus. Color differences among the wantuan made from different flours were not visibly perceived (ΔE < 5). Wantuan made from LG-5 flour exhibited highest textual quality due to its greatest resilience (0.376), good springiness (0.933) and accepted chewiness (1093.31). Concluding, steaming prior to grinding could improve the qualities of buckwheat flour for wantuan making.

The contribution of cell wall integrity to gastric emptying and in vitro starch digestibility and fermentation performance of highland barley foods.

Studies have shown that the structure, composition, and bioavailability of compounds in whole grains are affected by processing and the role of cells walls. In this study, the effects of different processing methods on highland barley, one of the mostly widely produced whole grains worldwide, were investigated. The processing methods applied were flaking-boiling (HB flake), sand-roasting (Puffed HB), and sand-roasting-milling (Tsamba). Results showed Puffed HB and Tsamba had higher levels of damaged starch content, starch short-range molecular order, and relative crystallinity than HB flake. The half-time of gastric emptying (t1/2) was the slowest for Tsamba (132.3 min) compared to HB flake (122.5 min) and Puffed HB (84.0 min), indicating the slowest gastric emptying rate, which could be attributed to its high viscosity of gastric digesta. After in vitro gastroduodenal digestion, Puffed HB exhibited the lowest starch digestibility and the least amount of ß-glucan due to its less damaged cellular structure. Furthermore, Puffed HB resulted in a 21% and 18% higher in vitro production of total short-chain fatty acids than Tsamba and HB flake, respectively. Besides, undigested starch of Puffed HB after in vitro gastroduodenal digestion delayed in vitro fecal fermentation of ß-glucan. Our study provided insight into the potential mechanisms of how cell wall integrity affected the gastric emptying, in vitro starch digestibility, and in vitro fecal fermentation of highland barley foods.

Ozone exposure tunes the physicochemical properties of sweet potato starch by modifying its molecular structure.

Ozonation is an efficient method for improving the technical performance of some starches, but the feasibility of its use for sweet potato starch remains unknown. The effects of aqueous ozonation on the multi-scale structure and physicochemical properties of sweet potato starch were explored. Structurally, ozonation did not generate significant alterations at the granular level (size, morphology, lamellar structure, and long-range and short-range ordered structures), but led to tremendous changes at the molecular level, including converting hydroxyl groups to carbonyl and carboxyl groups and depolymerizing starch molecules. These structural changes resulted in prominent alternations in the technological performance of sweet potato starch, such as increases in water solubility and paste clarity and decreases in water absorption capacity, paste viscosity, and paste viscoelasticity. For these traits, their amplitudes of variation elevated when the ozonation time was extended and peaked at the longest ozonation time (60 min). The greatest changes in paste setback (30 min), gel hardness (30 min), and the puffing capacity of the dried starch gel (45 min) were observed at moderate ozonation times. In summary, aqueous ozonation is a new method for fabricating sweet potato starch with improved functionality.

Unraveling the regulating mechanisms of moisture content in the puffing of sweet potato starch gel.

Starch-based puffed crisps are a major group of popular snacks. In this work, the effects and underlying mechanisms of moisture content (MC) on the puffing of sweet potato starch gels were explored. The results showed that the gel with 12 % MC generated the highest puffing ratio (8.96), then followed by gels with 16 % MC (8.45) and 8 % MC (8.28). All starch gels presented a two-stage puffing pattern, but their evolutions with the heating temperature were highly dependent on the MC of gels. The relative puffing area percentages of gels with 8 % MC, 12 % MC and 16 % MC in the first (second) stages were 57.64 % (42.36 %), 60.66 % (39.34 %), and 18.36 % (81.64 %), respectively. The final pores in puffed products originated from the small water clusters that were regionalized in gel cells. The air cells started to expand as the gels with 8 % MC, 12 % MC and 16 % MC respectively reached the glass transition temperatures of 158.45 °C, 142.15 °C and 111.03 °C. The puffing was a joint consequence of the extensibility of cell walls and the pressure of water vapor in cells and the MC of the gels could regulate both of them. This study would facilitate the production of starch snacks with higher quality.

Coating peanut shell lignin nanospheres with gelatin via non-covalent adsorption: Key parameters, consequences, and underlying interactions.

In the present work, lignin nanospheres (LNS, average diameter 166.43 nm) were prepared and the affecting parameters, the absorbed types, and mechanisms of their interactions with type-A gelatin (AG) were explored. The findings demonstrated that upon AG coating, the ζ-potential of LNS sharply decreased and concluded a negative-to-positive shift, while the average diameter and polydispersity index increased significantly. AG presented the highest coating capacity (0.32 mg/mg, db) onto LNS (0.5 mg/mL) at an optimum pH of 4.0 and an AG concentration of 1.0 mg/mL. The adsorption of AG onto LNS could be well described by the Hill model (R2 = 0.9895), which was characterized as positive synergistic adsorption by the Hill coefficient (1.32) and physical adsorption by the free energy (3.70 kJ/mg). The spectral analysis revealed that the interactions between AG and LNS were mainly driven by electrostatic forces (ΔG < 0, ΔH < 0, and ΔS > 0) together with the assistance of hydrogen bonds and hydrophobic interactions, which companied a decrease of α-helix (4.04 %) and ß-turn (0.60 %) and an increase of ß-sheet (3.10 %) and random coil (1.53 %) of the secondary structure of AG. The results herein certainly favored the hydrophilic/hydrophobic change of LNS/AG and the quality control of a binary system consisting of lignin and gelatin.

Linear and non-linear rheological properties of water-ethanol hybrid pectin gels for aroma enhancement.

Whereas water-ethanol hybrid gels present an opportunity to realize aroma enhancement, translating hypothesis into practice is limited by poorly defined viscoelastic characteristics of those gels. In this work, the linear and non-linear rheological properties of water-ethanol hybrid pectin gels (WEPGs) were studied. Those WEPGs are physical gels in nature and the WEPG of 28.6% v/v ethanol differs basically from those of higher ethanol concentrations in the gel strength, resistance to deformation and non-linear properties. The retention of isopentyl acetate of WEPGs is dramatically improved by increasing the ethanol concentration to 33.3% v/v in the co-solvent system, but it is not further improved at 37.5% v/v. The cluster analysis reveals strong positive correlations between the isopentyl acetate release concentration and v 3/v 1 and absolute value of S/T ratio under 100% strain, suggesting the non-linear rheological responses of WEPGs have to be taken into account for which the enhancement of aroma is desired.

Hydrophobically modified polysaccharides and their self-assembled systems: A review on structures and food applications.

By reviewing the published literatures, especially from 2016 to 2021, preparative approaches of hydrophobically modified polysaccharides (HMP), mechanisms underlying their self-aggregation, and food applications of HMP and their self-aggregates, as well as perspectives and challenges, were discussed. Up to ten methods were reported for HMP preparations from various polysaccharides with different hydrophobic substituents. In contrast to their unmodified-counterparts, HMP displayed stronger assembling tendencies to form multimolecular self-aggregates. Different types of self-aggregates including micelles, polymersomes, hydrogels, and reverse-micelles, were analyzed and they were depended on structural parameters of HMP and their environmental conditions. Basically, their formation was mainly driven by intermolecular interactions of HMP such as hydrophobic, hydrogen-bonding, and electrostatic interactions. HMP and their self-aggregates could be used in food fields in different ways, such as carriers for targeted-delivery, controlled-release and stabilization of bioactive compounds, stabilizers for emulsions, and functional ingredients for antimicrobial films, improving nutrition and properties of foods.

Effect of Sand-Frying-Triggered Puffing on the Multi-Scale Structure and Physicochemical Properties of Cassava Starch in Dry Gel.

This study revealed the underlying mechanisms involved in the puffing process of dried cassava starch gel by exploring the development of the puffed structure of gel upon sand-frying, chiefly focused on the changes in the multi-scale structure and the physicochemical properties of starch. The results suggested that the sand-frying-induced puffing proceeded very fast, completed in about twenty seconds, which could be described as a two-phase pattern including the warming up (0~6 s) and puffing (7~18 s) stages. In the first stage, no significant changes occurred to the structure or appearance of the starch gel. In the second stage, the cells in the gel network structure were expanded until burst, which brought about a decrease in moisture content, bulk density, and hardness, as well as the increase in porosity and crispness when the surface temperature of gel reached glass transition temperature of 125.28 °C. Upon sand-frying puffing, the crystalline melting and molecular degradation of starch happened simultaneously, of which the latter mainly occurred in the first stage. Along with the increase of puffing time, the thermal stability, peak viscosity, and final viscosity of starch gradually decreased, while the water solubility index increased. Knowing the underlying mechanisms of this process might help manufacturers produce a better quality of starch-based puffed products.

Effects of Breaking Methods on the Viscosity, Rheological Properties and Nutritional Value of Tomato Paste.

Ultrasound-assisted processing has potential application advantages as an emerging technology for preparing tomato paste. This work explored the influence of ultrasound break at 22 °C (US-Break-22) and 65 °C (US-Break-65) on the viscosity, rheological properties and nutritional values of newly prepared tomato paste, compared with traditional thermal break at 65 °C (Break-65) and 90 °C (Break-90). Results showed that the US-Break-65 paste had the largest apparent viscosity, yield stress, consistency coefficient, solid-like nature, and large amplitude oscillatory shear behavior, followed by the US-Break-22 paste, Break-90 paste, and Break-65 paste. Based on the results of the pectin-related enzymes, particle size, and serum pectin of the pastes, it was revealed that the above-mentioned properties were mainly determined by the particle size and pectin content in their serum. The level of ascorbic acid followed the order of US-Break-22 paste > US-Break-65 paste > Break-65 paste > Break-90 paste. The level of total carotenoids followed the order of US-Break-22 paste ≈ US-Break-65 paste > Break-90 paste ≈ Break-65 paste. The level of total cis-carotenoids followed the order of US-Break-65 paste > US-Break-22 paste > Break-90 paste > Break-65 paste. The level of phenolics and antioxidant activities followed the same order of US-Break-22 paste > US-Break-65 paste > Break-90 paste > Break-65 paste. Overall, the viscosity, rheological properties and nutritional values of the tomato pastes prepared by US-Break-65 and US-Break-22 were significantly higher than those prepared by Break-65 and Break-90. Therefore, ultrasound assisted processing can prepare high quality tomato paste and can be widely implemented in the tomato paste processing industry.

A novel cholesterol-free mayonnaise made from Pickering emulsion stabilized by apple pomace particles.

Yolk-based mayonnaise is widely used to enhance the flavor of daily food. In view of health concerns on dietary cholesterol, novel mayonnaises (NMs) were made from Pickering emulsions stabilized by apple pomace particles using micro-jet (MJ-NM), ultrasonic (US-NM), and high-speed-shear homogenizer (HSS-NM), respectively. NMs and commercial mayonnaise (CM) were comparatively investigated in appearance, droplet size, rheological, tribological, and stability properties. NMs presented almost identical appearances to CM except for color. The droplets' size in NMs were larger than CM. Both NMs and CM demonstrated shear-thinning behavior and solid-like properties. Among mayonnaises, MJ-NM was demonstrated the most rapid thixotropy recovery with its storage modulus recovered within 51 s. Although both NMs and CM were of mixed tribology nature, NMs presented lower oral lubricity. Upon 210-day storage, both NMs and CM exhibited excellent stabilities without any oil-water separation occurred. Overall, the Pickering emulsions are promising and health alternatives for traditional mayonnaise.

Utilization of pomelo peels to manufacture value-added products: A review.

Pomelo peel as a by-product from pomelo consumption is rich in various nutrients and functional compounds, while most of the by-product is disposed as wastes. The utilization of pomelo peels could not only result in valued-added products/ingredients, but also reduce the environmental threats. By mainly reviewing the recent articles, pomelo peels could be directly used to produce candied pomelo peel, tea, jams, etc. Additionally, functional components (essential oils, pectin, polyphenols, etc.) could be extracted from pomelo peels and applied in food, pharmaceutical and chemical fields. The extraction methods exerted important influences on the composition, physicochemical properties, bioactivities and structures of the resultant fractions. Furthermore, pomelo peel was exploited to make adsorbents, bioethanol, etc. For the future investigations, the functionality- or bioactivity-oriented regimes to recovery valuable components from pomelo peel should be developed in an economic, effective and eco-friendly way and their applicability in large-scale production should be addressed.

Effect of temperature and pH on the encapsulation and release of ß-carotene from octenylsuccinated oat ß-glucan micelles.

Effect and working mechanism of temperature and pH on encapsulation and release of ß-carotene from octenylsuccinated-oat-ß-glucan-micelles (OSßG-Ms) were investigated. The stability and solubility of ß-carotene, and changes in surface hydrophilicity, core hydrophobicity, and size of ß-carotene-loaded-OSßG-Ms were determined. When exposed to temperature (25-45 °C) and pH (4.5-8.5), ß-carotene solubilization changed in parabolic manners. Size and absolute zeta-potential of ß-carotene-loaded-OSßG-Ms decreased with temperature, while they gave parabolic changing patterns with pH. Those results were ascribed to their hydrophilicity, hydrophobicity, and core/shell compactness via regulating molecule mobility, orientation, and interactions by temperature/pH. The higher temperature concluded with higher ß-carotene release, while a U-shaped release profile was observed with pH. Besides its diffusion, erosion-induced shrinking and collapsing of OSßG-Ms favored ß-carotene release at pH 1.2-4.5, which was replaced by swelling-induced structural-relaxation at pH 6.8-8.5. The results were favourable in controlling the behavior of ß-carotene-loaded-OSßG-Ms by selectively applying environmental parameters.

Micronized apple pomace as a novel emulsifier for food O/W Pickering emulsion.

In order to develop natural, food-grade particles as emulsifiers, wet-milled has been conducted to obtain apple pomace particles in varying sizes. Structural characteristics, physicochemical properties and Pickering emulsifying potential of the particle in different sizes were investigated. Particle size of apple pomace was gradually reduced from 12.9 µm to 550 nm during 8 h milling. With the decrease of particles size, the morphology became less angular. Meanwhile, some insoluble dietary fibers transformed into soluble ones, and the wettability tended to be hydrophilic, therefore, the water and oil holding capacities and free-radical-scavenging capacities increased. The properties of Pickering emulsions stabilized by wet-milled apple pomace particles in different sizes were then investigated. The decrease of particle size resulted in the size reduction of emulsion droplets, and gave rise to enhance gel-like properties and antioxidative activities of emulsions. The results demonstrated promising prospect of wet-milled apple pomace particles as emulsifiers in food industry.

Tuning the physicochemical properties of apple pectin films by incorporating chitosan/pectin fiber.

Various biodegradable or edible films were designed to deal with the environmental threats from plastic films. To overcome the defects of pectin film, the feasibility for the incorporation of CH/PE fiber was explored. Micron-scale novel artificial CH/PE fibers in needle, spindle or whisker shape with a diameter around 25 µm were fabricated via a shearing regime in virtue of electrostatic complexing. The incorporation of CH/PE fiber (mixture) and its size-fractioned portions (small and large) substantially changed PE films in diverse ways. Structurally, the fiber-incorporated films were heterogeneous with the fibers concentrated in the upper layer, although they presented similar FT-IR spectra and XRD pattern to PE film. Regarding the film performance, the incorporation of CH/PE fibers, especially the small portion, rendered the PE film with higher values in water-proof ability, thermal stability, break resistibility, stretchability and UV blocking capacity. More importantly, this work provided an innovative strategy to improve the performance of edible films.