The Construction of Sodium Alginate/Carboxymethyl Chitosan Microcapsules as the Physical Barrier to Reduce Corn Starch Digestion.

To enhance the resistant starch (RS) content of corn starch, in this work, carboxymethyl chitosan/corn starch/sodium alginate microcapsules (CMCS/CS/SA) with varying concentrations of SA in a citric acid (CA) solution were designed. As the SA concentration increased from 0.5% to 2%, the swelling of the CMCS/CS/SA microcapsule decreased from 15.28 ± 0.21 g/g to 3.76 ± 0.66 g/g at 95 °C. Comparatively, the onset, peak, and conclusion temperatures (To, Tp, and Tc) of CMCS/CS/SA microcapsules were higher than those of unencapsulated CS, indicating that the dense network structure of microcapsules reduced the contact area between starch granules and water, thereby improving thermal stability. With increasing SA concentration, the intact and dense network of CMCS/CS/SA microcapsules remained less damaged after 120 min of digestion, suggesting that the microcapsules with a high SA concentration provided better protection to starch, thereby reducing amylase digestibility. Moreover, as the SA concentration increased from 0.5% to 2%, the RS content of the microcapsules during in vitro digestion rose from 42.37 ± 0.07% to 57.65 ± 0.45%, attributed to the blocking effect of the microcapsule shell on amylase activity. This study offers innovative insights and strategies to develop functional starch with glycemic control properties, holding significant scientific and practical value in preventing diseases associated with abnormal glucose metabolism.

Effect of lecithin on the complexation between different botanically sourced starches and lauric acid.

This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids.

Effect of curdlan addition and thermal sterilization on the structural and properties of rice starch gel.

This study delves into the effects of curdlan integration and thermal sterilization on the rheological properties, structure, and quality attributes of concentrated rice starch gel. Acting as a heat-set polysaccharide, curdlan established a dual-network gel structure with rice starch gel, displaying strong interactions with rice starch, as confirmed by confocal laser scanning microscopy and Fourier-transform infrared spectroscopy. The addition of curdlan expedited the gel formation of rice starch, yielding a denser gel structure. Consequently, this enhanced G', solid-like behavior, textural properties, and cooking quality while reducing frequency-dependence. Given the cooling-induced gelation behavior of pure rice starch, thermal treatment disrupted inter-chain hydrogen bonding, compromising the structural integrity of the gel. This disruption manifested in a softer texture and diminished mechanical properties and cooking quality. Notably, this decline in mechanical properties and cooking quality of rice starch gel was markedly ameliorated with the incorporation of curdlan, particularly at a content of ≥1.0 %. Compared with pure RS, 1.0 % CD inclusion showed a reduction in cooking breakage rate by 30.69 % and an increase in hardness by 38.04 %. This work provides valuable insights for the advancement of fresh starch gel-based foods that exhibit exceptional quality and an extended shelf life.

Different effects of pea protein on the properties and structures of starch gel at low and high solid concentrations.

In the context of starch-protein composite gels, the influence of protein on gel formation significantly shapes the textural attributes of starch gels, leading to distinct outcomes. This study aimed to evaluate how different ratios of pea protein (PP) affect the properties and structures of starch-protein composite gels at low (10 wt%) and high (40 wt%) solid concentrations. The addition of PP had opposite effects on the two gels. Compared to the pure starch gel, the low-concentration composite gel (LCG) with 20 % PP experienced a 48.90 ± 0.33 % reduction in hardness, and the storage modulus (G') decreased from 14,100 Pa to 5250 Pa, indicating a softening effect of PP on LCG. Conversely, the hardness of the high-concentration composite gel (HCG) with 20 % PP exhibited a 62.19 ± 0.03 % increase in hardness, and G' increased from 12,100 Pa to 41,700 Pa, highlighting the enhancing effect of PP on HCG. SEM and fluorescence microscopy images showed that PP induced uneven network sizes in LCG, while HCG with a PP content of 20 %, PP, together with starch, formed a three-dimensional network. This study provides valuable insights and guidance for the design and production of protein-enriched starch gel products with different textural properties.

Water in water emulsion stabilized by liposomes developed from whey protein isolate and xanthan gum: Environmental stability and photoprotection effect for riboflavin.

The purpose of this work is to explore the feasibility of water in water (W/W) emulsion stabilized with liposomes as a water-soluble nutraceutical carrier. A W/W emulsion system composed of xanthan gum (XG) and whey protein isolate (WPI) with different amount (0.2 %, 0.4 %, and 0.6 %) of liposomes as stabilizer was constructed. Fast green staining observation showed that XG was the internal phase and WPI was the continuous phase respectively. Confocal laser scanning microscopy revealed that with the increase of liposomes concentration from 0.4 % to 0.6 %, the interface thickness of the W/W emulsions was approximately twice that of the 0.2 % liposome-stabilized emulsion.The emulsions remained stable under neutral and weakly alkaline conditions. The droplet sizes of the emulsions were little affected by ionic strength. The binding constant (Ka) for XG to riboflavin (12.22) was approximately 5 times that for WPI to riboflavin (2.46), suggesting that riboflavin had a stronger binding affinity for the XG molecule compared to WPI. The fluorescence spectra of riboflavin showed that 0.4 % and 0.6 % liposome stabilized emulsions could effectively retard the photodegradation of riboflavin under ultraviolet irradiation. The successful construction of liposomes stabilized W/W emulsion provides a novel strategy for delivering water-soluble bioactive substances.

Utilization of heat-induced curdlan gel to improve the cooking qualities of thermally sterilized fresh rice noodles.

Thermal sterilization is the most economical and efficient method to guarantee the shelf life of extruded fresh rice noodles, but it often leads to a high cooking breakage rate and poor elongation at break of the noodles. The aim of this study was to improve the edible quality of sterilized fresh rice noodles through the addition of low concentrations of curdlan (0.38 %-1.13 %), which can form a thermal-irreversible gel to resist high-temperature sterilization. Compared with the control group without curdlan, the cooking breakage rate of sterilized fresh rice noodles with 1.13 % curdlan decreased from 16.85 % to 5.22 %, the tensile strain increased from 91.15 % to 147.05 %, and the microstructure was more dense and uniform. The results showed that adding the proper amount of curdlan is an effective strategy to improve the quality of sterilized fresh rice noodles.

On the investigation of composite cooling/heating set gel systems based on rice starch and curdlan.

In pursuit of advancing the understanding of composite gel systems, this study delves into the intricate realm of rheology, structural elucidation, and mechanical attributes. Specifically, it scrutinizes the symbiotic interplay between rice starch, a cooling-set gel, and curdlan, a thermo-irreversible heating-set gel. A higher curdlan content enhances the inter-chain hydrogen bonding between rice starch and curdlan, resulting in a denser gel structure and thus increased moduli, solid-like behavior, and mechanical properties, and reduced frequency-dependence, especially at high temperatures (>65 °C). For example, with 50 % curdlan incorporation, G' (90 °C) improved by 252 %. Notably, thermal treatment can compromise the structural integrity of the rice starch gel, reducing strength and softening texture. However, this textural degradation can be effectively mitigated with, for example, 30 % curdlan incorporation, resulting in a 55-fold hardness increase at 85 °C. The knowledge gained from this work offers valuable guidance for tailoring starch-based gel products to specific properties.

Properties of Heat-Assisted pH Shifting and Compounded Chitosan from Insoluble Rice Peptide Precipitate and Its Application in the Curcumin-Loaded Pickering Emulsions.

Curcumin exhibits antioxidant and antitumor properties, but its poor chemical stability limits its application. Insoluble peptide precipitates formed by proteolysis of rice glutelin are usually discarded, resulting in resource waste. The coupled treatment of heat-assisted pH shifting and compounded chitosan (CS) was used to fabricate rice peptide aggregate-chitosan complexes (RPA-CS). The structure, interfacial behavior, emulsion properties, and digestibility of curcumin-loaded RPA-CS Pickering emulsions were investigated. Increasing the CS concentration led to lower interfacial tension but larger particle size, and the three-phase contact angle of the RPA-CS complexes approached 90°. Quartz crystal microbalance with dissipation (QCM-D) indicated that RPA-CS complexes with 6 g·kg-1 of CS (RPA-CS6) had the highest K1 (0.592 × 106 Hz-1) and K4 (0.487 × 106 Hz-1), suggesting that the softest interfacial layers were formed. The solid-liquid balance of RPA-RPA-CS emulsions was lower than 0.5, declaring that they had more elastic behavior than that of RPA emulsions. RPA-RPA-CS4-and RPA-CS6 emulsions had better storage stability, lower FFA release (79.8% and 76.3%, respectively), and higher curcumin bioaccessibility (65.2% and 68.2%, respectively) than RPA emulsions. This study showed that a low-value insoluble rice peptide precipitate could be used as a valuable emulsifier in foods, which may increase the economics and sustainability of the food supply.

A review of starch swelling behavior: Its mechanism, determination methods, influencing factors, and influence on food quality.

Swelling behavior involves the process of starch granules absorbing enough water to swell and increase the viscosity of starch suspension under hydrothermal conditions, making it one of the important aspects in starch research. The changes that starch granules undergo during the swelling process are important factors in predicting their functional properties in food processing. However, the factors that affect starch swelling and how swelling, in turn, affects the texture and digestion characteristics of starch-based foods have not been systematically summarized. Compared to its long chains, the short chains of amylose easily interact with amylopectin chains to inhibit starch swelling. Generally, reducing the swelling of starch could increase the strength of the gel while limiting the accessibility of digestive enzymes to starch chains, resulting in a reduction in starch digestibility. This article aims to conduct a comprehensive review of the mechanism of starch swelling, its influencing factors, and the relationship between swelling and the pasting, gelling, and digestion characteristics of starch. The role of starch swelling in the edible quality and nutritional characteristics of starch-based foods is also discussed, and future research directions for starch swelling are proposed.

Effects of peanut oligopeptides on the pasting properties of potato starch and digestive characteristics of dry, flat potato starch noodles.

In this study, we developed dry, flat potato starch noodles with an ideal taste and low digestibility. Peanut oligopeptide and potato starch were combined to form dry, flat potato starch noodles containing different peanut oligopeptide contents using a steam-slice method. Adding 5 % and 10 % peanut oligopeptides maintained the dry, flat starch noodles' quality. Scanning electron microscopy (SEM) analysis showed that dry, flat starch noodles containing peanut oligopeptides had more pores with pore sizes ranging from 0.30 µm to 2.00 µm. X-ray diffraction (XRD) results showed that peanut oligopeptide promoted the recrystallization of amylopectin during the retrogradation process after gelatinization, and the crystallinity of noodles ranged from 4.31 % (control noodles) to 18.24 % (noodles containing 10 % peanut oligopeptides). An in vitro simulated digestion test showed that the slowly digestible starch and resistant starch contents of noodles containing 10 % peanut oligopeptides were 18.24 % and 22.03 %-significantly higher than control starch noodles (14.88 % and 9.9 %, respectively). Therefore, when peanut oligopeptides were added to dry, flat starch noodles, it was a promising material for lowering blood sugar levels after meals.

Recent knowledge in phages, phage-encoded endolysin, and phage encapsulation against foodborne pathogens.

The use of antibiotics had reached a plateau due to antibiotic resistance, overuse, and residue. Bacteriophages have recently attracted considerable attention as alternative biocontrol agents. Here, we provide an up-to-date overview of phage applications in the food industry. We reviewed recently reported phages against ten typical foodborne pathogens, studies of competitive phage-encoded endolysins, and the primary outcomes of phage encapsulation in food packaging and pathogen detection. Furthermore, we identified existing barriers that still need to be addressed and proposed potential solutions to overcome these obstacles in the future.

Diversity of the protease-producing bacteria and their extracellular protease in the coastal mudflat of Jiaozhou Bay, China: in response to clam naturally growing and aquaculture.

The booming mudflat aquaculture poses an accumulation of organic matter and a certain environmental threat. Protease-producing bacteria are key players in regulating the nitrogen content in ecosystems. However, knowledge of the diversity of protease-producing bacteria in coastal mudflats is limited. This study investigated the bacterial diversity in the coastal mudflat, especially protease-producing bacteria and their extracellular proteases, by using culture-independent methods and culture-dependent methods. The clam aquaculture area exhibited a higher concentration of carbon, nitrogen, and phosphorus when compared with the non-clam area, and a lower richness and diversity of bacterial community when compared with the clam naturally growing area. The major classes in the coastal mud samples were Bacteroidia, Gammaproteobacteria, and Alphaproteobacteria. The Bacillus-like bacterial community was the dominant cultivated protease-producing group, accounting for 52.94% in the non-clam area, 30.77% in the clam naturally growing area, and 50% in the clam aquaculture area, respectively. Additionally, serine protease and metalloprotease were the principal extracellular protease of the isolated coastal bacteria. These findings shed light on the understanding of the microbes involved in organic nitrogen degradation in coastal mudflats and lays a foundation for the development of novel protease-producing bacterial agents for coastal mudflat purification.

Physicochemical properties and in vitro digestion behavior of emulsion gels stabilized by rice bran protein aggregates: Effects of heating time and induction methods.

To investigate the effects of heating time and induction methods on the physicochemical properties and in vitro digestion behavior of emulsion gels, rice bran protein aggregates (RBPAs) were formed by acid-heat induction (90 °C, pH 2.0) and the emulsion gels were further prepared by adding GDL or/and laccase for single/double cross-linked induction. Heating time affected the aggregation and oil/water interfacial adsorption behavior of RBPAs. Suitable heating (1-6 h) was conducive to faster and more adsorption of aggregates at the oil/water interface. While excessive heating (7-10 h) resulted in protein precipitation, which inhibited the adsorption at the oil/water interface. The heating time at 2, 4, 5 and 6 h was thus chosen to prepare the subsequent emulsion gels. Compared with the single cross-linked emulsion gels, the double-cross-linked emulsion gels showed higher water holding capacity (WHC). After simulated gastrointestinal digestion, the single/double cross-linked emulsion gels all exhibited slow-release effect on free fatty acid (FFA). Moreover, the WHC and final FFA release rate of emulsion gels were closely related to the surface hydrophobicity, molecular flexibility, sulfhydryl, disulfide bond and interface behavior of RBPAs. Generally, these findings proved the potential of emulsion gels in designing fat alternatives, which could provide a novel technique for the fabrication of low-fat food.

Construction and In Vitro Digestibility of Recrystallized Starch Encapsulated in Calcium Alginate Beads.

In order to reduce the digestion rate of starch in human body and improve the content of slowly digestible starch (SDS) and resistant starch (RS), millimeter calcium alginate beads encapsulated with different proportions of recrystallized starch were constructed in this study. First, we prepared recrystallized starch (RS3) by debranching waxy corn starch and retrogradation, and then encapsulated RS3 in calcium alginate beads by the ionic gel method. The microstructure of the beads was observed by scanning electron microscope, and the gel texture properties, swelling properties, and in vitro digestibility of the beads were studied. The results showed that the beads after cooking still maintained high hardness and chewiness, and the swelling power and solubility of the beads were lower than that of native starch. Compared with native starch, the content of rapidly digestible starch (RDS) in beads decreased, while the content of SDS and RS increased. The sample with the highest content of RS is RS31@Alginate1, whose content of RS is 70.10%, 52.11 times higher than that of waxy corn starch and 1.75 times higher than that of RS3. RS3 encapsulated in calcium alginate beads has a good encapsulation effect, and the content of SDS and RS is greatly increased. This study has important implications for reducing the digestion rate of starch and regulating the health of people with diabetes and obesity.

Different Characteristics of Annealed Rice Kernels and Flour and Their Effects on the Quality of Rice Noodles.

In this study, the characteristics of indica rice kernels (IRK) and flour (IRF) annealed in different conditions were evaluated, and the quality of rice noodles made with these IRK and IRF was determined. Native IRK and IRF were annealed in deionized water at a kernel or flour to water ratio of 1:3 (w/v) and temperatures of 50, 55, 60, and 65 °C for 12 and 24 h. Annealing increased the paste viscosity of IRK while decreasing that of IRF. Both annealed IRK and IRF exhibited increases in the gelatinization enthalpy change and relative crystallinity. Annealed IRK gel showed higher hardness, and annealed IRF gel displayed greater springiness. Unlike native rice noodles, annealed IRK noodles exhibited denser pores, while annealed IRF noodles exhibited a looser microstructure. With increasing annealing temperature and time, both annealed IRK and IRF noodles showed enhanced tensile properties. Rice noodles made from IRF annealed at 65 °C for 12 h exhibited a fracture strain of 2.7 times that of native rice noodles. In brief, IRK and IRF exhibited different degrees of susceptibility to annealing. Annealing had more significant effects on IRF than IRK. This study highlights the possibility of using annealed IRK and IRF in rice noodles.

The Mechanism Underlying the Amylose-Zein Complexation Process and the Stability of the Molecular Conformation of Amylose-Zein Complexes in Water Based on Molecular Dynamics Simulation.

The aim of this study was to employ molecular dynamics simulations to elucidate the mechanism involved in amylose-zein complexation and the stability of the molecular conformation of amylose-zein complexes in water at the atomic and molecular levels. The average root mean square deviation and radius of gyration were lower for amylose-zein complexes (1.11 nm and 1 nm, respectively) than for amylose (2.13 nm and 1.2 nm, respectively), suggesting a significantly higher conformational stability for amylose-zein complexes than for amylose in water. The results of radial distribution function, solvent-accessible surface area, and intramolecular and intermolecular hydrogen bonds revealed that the amylose-zein interaction inhibited water permeation into the amylose cavity, leading to enhanced conformational stabilities of the V-type helical structure of amylose and the amylose-zein complexes. Furthermore, the amylose in amylose-zein complexes displayed the thermodynamically stable 4C1 conformation. These findings can provide theoretical guidance in terms of the application of protein on starch processing aiming to improve the physicochemical and functional properties of starch (such as swelling capacity, pasting properties, and digestibility) for developing novel low-digestibility starch-protein products.

Effects of annealing temperature and time on the structural and physicochemical properties of sweet potato flour hydrogels.

The physicochemical properties of sweet potato flour (SPF) can be modified by annealing. Native SPF was annealed in deionized water at a flour-to-water ratio of 1:3 (w/v) and temperatures of 50, 55, 60, or 65 °C for either 12 or 24 h. Annealed SPF maintained the A-type crystalline region and displayed increased relative crystallinity, increased pasting temperature, and decreased breakdown. SPF gels showed enhanced hardness together with better springiness when SPF was annealed at low temperature/long time or high temperature/short time. Annealed SPF hydrogel sheets contained larger, more uniform, and smoother pores than native ones. Noticeably, hydrogel sheets made of SPF annealed at 50 °C for 24 h exhibited advanced fracture strain from 93% to 176%. Overall, this work showed that annealing could modulate the characteristics of SPR hydrogels, which may widen the extent of applications in food industries. However, the annealing conditions need to be optimized.

Numerical simulation and experimental study for ultrasonic vibration-assisted drilling of SiCp/AL6063.

Thrust force and metal chips are essential focuses in SiCp/AL6063 drilling operations. Compared with conventional drilling (CD), the ultrasonic vibration-assisted drilling (UVAD) has attractive advantages: for instance, short chips, small cutting forces, etc. However, the mechanism of UVAD is still inadequate, especially in the thrust force prediction model and numerical simulation. In this study, a mathematical prediction model considering the ultrasonic vibration of the drill is established to calculate the thrust force of UVAD. A 3D finite element model (FEM) for the thrust force and chip morphology analysis is subsequently researched based on ABAQUS software. Finally, experiments of CD and UVAD of SiCp/Al6063 are performed. The results show that when the feed rate reaches 151.6 mm/min, the thrust force of UVAD decreases to 66.1 N, and width of the chip decreases to 228 um. As a result, the errors of the mathematical prediction and 3D FEM model of UVAD are about 12.1 and 17.4% for the thrust force, and the errors of the CD and UVAD of SiCp/Al6063 are 3.5 and 11.4% for the chip width, respectively. Compared with the CD, UVAD could reduce the thrust force and improve chip evacuation effectively.

ZnO nanoparticles coated and stearic acid modified superhydrophobic chitosan film for self-cleaning and oil-water separation.

The aim of this study was to prepare superhydrophobic chitosan films using a ZnO nanoparticle coating and stearic acid hydrophobic modification. A 1 % concentration of ZnO nanoparticles and a 1 % concentration of stearic acid generated a superhydrophobic film with the largest contact angle (WCA) of 156°, which was attributed to the synergy of micro/nano-level hierarchical structure and low surface energy modification. The superhydrophobic film showed better stability to acid, alkali, heat, and UV irradiation than a neat chitosan film and a reduction in light transmittance of 14.4 % at 354 nm. The superhydrophobic chitosan film also showed excellent self-cleaning and oil-water separation performance. Our findings will expand the application of chitosan films in food packaging, outdoor self-cleaning materials and oil-water separations.

Versatile wheat gluten: functional properties and application in the food-related industry.

Gluten is a key component that allows wheat flour to form a dough, and it is also a byproduct of the production of wheat starch. As a commercial product, wheat gluten is increasingly used in the food-related industry because of its versatile functional properties and wide range of sources. Wheat gluten is manufactured industrially on a large scale through the Martin process and batter process and variants thereof. Gliadin and glutenin impart cohesiveness and elasticity properties, respectively, to wheat gluten. The formation of gluten networks and polymers depends mainly on covalent bonds (disulfide bonds) and noncovalent bonds (ionic bonds, hydrogen bonds, and hydrophobic interactions). The multifunctional properties (viscoelasticity, gelation, foamability, etc.) of wheat gluten are shown by rehydration and other processing techniques. Wheat gluten has been widely used in wheat-based products, food auxiliary agents, food packaging, encapsulation and release of food functional ingredients, food adsorption and heat insulation materials, special purpose foods, and versatile applications. In the future, wheat gluten protein will be used as an important raw material to participate in the development and preparation of various food and degradable materials, and the application potential of wheat gluten in food-related industries will be massive. This review summarizes the main manufacturing processes, composition, and structure of gluten protein, and the various functional properties that support its application in the food and related industries.

The versatile functional properties of wheat gluten are closely related to structureThe application as a binder and substitute for meat is growing in popularityRenewable and degradable gluten-based materials are important exploited fieldsWheat gluten shows vast potential and application value in food-related industry.