Constipation is a prevalent functional gastrointestinal disorder. Conventional laxative therapies for constipation often entail risks of dependence and adverse effects. With the growing recognition of the crucial role of gut microbiota dysbiosis in its pathogenesis, gut microbiota modulation has emerged as a core strategy in novel therapies. Synbiotics, a combination of probiotics and prebiotics, demonstrates significant therapeutic potential through synergistic mechanisms: prebiotics selectively promote the colonization and proliferation of probiotics, and they synergistically optimize gut microbiota composition, enhance the production of short-chain fatty acids, and subsequently improve intestinal barrier function, regulate immune responses, and stimulate intestinal motility. Clinical evidence indicates that specific synbiotic formulations outperform single-component interventions in improving stool frequency, consistency, and overall symptoms. This advantage stems from the “nutrition-microbiota-metabolism” multiple-pathway synergistic effect. Future research should prioritize the development of personalized synbiotic regimens based on gut microbiota functional prediction, conduct large-scale clinical trials for functional validation, and explore their integration with novel delivery systems and functional food carriers, thereby advancing the development of constipation treatment toward the integration of precision microbiota-based intervention and enhancing its clinical utility and patients’ quality of life.

This study investigated the hydrothermal phosphorylation modification of whey protein isolate (WPI90) using mixtures of sodium hexametaphosphate (SHMP) and tetrasodium pyrophosphate decahydrate (SPP) at different mass ratios (1:1, 1:2, and 2:1) applied at varying mass concentrations (0.03, 0.06, and 0.09 g/100 mL). The secondary structure, thermal stability, solubility, foaming properties, emulsifying properties, and water-holding capacity of WPI were determined before and after phosphorylation. The results indicated that the negative charges introduced by phosphorylation altered the structural characteristics of WPI. This modification resulted in an increase in α-helix content in the secondary structure and induced noticeable microstructural changes. Phosphate addition enhanced the thermal stability and kinetic stability after heating to varying degrees; the phosphorylated WPI solutions remained clear and transparent after heating, showing a turbidity approximately 80% lower than that of unmodified WPI90. All phosphorylation modifications altered the foaming and emulsifying properties of WPI. Notably, the addition of the 2:1 mixture at 0.06 and 0.09 g/100 mL resulted in a 3- to 4-fold increase in the emulsion stability of WPI and increased the water-holding capacity from 20% to 50% and 90%, respectively, demonstrating a remarkable modification effect. This study provides a feasible approach to address the stability limitations of WPI in food processing.

Whey protein (WP), an important protein in dairy products, is rich in amino acids and bioactive peptides, and possesses high nutritional value. However, its poor thermal stability leads to issues such as protein denaturation, precipitation, and oxidation under high-temperature and high-concentration conditions, which limit its application in functional foods, dietary supplements, foods for special medical purpose, and other related fields. Therefore, enhancing the thermal stability of WP has become particularly important. This paper reviews recent advances in physical, chemical, and biological modification techniques, as well as the application of molecular chaperones in improving the thermal stability of WP, and summarizes the key indicators to evaluate its thermal stability and degree of denaturation and aggregation. It also discusses the potential application value and development prospects of thermally stabilized WP in food, pharmaceutical, and other industries.

Sodium tripolyphosphate (STPP), sodium dihydrogen phosphate (SHP), disodium hydrogen phosphate (DSP), sodium hexametaphosphate (SHMP), and tetrasodium pyrophosphate (SPP) were employed for the moist-heat phosphorylation of whey protein isolate (WPI90) under varying temperatures and pH conditions. Phosphorylated proteins with stronger heat resistance were selected to determine their solubility, free sulfhydryl content, surface hydrophobicity, secondary structure, sodium, phosphorus, and calcium contents. Furthermore, they underwent ultra-high temperature (UHT, 135 ℃) processing followed by evaluation of their thermal stability indicators, including centrifugal precipitation rate, viscosity, and particle size as well as their solubility and structure. Commercial heat-stable whey protein was used as control. The results revealed that phosphorylation at 75 ℃ led to an increase in the content of free sulfhydryl groups and a decrease in surface hydrophobicity. The incorporation of phosphates increased the sodium and phosphorus contents while reducing both soluble and total calcium contents, with SPP and SHP resulting in the lowest soluble calcium levels (< 3 mg/g). Fourier transform infrared spectroscopy (FTIR) indicated alterations in protein secondary structure, characterized by a general decrease in β-sheet content and an increase in β-turn content. Phosphorylation at 85 ℃ increased the random coil content. All phosphates except DSP enhanced the thermal stability of whey protein at pH 7.0 and different temperatures (75, 80, and 85 ℃), preventing flocculation of whey protein after UHT treatment. The SHMP-modified protein demonstrated the lowest centrifugal precipitation rate and apparent viscosity after UHT treatment, with an overall particle size below 15 µm. Moreover, phosphorylation with SPP, STPP, and SHP at 75 ℃ improved the solubility of WPI90 to different extents, while phosphorylation with SHMP did not. For both 75 and 80 ℃, SPP phosphorylation resulted in the highest solubility of WPI90. In conclusion, this study demonstrates that moist-heat phosphorylation effectively modifies the structure and functionality of whey protein while influencing the salt ion contents in the protein system. Specifically, the addition of SHMP under neutral pH conditions significantly enhances the thermal stability of whey protein, being of guiding significance for the UHT processing of whey protein concentrate.

In this study, changes in the contents of α-lactalbumin and β-lactoglobulin of fresh mare milk were analyzed after heat treatments at different temperatures and for different durations, and changes in the volatile composition were also analyzed by electronic nose, electronic tongue and solid-phase microextraction coupled with gas chromatographymass spectrometry (SPME-GC-MS). The results showed that heat treatment at 85 ℃ for 10 s had the smallest effect on the protein content in mare milk. When the heating temperature was 95 ℃, the particle size of mare milk protein increased from 318.18 to 543.25 nm with the increase in heating time. The fresh taste of mare milk treated at 85 ℃ for 10 s, which had the weakest sour taste, was the closest to that of raw mare milk. Heat-treated mare milk contained more types of volatile flavor compounds and had higher contents of hydrocarbons, aromatics, ketones, and alcohols but significantly lower contents of acids than raw mare milk.

The enhancing effects of different pre-treatment techniques (addition of emulsifying salts, electrodialysis, and resin adsorption) on the stability of ultra-high temperature (UHT)-sterilized yak milk with standardized protein content was investigated by measurement of ethanol stability, protein precipitation rate, whey protein denaturation rate and turbidity stability index (TSI) as well as by using Fourier transform infrared spectroscopy (FTIR) and inductively coupled plasma mass spectrometry (ICP-MS). The results showed that all three pre-treatment methods significantly improved the heat stability of UHT-sterilized yak milk. Compared with the standardized control group, whey protein denaturation rate decreased by 92.02% and 90.15%, soluble calcium content by 3.94% and 13.93%, and protein precipitation rate by 11.71% and 20.40% in the samples treated by resin and electrodialysis, with an average TSI of 2.94 and 1.33, respectively. Whey protein denaturation rate decreased by 84.69%, and protein precipitation rate increased 18.39% in the emulsifying salt-treated sample. The resin-treated group had the highest absolute value of the zeta potential (22.83 mV), closely followed by the electrodialysis group (19.57 mV), suggesting that electrodialysis also improved the heat stability of UHT-sterilized yak milk. FTIR analysis revealed that after UHT treatment, both resin and electrodialysis groups showed an increase in the relative content of α-helix and a decrease in the relative content of β-sheet. In conclusion, this study demonstrates that adjusting the salt balance of yak milk can enhance its UHT stability, providing important guidance for the processing of UHT yak milk.

In this study, the effects of adding mixtures of mono- and di-fatty acid glycerides and Tween 80 with different hydrophilic-lipophilic balance (HLB) values on the stability and whipping characteristics of cream were studied, and the hardness, whipping rate, apparent viscosity, stability, and microstructure of the cream samples were detected. The results showed that with the increase in HLB value, the apparent viscosity of the emulsion decreased, and shear thinning occurred in all cream samples. The centrifugal creaming rate and turbiscan stability index (TSI) decreased first and then increased, and so did the absolute value of zeta potential. The results of whipping characteristics analysis showed that with the increase in HLB value, the whipping time and whipping rate of cream decreased, and the hardness after whipping increased first and then decreased, reaching a maximum of 1150.1 g when the HLB value was 9. At HLB values in the range of 9-11, cream exhibited a shorter whipping time, higher whipping hardness, appropriate whipping rate, and good mounting performance with no collapse or deformation. Meanwhile, the microstructure showed that the size of the cream bubbles was relatively uniform after whipping, and the fat globules around the bubbles were dense and close to each other, thus forming a better network structure to protect the bubbles and make the foam more stable. Therefore, the HLB value of mixed emulsifiers should be controlled in the range of 9-11 to obtain cream with good stability and whipping characteristics.