Journal of the Science of Food and Agriculture最新文献

Background: Polyphenols have a strong binding capacity with proteins, but the binding behavior of polyphenols with glycosylated proteins and the effects of binding on the structure of glycosylated proteins have been less studied.

Results: This study used enzymatic modification to prepare an oligochitosan-legumin complex (OLC) to investigate its interaction with (-)-epigallocatechin gallate (EGCG) and quercetin. Fluorescence spectroscopy experiments showed that the binding site of OLC to EGCG was 27.7 ± 2.47 and that of quercetin to OLC was 19.5 ± 2.92; the binding of one polyphenol affected the other's ability to bind to OLC. The FTIR and CD results showed secondary structural changes in OLC after incorporating polyphenols, with a decrease in the content of α-helix and an increase in the content of β-sheet. The OLC and OLC-polyphenol complexes showed smaller particle size and denser micromorphology. Moreover, OLC had a protective effect on EGCG and quercetin against thermal and ultraviolet light treatments compared to polyphenols alone.

Conclusion: Transglutaminase was used to catalyze the crosslinking of legumin and oligochitosan. The interaction between OLC and two polyphenols with different properties was studied, and OLC was successfully developed as a carrier to protect two bioactive substances. This study demonstrated the interaction mechanism between glycosylated proteins and polyphenols, providing a basis for the application of glycosylated proteins in encapsulation, protection, and delivery of bioactive substances. © 2025 Society of Chemical Industry.

Background: Exopolysaccharide (EPS) produced by Streptococcus thermophilus can significantly improve the viscosity, texture and taste of dairy products, which have broad application potential in the food industry. However, EPS production is typically low (< 100 mg L^-1) in S. thermophilus, making it difficult to meet industrialization requirements. The utilization of metabolic engineering for genetic modification of S. thermophilus is an efficient approach to enhance EPS biosynthesis.

Results: To our knowledge, there is lack of systematic investigation on engineering UDP-sugar synthetic pathways for EPS production in S. thermophilus. In the present study, the biosynthetic genes of EPS precursors UDP-glucose and UDP-galactose were regulated for improving EPS production in S. thermophilus AR333. Compared with the control, engineered strains by single overexpression of eight EPS precursor genes increased EPS production by 7-31%, respectively. Among of them, overexpressing glk encoding glucokinase and galE1 encoding UDP-galactose-4-epimase led to 275.37 and 288.65 mg L^-1 of EPS production, respectively. Moreover, co-overexpression of lacZ encoding β-galactosidase and galE1 achieved a remarkable 49% increase in the EPS production (329.51 mg L^-1). Transcriptional analysis further suggested that enhanced EPS synthesis in engineered strain can attributed to the upregulation of precursor genes and clusters of EPS genes.

Conclusion: Our results showed that engineered UDP-sugar synthesis is an efficient strategy to boost EPS production in S. thermophilus. © 2025 Society of Chemical Industry.

Backgroud: Freezing is a commonly used method to prolong the storage duration of egg yolk, which induces irreversible gelation after being stored below -6 °C. The present study examined the effects of pre-freezing and thawing conditions on the gelation of egg yolk liquid, accessing its rheological properties, molecular structure and water mobility.

Results: The results indicated that pre-freezing at -40 °C for 7 days followed by storage at -18 °C was a cost-effective method, with the consistency coefficient being decreased by approximately 30% compared to that of egg yolk liquid frozen directly at -18 °C. Pre-freezing was beneficial in generating smaller ice crystals, preventing the protein denaturation and aggregation caused by mechanical damage from larger ice crystals, and reducing the loss of protein molecular bound water. On the other hand, thawing in a 50 °C water bath was found to be the most effective method. The consistency coefficient of egg yolk liquid pre-freezed at -40 °C for 3 days and then thawed at 50 °C decreased by 73% compared to the sample directly frozen at -18 °C and then thawed at room temperature. The increase in fluidity of egg yolk after freezing was related to protection of bonding water and less cross-linking, as verified by the higher content of β-sheet and smaller particle size.

Conclusion: The pre-freezing process promoted the formation of a greater number of small ice crystals, which mitigated the mechanical damage to proteins and the consequent denaturation and aggregation. Additionally, thawing at elevated temperatures could effectively avoid recrystallization, protecting proteins from denaturation and aggregation, leading to a further reduction in gel strength and an increase in fluidity. The findings of the present study contribute to a better understanding of the factors influencing egg yolk gelation and offer insights into the development of enhanced freezing and thawing techniques for egg yolk. © 2025 Society of Chemical Industry.

Background: Black rice anthocyanins (BRA) offer significant health benefits but are limited in application due to their low bioavailability. Bovine serum albumin (BSA) nanoparticles (NPs) have been shown to effectively enhance the stability of encapsulated BRA. However, the mechanism of BRA-BSA NP formation and their molecular interactions remain unclear. This study prepared and characterized BRA-BSA NPs and investigated the formation mechanisms using computational simulations.

Results: The optimized BRA-BSA NPs had a particle size of 128.37 ± 4.10 nm, a zeta potential of -18.93 ± 0.32 mV and an encapsulation efficiency of 81.10 ± 0.08%. Characterization showed that the NPs were stabilized through hydrophobic interactions and hydrogen bonds. BRA-BSA NPs exhibited a slow release in the upper gastrointestinal tract. Molecular dynamics simulations, both all-atom and coarse-grained, revealed that anthocyanins bound to four primary sites on the BSA surface through hydrogen bonds and van der Waals forces. Furthermore, ethanol was shown to modulate the dissociation of amino acids, promoting BSA aggregation and self-assembly into NPs.

Conclusion: The results demonstrate that BSA NPs loaded with BRA serve as effective carriers with high encapsulation efficiency. Molecular dynamics simulations elucidated the molecular basis of cyanidin-3-O-glucoside-BSA interactions, as well as the self-assembly process of BSA. This study therefore provides valuable insights for developing BSA-based delivery systems for BRA, advancing the fields of bioactive encapsulation of nutraceuticals. © 2025 Society of Chemical Industry.

Background: Microbial fermentation is regarded as the best bioimprovement technique for changing the physicochemical characteristics and structural makeup of carbohydrates. In the present study, lotus root starch (LRS) was co-fermented with Saccharomyces cerevisiae and Lactiplantibacillus plantarum. The effects of single- and mixed-strain fermentation on the structure, physicochemical properties and digestibility of starch were investigated at different fermentation times.

Results: The results showed that cracks and grooves appeared on the surface of fermented LRS, particularly with prolonged mixed fermentation. Additionally, the particle size, dissociation, freeze-thaw dehydration shrinkage and hydration characteristics of starch significantly decreased. Structural characterization showed that fermentation promoted the alignment of LRS long chains towards shorter sequence structures, enhanced hydrogen-bonding interactions and increased the relative crystallinity of LRS by degradation of the amorphous region. Mixed fermentation also increased the viscosity, springiness, thermal stability and shear stability of LRS gels compared to single fermentation, effectively improving the digestive performance.

Conclusion: This study has confirmed that co-fermentation with L. plantarum and S. cerevisiae significantly influences both the multiscale structure and physicochemical properties of LRS. These results provide promising strategies for processing and nutritional enhancement of fermented lotus root products. © 2025 Society of Chemical Industry.

Background: Mulberry leaf protein (MLP) is a high-quality protein with significant nutritional value and functional properties. Enzymatic modification of proteins can enhance their functional properties by using proteases to covalently crosslink or hydrolyze proteins. This study investigates the potential of transglutaminase (TGase)-induced crosslinked MLP as an emulsifier in the formation of high-internal-phase Pickering emulsions.

Results: Crosslinked MLP samples were prepared with TGase concentrations ranging from 0 to 25 U g^-1. High-internal-phase Pickering emulsions (80% v/v) were formed at pH 8, with a crosslinking temperature of 50 °C, a TGase concentration of 20 U g^-1 and an optimal crosslinking time of 60 min. As the enzyme concentration increased, the content of exposed sulfhydryl groups progressively increased, while the total free sulfhydryl content remained relatively stable. After varying crosslinking durations, both total free and exposed sulfhydryl group contents initially increased before declining. Additionally, the content of free amino groups in MLP gradually decreased with higher enzyme dosages and longer crosslinking times. The surface hydrophobicity of crosslinked MLP increased initially, followed by a decrease, reflecting changes in the spatial structure of MLP. SDS-PAGE analysis confirmed the formation of polymer masses after TGase-catalyzed crosslinking. Under optimal crosslinking conditions, the high-internal-phase Pickering emulsion prepared with TGase-induced crosslinked MLP exhibited a relatively uniform droplet distribution.

Conclusion: TGase-induced crosslinking enhances both the emulsifying activity and stability of MLP emulsions. © 2025 Society of Chemical Industry.

Background: In the present work, the content of volatile and phenolic compounds in sweet wines and mistelas made from sun-dried Pedro Ximénez grapes, with and without skins during alcoholic fermentation, has been studied during their storage under oxidative conditions. Three possible significant factors have been considered: oxidative storage time, type of elaboration, and presence or absence of grape skins during alcoholic fermentation.

Results: The presence or absence of skins during alcoholic fermentation showed a low influence on the content of low molecular weight phenolic compounds and furfurals during the oxidative storage in stainless steel tanks. Storage time together with type of elaboration turned out to be the most influential factors, with decreases in phenolic compounds due to possible oxidative phenomena and increases in furfurals. The evolution of phenolic compounds during oxidative aging showed to be dependent on type of elaboration, with significant decreases at the beginning of storage for mistelas. In the case of volatile compounds, a high number of them showed significant differences in relation to the type of elaboration. The presence or absence of grape skins was, mainly, significant for ethyl esters, acids and alcohols, with higher relative extent in the absence of grape skins. For these compounds, the type of elaboration-aging time interaction was also the most significant type, with significant decreases during the first 3 months of aging in mistelas.

Conclusion: During the oxidative aging in stainless steel tanks, of sweet wines and mistelas elaborated with and without contact of grape skins during alcoholic fermentation, the main factor was oxidative aging time for phenolic and furanic compounds. Although, for volatile compounds, it was the type of elaboration, with mistelas showing a very different behavior to that of naturally sweet wines and natural sweet wines. © 2025 Society of Chemical Industry.

Background: Bulgur is a traditional food product and is widely consumed in Turkey and Middle Eastern countries. The main aim of this study was to investigate the potential of peas as a high-protein plant-based raw material in bulgur production.

Results: Cooked pea-based bulgur produced from Deren and Irmak can provide 32.8% and 28.4% of its caloric content from protein. Therefore, 'high in protein' labeling can be used for both pea-based bulgur samples. Bioavailabilities of Zn, Mg, P, Ca, Fe and Cu in the pea-based bulgur (Deren) were determined as 44%, 29%, 17%, 10%, 16% and 31%, respectively. One serving portion of cooked pea-based bulgur (Deren) could meet up to 28%, 26%, 15%, 9%, 44%, 15% and 51% of the daily mineral requirement for females of zinc, magnesium, phosphorus, calcium, manganese, iron and copper, respectively.

Conclusion: The outcomes of this research are anticipated to provide an impetus for understanding the impact of pea utilization in bulgur production, providing insights that could inform the development of nutritious and sustainable plant-based products to meet the demands of health-conscious consumers. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Mucilage is a natural polymer obtained from plants belonging to botanical families such as Plantaginaceae, Malvaceae, Linaceae and Cactaceae. The Opuntioideae subfamily has been the most studied among the Cactaceae due to its wide availability, adaptability and high tolerance to adverse environmental conditions. However, its low extraction yield is the main limitation of scaling up mucilage production. Numerous studies have explored methods to improve the yield and quality of mucilage, yet a comprehensive scientific-technological approach remains lacking. Key questions remain unanswered, such as how to maximize yield, what variables significantly influence the solid-liquid extraction process and what phenomena occur at the microscale level during extraction. This review examines the state of the art of mucilage extraction from Opuntioideae plants and identifies the extraction methods, stages, common pretreatments and variables that influence yield and their effect on mucilage properties. Additionally, it highlights mucilage composition and its relationship with rheological properties. The findings reveal that mucilage separation from cell tissue is a complex and multifactorial process. Critical knowledge gaps are identified, including the role of transport phenomena, the influence of particle size, the nature of components in the extracted solution and the intrinsic characteristics of plant materials. Moreover, innovative technologies for mucilage extraction have yet to be fully explored. © 2025 Society of Chemical Industry.

Background: The increased prevalence of hyperlipidemia significantly affects human health worldwide. Although drug treatment is very effective, the harm to the human body cannot be ignored. Improvement of lipid metabolism by natural medicinal and food homologous products is an effective approach to ameliorate hyperlipidemia and it has gradually become a research focus. In this research, we adopted HepG2 cell models and high-fat-diet-fed C57BL/6j mouse models to explore the effect of hawthorn total flavonoids (HTF) on hyperlipidemia. Moreover, we utilized western blot and gut microbiota analysis to elucidate the specific mechanism of HTF's influence on hyperlipidemia.

Results: We found that HTF significantly alleviated hyperlipidemia and its complications, as manifested by reduced body weight gain and fat accumulation, and improved the disorder of intestinal microorganisms. HTF protected the liver, reducing aspartate transaminase and lactate dehydrogenase levels, and ameliorating inflammatory infiltration. Fat droplet amounts and necrotic cell numbers in liver cells were also decreased. Mechanistically, HTF promoted AMP-activated protein kinase phosphorylation, inhibited sterol regulatory element binding protein 1c expression, downregulating the expression of lipid synthesis-related proteins (acetyl CoA carboxylase, fatty acid synthase, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase), thus suppressing liver lipid synthesis. HTF also functioned as a natural peroxisome proliferator-activated receptor α (PPARα) agonist. Activated PPARα enhanced mitochondrial oxidation and lipid consumption via upregulating carnitine palmitoyltransferase 1A. Peroxisome proliferator-activated receptor-γ coactivator expression was also elevated, activating mitochondrial activity, increasing cholesterol 7α-hydroxylase activity and cholesterol consumption, and reducing blood lipids. Additionally, HTF regulated intestinal flora abundance, restored the ratio of Firmicutes to Bacteroidetes, balanced gut-liver axis crosstalk, and alleviated hyperlipidemia.

Conclusion: The results demonstrated that HTF alleviated the pathological symptoms caused by hyperlipidemia, and had a certain protective effect on the liver. HTF also stimulated the lipid metabolism pathway and accelerated lipid consumption. © 2025 Society of Chemical Industry.