In order to improve the photodynamic inactivation (PDI) effect of curcumin, three kinds of nano-photosensitizers SiO₂@X-Cur were prepared by covalently coupling halogenated curcumin derivatives X-Cur (X=F, Cl or Br) into silica by Stöber method. The successful preparation of SiO₂@X-Cur was confirmed by spectral characterization, doping amount determination and microstructure analysis. The results showed that SiO₂@F-Cur had the best comprehensive performance, and its saturated solubility in water was 308.33 μg/mL, which was 3.75-fold that of curcumin. The singlet oxygen generation capability was particularly outstanding, achieving an indicator decay rate of 63% within 60 s. The light stability was considerably higher better than other samples (the fluorescence retention rate was 42.86% after irradiation for 30 min), and it also had high covalent doping stability. In addition, SiO₂@F-Cur had the best PDI effect on Vibrio parahaemolyticus. Under the condition of 2.0 mg/mL concentration and blue LED irradiation for 20 min, the total number of colonies decreased to 0.09 lg (CFU/mL). Therefore, SiO₂@F-Cur prepared in this study is an efficient and novel PDI nano-photosensitizer, which provides new ideas and research basis for guiding the development of novel aquatic product preservatives.

This study aimed to investigate the effects of different oligosaccharides on the quality and volatile aroma compounds of fermented green tea. Sucrose, isomalto-oligosaccharides, galacto-oligosaccharides, and fructo-oligosaccharides were added to Mao Jian green tea extract and subjected to fermentation with Lactiplantibacillus plantarum at 37 ℃. Changes in physicochemical properties, monomeric phenolic compounds, antioxidant activity, organic acid composition, and volatile compounds were analyzed before and after 48 h of fermentation. The results showed that, compared with sucrose-supplemented fermented green tea, oligosaccharide supplementation significantly increased total phenolic and flavonoid contents, monomeric phenol content changed significantly (P<0.05). Among them, galacto-oligosaccharide supplementation yielded the highest total phenolic content (2552.21 mg GAE/L), while isomalto-oligosaccharide supplementation yielded the highest total flavonoid content (365.83 mg RE/L). Oligosaccharide supplementation also markedly enhanced antioxidant activity (P<0.05). Galacto-oligosaccharide supplementation produced the strongest DPPH radical scavenging activity (79.20%) and ferric-reducing antioxidant power (23.95 mmol Trolox/L); however, fructo-oligosaccharide supplementation produced the highest ABTS⁺ radical scavenging activity (89.40%). In addition, significant differences (P<0.05) in organic acid were observed between oligosaccharide-supplemented samples and sucrose-supplemented samples. Oligosaccharide-supplemented samples had higher total volatile aroma compound levels than sucrose-supplemented samples, with increased alcohol, alkene, and ketone levels, and the formation of new volatile aroma compounds, such as isoamyl alcohol, lauric acid, and ethyl acetate, thereby conferring distinctive aroma characteristics. Among the oligosaccharides, isomalto-oligosaccharide supplementation yielded the highest volatile aroma compound content (43987.09 μg/L). Overall, these findings indicate that oligosaccharide supplementation not only significantly enhances the nutritional composition and antioxidant activity of fermented green tea but also enriches its aroma profile, providing a theoretical basis for the development of functional fermented tea products.

In order to investigate the nutritional quality of the muscle tissues of Decapterus macarellus from the South China Sea, the general nutritional composition, mineral elements, amino acid profile and fatty acid profile in both dorsal and ventral muscles were analyzed, and the nutritional value was evaluated. The results showed that no significant difference (P>0.05) was observed between the dorsal and ventral muscles in the content of moisture (69.35%~70.48%), protein (23.59%~24.60%) and ash (1.65%~1.79%). However, the fat content in the ventral muscles (0.94%) was significantly (P<0.05) higher than that in the dorsal muscles (0.74%). The contents of potassium (4599.9~4661.1 mg/kg) and magnesium (412.2~424.6 mg/kg) in the dorsal and ventral muscles did not differ significantly (P>0.05), while there were significant (P<0.05) differences in the contents of sodium (905.2~996.9 mg/kg), calcium (271.6~360.5 mg/kg), iron (11.1~13.1 mg/kg) and zinc (7.3~10.3 mg/kg). Specifically, the dorsal muscles exhibited higher zinc content, and the ventral muscles contained higher levels of sodium, calcium, and iron. The amino acid composition was similar between the dorsal and ventral muscles, with a high lysine content (2.1~2.2 g/100 g). The ratio of essential amino acids to total amino acids was 0.41, and the ratio of essential amino acids to non-essential amino acids was 0.69, meeting the criteria for high-quality protein. The essential amino acid index ranged from 0.75 to 0.86, indicating that Decapterus macarellus was an available protein source. There was no significant difference (P>0.05) in the DHA+EPA content (48.59%~50.00%) and the ratio of total n-6 polyunsaturated fatty acids to total n-3 polyunsaturated fatty acids. However, the ratio of total polyunsaturated fatty acids to total saturated fatty acids in the ventral muscles (1.51) was significantly higher than that in the dorsal muscles (1.44) (P<0.05). These results suggest that the muscle tissues of Decapterus macarellus, especially the ventral muscles, possess high nutritional value and represent a high-quality resource with potential for high-value processing and utilization in the South China Sea.

To improve the water solubility of Badam kernel protein (BKP) and expand its application scope, this study prepared BKP-L-arginine (L-Arg)/L-lysine (L-Lys) mixed emulsions by introducing L-Arg and L-Lys into BKP, respectively. Fourier transform infrared spectroscopy, intrinsic fluorescence spectroscopy, ultraviolet spectroscopy, and other analytical techniques were employed to characterize the structural and physicochemical properties of the mixed emulsions. The results demonstrated that L-Arg/L-Lys primarily enhanced the water solubility of BKP by elevating the pH of the BKP solution. Compared with the pH-adjustment treatment group (control group), the L-Arg treatment group and L-Lys treatment group significantly improved the water solubility of BKP. Specifically, the L-Arg treatment and L-Lys treatment increased the water solubility of BKP from 67.83% in the control group to 83.57% and 81.77%, respectively (P<0.05). Furthermore, the introduction of L-Arg and L-Lys also significantly improved the emulsifying activity index (EAI) and emulsifying stability index (ESI) of BKP, compared with the control group, the L-Arg and L-Lys treatments increased EAI by approximately 64.13 m²/g and 57.24 m²/g, respectively (P<0.05), and increased ESI by 37.00% and 29.02%, respectively (P<0.05). Modification with L-Arg and L-Lys can effectively overcome the inherent water solubility limitation of BKP and confer better emulsifying capacity to it. Owing to its excellent water solubility and emulsifying properties, the modified BKP is anticipated to serve as a high-performance natural protein additive, finding widespread application in emulsion-type food systems such as beverages, sauces, and dairy products, thus possessing broad application prospects.

Objective: This study aimed to isolate and screen probiotic strains with excellent probiotic properties and metabolic regulatory functions (hypoglycemic and hypocholesterolemic activities) from fermented camel milk in Xinjiang. Methods: Firstly, lactic acid bacteria were isolated and purified from Xinjiang fermented camel milk using traditional microbial isolation techniques. Their potential probiotic properties were systematically evaluated via assays of simulated artificial gastric juice tolerance, bile salt tolerance, auto-aggregation ability, and hydrophobicity. Furthermore, the in vitro hypoglycemic potential was assessed using α-glucosidase inhibition rate and α-amylase inhibition rate as core indicators, while the in vitro hypocholesterolemic efficacy was evaluated based on key parameters including glycine/taurine bile salt hydrolase activity and cholesterol degradation rate. Finally, the antibacterial ability and biological safety of the candidate strain was comprehensively evaluated through antibacterial spectrum determination, hemolysis test, and antibiotic sensitivity test. Results: A total of multiple lactic acid bacteria strains were successfully isolated from the fermented camel milk. After primary screening, 10 candidate strains with strong tolerance to simulated artificial gastric juice (pH3.0) and bile salts (0.2%) were obtained, among which 6 strains exhibited excellent in vitro adhesion ability. Through secondary screening, one Lactobacillus acidophilus strain (designated CCNH655) was ultimately selected. This strain simultaneously displayed superior hypoglycemic activity (as indicated by α-glucosidase inhibition rate 67.19%±5.38% and α-amylase inhibition rate 86.75%±4.34%) and hypocholesterolemic efficacy (reflected by glycine bile salt hydrolase activity 3.89±0.35 U/mL, taurine bile salt hydrolase activity 6.91±0.48 U/mL, and cholesterol degradation rate 79.39%±4.76%) functions. Additionally, it showed a relatively broad antibacterial spectrum, no hemolytic activity, and sensitivity to 9 antibiotics, thus meeting the safety evaluation standards for probiotics. Conclusion: L. acidophilus CCNH655 possesses excellent probiotic properties, significant metabolic regulatory functions, and favorable biological safety. It provides an important strain resource and scientific support for the development of novel functional probiotic products and fermented dairy products targeting the improvement of glucose and lipid metabolism.

Objective: This study aimed to investigate Lactobacillus salivarius S54, a strain isolated from buffalo milk with potential probiotic properties, through whole-genome sequencing and phenotypic validation to systematically evaluate its safety, tolerance, and probiotic characteristics, thereby providing a theoretical basis for developing novel probiotic products. Methods: The complete genome of the strain was sequenced using third-generation sequencing technology. Antibiotic resistance genes and virulence factor genes were screened using the CARD and VFDB databases to assess its safety. Secondary metabolite biosynthesis gene clusters were predicted via genome mining tools. Functional annotation and tolerance-related gene analysis were performed using databases such as KEGG. In vitro experiments, including gastrointestinal fluid tolerance, antibacterial activity, antioxidant capacity, and prebiotic utilization assays, were conducted to validate its probiotic properties. Results: The genome of Lactobacillus salivarius S54 consisted of a circular chromosome of 1980939 bp with a GC content of 33.04%, and a predicted plasmid of 168151 bp. No known pathogenic virulence factors or antibiotic resistance genes were detected. A gene cluster encoding antimicrobial and antioxidative secondary metabolites was identified. Functional annotation revealed multiple genes associated with tolerance, and in vitro experiments confirmed its strong antibacterial and antioxidant activities. The strain exhibited high tolerance to high temperatures and gastrointestinal fluids, as well as the ability to utilize common prebiotics for growth. Conclusion: Lactobacillus salivarius S54 demonstrates favorable probiotic properties and a high safety profile, making it a promising candidate for the development of probiotic formulations or fermented dairy products, with significant potential for future applications.

To improve the texture deterioration and whey separation problems of low-fat yogurt due to its low fat content and enhance its storage quality. In this study, the blueberry pulp dietary fiber (BPDF) was first modified by ultrasonic-assisted enzymatic method, and the optimal process was determined through single-factor and response surface optimization. Subsequently, the influence of different concentrations of modified BPDF on the storage quality of low-fat yogurt was explored. The results showed that under the conditions of ultrasonic power of 443 W, treatment time of 20 min, addition amount of compound enzyme of 2.5%, temperature of 60 ℃, and enzymatic hydrolysis time of 2.5 h, the yield of soluble dietary fiber (SDF) prepared was the highest, reaching 15.87%. Moreover, its water-holding capacity, oil-holding capacity, swelling power and solubility were all significantly improved (P<0.05). Furthermore, the modified BPDF was applied to low-fat yogurt, which could significantly enhance the texture and rheological indicators such as hardness, cohesion, and storage modulus (G') of the product within a 28-day refrigeration period (P<0.05). Among them, the group with 2% modified BPDF addition performed the best throughout the storage period. Not only was the whey precipitation rate 29.72% lower than that of the control group at 28 days of storage, but also the antioxidant performance was higher (the DPPH free radical scavenging rate was always above 80%, and the ABTS⁺ free radical scavenging rate remained above 60%), and the sensory score ranked first among all groups. This study provides a new solution for improving the storage quality of low-fat yogurt and the high-value utilization of fruit residue.

Objective: We optimized the sulfation modification process of Moutan cortex polysaccharide (MCP) and systematically evaluated the structural characteristics, antioxidant activity, and hypoglycemic potency of sulfated MCP (S-MCP). Methods: MCP were sulfated using concentrated sulfuric acid method. The process parameters were optimized using single-factor experiments, response surface methodology, and using degree of substitution (DS) as an index. S-MCP structure was characterized by FTIR, DLS, and SEM. Its antioxidant and hypoglycemic activities were evaluated in vitro and in vivo. Results: Optimal sulfation conditions for MCP included 39 min esterification time, 1.5 mL concentrated sulfuric acid, and 30 mg of ammonium sulfate. Under these conditions, the DS of S-MCP was 0.07391±0.0020. Structural characterization confirmed successful introduction of sulfate groups onto S-MCP. The S-MCP particle size (294.44±40.62 nm) was smaller than that of MCP (356.32±26.07 nm), and its microscopic characteristics changed from loose and porous to fragmented and layered. In vitro activity experiments showed respective scavenging rates of S-MCP against DPPH, ABTS⁺, and hydroxyl radicals of 64.85%, 82.42%, and 71.34% at 3.0 mg/mL significantly higher than those of MCP. Scavenging was also shown to be concentration-dependent. S-MCP displayed more potent inhibition of α-glucosidase (43.92% at 1.0 mg/mL) than MCP (31.31%). The mouse glucose tolerance test results showed that S-MCP significantly reduced the blood glucose levels after starch and sucrose loading, and decreased the area under the curve. Conclusion: Sulfation can effectively enhance MCP antioxidant and hypoglycemic activities, providing a scientific basis for their development and application in functional foods and pharmaceuticals.

To develop high value-added mutton tallow products, high-melting-point fractions were prepared from Altay sheep rump fat using a dry fractionation process combined with solvent-assisted fractionation. Solid fat yield, melting point, peroxide value, and acid value were selected as evaluation indices. Single-factor experiments were conducted to investigate the effects of various parameters on the fractionation efficiency, followed by Box-Behnken response surface design. The Analytic Hierarchy Process-Criteria Importance Through Intercriteria Correlation (AHP-CRITIC) method was applied to assign subjective and objective weights to each evaluation index, with the comprehensive score used as the response value. Physicochemical properties and fatty acid composition of the fractionated products were analyzed. The optimal conditions were determined as an oil-to-solvent ratio of 1:2, crystallization temperature of 20  °C, cooling rate of 8  °C/h, and crystallization time of 12  h. Under these conditions, the solid fat yield reached 33.23%, melting point was 50.1  °C, peroxide value was 0.02 mg/g, acid value was 0.42  mg/g, and the comprehensive score was 93.88. The high-melting-point mutton tallow fraction exhibited peroxide value, acid value, saponification value, malondialdehyde content, and iodine value of 0.025  mg/g, 0.44  mg/g, 195.38  mg/g, 1.94  nmol/mL, and 42.42  g/100 g, respectively, which were significantly lower than those of the raw tallow and the solid fat obtained by dry fractionation at 28  °C (28S) (P<0.05). The saturated fatty acid content increased from 43.94% in raw tallow to 47.8% in 28S, and further to 63.21% in the solid fat obtained by the combined fractionation method at 20  °C (20S). These results indicate that the high-melting-point fraction exhibits markedly enhanced oxidative stability and melting point, thereby improving its potential as a specialty fat. Compared with raw tallow, the saturated fatty acid content increased by 19.27% (P<0.05), providing a reference for the rational development of high-melting-point mutton tallow fractions and the enrichment process of saturated fatty acids.

To investigate the suitability of different tea plant strains bred from local populations in Guangxi for green tea production, fresh leaves of nine new tea strains were used as raw materials to process green tea, with Fuyun No. 6 as a control. The differences in sensory quality, major biochemical components, and aroma components were analyzed. Results showed that all of the nine new tea strains produced green tea with overall sensory evaluation scores above class B. Among them, strains H012, 2018-11, 2015-14, and Pin-2 achieved class A scores, outperforming the control sample. Regarding taste profiles, the respective features were: brisk and mellow, aromatic with robust body, fresh and mellow, and floral with intense, well-rounded flavor. Aroma characteristics for these strains were identified as rich tender chestnut, tender with floral overtone, strong and persistent floral, and pronounced floral notes. Biochemical analyses revealed significant differences in major constituents and their contents across green teas from the nine new strains. Water extract, flavonoids, tea polyphenols and total catechin contents were also markedly higher in strains 2015-11, 2018-10, 2018-18, and Pin-2 relative to the control (P<0.05). Free amino acid content was elevated in strains H012, 2018-10, 2018-11, and 2015-14. A lower phenol-to-amino acid ratio was observed in strains H012, 2018-11, 2015-14, and 2018-10, while Pin-2 exhibited a higher ratio. The correlation analysis showed that the taste score was positively correlated with the content of free amino acids (P<0.01), and negatively correlated with the content of tea polyphenols and phenol-amine ratio. This suggested an alignment between biochemical composition and sensory assessment. Aroma component analysis detected 193 volatile compounds in green teas from the different strains and the control, primarily comprising alcohols, hydrocarbons, nitrogenous compounds, aldehydes, esters, and ketones. Among these classes, alcohols represented the highest relative abundance. A PLS-DA model constructed from aroma profile data effectively distinguished among the ten green tea samples. Incorporating relative odor activity values, eight key differential aroma constituents were identified. In summary, all nine new tea strains demonstrate suitability for green tea manufacturing. Among these, H012, 2018-11, 2015-14, and Pin-2 exhibit notable advantages for the development of premium specialty green teas, each with individual characteristics. This research provides a scientific foundation for the utilization of Camellia sinensis germplasm resources in Guangxi and the selection of high-quality raw materials for distinguished green tea production.