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This study aimed to investigate the impact of Monascus on bioactive peptides, particularly angiotensin-converting enzyme (ACE) inhibitory peptides, during cheese maturation. The content of soluble nitrogen, α-glucosidase and ACE inhibitory activities during the ripening process were investigated. Cheese not inoculated with Monascus as a control group. The peptide profile of Monascus cheese was identified. The potential bioactive peptides were screened by bioinformatics and molecular docking, and the selected peptides were synthesized and evaluated. The results showed that compared with the control group, the pH 4.6 soluble nitrogen content (pH 4.6-SN) and trichloroacetic acid soluble nitrogen (TCA-SN) of Monascus cheese were increased by 57.98% and 38.34%, and the α-glucosidase and ACE inhibitory activities were increased by 32.21% and 73.98%, respectively. A total of 1 796 peptides were identified in the extract of Monascus cheese, including 51 ACE inhibitory peptides, 28 antioxidant peptides and 7 glucose-lowering peptides. Two ACE inhibitory peptides YPFPGPI and FPEVFGK were selected, whose half-maximal inhibitory concentration values were 207.31 and 410.61 μmol/L, respectively. The inhibition type was non-competitive. This study has provided a rapid screening method for ACE inhibitory peptides, and has proved that the addition of Monascus in cheese can effectively improve the ACE inhibitory activity, which provides a reference for exploring the potential functional properties of Monascus cheese.

To investigate the effects of cimifugin on adipogenesis and tumor necrosis factor (TNF-α)-induced insulin resistance (IR) and inflammation in 3T3-L1 adipocytes. 3T3-L1 adipocytes were treated with 3-isobutyl-1-methyl-xanthine, dexamethasone, and insulin or cimifugin and then Oil Red O staining and intracellular triglyceride content detection were performed to assess adipogenesis. Subsequently, after cimifugin treatment, TNF-α was used to induce IR and inflammation. The results showed that cimifugin reduced intracellular lipids accumulation of 3T3-L1 adipocytes. Cimifugin improved IR of 3T3-L1 adipocytes induced by TNF-α, as reflected in decreased adiponectin, GLUT-4, and IRS-1 mRNA and protein expression. Moreover, cimifugin reduced TNF-α-induced pro-inflammatory factors production and phospho-P65 expression, and MAPK pathway activation in the 3T3-L1 adipocytes. These findings suggested that cimifugin might be useful for the prevention and therapy of obesity-related IR and inflammation.

Objective: This study aimed to determine the optimal conditions for ultra-high pressure (HHP) cream cheese. Methods: The influence of non-thermal processing pressure on the texture, flavor and shelf life of homemade cream cheese were explored. By using the texture profile analysis (TPA), solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS), and colony counting method, the texture, flavor substances, and microorganisms of cheese were identified and evaluated. Results: After HHP treatment, the hardness, adhesiveness, and resilience of cream cheese decreased. The springiness of cheese reached the highest at 300 MPa, significantly increasing by 14.0% (P＜0.05). When the pressure is more than or equal to 400 MPa, the content and species of volatile substances in cheese are significantly reduced. Principal component analysis showed that 200 and 300 MPa treated cheese and unpressurized cheese were both in the first principal component area. After HHP treatment of artificially dyed cream cheese, the number of bacterial colonies decreased significantly (P＜0.05), and the greater the treatment pressure, the better the bactericidal effect. When the HHP treatment pressure is greater than or equal to 300 MPa, the shelf life of cheese was effectively extended from 7 days to 21 days. Conclusion: The cream cheese treated by HHP has a good texture and original flavor while effectively extending the shelf life.

The addition of adjunct culture has a significant impact on the quality of cheese. To screen adjunct culture with high protein hydrolysis and antioxidant capacity, this study evaluated 12 strains of lactic acid bacteria based on the acid production, protease activity, proteolysis, and antioxidant capacity. The potentially beneficial strain was used as adjunct culture to make quark cheese. The effect of adjunct culture on cheese quality was assessed by examining physicochemical indices, titration acidity changes, lactic acid bacteria count, texture alterations, and antioxidant activity during storage. Results showed that Lactobacillus kefiranofaciens XZ-54, which had a weak acid-producing capacity, high protease activity, protein hydrolysis, and antioxidant capacity, had the potential to be used as an adjunct fermenter for quark cheese. The addition of XZ-54 had no significant effect on the physicochemical parameters, hardness, and spread ability of quark cheese (P > 0. 05), and the viable counts of XZ-54 in the cheese were maintained above 107 CFU/ g during the 21-day storage period. Additionally, it significantly enhanced the DPPH free radical, ABTS cationic radical, and hydroxyl radical scavenging activities of the cheese. Therefore, Lactobacillus kefiranofaciens XZ-54 could be effectively employed as an adjunct culture in quark cheese, improving its antioxidant qualities and demonstrating significant potential for development and application. [ABSTRACT FROM AUTHOR]