Journal of Agricultural and Food Chemistry最新文献

2-Methylfuran (2-MF) is a well-known industrial chemical and also formed via thermal treatment of food. One main source of 2-MF in the human diet is coffee. 2-MF is known to form 3-acetylacrolein (AcA, 4-oxopent-2-enal) via cytochrome P 450 metabolism and further reacts with amino acids in vivo. Still the reactivity toward other biomolecules is rather scarce. Therefore, AcA was synthesized, and its reaction with 2'-deoxyadenosine (dA), 2'deoxyguanosine (dG), 2'deoxycytosine (dC), and 2'-deoxythymidine (dT) was tested. For this purpose, adduct formation was performed by acid hydrolysis of 2,5-dihydro-2,5-dimethoxy-2-methylfuran (DHDMMF) as well as pure AcA. The structures of these adducts were confirmed by UPLC-ESI⁺-MS/MS fragmentation patterns and ¹H-/¹³CNMR spectra. Except for dT, which showed no reactivity, all adducts of AcA were characterized, which enabled the development of sensitive quantification methods via (U)HPLC-ESI^±-MS/MS. Pure AcA was synthesized by oxidation of 2-MF using dimethyldioxirane (DMDO), and its behavior in aqueous medium was studied. Incubations of AcA and isolated DNA of primary rat hepatocytes (pRH) showed time- and dose-dependent formation of the identified DNA adducts dA-AcA, dG-AcA, or dC-AcA. In contrast, the DNA adducts dA-AcA, dG-AcA, or dC-AcA were not detected on a cellular level when pRH were incubated with 2-MF or AcA. This indicates an efficient detoxification or reaction with biomolecules in the cell, although the induction of other DNA damage, possibly also by other metabolites, cannot be ruled out in principle.

In the context of valorizing underutilized crops, this study investigated the starch and protein characteristics of chestnut varieties (Balestrera and Rossera) and their potential for use at 15% and 25% in reformulating gluten-free baked snacks and fresh pasta. Chestnut varieties differ in protein and starch content (Balestrera > Rossera), as well as in amylose, dietary fiber, and lipids (Balestrera < Rossera). Differences in starch and amylose content affected starch gelatinization (Balestrera < Rossera), pasting and retrogradation properties, and water absorption capacity at 90 °C (Balestrera > Rossera). No differences in water and oil absorption capacity and mixing properties were observed, neither in the protein profile nor in the nature of protein aggregates. Both varieties exhibited a good aptitude for producing gluten-free baked snacks and fresh pasta, even at enrichment levels of 25%. Overall, this study could provide valuable information for the development of gluten-free products using sustainable, underutilized crops.

Probiotics are increasingly being used as an adjunctive therapy for ulcerative colitis. However, some safety issues have been found in the clinical use of probiotics. Postbiotics have attracted much attention due to their storage stability, safety, and potential functions, but the dose required to exert a significant protective effect is unknown. Therefore, this study evaluated the potential mechanisms of different doses (200, 400, 600 mg/kg) of Lactobacillus rhamnosus 1.0320 postbiotics (1.0320P) in alleviating dextran sodium sulfate (DSS)-induced colitis. The study revealed that 1.0320P could mitigate DSS-induced colitis with signs of reductions in the disease activity index, amelioration of colon tissue damage, decreased secretion of proinflammatory cytokines, reduced oxidative stress levels, and lower bone marrow peroxidase activity. Furthermore, high dose of 1.0320P could upregulated the expression of key proteins in the Nrf2/ARE pathway (NQO1, Nrf2, and HO-1) and downregulated the expression of key proteins in the TLR4/NF-κB signaling pathway (TLR4, MyD88, and NF-κB p65). In addition, high dose of 1.0320P could upregulate the expression of tight junction (TJ) proteins including ZO-1, Occludin, and Claudin-1, contributing to the restoration of the intestinal mucosal barrier function. Additionally, 1.0320P was found to effectively correct imbalances in the intestinal microbiota and enhance the synthesis of short-chain fatty acids (SCFAs), thereby regulating homeostasis in the intestinal internal environment. Overall, our findings suggest that postbiotics could ameliorate colonic inflammation while being somewhat dose-dependent. This study provides new insights into postbiotics as a next-generation biotherapeutic agent for the treatment of ulcerative colitis and even other diseases.

7-Dehydrocholesterol (7-DHC), a direct precursor of vitamin D3, has attracted increasing attention in microbial fermentation recently. In this study, 7-DHC biosynthesis in diploid Saccharomyces cerevisiae with robust ergosterol production was achieved by heterologous 24-dehydrocholesterol reductase expression, generating 44.1 mg/L 7-DHC, whereas the titer of ergosterol decreased by 40.5%. The ergosterol biosynthetic pathway was completely blocked by knocking out ERG6 and ERG5, affording a 4.2-fold increase in the 7-DHC titer. Subsequently, the facilitation of the mevalonate and the postsqualene pathways accompanied by elimination of transcriptional repressors enhanced 7-DHC synthesis, and the 7-DHC titer reached 738.5 mg/L in a shake flask. Further validation in a 50 L fermenter demonstrated that the 7-DHC titer reached 3.80 g/L within just 24 h, with productivity reaching 158.3 mg/L/h, setting a new benchmark as the highest reported to date. This study paves the way toward a large-scale and cost-effective manufacture of 7-DHC.