Food Science and Biotechnology最新文献

This review comprehensively examines the advancements in engineering thermostable phytase through genetic modification and immobilization techniques, focusing on developments from the last seven years. Genetic modifications, especially protein engineering, have enhanced enzyme’s thermostability and functionality. Immobilization on various supports has further increased thermostability, with 50–60 % activity retention at higher temperature (more than 50 °C). In the food industry, phytase is used in flour processing and bread making, reducing phytate content by around 70 %, thereby improving nutritional value and mineral bioavailability. In the feed industry, it serves as a poultry feed additive, breaking down phytates to enhance nutrient availability and feed efficiency. The enzyme’s robustness at high temperatures makes it valuable in feed processing. The integration of microbial production of phytase with genetically engineered strains followed by carrier free immobilization represents a synergistic approach to fortify enzyme structure and improve thermal stability. These advancement in the development of phytase enzyme capable of withstanding high temperatures, thereby pivotal for industrial utilization.

In this study, we investigated the impact of different temperatures (10 °C, 4 °C, and − 1 °C) on salted kimchi cabbage. The diversity of white colony forming yeast (WCFY) on kimchi cabbage was assessed. The culture-dependent method revealed Candida as the predominant yeast, whereas the culture-independent method showed variations in the WCFY community based on storage temperatures. Meanwhile, the bacterial communities of salted kimchi cabbage were analyzed at different temperatures, with Latilactobacillus being the most abundant after WCFY observation. Other major LAB involved in kimchi fermentation were also observed at all temperatures. Additionally, the yeast communities revealed that Kazachstania, Candida, and Mrakia showed the highest relative abundance at 10 °C, 4 °C, and − 1 °C, respectively, as the storage period increased. Furthermore, correlation analysis showed that Candida had significant negative correlations between Levilactobacillus, Lactiplantibacillus, and Latilactobacillus. These findings suggest that the microbial community at different storage temperatures can affect the quality and safety of kimchi cabbage.

Food preservatives are a large class of food additives that generally prevent microbiological spoilage. Sodium acetate (SA) and sodium sulfite (SS) are food preservatives, and the aim of this study was to investigate their genotoxic and cytotoxic effects. The genotoxic effects of SA and SS were examined by chromosomal aberrations (CA) and micronucleus (MN) assays in human lymphocytes in vitro. In addition, the effects of these two preservative additives on mitotic index (MI) and nuclear division index (NDI) were also investigated. SA and SS significantly induced CAs and MN frequencies and caused a decrease in MI especially at higher concentrations. Neither food preservative caused any change in the NDI. In the light of the data obtained, it was concluded that SA and SS may have cytotoxic and genotoxic effects on human lymphocytes, especially at high concentrations. Therefore, their use at lower concentrations, which may be safer, should be encouraged.

This research was conducted to investigate the anti-obesity effects of black tea or green tea kombucha (BK, GK) and compared their compositional differences. As a result of kombucha treatment during the adipocyte differentiation process, peroxisome proliferator-activated receptor γ was significantly decreased, and CCAAT/enhancer binding protein α and adipocyte protein 2 showed a tendency to decrease with BK treatment. Oil red O staining results also demonstrated a reduction of lipid accumulation by BK treatment compared to the control. In mature adipocytes, BK significantly upregulated the gene expression of hormone-sensitive lipase and tended to increase the expression of adipose triglyceride lipase and adiponectin. Additionally, as a biomarker of lipolysis, glycerol content also marginally increased with either BK or GK treatment. The differences were observed in tea polyphenol compound and organic acid contents between BK and GK. In conclusion, these results suggest that black tea kombucha may have anti-obesity activity.

In this study, a novel active food packaging hybrid nanofibrous mats were fabricated from gelatin (G), chitosan (Ch), polyamide-6 (PA6), and Cedrus atlantica essential oil (CAEO) via an electroblowing technique. The G-Ch-PA6 nanofibrous mats containing varying concentrations (0, 1, 3, and 5%, m/m) of CAEO were produced and thermally crosslinked. These hybrid mats underwent comprehensive characterization, including morphology assessment, surface wetting analysis, thermal stability examination, antioxidant evaluation, bioactivity testing, and more. Morphological investigation revealed that the incorporation of different CAEO concentrations influenced the average diameter of the nanofibers, which ranged from 335.09 to 541.90 nm. Moreover, the antioxidant properties of nanofibrous mats were assessed using DPPH and ABTS methods, revealing a linear relationship between antioxidant activity and the loading amount of CAEO. These findings underscore the potential of the G-Ch-PA6-CAEO5 nanofibrous mat as a multifunctional active packaging material, promising in the preservation and freshness monitoring of fruits such as tangerines.

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The quality of marinade is closely related to its recycling frequency, and affects the flavor and quality of leisure dried tofu. The changes in physicochemical parameters, oxidation indicators, and volatile constituents of marinade under different recycling frequencies (0, 3, 6, 9, 12, 15) were systematically investigated in this work. The results showed that the levels of amino acid nitrogen, viscosity, soluble solids, and salinity in the marinade were significantly increased with recycling frequency. The increase in marinade recycling frequency led also to a rise in the peroxide value and thiobarbituric acid reactive substances from 2.13 meq/kg and 0.17 mg/kg to 4.02 meq/kg and 0.94 mg/kg, respectively, suggesting slight oxidation. Marination yielded 101 volatile constituents, mainly including 35 alcohols, 21 hydrocarbons, 15 aldehydes, 9 aromatics. Pearson correlation analysis revealed that the levels of cedrene, cineole, and myrcene were closely related to the quality and flavor of marinade under different recycling times.

To improve loading efficiency and extend the release of carvacrol (Car) for prolonged food preservation, a nanocarrier (NP2) was developed with an encapsulated layer by surface modification of modified HNT (NP1) through silica hydroxylation with chitosan (CS). The study revealed that the tubular structure of the nanotube remained intact post-etching treatment, resulting in a loading efficiency of Car up to 32%, which was 4.6 times higher than untreated HNT. Subsequently, NP2 was successfully prepared and maintained stable loading efficiency. To further understand the loading mechanism of Car by HNT, molecular modeling was utilized to examine the molecular-level interactions, specifically focusing on the hydrogen bonds formed by hydroxyl groups. The resulting nanocomposites (NP2-Car) displayed UV and thermal protection properties. By incorporating NP2-Car into a CS matrix, an active film (CS/NP2-Car) with effective slow-release and antimicrobial capabilities was created, demonstrating its potential for food preservation applications.

Rice bran production significantly contributes to global environmental deterioration, yet its potential remains underutilized. This review discusses the nutritional composition, bioactive compounds, health benefits, limitations, and potential application of rice bran in both food and non-food sectors. While minor variations exist between pigmented and non-pigmented rice bran, the former is abundant in phytochemicals, which offer therapeutic benefits. The primary limitations hindering rice bran’s food application include rancidity, toxic heavy metals, and antinutrients. Effective stabilization is crucial to extend rice bran’s shelf life. Despite these challenges, rice bran holds significant potential for value-added products. Hence, its rich composition and diverse applications underscore its importance as a valuable resource for sustainable production practices.

Peroxisome proliferator-activated receptor γ (PPAR-γ) is crucial in forming cholesterol stones. Sodium butyrate (NaB), a short-chain fatty acid, shows potential for gallstone treatment by activating PPAR-γ. This study aimed to elucidate the effects of NaB on cholesterol gallstones in mice fed a lithogenic diet (LD). Ezetimibe (5 mg/day) was used as a positive control, and a PPAR-γ antagonist (CW9661, 4 mg/kg/day) was used to investigate PPAR-γ. Body weight, gallstone incidence, lipid concentrations in blood, bile, and liver, liver function evaluation, histological analysis, and cholesterol metabolism-related gene expression were evaluated. NaB and ezetimibe suppressed gallstone formation, serum AST, ALT, and ALP levels, and serum/liver TG and TC. They also reduced bile cholesterol and phospholipids, and liver histological damage. NaB activated PPAR-γ, CYP7A1, ABCA1, and ABCB11 while suppressing ABCG5/G8 gene expression. CW9661 reversed NaB’s benefits in LD mice. This study provides scientific evidence that NaB activated PPAR-γ to improve gallstones.

In this study, grapefruit seed extract (GSE)-loaded nanoparticles (GNPs) were formed through ionic gelation between chitosan (CS) and sodium dodecyl sulfate (SDS) to improve antibacterial activity against oral bacteria, such as Streptococcus mutans, and to demonstrate the impact of particle size on antimicrobial activity. Particle size was negatively correlated with the antibacterial effect; the smaller GNPs showed significantly higher antimicrobial activity than the other particles. The optimal formulation of the smaller GNPs was determined using response surface methodology (RSM). The optimized GNPs improved antibacterial activity, which was approximately 3.5 times higher than that of free GSE (p < 0.05). Moreover, the GNPs were effective at reducing bacterial growth, achieving a reduction of more than 3 log₁₀ CFU/mL within the first 3 h and complete inhibition of bacterial growth after 9 h. This study suggests that nanoencapsulation significantly enhances its antibacterial activity against oral bacteria.