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The market value of strawberries is considerably impacted by quality deterioration and senescence during postharvest storage. In the study, the effect of isoreticular metal-organic skeleton (IRMOF-3) nanoparticles loaded with eugenol/chitosan-based active packaging film on the metabolism of reactive oxygen species (ROS) and the change rule of the structure of the microbial community in strawberries inoculated with strawberries spoilage bacteria (Botrytis cinerea) during the storage period was investigated. The results demonstrated that composite film contribute to the sustenance of reduced hydrogen peroxide and superoxide anion concentrations and the suppression of malondialdehyde accumulation, in contrast to the control group. This investigation revealed that the composite film significantly bolstered the antioxidant enzyme activities and disease resistance-related enzyme activities of strawberries, encompassing polyphenol oxidase, peroxidase, superoxide dismutase (SOD), and catalase (CAT). Moreover, the transcription levels of SOD and CAT genes were notably elevated in strawberries packed within the composite films. Besides, the composite film had an inhibitory effect on pathogenic bacterial genera (Ralstonia , Sphingomonas , and Erwinia) and fungal genera (Botrytis cinerea) that cause strawberries spoilage and a delayed decline in bacterial genera (unidentified_ Chloroplast and Chryseobacterium) and fungal genera (Rhodotorula) that are biocontrols of strawberries postharvest diseases. Therefore, this study provides novel perspectives on the mechanisms underlying the preservation of fruits and vegetables, focusing on alterations in ROS metabolism and microbiota composition during storage. • An active film with chitosan/eugenol loaded IRMOF-3 nanoparticles was developed. • The active film reduced H 2 O 2 and O 2 − release and MDA accumulation. • Active membrane up-regulated the expression of genes for SOD and CAT. • Activated film packaging regulated ROS metabolism in strawberry. • Analysis of changes in the microbial community of strawberries during storage. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Bacillus licheniformis is one of the major spore-forming bacteria with great genotypic diversity in raw milk, dairy ingredients, and final dairy products; it is found throughout the dairy-processing continuum. Although being widely used as a probiotic strain, this species also serves as a potential risk in the dairy industry based on its roles in foodborne illness and dairy spoilage. Biofilm formation of B. licheniformis , combined with the heat resistance of its spores, make it impossible to prevent the presence of B. licheniformis in final dairy products by using traditional cleaning and disinfection procedures. Despite the extensive efforts to identify B. licheniformis in various dairy samples, no reviews have been written on both hazards and benefits of this sporeformer. This review discusses the prevalence of B. licheniformis from raw milk to commercial dairy products, biofilm formation and spoilage potential of B. licheniformis , and possible prevention methods. In addition, the potential benefits of B. licheniformis in the dairy industry are also summarized. [ABSTRACT FROM AUTHOR]

Pediococcus acidilactici provides a special taste during dough fermentation, but its improper presence will accelerate the spoilage of rice noodles products. In this study, propidium monoazide (PMA) based methodologies on viable cells quantification of P. acidilactici were developed, evaluated and applied in rice noodles products. Prior to qPCR and RT-qPCR detection, PMA treatment was included to effectively remove the residual DNA from membrane-compromised (dead) cells. Firstly, considering the influence of food component and PMA on qPCR result determination, 4 standard curves corresponding Ct value to P. acidilactici cell number were established in 4 different rice noodle products, respectively. The 4 standard curves were subsequently applied for viable cell quantification of P. acidilactici. Secondly, mimicking the storage conditions of rice noodles products and growth states of P. acidilactici , planktonic and biofilm (early, mediate, mature) cells in 4 types of rice noodles products stored at −20 °C and 4 °C were taken into consideration to evaluate the efficiency of PMA-qPCR for viable cell quantification. Thirdly, stress response gene expression in P. acidilactici was monitored by PMA-RT-qPCR and compared with culturable and viable cell number quantification. The PMA-qPCR method with specific standard curves for 4 types of rice noodle products was applicable for viable cell quantification of P. acidilactici in planktonic and biofilm (early, mediate, and mature) states. The planktonic and biofilm cells of P. acidilactici maintained high and stable in both culturable and viable cell number in different growth states, rice noodles products, and low temperature conditions, but acquired significantly different gene expression levels. The findings provided viable cells quantification methods and an alarm for P. acidilactici contamination risk in instant rice noodles products. • PMA based methods for viable cell quantification of P. acidilactici were developed. • Individual PMA-qPCR standard curve for 4 rice noodle products was generated for viable cell quantification. • Planktonic and biofilm cells in 4 rice noodles products during storage were quantified by PMA-qPCR. • PMA was also applicable for stress response gene expression analysis by RT-qPCR. • P. acidilactici acquired stable culturable and viable cell number but changed gene expression. [ABSTRACT FROM AUTHOR]

This study aimed to address the challenge of extending the shelf life of Boletus wild mushrooms, which are prone to environmental and microbial contamination. An antibacterial film composed of polylactic acid (PLA) and mesoporous silica nanoparticles loaded with citral (CMP film) was developed for this purpose. Fifteen quality indices were assessed, and the data were integrated using AHP and TOPSIS to evaluate the film's efficacy. The CMP film effectively maintained the quality of mushroom over time. Additionally, a Nonlinear Global Optimization-Long Short-Term Memory (NGO-LSTM) model was employed to predict storage quality, using seven highly correlated quality indicators. The model achieved a high predictive accuracy, with the R2 exceeding 0.999. This study presents a novel packaging solution and a predictive model that together enhance the storage and quality control of Boletus wild mushrooms. [Display omitted] • Mesoporous silica nanoparticle film can slow down the quality degradation of Boletus. • The comprehensive quality index of Boletus caused by the storage time are new detected. • LSTM model was first used to predict mushroom quality. • NGO-LSTM can be employed as the appreciate approach to evaluate the shelf life of Boletus. [ABSTRACT FROM AUTHOR]

In this study, we screened out the dominant spoilage microorganisms during the cold storage of morels, prepared composite paper with a targeted selection of antimicrobial active substances, applied the composite paper to morels for cold storage and preservation, and investigated the changes of physicochemical indexes, flavor-presenting nucleotides and enzyme activities throughout the process of storage, and evaluated the freshness preservation effect. The pathogenic microorganisms during the natural spoilage of Morels were isolated and purified at 4 °C. The dominant spoilage microorganisms obtained were: bacterium B1 (Lelliia amnigena), fungi F2 (Paecilomyces penicillatus) and F3 (Mucor hiemalis). Inhibition experiments were carried out by selecting various active antimicrobial agents—lemon essential oil, clove essential oil and nisin (NI)—against the dominant spoilage microorganisms B1, F2 and F3. Comparing the inhibitory effects, NI was selected as an inhibitor for the dominant spoilage microorganisms following comprehensive consideration. The antimicrobial system (NI/C-CNC) was prepared by incorporating NI into carboxylated cellulose nanocrystals (C-CNC), and it exhibited a strong blocking effect on ultraviolet rays, which became more pronounced with the increase of NI addition. The composite paper NI-C was prepared using the NI/C-CNC antimicrobial system and absorbent paper (100 % virgin wood pulp), which showed better mechanical properties and reduced water vapor transmission rate (WVP). NI-C composite paper was applied to the preservation of morels, which effectively inhibited the dominant pathogenic bacteria. The flavor 5′-nucleotides were effectively protected, and it significantly slowed down the change in hardness during storage of morels. It also inhibited lipid peroxidation, as evidenced by the accumulation of malondialdehyde (MAD) content and reactive oxygen species (ROS), and had a positive effect on the control of enzyme activity. NI-C antimicrobial composite paper has good application prospects in the field of packaging of morels. • Isolation and purification of spoilage microorganisms from morels. • Selection of antimicrobial agents for dominant spoilage microorganisms. • Composite paper protects flavor 5′-nucleotides in morels. • Composite paper effectively slowed down the trend of enzyme activity change. • Composite paper can delay the deterioration of morels and maintain the quality of morels. [ABSTRACT FROM AUTHOR]

Biofilms formed by Bacillus licheniformis usually serve as a continuous bacterial contamination in the dairy industry. The purpose of this study was to explore how 1% organic acids (citric acid, phenyllactic acid, malic acid, and butyric acid) and their 1% organic peroxyacids (peroxycitric acid, peroxyphenyllactic acid, peroxymalic acid, and peroxybutyric acid) can inactive the planktonic and biofilm cells of B. licheniformis. Results demonstrated that the number of B. licheniformis planktonic cells was increased from 4 to 6.46 Log CFU mL−1 when treated with water. Organic peroxyacids, especially peroxyphenyllactic acid (PPA), obviously inactivated planktonic cells of B. licheniformis by a range of 3.32–4.14 Log CFU mL−1. Moreover, organic peroxyacids could also decrease the cell surface hydrophobicity of bacteria, and effectively control the Ca2+-mediated biofilm formation by B. licheniformis in 96-well plates (reduction of OD values by 0.14–0.33) and on stainless steel (reduction of cell counts by 1.20–2.49 Log CFU cm−2). The low minimum biofilm eradication concentration of PPA (0.125%) also suggests its strong biofilm inactivation activity, which could serve as a novel and environmentally friendly biofilm control agent in the dairy industry. [ABSTRACT FROM AUTHOR]

As a major human and animal pathogen, Staphylococcus aureus can attach to medical implants (abiotic surface) or host tissues (biotic surface), and further establish robust biofilms which enhances resistance and persistence to host immune system and antibiotics. Cell-wall-anchored proteins (CWAPs) covalently link to peptidoglycan, and largely facilitate the colonization of S. aureus on various surfaces (including adhesion and biofilm formation) and invasion into host cells (including adhesion, immune evasion, iron acquisition and biofilm formation). During biofilm formation, CWAPs function in adhesion, aggregation, collagen-like fiber network formation, and consortia formation. In this review, we firstly focus on the structural features of CWAPs, including their intracellular function and interactions with host cells, as well as the functions and ligand binding of CWAPs in different stages of S. aureus biofilm formation. Then, the roles of CWAPs in different biofilm processes with regards in development of therapeutic approaches are clarified, followed by the association between CWAPs genes and clonal lineages. By touching upon these aspects, we hope to provide comprehensive knowledge and clearer understanding on the CWAPs of S. aureus and their roles in biofilm formation, which may further aid in prevention and treatment infection and vaccine development. [ABSTRACT FROM AUTHOR]

[Display omitted] • β -sitosterol oleogel-based emulsion loaded with astaxanthin was designed. • Astaxanthin encapsulation in SM emulsion improve bioaccessibility. • Both network structure and composition affect lipolysis and bioavailability. In this study, three types of β -sitosterol-based oleogels (β -sitosterol + γ -oryzanol oleogels, β -sitosterol + lecithin, oleogels and β -sitosterol + monostearate oleogels), loaded with astaxanthin, were employed as the oil phase to create oleogel-based emulsions (SO, SL, and SM) using high-pressure homogenization. The microstructure revealed that fine-scale crystals were dispersed within the oil phase of the droplets in the β -sitosterol oleogel-based emulsion. The bioaccessibility of astaxanthin was found to be 58.13 %, 51.24 %, 36.57 %, and 45.72 % for SM, SL, SO, and the control group, respectively. Interestingly, the release of fatty acids was positively correlated with the availability of astaxanthin (P = 0.981). Further analysis of FFAs release and kinetics indicated that the structural strength of the oil-phase in the emulsions influenced the degree and rate of lipolysis. Additionally, the micellar fraction analysis suggested that the nature and composition of the oleogelators in SM and SL also impacted lipolysis and the bioaccessibility of astaxanthin. Furthermore, interfacial binding of lipase and isothermal titration calorimetry (ITC) measurements revealed that the oleogel network within the oil phase of the emulsion acted as a physical barrier, hindering the interaction between lipase and lipid. Overall, β-sitosterol oleogel-based emulsions offer a versatile platform for delivering hydrophobic molecules, enhancing the bioavailability of active compounds, and achieving sustained release. [ABSTRACT FROM AUTHOR]

With refrigeration and freezing functions, refrigerator aids in maintaining the flavor textural and nutritional value of food to the maximum extent, and inhibiting the growth and multiplication of microorganisms, thus is considered to be one of the best household food preservation methods. However, food-borne pathogens and spoilage bacteria (commonly called cryogenic microorganisms) have been generally detected in domestic refrigerators. An overview of diversity, outbreaks, virulence, antibiotic resistance, and survival mechanism of cryogenic microorganisms and correspondence food habitats in domestic refrigerators were provided in this review. Precautions for effective safety control of cryogenic microorganisms in refrigerator could be subsequently arouse. The survival of cryogenic microorganisms in refrigerators has become an important factor causing food safety issues. In view of this, an in-depth investigation and analysis of food safety issues caused by microorganisms in refrigerators were conducted in this review. • Potential threat is posed by cryogenic microorganisms in household refrigerators. • Diversity, virulence, antibiotic resistance of cryogenic microorganisms are important. • Cryogenic microorganisms acquire multiple survival mechanisms at low temperatures. • Effective safety control of cryogenic microorganisms in refrigerator is necessary. [ABSTRACT FROM AUTHOR]