Bacillus cereus, an important pathogen responsible for causing foodborne diseases worldwide, releases pore-forming enterotoxins, which target host epithelial cells, leading to osmotic lysis and ultimately manifesting as diarrheal syndrome. Moreover, some B. cereus strains carry antimicrobial resistance genes that confer multidrug resistance against a spectrum of antibiotics. Characterizing the survival traits of multidrug-resistant (MDR) B. cereus strains in the intestinal microenvironment is essential for developing targeted strategies to effectively manage diarrheal foodborne diseases caused by this pathogen. This study used whole-genome sequencing (WGS) to evaluate the pre- and post-digestion toxigenic potential, antimicrobial resistance profiles, and genetic diversity of MDR B. cereus strains isolated from food samples in Guangdong Province, China. The four B. cereus isolates investigated in this study exhibited a genetic diversity, as determined by multilocus sequence typing analysis of WGS data. All four isolates produced the diarrheal toxins Hbl, Nhe, and CytK to varying levels, indicative of their potential to cause outbreaks of foodborne diseases. Each of the four isolates exhibited resistance to more than three classes of antibiotics, fulfilling the criterion for multidrug resistance. At an initial concentration of 9 log colony-forming units (CFU)/mL, the intestinal concentration of these four isolates crossed the threshold required to induce widespread diarrhea in the general population. Under rice slurry protection, all tested isolates maintained intestinal concentration beyond the threshold when the initial concentration was increased to ≥8 log CFU/mL. Moreover, the upregulations of genes associated with acid tolerance, bile tolerance and stress response were observed in the surviving MDR B. cereus isolates. Digestion markedly altered the antibiotic resistance profiles of the MDR B. cereus isolates. In the absence of a food matrix, the MDR isolates lost their resistance to imipenem, meropenem, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole post-digestion and was influenced by the initial concentration of the strains. In the presence of food matrix rice slurry, the effects of digestion on the antibiotic resistance of MDR B. cereus isolates can be mitigated, enabling them to maintain their antibiotic resistance to the greatest extent. Most remarkably, after digestion, the isolates Bce055 and Bce166 exhibited newly emergent resistance to cefotetan and trimethoprim-sulfamethoxazole, respectively. Our findings clarify the fate of MDR B. cereus isolates in the gastrointestinal tract and inform the development of prevention and control strategies for foodborne diseases caused by this pathogen.

Pentachlorophenol (PCP) is a ubiquitous emerging persistent organic pollutant detected in the environment and foodstuffs. Despite the dietary intake of PCP being performed using surveillance data, the assessment does not consider the bioaccessibility and bioavailability of PCP. Pork, beef, pork liver, chicken and freshwater fish Ctenopharyngodon Idella-fortified by three levels of PCP were processed by RIVM and the Caco-2 cell model after steaming, boiling and pan-frying, and PCP in foods and digestive juices were detected using isotope dilution–UPLC-MS/MS. The culinary treatment and food matrix were significantly influenced (p < 0.05) in terms of the bioaccessibility and bioavailability of PCP. Pan-frying was a significant factor (p < 0.05) influencing the digestion and absorption of PCP in foods, with the following bioaccessibility: pork (81.37–90.36%), beef (72.09–83.63%), pork liver (69.11–78.07%), chicken (63.43–75.52%) and freshwater fish (60.27–72.14%). The bioavailability was as follows: pork (49.39–63.41%), beef (40.32–53.43%), pork liver (33.63–47.11%), chicken (30.63–40.83%) and freshwater fish (17.14–27.09%). Pork and beef with higher fat content were a key factor in facilitating the notable PCP bioaccessibility and bioavailability (p < 0.05). Further, the exposure of PCP to the population was significantly reduced by 42.70–98.46% after the consideration of bioaccessibility and bioavailability, with no potential health risk. It can improve the accuracy of risk assessment for PCP.

In the present study, the digestion behavior of alkaline-induced egg white gels (EWG) with xanthan gum (XG) and konjac gum (KG) preventing high-temperature liquefaction was compared with the aim of revealing the mechanism by which different polysaccharide crosslinking microstructures regulate gel digestion. The results indicated that XG and KG formed dense pore structures with EWG, but XG enhanced the storage modulus of EWG, while KG showed the opposite effect. The analysis of the digestive behavior revealed that polysaccharides decreased the digestibility of EWG and retarded protein digestion, polysaccharides showed fragmentation but were not hydrolyzed to monosaccharides, and the absolute values of ζ-potential and antioxidant properties increased after digestion. Compared to KG, XG with the specific structure performed excellent stability during digestion. Correlation analysis shows that the digestive properties of EWG was affected by the crosslinked structures. This study provides scientific basis for the high-temperature fission blocking of canned EWG food.

Meatballs are manufactured with great craftsmanship, but the brittle quality of meatballs is not resistant to frozen storage, which limits the large-scale promotion of meatballs for transportation. Meanwhile, the 'brittle mechanism' of meatballs is still unclear and it is difficult to solve the scientific problem of brittle quality loss of meatballs from the root. This study revealed the mechanism underlying the brittleness of pork meatballs gel. In this study, the rheological properties, textural quality, molecular forces and microstructure of meatballs were characterized using fresh meat (FsM group), ambient meat group, frozen meat group, and ground meat group. The results showed that the FsM group presented better sensorial characteristics. The rheological properties of the FsM group exhibited higher storage modulus (G ') and loss modulus (G ''), indicating better viscoelastic properties. The results of textural determination reflected that the FsM group showed improved brittleness quality and the brittleness was supported by hydrophobic interactions and disulfide bonds. The FsM group with good brittleness quality formed a 'large cavity' microstructure. The correlations analysis revealed a correlation between the texture properties of meatballs and their protein molecular forces. Our findings clearly provide new insights into the mechanism underlying the brittleness of meatballs. To determine the effect of pork freshness on the brittleness of pork meatballs and to investigate in depth the molecular mechanism of meatball brittleness formation, we monitored the rheological properties of minced meat, and calculating the yield rate and salt-soluble protein content. Using Raman spectroscopy, we determined the microstructure, textural properties and intermolecular forces. Finally, correlation analysis were applied to investigate the brittleness mechanism from a subjective level, an objective perspective and internal structure, and provided a theoretical basis for the pork meatball brittleness mechanism and its future maintenance. image

In this paper, the effects of the polysaccharide-addition order (before and after homogenisation) on the stability of nanoemulsion stabilised by sonicated egg white peptides and the in vitro digestive behaviour of loaded β-carotene were investigated. The pyrene fluorescence results showed that the concentration of micelles formed by flaxseed gum (FG) in complex with peptides was significantly higher than that of peach gum (PG). The order of polysaccharide-addition affected the emulsion properties and stability; adding polysaccharides before homogenisation led to protein bridging flocculation, low polysaccharide coverage and a higher interfacial adsorbed protein content of the emulsion. PG enhanced potential spatial resistance and electrostatic repulsion, effectively prevented emulsion flocculation and improved electrostatic stability. After homogenisation, FG was added to emulsions to improve environmental stability, including ionic, temperature and storage stability. Due to the viscosity of polysaccharides and the formed polysaccharide-protein-lipid aggregates, the increasing degree of bridging flocculation promoted the prominent of apparent viscosity, and the G' and G'' exhibited a frequency-dependent increase. The polysaccharide type and mode changed the surface loading charge and droplet interface thickness, delayed the destruction of the droplet structure by protease, and slowed the release of β-carotene to form micelles. In this study, a stable emulsion system and an efficient emulsion transport system for bioactive substances were obtained by regulating polysaccharides adding order, which is significant for constructing an efficient food emulsion delivery system.

: Objective：A comprehensive evaluation method was utilized to explore for the brittleness quality of Chaoshan crisp meatballs. Method: Textural profile analysis and puncture test were used to determine the textural property of Chaoshan crisp meatballs, and sensory evaluation were carried out simultaneously, and the correlation analysis between sensory and instrumental evaluation was studied. Result: The TPA parameters, including hardness and chewiness, were significantly correlated with the sensory evaluation parameters about hardness, springiness, brittleness and chewiness (r=0.554~0.793, P<0.05). The resilience of TPA was significantly correlated with the texture brittleness and organization of sensory evaluation (r=0.556, 0.625, P<0.05). The breaking force of puncture test was significantly correlated with sensory evaluation indexes (r=0.595~0.709, P<0.05). Two main components were obtained by PCA (principal component analysis) of the texture evaluation data, and their cumulative variance contribution rate was 74.5%. Conclusion: Therefore, the brittleness quality of Chaoshan crisp meatballs could be evaluated comprehensively by the combination of hardness and chewiness of TPA, breaking force in puncture test and sensory evaluation, which would lay the foundation for constructing an objective, accurate and convenient sensory evaluation system for Chaoshan crisp meatballs.

In this study, succinic anhydride (SA) and octenyl succinic anhydride (OSA) were used to modify the egg white protein (EWP), and acylated EWP was further prepared as a gel by adding NaOH and heat modification. The results showed that the acylation degree for the SA- and OSA-added groups reached 57.68% and 26.95%, respectively, and the average size, the absolute value of ζ-potential, increased significantly with SA and OSA addition, indicating that acylation improved the stability of EWP solution. Furthermore, the surface hydrophobicity increased for the SA-added group while decreasing for the OSA-added group, and the acylation process exposed the flexibility part of the protein molecule. Acylated EWP prepared gel (EWG) showed a translucent and slightly yellow appearance (except for the sol state of the OSA-added 1:50 group), the gel strength, water-holding capacity and rheological properties for SA-added EWG were remarkably reduced while OSA-added EWG improved apparently. Intermolecular forces analysis indicated that the addition of SA promoted the formation of disulfide bonds and strengthened proteins interactions while adding OSA weakened the interactions. Microstructural observations revealed a rougher gel network structure and weaker protein cross-linking in the gel prepared after the acylation of proteins. However, the high efficiency of SA and promotion of protein-molecule interactions were unable to counteract the negative effect of SA on the extension of the gel network structure, and the interaction between OSA expanded the formation of the gel network structure.

In this study, a Bayesian-based decision fusion technique was developed for the first time to quickly and non-destructively identify codfish using near infrared (NIRS) and Raman spectroscopy (RS). NIRS and RS spectra from 320 codfish samples were collected, and separate partial least squares discriminant analysis (PLS-DA) models were developed to establish the relationship between the raw data and cod identity for each spectral technique. Three decision fusion methods: decision fusion, data layer or feature layer, were tested and compared. The decision fusion model based on the Bayesian algorithm (NIRS-RS-B) was developed on the optimal discrimination features of NIRS and RS data (NIRS-RS) extracted by the PLS-DA method whereas the other fusion models followed conventional, non-Bayesian approaches. The Bayesian model showed enhanced classification metrics (92% sensitivity, 98% specificity, 98% accuracy) that were significantly superior to those demonstrated by any of other two spectroscopic methods (NIRS, RS) and the two data fusion methods (data layer fused, NIRS-RS-D, or feature layer fused, NIRS-RS-F). This novel proposed approach can provide an alternative classification for codfish and potentially other food speciation cases.

Xanthan gum (XG) was added to egg-white-gel-derived peptides to create complexes and stabilise nanoemulsion under high-pressure homogenisation. This procedure was performed to investigate the stabilisation of nano -emulsions by small-molecule peptides under alkaline conditions (pH 11.0). The emulsion stability, including ionic, temperature and storage stability, and lipid oxidation were explored. The inclusion of XG altered the spatial structure of the peptides, which created cross-linked entangled aggregates. Furthermore, the protein peptides forming complexes with XG following sonication and heat treatment were more stable. They exhibited higher absolute zeta-potential values, surface hydrophobicity, and lower interfacial tension. The emulsion stabilised by 2.0 mg/mL complexes at a pH of 11.0 revealed that the addition of XG enhanced the homogeneity of the nanoemulsion droplets, presenting a single high particle size peaks and absolute zeta-potential values. The surface -absorbed protein content and the concentrations of the emulsions stabilised by sonication and the heat-treated peptides and XG complexes were higher. Moreover, the fluorescence microscope observed a higher surface coverage thickness of the emulsion droplets, effectively preventing oil oxidation. The emulsion environmental stability measurements found that the prepared emulsions were sensitive to salt ions and stable to temperature. Together with heat-treated peptides and XG complexes, sonication-stabilised emulsions exhibited better stability during storage. This study advances the possibility of stabilising the nanoemulsions of small-molecule peptides under alkaline conditions.

Glycosylation is considered to be an effective method to improve the emulsifying property of proteins, and this work investigates and discusses the correlation between the molecular structure of glycosylated egg white protein (EWP) and its emulsifying capacity. Three types of monosaccharides, including glucose, D-galactose and mxylose, were utilized to conjugate with EWP in a wet glycosylation environment. Molecular structural properties of EWP, involving surface hydrophobicity, secondary and tertiary structures, protein flexibility, and free sulfhydryl group content, were determined. The results showed that the degree of grafting (DG), browning intensity and apparent viscosity increased significantly (P < 0.05) with the monosaccharides proportion improved, and the intrinsic fluorescence intensity and surface hydrophobicity of EWP decreased obviously during glycosylation, and the absolute value of zeta potential, protein flexibility and free sulfhydryl content improved remarkably (P < 0.05). Emulsifying capacity results showed that glycosylation improved emulsifying activity and emulsifying stability of EWP, especially after the addition of mxylose. The particle size analysis exhibited that the D-4(,3) and D-3(,2) declined obviously (P < 0.05) as DG increased. Correlation analysis revealed the improvement of the emulsifying capacity of glycosylated EWP showed in a DG-dependent manner, as remarkably influenced by molecular flexibility, surface hydrophobicity, tertiary structure changes and free sulfhydryl. The work provides a deep insight into the molecular conformation-emulsifiability relationship of EWP-monosaccharides conjugates.

In this paper, prepared alkali-induced egg white gel (EWG) was treated at different temperatures (100-121 degrees C) to explore the hydration mechanism under high temperatures (>= 100 degrees C). The physicochemical, mechanical and rheological properties and intermolecular interactions of the EWG were investigated. Results showed that with increasing temperature the pH, free alkalinity and surface hydrophobicity of EWG increased initially but then decreased, together with gel hydration, and the browning intensity increased markedly. The mechanical properties, including hardness, puncture strength and springiness, rheological characteristics-determined via apparent viscosity and frequency sweep results-and water-holding capacity significantly decreased as temperature increased. Fourier-transform infrared (FTIR) spectroscopy revealed that the beta-sheet contents decreased significantly, and the a-helical and beta-turn contents improved markedly with increasing temperature. The protein fraction results showed that hydrogen bonds, hydrophobic interactions and disulphide bonds were destroyed in the heating process. This study provides deep insights into EWG destruction under high temperature and the relationship with intermolecular interactions, enabling control over EWG quality.

As a persistent organic pollutant, pentachlorophenol (PCP) has serious impacts on human health. However, its presence in animal source food products sold in the Guangdong Province (GD) of China, and the resultant dietary exposure have not been elucidated. To address this gap, 3,100 samples from seven food categories, including beef, pork, mutton, offals, broilers, hen eggs, and farmed freshwater fish, marketed throughout four geographical regions of GD, were collected from 2015 to 2018. Gas chromatography coupled with mass spectrometry was employed to detect PCP levels in these food matrices. PCP was found in all food categories, but the average contamination levels were low, ranging from 0.40 µg/kg wet weight (ww) (hen eggs) to 5.85 µg/kg ww (offals). However, higher concentrations of PCP were detected (P < 0.05) in animal source food from the North region. Additionally, a temporal declining trend was observed in this four-year consecutive survey. The estimated human dietary exposure of PCP to population groups, including the general population and subgroups (male and female, children, and adults), was found to be far below the permissible daily intake (3 µg/kg body weight). Therefore, the health impacts of PCP should be correspondingly low for local residents, based on current toxicological knowledge. Regional exposure patterns varied due to different extents of contamination in the four areas, and pork, broilers, and freshwater fish were the major sources of dietary PCP exposure. PRACTICAL APPLICATION: As a persistent organic pollutant, pentachlorophenol (PCP) has serious impacts on human health. However, its presence in animal source food products sold in Guangdong Province of China, and the resultant dietary exposure have not been elucidated. In this study, we conducted an in-depth investigation on the occurrence of PCP in major foodstuff categories, including beef, pork, mutton, broilers, offals, hen eggs, and farmed freshwater fish, marketed in all 21 prefecture-level divisions of Guangdong Province, in order to provide integral insights for regulatory authorities.

The effects of Ca(OH)2 on the physicochemical, mechanical and microstructural characteristics, intermolecular forces and protein patterns of preserved egg white (PEW) were investigated. Results suggested that Ca(OH)2 (0.1%) reduced the free alkalinity content and turbidity and increased the brightness of PEW. The surface hydrophobicity of PEW protein with added Ca(OH)2 decreased during the pickling period owing to the hydrophobic residues being hidden in the interior of the protein. Total content of sulfhydryl and disulfide bonds in PEW decreased. Non-specific cross-linking, hydrogen bonds and hydrophobic interactions were the primary intermolecular forces. For textural properties, hardness and springiness had obvious prominence. A loose porous and regular network-like microstructure formed as the Ca(OH)2 increased and Ca(OH)2 delayed denaturation of the PEW protein. The physical properties of PEW correlated with molecular interactions and the microenvironment. Ca(OH)2 improved the contribution of surface hydrophobicity, disulfide bonds and hydrophobic interactions to the gelation process.

In recent years, the frequent economically motivated adulteration (EMA) caused by component displacement, illegal addition, and other problems makes the food authenticity become a global issue, which requires appropriate identification methods. Raman spectroscopy combination with chemometrics becomes a rapid, non-destructive method to verify the nature or origin of food. This review assembles and comprehensively summarizes the principle, workflow, advantages, challenges and applications of Raman spectroscopy in food authenticity. Besides, existing problems and outlooking on Raman spectroscopy are also discussed.

以真空包装的黄田扣肉为研究对象,研究其在4℃贮藏过程中的品质变化,从而预测其保质期.结果表明:随着贮藏时间的延长,黄田扣肉感官评分呈显著下降趋势(P＜0.05),在第30天时感官评分达到限值;芋片硬度、咀嚼性呈下降趋势(P＞0.05),扣肉的各部分pH值显著下降(P＜0.05);挥发性盐基氮和酸价增加显著(P＜0.05),第30天时,挥发性盐基氮和酸价均未超出国标限值,大肠杆菌及菌落总数均未超出国标限值,金黄色葡萄球菌、沙门氏菌未被检出.因此,在4℃贮藏条件下的黄田扣肉品质随贮藏时间的延长而下降,保质期为30 d.

This paper investigated the gelling characteristics of ethanol-induced egg white gel (EEWG) and also evaluated the ability of EEWG to delivery curcumin and tea polyphenols (TP). Results showed that a high concentration of ethanol induced egg white (EW) to form gel, which was attributed to the increase of zeta potential in absolute value and free sulfhydryl content. A high concentration of ethanol reduced the intrinsic fluorescence, mainly of tryptophan, and increased the viscosity. EEWG with a high concentration of protein represented greater hardness and water-holding capacity combined with the formation of abundant small bubbles. The addition of TP decreased the hardness value and water-holding capacity and reduced the storage modulus and loss modulus, determined by a rheometer, for further prevention of EW protein denaturation. The curcumin and TP stabilities were improved after adding a higher concentration of protein during storage. Adding a proper concentration of ethanol (30-40 mL/100 mL) increased the bioaccessibility of curcumin and improved the antioxidant activity and protein digestibility, but this was decreased after EEWG was loaded with TP. These results suggested that EW protein could improve the delivery of a hydrophobic active substance.

The mushroom Ganoderma lucidum (G. lucidum Leyss. ex Fr.) Karst has been a traditional Chinese medicine for millennia. In this study, we isolated the Ganoderma lucidum spore oil (GLSO) and evaluated the effect of GLSO on skin burn wound healing and the underlying mechanisms. Mice were used to perform skin wound healing assay. Wound analysis was performed by photography, hematoxylin/eosin staining, Masson’s Trichrome staining and immunohistochemical analysis. Microbiota on the wounds were analyzed using the 16s rRNA sequence and quantitative statistics. The lipopolysaccharide (LPS) content was examined in skin wounds and serum using an enzyme-linked immunosorbent assay (ELISA). The expression of Toll-like receptor 4 (TLR4) and the relative levels of inflammatory cytokines were determined by qPCR and immunofluorescence assay. A pseudo-germfree mouse model treated with antibiotics was used to investigate whether GLSO accelerated skin burn wound healing through the skin microbiota. We found that GLSO significantly accelerated the process of skin wound healing and regulated the levels of gram-negative and gram-positive bacteria. Furthermore, GLSO reduced LPS and TLR4, and levels of some other related inflammatory cytokines. The assay with the pseudo-germfree mice model showed that GLSO had a significant acceleration on skin wound healing in comparison with antibiotic treatment. Thus, GLSO downregulated the inflammation by regulating skin microbiota to accelerate skin wound healing. These findings provide a scientific rationale for the potential therapeutic use of GLSO in skin burn injury.

以贺州土猪五花肉为研究对象,以黄酒浓度、油炸温度和油炸时间为单因素实验指标,丙烯酰胺含量、色泽、硬度和感官评分为评价指标,采用综合加权评分法,利用正交试验对五花肉油炸工艺进行优化,并进行验证.结果 表明,黄田扣肉加工过程中油炸五花肉的最佳工艺为:黄酒浓度为20％,油炸时间6min,油炸温度170℃,最佳工艺条件下制备的五花肉中丙烯酰胺含量较少,为0.43 mg/kg,扣肉皮色泽金黄,AE为20.36,皮弹性良好,硬度适中,为399.54 g,综合评分最高87分.

Alcohol is a globally well-established cause of fatty liver disease (FLD). Increased salt consumption is associated with an increased prevalence of adipocyte hypertrophy and liver injury. In this study, high dietary salt potentiated chronic alcohol-induced hepatic damage. We explored the physiological mechanism of alcoholic FLD in the gastrointestinal tract. Male C57BL/6J mice (8-week-old) were fed a high-salt diet (HSD; 4% NaCl) with or without chronic ethanol (CE) for 1 month. The fecal microbiota, serum biochemical indices, intestinal permeability, level of liver damage, and liver mitochondria were evaluated. The HSD, CE, and their combination (HSDE) significantly changed the gut microbiota's structure, and the HSDE mice contained more probiotic species (e.g., Bifidobacterium and Lactobacillus). The serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels were increased, and the lipid was accumulated in the liver tissues in the CE, HSD, and HSDE groups, which indicated liver damage, especially in the HSDE group. The increased intestinal permeability and mitochondrial dysfunction in the liver cells caused greater injury in the HSDE group than in the other groups. Thus, consuming HSD with alcohol contributes to FLD development and progression.

Egg white protein (EWP) can form a gel under alkali condition, but there have been few reports on the gelling of EWP with the addition of Ca(OH)2. In this paper, the effects of Ca(OH)2 and the heating process on the rheological, mechanical and microstructural properties, and intermolecular interactions of egg white gel (EWG) were investigated. Results suggested that the pH of EWG increased markedly upon addition of Ca(OH)2 but declined after heating, and the surface hydrophobicity of EWP decreased significantly due to the embedding and destruction of hydrophobic groups. And sulfhydryl groups and disulfide bonds contents decreased after heating. Secondary structural analysis showed that β-sheet content increased, and β-turn content decreased after the addition of Ca(OH)2, while heating decreased random structures and α-helical content and increased β-turn content. The results of electrophoresis revealed that the addition of Ca(OH)2 degraded protein patterns gradually, while heating destroyed EWP. Textural test results demonstrated the hardness value increased remarkably upon addition of Ca(OH)2 and heating, but springiness declined gradually. The addition of Ca(OH)2 improved storage (G′) and loss (G″) modulus of EWG, which might relate to the formation of calcium bridges and ion interactions. The surface morphology of EWG transformed from yellow to brown or red after heating. Rough and irregular microstructure formed when the amount of Ca(OH)2 increased, while the microstructure became more compact and regular after heating. These results suggested that addition of Ca(OH)2 significantly affected the represented characteristics of EWG, and heating changed the intermolecular interactions and physicochemical properties.