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Placenta is highly vascularized, which is critically for its function in nutrient transportation. Maternal obesity reduces placental vascularization, thus, negatively affecting fetal development an...

Listeria monocytogenes forms biofilms on food-contact surfaces providing this pathogen with the potential to serve as a constant cross-contamination source. The objective of this study is to examine the efficacy of steam treatment against the biofilm of L. innocua, a well-known L. monocytogenes surrogate, on common food-contact surfaces using a pilot-scale steam treatment blancher. Saturated steam at 100 °C was effective in inactivating L. innocua in biofilms on all tested food-contact surfaces with a 6-sec steam treatment attaining a 2.4–3.1 log10 CFU/coupon (1.5 cm × 1.5 cm) reduction depending on the type of surface. However, the effectiveness of steam decreased dramatically during prolonged steam treatment with tailing effects more pronounced on rubber, low-density polyethylene (LDPE), polyvinyl chloride (PVC), followed by polyester (polyethylene terephthalate, PET), and then stainless steel (SS). A 30–180 s steam exposure at 100 °C caused a 4.0–6.4 log10 CFU/coupon reduction of L. innocua biofilm on SS, and 3.0–4.8, 2.8–4.2, 2.7–4.5 and 2.6–3.3 log10 reductions on PET, LDPE, PVC, and rubber surfaces, respectively. Organic soil from 1:10 diluted apple juice did not compromise the bactericidal effects of steam against L. innocua biofilm on all tested surfaces. Repeated steam exposure did not impact hydrophobicity and roughness parameters of SS, PET, and rubber coupons, but decreased hydrophobicity of PVC and LDPE, increased the Rz value of PVC, and decreased Rp and Rz values for LDPE surface. Data suggested that a short time steam exposure alone or in combination with other interventions likely provides effective mitigation treatments to control Listeria biofilm on SS, PET, and rubber surfaces.

OBJECTIVES: The incidence of inflammatory bowel disease (IBD) is rapidly increasing worldwide. Patients with IBD experience increased susceptibility to colorectal cancer and are associated with morbidity and mortality. Diets are known factors associated with IBD. This study examined the beneficial effects of dietary purple potato against spontaneous colitis and improving gut microbiota in interleukin (IL)-10-deficient mice, a commonly used IBD mice model. METHODS: IL-10-deficient mice at 7-week-old were assigned to a standard rodent diet (CON) or a control diet supplemented with 10% purple potato (dry feed weight) for 11 weeks, when colonic tissues were collected for histological and biochemical analyses. RESULTS: Purple potato supplementation had no effect on feed intake and body weight in IL-10-deficient mice during the 11-week feeding trial. Purple potato supplementation improved the colitis symptom and the integrity of the colonic epithelial structure with reduced inflammation and pathological scores. Furthermore, the density of goblet cells and differentiation markers for goblet cells was enhanced due to PP supplementation. CONCLUSIONS: Data collectively showed that dietary purple potato supplementation had protective effects against colitis onset in IL-10-deficient mice and improved gut epithelial structure, providing a promising dietary approach for the management and prevention of colitis. FUNDING SOURCES: USDA-NIFA and Northwest Potato Research Consortium.

In this study, thermal processes were developed for cocoa powder against Salmonella and Listeria monocytogenes in a pilot Radiofrequency (RF) unit and validated using their respective surrogates Enterococcus faecium NRRL B-2354 and Listeria innocua. For 1.0 kg cocoa powder samples, RF heating to 90 °C provided 1.74–1.84 log reduction of E. faecium. A 48 min holding post-RF heating provided an additional 3.65 and 2.24 log10 CFU/g reduction of E. faecium for insulated and non-insulated samples, respectively. Compared to E. faecium, L. innocua was less resistant to RF heating in aw 0.45 cocoa powder; RF heating to 75 °C coupled with 24 min insulated holding resulted in an additional 5.64 log10 CFU/g reduction. These data suggested that E. faecium was a conservative surrogate strain for controlling Salmonella and L. monocytogenes during RF processing of cocoa powder. To achieve maximal microbial reduction and improve energy efficiency, an insulated holding following RF heating is highly recommended. According to the predictive line obtained from the Bigelow model, a 7.6 min RF heating plus 48 min insulated holding attained a 5-log reduction of E. faecium without a negative impact on the color of cocoa powder.

OBJECTIVES: Purple-fleshed potato is a good dietary source of phenolic compounds, including anthocyanins, flavonols, and chlorogenic acids. The objective of this study is to examine impacts of cooking methods including boiling, steaming and the newly developed vacuum-sealed boiling (VSBoiling), on extractability and bioactivity of phenolic compounds in purple potato (PP). METHODS: Following cooking, polyphenolic compounds were extracted from raw PP or cooked PP and analyzed for total phenolic content, composition, and free radical scavenging activity. In addition, anti-oxidative and anti-inflammatory effects of extracts were tested in cultured Caco-2 cells. RESULTS: Steaming and boiling slightly reduced the extractable chlorogenic acid content, while VSBoiling increased its content. VSBoiling and steaming effectively preserved the radical scavenging activities of PP, while boiling resulted in a significant reduction compared to the extract from raw potatoes. In human colonic epithelial Caco-2 cells, all PP extracts effectively suppressed hydrogen peroxide-induced bursts of intracellular reactive oxygen species, and suppressed tumor necrosis factor-α induced inflammation in Caco-2 cells, while VSBoiling group showed the highest activity. CONCLUSIONS: The contents and bioactivity of extractable polyphenols are largely retained in PP subjected to different cooking processes. VSBoiling resulted in the highest extractability of phenolic compounds and their biological function among tested cooking methods. FUNDING SOURCES: USDA-NIFA and Northwest Potato Research Consortium.

Reported outbreaks and recalls related to spices, including an on-going recall of cinnamon involved apple chips, reveal a need to understand thermal inactivation of Salmonella in spices. Recent studies have documented quantitative relationships between water activity (aw) and thermal resistance of Salmonella in a wide range of low-moisture foods. Such quantitative data are useful in developing effective thermal treatments. However, the influence of aw on thermal inactivation of Salmonella in spices has not been systematically studied. Cinnamon is known for its antimicrobial effect on pathogenic bacteria. We hypothesized that the synergetic effect of heat and the natural antimicrobial compounds in cinnamon would reduce the intensity of thermal treatments for cinnamon compared to that for other low-moisture foods. This study investigated the thermal resistance of Salmonella Enteritidis PT 30 in ground cinnamon at three inactivation temperatures (70, 75 and 80 °C). The log10 D-values of S. Enteritidis PT 30 in ground cinnamon decreased linearly with increasing aw and treatment temperature. By comparing the log10 D-values obtained in ground cinnamon with the reported log10 D80°C-values of S. Enteritidis PT 30 in other low-moisture foods, we found that the thermal treatments at 70 °C for S. Enteritidis PT 30 in cinnamon powder was roughly equivalent to the treatments at 80 °C for the same bacterial strain in other low-moisture foods, such as wheat flour and egg powders. Thus, milder thermal treatments can be used for the control of Salmonella in cinnamon powder, and perhaps other spices or herbs that contain antimicrobial compounds, for better retention of product quality.

Salmonellosis has been frequently associated with the consumption of high-sugar, low-moisture foods. Honey and high fructose corn syrup (HFCS) are widely used liquid sugars that are added as humectants in low-moisture foods. The objective of this study was to determine the ability of Salmonella and its presumable surrogate, Enterococcus faecium NRRL B-2354, to survive in honey and HFCS during storage at room temperature (~22 °C). Using freeze-dried and lawn grown bacteria, the survival of Salmonella and E. faecium in honey and HFCS was determined. Regardless of the inoculation methods, more than 5 log10 reductions were observed in both bacteria in honey and HFCS after 21-days of storage at 22 °C. The pathogens and surrogate in honey and HFCS fell below the detectable limit after 28-days of storage. Thus, the tested bacteria are not able to survive in honey and HFCS over one-month storage at room temperature. The similar level of bacterial reduction in honey and HFCS in storage suggests that the main cause was not the commonly perceived antimicrobial agents in honey. In addition to high acidity of these liquid sugars, the extremely high osmotic pressure is likely the main reason for bacterial death in honey and HFCS during storage. The data provided useful information in developing effective microbial-safe strategies to be incorporated in the preparation or storage of low-moisture food and ingredients.

Egg white powders typically undergo thermal treatment at 60 °C for 10–14 days to control Salmonella. Increasing water activity (aw) of egg white powders and treatment temperature can sharply reduce processing time, but its effect on product quality is unclear. This study aims to determine the impacts of aw and dry-heating time on egg white powders’ color and bulk properties. Egg white powders were conditioned to three different aw (0.30, 0.45, 0.60) in equilibration chambers at 23 °C. The samples were then treated at 80 °C for up to 24 h. These treatments were selected based on an earlier study to achieve more than 6-log reduction of Salmonella in egg white powders. After treated, the egg white powders samples with higher aw and longer dry heating time were significantly brighter (L* = 91.7 ± 0.01) and showed a soft yellow coloration (H* = 95.58 ± 0.05, C* = 18.02 ± 0.05). The loose, tap and particle bulk densities of the treated samples decreased with higher aw, but increased with longer dry-heating time. The Hausner ratio for treated samples was ≈1.5, indicating that samples are difficult to fluidize.

Key points Maternal high-fat diet impairs brown adipocyte function and correlates with obesity in offspring. Maternal resveratrol administration recovers metabolic activity of offspring brown adipose tissue. Maternal resveratrol promotes beige adipocyte development in offspring white adipose tissue. Maternal resveratrol intervention protects offspring against high-fat diet-induced obesity. Abstract Promoting beige/brite adipogenesis and thermogenic activity is considered as a promising therapeutic approach to reduce obesity and metabolic syndrome. Maternal obesity impairs offspring brown adipocyte function and correlates with obesity in offspring. We previously found that dietary resveratrol (RES) induces beige adipocyte formation in adult mice. Here, we evaluated further the effect of resveratrol supplementation of pregnant mice on offspring thermogenesis and energy expenditure. Female C57BL/6 J mice were fed a control diet (CON) or a high-fat diet (HFD) with or without 0.2% (w/w) RES during pregnancy and lactation. Male offspring were weaned onto a HFD and maintained on this diet for 11 weeks. The offspring thermogenesis and related regulatory factors in adipose tissue were evaluated. At weaning, HFD offspring had lower thermogenesis in brown and white adipose tissues compared with CON offspring, which was recovered by maternal RES supplementation, along with the appearance of multilocular brown/beige adipocytes and elevated thermogenic gene expression. Adult offspring of RES-treated mothers showed increased energy expenditure and insulin sensitivity when on an obesogenic diet compared with HFD offspring. The elevated metabolic activity was correlated with enhanced brown adipose function and white adipose tissue browning in HFD+RES compared with HFD offspring. In conclusion, RES supplementation of HFD-fed dams during pregnancy and lactation promoted white adipose browning and thermogenesis in offspring at weaning accompanied by persistent beneficial effects in protecting against HFD-induced obesity and metabolic disorders.

An effort was made to understand the impacts of dried cherry pomace (by-product of cherry juice processing) inclusion into corn starch extrudates on their direct expansion characteristics. The effect of pomace particle sizes (whole unfractionated ( 500 μm), 500 μm) and levels of pomace inclusion (0, 5. and 15% (w/w)) were specifically investigated. Feed moisture content of 15.5 ± 0.5% (w.b.) and the extruder barrel temperature of 140 °C were kept constant with varying extruder screw speed (150, 200, and 250 rpm). The radial expansion ratio (ER) increased with 5% pomace level of inclusion compared with control but decreased significantly (p

Promoting brown adipose tissue (BAT) development is an attractive strategy for the treatment of obesity, as activated BAT dissipates energy through thermogenesis; however, the mechanisms controlling BAT formation are not fully understood. We hypothesized that as a master regulator of energy metabolism, AMP-activated protein kinase (AMPK) may play a direct role in the process and found that AMPKα1 (PRKAA1) ablation reduced Prdm16 expression and impaired BAT development. During early brown adipogenesis, the cellular levels of α-ketoglutarate (α-KG), a key metabolite required for TET-mediated DNA demethylation, were profoundly increased and required for active DNA demethylation of the Prdm16 promoter. AMPKα1 ablation reduced isocitrate dehydrogenase 2 activity and cellular α-KG levels. Remarkably, postnatal AMPK activation with AICAR or metformin rescued obesity-induced suppression of brown adipogenesis and thermogenesis. In summary, AMPK is essential for the epigenetic control of BAT development through α-ketoglutarate, thus linking a metabolite to progenitor cell differentiation and thermogenesis.

Organic food production is expanding rapidly. However, this industry is hampered by the lack of effective antimicrobial agents which can be used in organic food production. This study examined the antimicrobial activity of Cinnamon cassia oil against major pathogens causing bacterial bovine mastitis, its miscibility in milk and possible antimicrobial mechanisms. C. cassia oil had inhibitory activity against all tested pathogen isolates from bovine mastitis. We conducted disk diffusion assay and found that discs with 20 μL of 2% (v/v) C. cassia oil solution resulted in inhibition zones of 29.6, 19.1, 27.0, 33.3 and 30.7 mm for Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hyicus, Staphylococcus xylosus and Escherichia coli 29, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of C. cassia oil was 0.00625% and 0.025% (v/v) for S. hyicus, 0.025% and 0.10% (v/v) for E. coli 29, and 0.0125% and 0.05% for S. aureus, S. epidermidis and S. xylosus, respectively. We selected two common mastitis pathogens, a representative S. aureus isolate and E. coli 29 for further analyses. Based on time-kill assay in LB broth with 0.15% agar, 2MBC of C. cassia oil generated bactericidal effects on S. aureus and E. coli 29 within 30 min, and 4MBC caused 6 log reduction of S. aureus and E. coli 29 within 30 min. In milk, C. cassia oil at 4MBC reduced ∼6.0 Log10 CFU/ml of S. aureus and E. coli 29 to undetectable level within 8 h. Using propidium iodide staining, we observed membrane damage on both S. aureus and E. coli 29 cells during incubation with C. cassia oil. In addition, C. cassia oil treatment at MIC impaired membrane integrity of E. coli and S. aureus, which was followed by a decrease in ATP synthesis. Bacterial extracellular signaling quorum sensing orchestrates important events related to bacterial pathogeneses through excreting autoinducer (AI). Sub-inhibitory concentration of C. cassia oil repressed AI-2, a universal signal molecule mediating quorum sensing, production in S. aureus and E. coli 29 isolates. Collectively, our data show that C. cassia oil provides an exciting potential to be used as an alternative antimicrobial for bovine mastitis in organic dairy farms.

Non-O157 Shiga toxin producing Escherichia coli (STECs) have become a growing concern to the food industry. Grape seed extract (GSE), a byproduct of wine industry, is abundant in polyphenols that are known to be beneficial to health. The objective of this study was to evaluate the effect of GSE on the growth, quorum sensing, and virulence factors of Centers for Disease Control and Prevention (CDC) "top-six" non-O157 STECs. Minimal inhibitory concentration (MIC) of GSE was 2mg/ml against E. coli O26:H11, and 4mg/ml against the other non-O157 STECs tested. Minimal bactericidal concentration (MBC) was the same as MIC for all six non-O157 STECs tested. At 5×10(5)CFU/ml inoculation level, 4mg/ml GSE effectively inhibited the growth of all tested strains, while 0.25-2mg/ml GSE delayed bacterial growth. At a higher inoculation level (1×10(7)CFU/ml), GSE had less efficacy against the growth of the selected six non-O157 STECs. Its impact on bacterial virulence was then assessed at this inoculation level. Autoinducer-2 (AI-2) is a universal signal molecule mediating quorum sensing (QS). GSE at concentration as low as 0.5mg/ml dramatically reduced AI-2 production of all non-O157 STECs tested, with the inhibitory effect proportional to GSE levels. Consistent with diminished QS, GSE at concentration of 0.125mg/ml caused marked reduction of swimming motility of all motile non-O157 STECs tested. In agreement, GSE treatment reduced the production of flagella protein FliC and its regulator FliA in E. coli O103:H2 and E. coli O111:H2. Furthermore, 4mg/ml GSE inhibited the production of Shiga toxin, a major virulence factor, in E. coli O103:H2 and E. coli O111:H2. In summary, GSE inhibits the growth of "top-six" non-O157 STECs at the population level relevant to food contamination. At higher initial population, GSE suppresses QS with concomitant decrease in motility, flagella protein expression and Shiga toxin production. Thus, GSE has the potential to be used in food industry to control non-O157 STEC.

Key points Maternal obesity reduces adipogenic progenitor density in offspring adipose tissue. The ability of adipose tissue expansion in the offspring of obese mothers is limited and is associated with metabolic dysfunction of adipose tissue when challenged with a high-fat diet. Maternal obesity induces DNA demethylation in the promoter of zinc finger protein 423, which renders progenitor cells with a high adipogenic capacity. Maternal obesity demonstrates long-term effects on the adipogenic capacity of progenitor cells in offspring adipose tissue, demonstrating a developmental programming effect. Abstract Maternal obesity (MO) programs offspring obesity and metabolic disorders, although the underlying mechanisms remain poorly defined. Progenitor cells are the source of new adipocytes. The present study aimed to test whether MO epigenetically predisposes adipocyte progenitors in the fat of offspring to adipogenic differentiation and subsequent depletion, which leads to a failure of adipose tissue plasticity under positive energy balance, contributing to adipose tissue metabolic dysfunction. C57BL/6 female mice were fed either a control diet (10% energy from fat) or a high-fat diet (45% energy from fat) for 8 weeks before mating. Male offspring of control (Con) and obese (OB) dams were weaned onto a regular (Reg) or obesogenic (Obe) diet until 3 months of age. At weaning, male OB offspring had a higher expression of Zinc finger protein 423 (zfp423), a key transcription factor in adipogenesis, as well as lower DNA methylation of its promoter in progenitors of epididymal fat compared to Con offspring, which was correlated with enhanced adipogenic differentiation. At 3 months of age, progenitor density was 30.9 ± 9.7% lower in OB/Obe compared to Con/Obe mice, accompanied by a limited expansion of the adipocyte number when challenged with a high-energy diet. This difference was associated with lower DNA methylation in the zfp423 promoter in the epididymal fat of OB/Obe offspring, which was correlated with greater macrophage chemotactic protein-1 and hypoxia-inducible factor 1α expression. In summary, MO epigenetically limits the expansion capacity of offspring adipose tissue, providing an explanation for the adipose metabolic dysfunction of male offspring in the setting of MO.

In this paper we study the blowup behavior of the minimizing sequence to certain nonlinear elliptic equation with negative critical exponents. We analyze the location for blowup point and the asymptotic behavior of solutions near the blowup point.

Escherichia coli O157:H7 is one of the most notorious foodborne pathogens causing serious disease at low infectious dose. To protect consumers from deadly foodborne E. coli O157:H7 infection, it is vital to develop a simple, reliable, sensitive and rapid method which can detect low level E. coli O157:H7 in foods at real-time. We have successfully developed a novel immunochromatographic assay (ICA) with enhanced sensitivity for the visual and quantitative detection of E. coli O157:H7. Sandwich-type immunoreactions were performed on the ICA, and Pt-Au bimetal nanoparticles (NPs) were accumulated on the test zone. The signal amplification is based on Pt-Au bimetal NPs possessing high peroxidase activity toward 3,3',5,5'-tetramethylbenzidine, which can produce characteristic colored bands and thus, enable visual detection of E. coli O157:H7 without instrumentation. The innovative aspect of this approach lies in the visualization and quantification of target pathogen through the detection of color intensity. Due to the excellent peroxidase activity of Pt-Au NPs, they emit strong visible color intensity in less than 1 min for visual observation even in low concentration range of E. coli O157:H7. Quantification was performed using a commercial assay meter. The sensitivity was improved more than 1000-folds compared to the conventional test strip based on colored gold-colloids. Although the feasibility was demonstrated using E. coli O157:H7 as a model analyte, this approach could be easily developed to be a universal signal amplification technique and applied to detection of a wide variety of foodborne pathogens and protein biomarkers.

Protein-inorganic nanoflowers, composed of protein and copper(II) phosphate (Cu3(PO4)2), have recently grabbed people's attention. Because the synthetic method requires no organic solvent and because of the distinct hierarchical nanostructure, protein-inorganic nanoflowers display enhanced catalytic activity and stability and would be a promising tool in biocatalytical processes and biological and biomedical fields. In this work, we first coimmobilized the enzyme, antibody, and Cu3(PO4)2 into a three-in-one hybrid protein-inorganic nanoflower to enable it to possess dual functions: (1) the antibody portion retains the ability to specifically capture the corresponding antigen; (2) the nanoflower has enhanced enzymatic activity and stability to produce an amplified signal. The prepared antibody-enzyme-inorganic nanoflower was first applied in an enzyme-linked immunosorbent assay to serve as a novel enzyme-labeled antibody for Escherichia coli O157:H7 (E. coli O157:H7) determination. The detection limit is 60 CFU L(-1), which is far superior to commercial ELISA systems. The three-in-one antibody (anti-E. coli O157:H7 antibody)-enzyme (horseradish peroxidase)-inorganic (Cu3(PO4)2) nanoflower has some advantages over commercial enzyme-antibody conjugates. First, it is much easier to prepare and does not need any complex covalent modification. Second, it has fairly high capture capability and catalytic activity because it is presented as aggregates of abundant antibodies and enzymes. Third, it has enhanced enzymatic stability compared to the free form of enzyme due to the unique hierarchical nanostructure.

Antimicrobial sanitizers applied through a manifold spray-bar brush bed system is a main intervention strategy to prevent cross-contamination of foodborne pathogens on fresh apples. To date, information about antimicrobial efficacy of sanitizers including peroxyacetic acid (PAA) intervention is mainly based on laboratory submerging testing which cannot be directly applied into spray-bar system in apple processing facility due to differences in processing parameters. Previously, we examined anti-Listeria efficacies of PAA in laboratory testing. The studies herein further verified the effectiveness of the selected PAA treatments in a pilot apple spray processing line against Listeria monocytogenes surrogate strains, Enterococcus faecium NRRL B-2354 and Listeria innocua, on apples of the selected varieties. The quality attributes of apples after the selected treatments were further evaluated. A 2-min, 80 ppm PAA treatment at 43 °C and 46 °C resulted in 2.4 and 2.4–2.7 Log10 CFU/apple reduction of E. faecium on different apple varieties, respectively, which had similar reductions compared to L. monocytogenes (2.3–2.5 and 2.5–2.8 Log10 CFU/apple reduction), indicating that E. faecium NRRL B-2354 is a suitable surrogate of L. monocytogenes for evaluating PAA efficacy at test temperatures (22–46 °C). Using this pilot spray-bar system, we further showed that a 30-sec spray wash of 80 ppm PAA at 22 °C and 44–46 °C resulted in 0.8–1.1 and 1.5–1.6 Log10 CFU/apple reduction of E. faecium on apple of the selected varieties, respectively, which were comparable to those of L. innocua. In addition, PAA applied at 44–46 °C did not affect the firmness, total soluble solids content and titratable acidity of apple fruits of tested varieties compared to its application at ambient temperature over 3-week of commercial storage. This study showed that E. faecium NRRL B-2354 is a suitable surrogate strain of L. monocytogenes during the pilot fresh apple processing and provides valuable practical data of PAA spray-bar intervention to the apple industry, facilitating compliance with the Preventive Controls for Human Food Rule.

In response to the increasing consumer demand for high-quality, minimally processed ready-to-eat (RTE) meals, the food industry has shown strong interests in exploring new processing technologies for production of safe RTE meals with an adequate shelf life in cold distribution chains. The purpose of this research was to understand the effect of high-pressure processing (HPP) and microwave-assisted thermal pasteurization on the quality attributes of green beans. The pasteurization conditions were selected as 600 MPa at 25 °C for 10 min for HPP and 70 °C for 2 min for processing with microwave-assisted pasteurization system (MAPS). Survival of L. innocua ATCC 51742 in green bean brine solution was analyzed right after the pasteurization processes. The quality attributes of the green beans, such as color, chlorophyll content, texture, vitamin C content, and pH, were further determined during storage at 2 °C for 36 days and 10 °C for 20 days. High-pressure treatment resulted in a 3.7-log CFU/g reduction in L. innocua ATCC 51742, whereas MAPS processing showed a 9.0-log CFU/g reduction. Both pasteurization processes provided significantly better green color retention when the beans were stored at 2 °C than when they were stored at 10 °C. Regardless of the pasteurization methods, the change in the greenness (a*) value of the beans followed similar trends during storage. Both methods caused an increase in the total color difference (ΔE) and a decrease in hue angle (yellowness) during storage (p

During fresh apple packing, wash water in the dump tank and flume systems is reused during daily production, resulting in high levels of organic matter in the wash water. This study evaluated the antimicrobial efficacy of sodium acid sulfate (SAS), a Generally Recognized as Safe compound, against Listeria monocytogenes on fresh apples in a water system with high organic load. SAS at 1.0% reduced L. monocytogenes population in water with 1000 ppm chemical oxygen demand (COD) by more than 5.0 Log10 CFU/ml in 5 min, 2.0–3.0% SAS reduced L. monocytogenes to undetectable levels (10 CFU/ml) within 2 min regardless of organic levels. When applied on apples, a 2-min wash with SAS at 1.0, 1.5, 2.0, and 3.0% reduced L. monocytogenes by ~1.3, 1.9, 2.3, and 3.0 Log10 CFU/apple in clean water, respectively. High organic load in wash water up to 4000 ppm COD had no impact on the bactericidal effect of SAS against L. monocytogenes on fresh apples regardless of SAS concentrations. Shortening the contact time from 2 min to 30 s significantly reduced the antimicrobial efficacy of 25 ppm chlorine and 1.0–2.0% SAS but not that of 3.0% SAS. In addition, SAS at 1.0% demonstrated a better efficacy than 25 ppm chlorine in reducing fruit-to-water cross-contamination regardless of organic matter. SAS also showed a comparable efficacy as 25 ppm chlorine in reducing fruit-to-fruit cross-contamination in water with organic matter. The collective data indicate that SAS, as an enviroment-friendly compound, has the potential to be used as an alternative antimicrobial washing aid in dump tank process water intervention in apple packing facilities.

Peroxyacetic acid (PAA) is a commonly used antimicrobial in apple spray-bar interventions during post-harvest packing. However, limited information is available about its efficacy against foodborne pathogens on fresh apples under commercial packing conditions. In this study, the practical efficacies of PAA against Listeria monocytogenes on fresh apples during spray-bar operation at ambient and elevated temperature were validated in three commercial packing facilities using Enterococcus faecium NRRL B-2354 as a surrogate strain. Apples were inoculated with E. faecium at ~6.5 Log10 CFU/apple and subjected to PAA spray-bar interventions per commercial packing line practice. At each temperature and contact time intervention combination, 20–24 inoculated apples were processed together with 72–80 non-inoculated apples. Applying 80 ppm PAA at ambient temperature (17–21 °C) achieved a similar log reduction (P > 0.05) of E. faecium on Granny Smith apples (GSA) in three apple packing facilities, which caused 1.12–1.23 and 1.18–1.32 Log10 CFU/apple reductions of E. faecium on GSA for 30-sec and 60-sec intervention, respectively. Increasing the temperature of the PAA solution to 43–45 °C enhanced its bactericidal effect against E. faecium, causing 1.45, 1.86 and 2.19 Log10 CFU/apple reductions in three packing facilities for a 30-sec contact, and 1.50, 2.24, and 2.29 Log10 CFU/apple reductions for a 60-sec contact, respectively. Similar efficacies of PAA at both ambient and elevated temperature were also observed on Fuji apples. Spraying PAA on apples at ambient or elevated temperature reduced the level of E. faecium cross-contamination from inoculated apples to non-inoculated apples but could not eliminate cross-contamination. Data from this study provides valuable technical information and a reference point for the apple industry in controlling L. monocytogenes and verifying the effectiveness of their practices.

Recent foodborne outbreaks in low-moisture foods were caused mostly by Salmonella. The main common carbohydrates in low-moisture high-sugar products are D-glucose and D-fructose. There is a lack of information on the thermal resistance of Salmonella in pure sugar and high-sugar products with low water activity (aw) levels. The objective of this study was to study the thermal resistance of Salmonella Enteritidis PT30 in sugar products. Two pure sugars (glucose and fructose) and honey powder were selected for this research. The initial aw and moisture content for glucose, fructose, and honey powder are 0.30, 0.30, 0.40 and 0.02, 0.15, and 0.50% db., respectively. The D-values of Salmonella in different sugar products are determined at low aw levels (0.18, 0.30, 0.40, and 0.50 measured at 80 °C). The results showed that the D80 °C-values of S. Enteritidis PT30 decreased with increasing aw of all samples. At aw80 °C 0.18, S. Enteritidis PT30 in glucose powder has higher D-value than those in fructose and honey powder whereas, at aw80 °C 0.30, 0.40, and 0.50, S. Enteritidis PT30 in fructose powder has higher D-values than glucose and honey powder at 80 °C. Zaw values of S. Enteritidis PT30 in fructose and honey powder are comparable but was lower in glucose because of the phase change. The results of this study provide insights on understanding the thermal resistance of Salmonella in sugars and guidance on thermal process design to improve the safety of low-moisture high-sugar products.

Salmonella is a leading cause of foodborne illness associated with low-moisture foods. In addition to being able to survive in low-moisture environments during long storage, Salmonella has shown sharply increased thermal tolerance making it difficult to control in low-moisture foods. This research utilized soy protein powder as a food career to study the thermal resistance of Salmonella under a wide range of temperatures and aw. Salmonella inoculated soy protein powder samples were pre-equilibrated to aw from 0.13 to 0.82 at room temperature, then subjected to heat treatment (60 to 99 oC) under isothermal conditions. The aw of soy protein powders at 25 to 99 oC were measured using high-temperature aw cells with humidity sensors. The D-values as a function of high-temperature aw from 0.25 to 0.70 showed a semi-log relationship under each treatment temperature level from 70 to 99 oC. Slightly downward trends were observed when the high-temperature aw was above 0.70, showing increased effectiveness of thermal inactivation. Results from this study provide insights to assist the design of thermal treatments for control of Salmonella in intermediate- and low-moisture foods.

OBJECTIVES: Grape pomace (GP), a by-product of the wine and juice industry, is rich in bioflavonoids and dietary fibers. We hypothesized that grape pomace has protective effects against colitis-associated colorectal cancer (CRC). METHODS: Nine-week-old female mice were fed a control diet (CON) or CON with 5% grape pomace (GP) for 2 weeks, when mice were subjected to azoxymethane (AOM)/dextran sulfate sodium (DSS) for colorectal cancer (CRC) induction. All animals were received 1% DSS in drinking water for 7 days followed by a 21-day recovery in a 3-cycle experimental period, while receiving their respective diet. RESULTS: GP supplementation ameliorated the disease activity index (DAI) score, reduced tumor number, tumor size and pathological scores in AOM/DSS treated mice. Furthermore, dietary GP suppressed colonic expression of inflammatory cytokines, IL-1β and TNF-α, and inhibited NF-κB inflammatory signaling. Colorectal inflammation is known to enhance Wnt signaling and cell proliferation. In agreement, the content of β-catenin, a key downstream mediator of Wnt signaling, was reduced so for the expression of Cyclin D1 phosphorylation and content of p53 and PCNA level in GP-fed mice. In addition, GP reduced the expression of ALDH1, a marker of cell stemness, and increased the expression of Cdx2, a key transcription factor initiating epithelial cell differentiation. Consistently, DNA methylation of the promoter region of Cdx2 gene and hypermethylation of GpG island methylator phenotype (CIMP), which commonly occurs during CRC carcinogenesis, was alleviated in GP group. CONCLUSIONS: GP supplementation suppressed colitis-associated CRC carcinogenesis associated with the suppression of inflammation and cell proliferation and the enhancement of DNA demethylation in Cdx2 and CIMP genes in the colon. FUNDING SOURCES: USDA-NIFA 2018–67,017-27,517.

OBJECTIVES: Maternal obesity (MO) predisposes metabolic dysfunction in offspring muscle. Skeletal muscle-dependent non-shivering thermogenesis (NST) is emerging as a critical mechanism for maintaining energy homeostasis, but the effects of maternal exercise on muscle-based thermogenesis in offspring remains unexplored. In addition, the impact of maternal obesity and exercise on fetal muscle development is unclear, which will also be examined. The objective of the current study is to explore the effects of maternal exercise on muscle-based thermogenesis and myogenesis in fetuses impaired due to MO. METHODS: Female C57BL/6 J mice were randomized and assigned to either control (CON, 10 kcal% from fat) or obesogenic diet (OB, 60 kcal% from fat) for 8 weeks to induce obesity and then mated. Then, pregnant mice in obesogenic diet were further separated into two groups with/without exercise (daily 60 min exercise) during pregnancy, which resulted in three treatments: control (CON), OB, and OB-EX (n = 6 per group). Fetal skeletal muscles were collected at embryonic day 18.5 (E18.5). In another cohort of animals, maternal mice were allowed to give birth and surface temperature of neonates was measured. Statistical analysis were conducted using one way analysis of variance (ANOVA); a pregnancy/litter was considered as an experimental unit. RESULTS: OB reduced surface temperature of neonates (P

OBJECTIVES: This study tested the hypothesis that sulforaphane (SFN) enhances intestinal integrity and epithelial regeneration via AMPK/Nrf2 activation. METHODS: Male mice at 8-wk-old were subjected to control diet (CON) or CON with 600 ppm SFN for 4 weeks, and then half of mice within each dietary group were subjected to colitis induction (9-day-2.5% DSS treatment in drinking plus 9-day-recovery), while remaining their respective diet. RESULTS: SFN administration alleviated acute DSS-induced body weight loss and reduced disease activity index (DAI) score, as well as colon shortening in DSS-treated mice. Additionally, SFN supplementation decreased the mRNA expression of inflammatory markers, interleukin (IL)-1β, while increased anti-inflammatory marker IL-10 in DSS-challenged mice. Furthermore, SFN protected colonic epithelial structure, which was associated with activated AMPK signaling, increased Nrf2 and heme oxygenase-1 content in DSS-induced colitis mice. The roles of AMPK/Nrf2 signaling in mediating the improvement of gut epithelial regeneration following DSS-induced injury will be further studied. CONCLUSIONS: SFN supplementation had protective effects against DSSinduced colitis and improved gut epithelial structure, which was associated with activation of AMPK/NrF2 signaling. Dietary SFN is a promising approach for the management and prevention of colitis. FUNDING SOURCES: USDA-NIFA 2018-67,017-27,517.

Summary Chitin, a long-chain polymer of N-acetyl-D-glucosamine (NAG) and the most abundant natural nitrogen-containing organic material in the world, is far under-utilized than other biomass resources. Herein, we demonstrate a highly efficient deoxygenation process to convert chitin monomer, i.e., NAG, into various amines, which are the ubiquitous platform chemicals in chemical industry. In the presence of H2 and Ru/C catalyst, the oxygen atoms in the glucosamine molecules are removed in the form of H2O and/or CO/CO2, whereas CO is hydrogenated to CH4. By optimizing the reaction conditions, ∼50% yield of various amines was obtained via the selective deoxygenation of NAG. The reaction mechanism has been proposed. These findings not only promote shell biorefinery in green chemistry and fishery industry but also provide chemicals for material science, resulting in expanding cooperation in new areas such as clean energy, energy conservation, environment protection, and infrastructure., Graphical Abstract, Highlights • Utilization of the fixed nitrogen from the ocean • Greener production of amines and ammonium from chitin • Oxygen in glucosamine was removed in the form of H2O and/or CO/CO2 • Reaction pathways to produce amines from N-acetyl-D-glucosamine (NAG), Chemical Engineering; Catalysis; Green Chemistry

Dry dairy powder is a commonly used ingredient for ready-to-eat foods. It has been implicated in multiple foodborne outbreaks. Listeria monocytogenes can survive in low moisture conditions for a long duration. However, there is no information on Listeria survival in dry milk powder during storage and thermal treatments. The objectives of this study were to examine the stability of L. monocytogenes in non-fat dry milk (NFDM) during extended storage and further analyze thermal resistance of L. monocytogenes in NFDM under different water activities (aw) and its thermal stability after 1-year storage. We observed approximately 1.75 and 2.93 log CFU/g reduction of L. monocytogenes in aw 0.25 NFDM over 1-year storage at 4 and 22 °C, respectively. Thermal resistance of L. monocytogenes was inversely related to aw, and the inactivation kinetic curves of L. monocytogenes in NFDM at target aw showed a log-linear trend under all tested conditions. For aw 0.25, 0.30, and 0.45 NFDM, the ranges of D-values, were 66.2 - 21.3, 33.5 - 9.4, and 14.6- 4.3 min at 70, 75 and 80 °C, respectively. The z-values for L. monocytogenes in NFDM at aw 0.25-0.45 were 14.62 - 15.95 °C. Furthermore, the thermal stability of L. monocytogenes in aw 0.25 NFDM post 6-month or 12-month storage under refrigerated or ambient storage did not deviate much from that in NFDM prior to the storage. Data indicated that a 60-min heat treatment at 80 °C resulted in ∼ 5-log reduction of L. monocytogenes in NFDM of aw 0.30. This provides a promising intervention strategy to enhance bactericidal efficacy of thermal treatment while maintaining the quality of milk powder.

The attachment of Escherichia coli O157:H7 to intestinal epithelial cells is indispensable for its pathogenesis. Besides translocated-intimin receptor (Tir), E. coli O157:H7 interacts with host cell surface receptors to promote intimate adhesion. This study showed that integrin β1 was increased in Caco-2 cells upon E. coli O157:H7 infection, while Caco-2 cells subjected to integrin β1 antibody blocking or CRISPR/Cas9 knockout had reduced bacterial attachment. Infection of E. coli O157:H7 inactivated focal adhesion kinase (FAK) and paxillin, increased focal adhesion (FA) and actin polymerization, and decreased cell migration in Caco-2 cells, which were rescued by integrin β1 antibody blocking or knockout. Pre-treatment with quercetin, known for its anti-oxidant and anti-inflammatory activity, reduced bacterial infection to Caco-2 cells, which might be partially via interfering integrin β1 and FAK association augmented by E. coli O157:H7. In addition, quercetin decreased FA formation induced by bacterial infection and recovered host cell motility. Taken together, data showed that E. coli O157:H7 interacts with integrin β1 to facilitate its adhesion to host cells. Quercetin inhibits bacterial infection possibly by blocking the interaction between E. coli O157:H7 and integrin β1. Collectively, these data indicate that quercetin provides an alternative antimicrobial to mitigate and control E. coli O157:H7 intestinal infection, and suggest potential broad benefits of quercetin and related polyphenols in fighting other enteric pathogen infections.

X chromosome inactivation (XCI) in females needs to be maintained in newly synthesized chromosome during each cell proliferation cycle, and improper XCI may reactivate X chromosome oncogenes which links to carcinogenesis. However, mechanisms maintaining XCI during cell proliferation remain unclear. During XCI, PRC1 canonical or PRC1-like proteins are assumed to ubiquitinate H2A, which forms a "reversibly" silenced chromatin, while during the maintenance stage of XCI, macroH2As instead of H2As are enriched in the inactivated X chromosome to form a stable silencing status. Recently studies suggested that Breast cancer type 1 (BRCA1), a tumor suppressor commonly mutated in breast cancer cells, can catalyze macroH2A ubiquitination, which prompted us to hypothesize that BRCA1 instead of PRC1 mediates macroH2A ubiquitination and maintains XCI during cell proliferation. Based on RNA immunoprecipitation and confocal microscopic imaging, we found that BRCA1 directly interacts with XIST, a key LncRNA mediating XCI, which colocalizes with mH2A in inactivated X chromosome. Loss of either XIST or BRCA1 decreased the ubiquitination level of macroH2A, suppressing DNA methylation of X chromosome genes, which leads to failure of heterochromatin formation in proliferating breast cancer and mammary gland epithelial cells. Furthermore, this ubiquitination by BRCA1 was not replaceable by PRC1. Using domain-specific deletion, the interaction between XIST and BRCA1 was narrowed to exon 2-7. Our data showed that BRCA1 interacts with XIST to ubiquitinate the macroH2A on X chromosome, which is required for XCI maintenance in mammary gland epithelial cells during cell proliferation. These data provide a novel mechanism explaining the frequent BRCA1 mutations occurred during breast carcinogenesis.

Sanitizers are commonly used in post-harvest interventions to reduce potential foodborne pathogen contamination of fresh produce. An appropriate non-pathogenic surrogate of Listeria monocytogenes is needed to verify the laboratory obtained antimicrobial intervention results in commercial facilities. The objective of this study was to identify a surrogate of L. monocytogenes to validate the sanitation efficiency of fresh apples. We evaluated and compared the behavior of Listeria innocua, Enterococcus faecium NRRL B-2354, Pediococcus acidilactici and Lactobacillus plantarum, to that of L. monocytogenes on apples regarding attachment, survival during storage, and resistance to various antimicrobial washes. L. monocytogenes, E. faecium and L. innocua persisted on fresh apple surfaces at 6.4–6.5 Log10 CFU/apple for 48 h at room temperature, while L. plantarum and P. acidilactici slightly decreased. All the selected surrogate candidates demonstrated comparable adhesion strength with L. monocytogenes in response to three sequential water washes. E. faecium and L. innocua showed similar or higher antimicrobial resistance than L. monocytogenes to chlorine, neutral electrolyzed water, JC9450, peroxyacetic acid (PAA), and Neo-Pure, regardless of apple variety or contact time. However, L. plantarum and P. acidilactici were significantly more susceptible to PAA and Neo-Pure than L. monocytogenes. Data, collectively, identified E. faecium as a promising non-Listeria surrogate of L. monocytogenes for in-plant validation of sanitizer interventions of fresh apples or other related fresh produce.

Listeria monocytogenes contaminated processing equipment and the general packing environment have been implicated in deadly foodborne listeriosis outbreaks, highlighting the significance of proper sanitization and disinfection of food contact surfaces. This study aims to comprehensively evaluate antimicrobial efficacy of commercially available, economical sanitizers at practical concentrations against L. monocytogenes biofilm formed on polystyrene surfaces under different conditions. Ozonated water 1-min treatment at 1.0, 2.0, and 4.0 ppm resulted in ∼0.9, 3.4, and 4.1 log reduction of L. monocytogenes single strain biofilm grown on polystyrene surfaces, respectively. However, its efficacy was dramatically diminished in multi-strain L. monocytogenes biofilm and was further compromised by aged biofilm and in the presence of organic matter. Quaternary ammonium compounds (QAC) at 100/400 ppm, chlorine at 100/200 ppm, chlorine dioxide at 2.5/5.0 ppm and peroxyacetic acid (PAA) at 80/160 ppm resulted in 2.4/3.6, 2.0/3.1, 2.4/3.8, and 3.6/4.8 log reduction of L. monocytogenes single strain biofilm, respectively. Antimicrobial efficacies of all tested sanitizers against 7-day-old biofilm were much lower when compared to 2-day-old biofilm, with PAA being the least influenced by the age of the biofilm. Organic matter conditioning with diluted milk or apple juice dramatically impacted the antimicrobial efficacy of all sanitizers. PAA treatment of 1 min at 160-200 ppm resulted in a 3.2-3.5 log reduction against 7-day-old biofilm in the presence of organic matter, thus showing its effectiveness in eradicating L. monocytogenes biofilm on polystyrene surface. Collectively, data highlight the importance of timely and thoroughly cleaning food contact surfaces before disinfection and provides practical information and guidance for the food industry in selecting the most effective sanitizer in their sanitizing regimes to eliminate L. monocytogenes biofilm.

Gut epithelium covers the inner layer of the gastrointestinal tract and provides a physical barrier to separate the host from its external environment, and its barrier function is critical for maintaining host health. AMP-activated protein kinase (AMPK) as a master regulator of energy metabolism plays a critical role in epithelial barrier function. AMPK activation promotes epithelial differentiation and facilitates cell polarity establishment, both of which strengthen epithelial barrier. In addition, AMPK promotes the assembly of tight junctions and adherens junctions by direct phosphorylation of proteins composing apical junctions, junctional anchors, and cytoskeletons. Pharmacological and nutraceutical compounds, as well as physiological states triggering AMPK activation strengthen epithelial barrier function. This review summarized recent progress in delineating the regulatory roles of AMPK in apical junction formation and barrier function of intestinal epithelium.

Salmonella is capable of surviving in a low moisture environment for long periods. Once adapted to the xeric conditions, the thermal resistance of Salmonella is enhanced. Cocoa powder is a low water activity (aw) food (LawF) that is an essential component in a wide variety of desserts and ready-to-eat (RTE) foods and drinks. The aim of this study was to evaluate the desiccation and thermal resistance of Salmonella in cocoa powder, as well as to examine the suitability of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing. Natural unsweetened cocoa powder was inoculated with a 3-strain Salmonella cocktail or E. faecium and was equilibrated to aw 0.30 and 0.45 at room temperature, then subjected to isothermal treatments at 70–80 °C or 12-month storage at RT (room temperature, 22.0 ± 0.5 °C, aw 0.30). At 70 and 80 °C, D-values of both Salmonella and E. faecium increased with decreasing aw. D-values of Salmonella at aw 0.30 cocoa powder were 46.2 ± 4.7, 20.5 ± 1.7, and 11.5 ± 0.9 min at 70, 75 and 80 °C, respectively. Higher heat resistance of E. faecium in aw 0.30 cocoa powder was observed with D-values of 59.9 ± 5.0, 28.9 ± 1.8, and 16.1 ± 1.4 min at 70, 75, and 80 °C, respectively. However, E. faecium demonstrated less heat resistance than Salmonella when aw was increased to 0.45. D-values for Salmonella at aw 0.45 were 31.6–7.0 min at 70–80 °C compared to 25.8–4.7 min for E. faecium. During 12 months of storage at RT, surviving E. faecium population in aw 0.30 cocoa powder was higher than that of the Salmonella cocktail; the population decreased by 1.39 and 3.75 logs, respectively. These findings indicate that the suitability of E. faecium as a surrogate organism for Salmonella is influenced by aw of cocoa powder. The aw correlates with thermal inactivation rates in both Salmonella and E. faecium, and should be considered as a significant contributor to the thermal resistance of Salmonella in cocoa powder.

Salmonella spp. exhibit prolonged survivability and high tolerance to heat in low-moisture foods. The reported thermal resistance parameters of Salmonella spp. in low-moisture foods appear to be unpredictable due to various unknown factors. We report here that temperature-dependent water activity (a w, treatment temperature ) plays an important role in the sharply increased thermal resistance of Salmonella enterica serovar Enteritidis PT 30 and its potential surrogate Enterococcus faecium NRRL B-2354. In our study, silicon dioxide granules, as carriers, were separately inoculated with these two microorganisms and were heated at 80°C with controlled relative humidity between 18 and 72% (resulting in corresponding a w,80°C values for bacteria between 0.18 and 0.72) in custom-designed test cells. The inactivation kinetics of both microorganisms fitted a log-linear model ( R 2 , 0.83 to 0.97). Reductions in the a w,80°C values of bacterial cells exponentially increased the D 80°C (the time needed to achieve a 1-log reduction in a bacterial population at 80°C) values for S . Enteritidis and E. faecium on silicon dioxide. The log-linear relationship between the D 80°C values for each strain in silicon dioxide and its a w,80°C values was also verified for organic wheat flour. E. faecium showed consistently higher D 80°C values than S . Enteritidis over the a w,80°C range tested. The estimated z aw (the change in a w,80°C needed to change D 80°C by 1 log) values of S . Enteritidis and E. faecium were 0.31 and 0.28, respectively. This study provides insight into the interpretation of Salmonella thermal resistance that could guide the development and validation of thermal processing of low-moisture foods. IMPORTANCE In this paper, we established that the thermal resistance of the pathogen S . Enteritidis and its surrogate Enterococcus faecium , as reflected by D values at 80°C, increases sharply with decreasing relative humidity in the environment. The log-linear relationship between the D 80°C values of each strain in silicon dioxide and its a w,80°C values was also verified for organic wheat flour. The results provide new quantitative insight into the way in which the thermal resistance of microorganisms changes in low-moisture systems, and they should aid in the development of effective thermal treatment strategies for pathogen control in low-moisture foods.

Epithelial cultures are commonly used for studying gut health. However, due to the absence of mesenchymal cells and gut structure, epithelial culture systems including recently developed three-dimensional organoid culture cannot accurately representin vivogut development, which requires intense cross-regulation of the epithelial layer with the underlying mesenchymal tissue. In addition, organoid culture is costly. To overcome this, a new culture system was developed using mouse embryonic small intestine. Cultured intestine showed spontaneous peristalsis, indicating the maintenance of the normal gut physiological structure. During 10 days ofex vivoculture, epithelial cells moved along the gut surface and differentiated into different epithelial cell types, including enterocytes, Paneth cells, goblet cells and enteroendocrine cells. We further used the establishedex vivosystem to examine the role of AMP-activated protein kinase (AMPK) on gut epithelial health. Tamoxifen-induced AMPKα1 knockout vastly impaired epithelial migration and differentiation of the developingex vivogut, showing the crucial regulatory function of AMPKα1 in intestinal health.

Protocols designed for the adipogenic differentiation of human and mouse cells are commonly used for inducing the adipogenesis of bovine stromal vascular cells. However, likely due to metabolic differences between ruminant and non-ruminant animals, these methods result in only few cells undergoing complete adipogenesis with minimal lipid droplet accumulation. Here, we discuss the development of an adipogenic differentiation protocol for bovine primary cells through a three-dimensional spheroid culture. Stromal vascular cells derived from bovine intramuscular fat were isolated and stored in liquid nitrogen before culturing. Cells were cultured in hanging drops for 3 days to allow for the formation of spherical structures. The spheroids were then transferred to cell culture plates with endothelial basal medium-2 for 3 days and in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with a standard adipogenic cocktail for 3 additional days, which were then allowed to fully differentiate for 3 days in DMEM supplemented with insulin. Compared with conventional two-dimensional culture, cells in a three-dimensional spheroid culture system had higher adipogenic gene expression and consequently contained more adipocytes with larger lipid droplets. In addition, endothelial induction of spheroids prior to adipogenic differentiation is essential for efficient induction of adipogenesis of bovine stromal vascular cells, mimicking in vivo adipose development. In summary, the newly developed three-dimensional spheroid culture method is an efficient way to induce adipogenic differentiation and study adipose development of cells derived from ruminant animals, which also can be used for studying the role of angiogenesis in adipose development.

Beyond their nutritional impact to colonic epithelial cells, the intestinal microbiota metabolite butyrate has pleotropic effects to host cells and is known for its beneficial effects on intestinal homeostasis and metabolism. However, it remains unclear how it modulates mast cell function. Here, we demonstrate that butyrate profoundly inhibited proliferation of mouse mastocytoma P815 cells through inducing cell cycle arrest and apoptosis, as well as decreasing c-Kit activation. In addition, butyrate increased early- and late-stage apoptotic P815 cells. In murine bone marrow-derived mast cells (BMMC), butyrate-suppressed FcεRI-dependent tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) release without affecting β-Hexosaminidase, but that was associated with decreased mitogen-activated protein kinase extracellular signal-regulated kinase 1/2, p38 and c-Jun N-terminal kinases activation. Butyrate treatment substantially enhanced histone 3 acetylation in both P815 and BMMC and decreased FcεRI-dependent mRNA expression of tnf-α and il-6 in BMMC, mimicking the effect of Trichostatin A, a known histone deacetylase inhibitor. Chromatin immunoprecipitation revealed that butyrate enhanced acetylation of the tnf-α and il-6 promoter regions but blocked RNA polymerase II binding to the promoters of tnf-α and il-6 genes, indicating suppressed transcription initiation. These phenotypes mimicked those of Trichostatin A treatment. In conclusion, butyrate inhibits cell proliferation and increases cell apoptosis in mastocytoma P815 cells and suppresses FcεRI-dependent cytokine production in murine primary BMMC, which are likely mediated by HDAC inhibition.

The abundance and cross-linking of intramuscular connective tissue contributes to the background toughness of meat, and is thus undesirable. Connective tissue is mainly synthesized by intramuscular fibroblasts. Myocytes, adipocytes and fibroblasts are derived from a common pool of progenitor cells during the early embryonic development. It appears that multipotent mesenchymal stem cells first diverge into either myogenic or non-myogenic lineages; non-myogenic mesenchymal progenitors then develop into the stromal-vascular fraction of skeletal muscle wherein adipocytes, fibroblasts and derived mesenchymal progenitors reside. Because non-myogenic mesenchymal progenitors mainly undergo adipogenic or fibrogenic differentiation during muscle development, strengthening progenitor proliferation enhances the potential for both intramuscular adipogenesis and fibrogenesis, leading to the elevation of both marbling and connective tissue content in the resulting meat product. Furthermore, given the bipotent developmental potential of progenitor cells, enhancing their conversion to adipogenesis reduces fibrogenesis, which likely results in the overall improvement of marbling (more intramuscular adipocytes) and tenderness (less connective tissue) of meat. Fibrogenesis is mainly regulated by the transforming growth factor (TGF) β signaling pathway and its regulatory cascade. In addition, extracellular matrix, a part of the intramuscular connective tissue, provides a niche environment for regulating myogenic differentiation of satellite cells and muscle growth. Despite rapid progress, many questions remain in the role of extracellular matrix on muscle development, and factors determining the early differentiation of myogenic, adipogenic and fibrogenic cells, which warrant further studies.

The effects of dietary grape seed extract (GSE) on protecting jejunum epithelial were investigated using interlukin-10-deficient mice. GSE supplementation increased villus length, mucosal thickness and enhanced goblet cell density associated with enhanced expression of villin and two key differentiation transcription factors, Hairy/Enhancer of Split 1 (Hes1) and Kruppel-Like Factor-4 (Klf4), and increased p21 (CIP1/WAF1) content. Additionally, expression of nutrient transporters, alanyl aminopeptidase and glucose transporter-2 were increased in GSE supplemented jejunum. Consistent with its anti-inflammatory effects, GSE supplementation decreased tumor necrosis factor-α and interferon-γ expression and down-regulated NF-κB signalling. Furthermore, GSE decreased total alkaline phosphatase activity with a concomitant increase in intestinal alkaline phosphatase protein. Thus, GSE improves jejunum health in interlukin10-deficient mice likely through suppressing inflammation and regulating alkaline phosphatase.

Biofilms are surface-associated communities of microorganism embedded in extracellular matrix. Exopolysaccharide is a critical component in the extracellular matrix that maintains biofilm architecture and protects resident biofilm bacteria from antimicrobials and host immune attack. However, self-produced factors that target the matrix exopolysaccharides, are still poorly understood. Here, we show that PslG, a protein involved in the synthesis of a key biofilm matrix exopolysaccharide Psl in Pseudomonas aeruginosa, prevents biofilm formation and disassembles existing biofilms within minutes at nanomolar concentrations when supplied exogenously. The crystal structure of PslG indicates the typical features of an endoglycosidase. PslG mainly disrupts the Psl matrix to disperse bacteria from biofilms. PslG treatment markedly enhances biofilm sensitivity to antibiotics and macrophage cells, resulting in improved biofilm clearance in a mouse implant infection model. Furthermore, PslG shows biofilm inhibition and disassembly activity against a wide range of Pseudomonas species, indicating its great potential in combating biofilm-related complications.

Nutrient fluctuations during the fetal stage affects fetal development, which has long-term impacts on the production efficiency and quality of meat. During the early development, a pool of mesenchymal progenitor cells proliferate and then diverge into either myogenic or adipogenic/fibrogenic lineages. Myogenic progenitor cells further develop into muscle fibers and satellite cells, while adipogenic/fibrogenic lineage cells develop into adipocytes, fibroblasts and resident fibro-adipogenic progenitor cells. Enhancing the proliferation and myogenic commitment of progenitor cells during fetal development enhances muscle growth and lean production in offspring. On the other hand, promoting the adipogenic differentiation of adipogenic/fibrogenic progenitor cells inside the muscle increases intramuscular adipocytes and reduces connective tissue, which improves meat marbling and tenderness. Available studies in mammalian livestock, including cattle, sheep and pigs, clearly show the link between maternal nutrition and the quantity and quality of meat production. Similarly, chicken muscle fibers develop before hatching and, thus, egg and yolk sizes and hatching temperature affect long-term growth performance and meat production of chicken. On the contrary, because fishes are able to generate new muscle fibers lifelong, the impact of early nutrition on fish growth performance is expected to be minor, which requires further studies.

Obesity is increasing rapidly worldwide and is accompanied by many complications, including impaired muscle regeneration. The obese condition is known to inhibit AMPK activity in multiple tissues. We hypothesized that the loss of AMPK activity is a major reason for hampered muscle regeneration in obese subjects. We found that obesity inhibits AMPK activity in regenerating muscle, which was associated with impeded satellite cell activation and impaired muscle regeneration. To test the mediatory role of AMPKα1, we knocked out AMPKα1 and found that both proliferation and differentiation of satellite cells are reduced after injury and that muscle regeneration is severely impeded, reminiscent of hampered muscle regeneration seen in obese subjects. Transplanted satellite cells with AMPKα1 deficiency had severely impaired myogenic capacity in regenerating muscle fibers. We also found that attenuated muscle regeneration in obese mice is rescued by AICAR, a drug that specifically activates AMPK, but AICAR treatment failed to improve muscle regeneration in obese mice with satellite cell–specific AMPKα1 knockout, demonstrating the importance of AMPKα1 in satellite cell activation and muscle regeneration. In summary, AMPKα1 is a key mediator linking obesity and impaired muscle regeneration, providing a convenient drug target to facilitate muscle regeneration in obese populations.

Escherichia coli O157:H7 produces Shiga toxin (Stx) which is heat stable and causes Hemolytic Uremic Syndrome (HUS), a serious disease associated with bloody diarrhea and even death. To ensure food safety, both live E. coli O157:H7 and its toxin production in food products need to be controlled. Natural ingredients with inhibitory effects on E. coli O157:H7 growth and toxin production are top choices of antimicrobials for the food industry. The objectives of this study were to evaluate efficacy of grape seed extract (GSE) against the growth, swimming motility and Stx production of E. coli O157:H7. The disc diffusion assay indicated that 3.2 mg GSE per disc resulted in an inhibition zone of 14.8 ± 0.21 mm. The minimal inhibitory concentration of GSE against E. coli O157: H7 was 4.0 mg/ml. At high inoculation level (1 × 107 CFU/ml), including GSE at 0.25–2.0 mg/ml reduced Stx production without inhibiting E. coli O157:H7 growth. At 5 × 105 CFU/ml inoculation level, 2.0 and 4.0 mg/ml GSE effectively inhibited the growth of E. coli O157:H7 for at least 72 h, however, a low level of GSE (0.125–1.0 mg/ml) enhanced E. coli O157:H7 growth and Stx2 production. At 4 mg/ml, GSE completely abolished Stx2 production in addition to it bactericidal effect against E. coli O157:H7. In addition, GSE at concentration as low as 0.125% blocked the swimming motility, which is important for E. coli O157:H7 surface adherence. In conclusion, GSE is effective in inhibiting the motility of E. coli O157:H7, GSE shows potential to be used as a natural antimicrobial to control E. coli O157:H7.

Scope Perturbation of gut epithelial barrier function induces inflammation and other health problems that originate from the gut. Purple potato contains a high content of beneficial polyphenolic compounds. The objective of this study is to evaluate the effect of purple potato extract (PPE) on intestinal differentiation and barrier function, and explore its underlying mechanism using Caco-2 cells and ex vivo cultured gut tissues. Methods and results PPE increases transepithelial electrical resistance and decreases FITC-dextran paracellular flux in Caco-2 cells, which are associated with strengthened intestinal epithelial differentiation in both Caco-2 cells and ex vivo guts. Furthermore, PPE treatment enhances AMP-activated protein kinase (AMPK) activity, concomitant with the increased expression of CDX2, a key transcriptional factor regulating intestinal epithelial differentiation. Knocking out AMPK using CRISPR/Cas9 system abolishes the positive effects of PPE on intestinal epithelial differentiation and barrier function, in junction with the reduced expression of CDX2. Conclusion PPE improves gut epithelial differentiation and barrier function via activating AMPK, indicating that PPE, as well as associated purple potato consumption, could be used as a supportive dietary therapeutic strategy for improving gut epithelial health.