Impact of packaging atmosphere, oregano essential oil, and storage temperature on cold-adapted Salmonella Enteritidis and Salmonella Typhimurium on ready-to-eat smoked turkey.

The hazard of diseases created by S. Enteritidis and S. Typhimurium is relatively high in turkey meat products. Combinations of preservation methods are utilized in many strategies, such as mild heat with decreased water activity, a changed atmosphere, refrigerated storage, and decreased heat treatment with some acidification. Within the domain of ready-to-eat food technology, a range of preservation methods are typically utilized to enhance shelf life, such as applying mild heat in tandem with reduced water activity, employing modified atmosphere packaging, utilizing refrigerated storage, and utilizing reduced heat treatment combined with acidification. This investigation aimed to determine how S. Enteritidis and S. Typhimurium grew when sliced ready-to-eat smoked turkey (RTE-SM) was stored at 0, 5, 10, and 15°C for various periods. The study also examined the effects of modified atmosphere packaging (MAP) (40% CO2 and 60% N2) and VP on these growth patterns. Total viable count (TVC), lactic acid bacteria (LAB), pH, and redox potential levels were determined. The control experiment on RTE-SM showed no Salmonella growth within 30 d of storage at any temperature. This indicated that the RTE-SM in use did not initially contain S. Typhimurium and S. Enteritidis. Results indicated that the storage of RTE-SM using a combination of VP, MAP, and MAPEO with storage at 0 and 5°C did not allow for the pathogen to grow throughout storage. In comparison, at 10 and 15°C after one day, which allowed for minor growth (0.17-0.5 log CFU/g)? In contrast, at 0 and 5°C, Salmonella survives until the end of storage (173 d). However, the combination of MAPEO with the same storage temperatures achieved the elimination of the pathogen in the meat after 80 d. The combination of both packaging systems with high temperatures (10 or 15°C) allowed for the multiplication and growth of the bacterium through the product's shelf life of more than 1 log CFU/g. Thus, a combination of MAP or MAPEO with low storage temperatures (0 or 5°C) inhibited the growth of the pathogen.

Does dietary supplementation with lettuce seed oil enhance broiler performance, immunity, lipid profile, liver and kidney functions, antioxidant parameters, and intestinal microbiota?

The aim of this research was to evaluate the influence of lettuce seed oil (LSO) on the performance, carcass yield, kidney and liver indices, immunity, lipid profile, and cecal microbiota of fattening chicks. A total of 200, 7-day-old Cobb-500 were distributed into 5 experimental groups; each group contained 5 replicates with 8 birds each. The first group 1) the basal diet (only); 2) the basal diet plus lettuce seed oil (0.50 mL/kg); 3) the basal diet plus lettuce seed oil (1.00 mL/kg); 4) the basal diet plus lettuce seed oil (1.50 mL/kg); and 5) the basal diet plus lettuce seed oil (2.00 mL/kg). No significant effect was observed on growth performance, carcass traits, or kidney function at any level of oil. But, liver function was significantly affected due to LSO levels. Serum lipid profiles (total cholesterol-TC, triglyceride-TG, low-density lipoprotein-LDL, and very low-density lipoprotein-VLDL) were significantly reduced by using LSO levels compared to the control group. Dietary LSO significantly increased immunological and antioxidant parameters, except for malondialdehyde-MDA, which was reduced. On the other hand, the cecal microbiota was significantly improved by LSO additives. It was concluded that the dietary supplementation of LSO had beneficial effects on liver and kidney functions, lipid profile, immunity, antioxidant parameters, and the bacteriology of fattening chicks.

Characterization and Biodegradation of Phenol by Pseudomonas aeruginosa and Klebsiella variicola Strains Isolated from Sewage Sludge and Their Effect on Soybean Seeds Germination.

Phenols are very soluble in water; as a result, they can pollute a massive volume of fresh water, wastewater, groundwater, oceans, and soil, negatively affecting plant germination and animal and human health. For the detoxification and bioremediation of phenol in wastewater, phenol biodegradation using novel bacteria isolated from sewage sludge was investigated. Twenty samples from sewage sludge (SS) were collected, and bacteria in SS contents were cultured in the mineral salt agar (MSA) containing phenol (500 mg/L). Twenty colonies (S1 up to S20) were recovered from all the tested SS samples. The characteristics of three bacterial properties, 16S rDNA sequencing, similarities, GenBank accession number, and phylogenetic analysis showed that strains S3, S10, and S18 were Pseudomonas aeruginosa, Klebsiella pneumoniae, and Klebsiella variicola, respectively. P. aeruginosa, K. pneumoniae, and K. variicola were able to degrade 1000 mg/L phenol in the mineral salt medium. The bacterial strains from sewage sludge were efficient in removing 71.70 and 74.67% of phenol at 1000 mg/L within three days and could tolerate high phenol concentrations (2000 mg/L). The findings showed that P. aeruginosa, K. pneumoniae, and K. variicola could potentially treat phenolic water. All soybean and faba bean seeds were germinated after being treated with 250, 500, 750, and 1000 mg/L phenol in a mineral salt medium inoculated with these strains. The highest maximum phenol removal and detoxification rates were P. aeruginosa and K. variicola. These strains may help decompose and detoxify phenol from industrial wastewater with high phenol levels and bioremediating phenol-contaminated soils.

Does the Use of Different Types of Probiotics Possess Detoxification Properties Against Aflatoxins Contamination in Rabbit Diets?

The present work was carried out to study the ability of five probiotics on the in vitro degradation of Aflatoxins B1 (AFB1). The best results of in vitro were tested on the detoxification of AFB1 in rabbits. A total of 40 growing New Zealand White (NZW) male rabbits were assigned to five experimental groups. Animals were fed the following diets: basal diet (control), basal diet contaminated with 300 ppb AFB1, basal diet contaminated with 300 ppb AFB1. + probiotic 3 (0.5 g/kg diet), basal diet contaminated with 300 ppb AFB1 + ajowan (0.5 g/kg diet), and basal diet contaminated with 300 ppb AFB1 + probiotic 3 (0.5 g/kg diet) + ajowan (0.5 g/kg diet). Live body weight significantly (P < 0.05) decreased in rabbits fed AFB1 contaminated diet compared to the control rabbits. All additives improved (P < 0.05) the live body weight. The best improvement occurred with probiotics + ajowan. The addition of probiotics increased (P < 0.05) daily body weight gain in all weeks except the first week. Adding ajowan or ajowan + probiotic led to a significant (P < 0.05) increase in live body weight gain and feed intake compared to rabbits fed AFB1 alone. The digestion coefficients of dry matter (DM), organic matter (OM), crude fiber (CF), ether extract (EE), nitrogen-free extract (NFE), and digestible crude protein (DCP) significantly (P < 0.05) decreased in rabbits fed AFB1 contaminated diet. All additives improved (P < 0.05) the digestibility coefficients of DM, OM, EE, CF, NFE, and total digested nutrients (TDN)%. The best improvement occurred with probiotics + ajowan. Concentrations of serum total protein, albumin and globulin significantly (P < 0.05) decreased in rabbits fed AFB1 contaminated diet compared with the control rabbits. In conclusion, the addition of probiotic 3 (AVI-5-BAC) + ajowan could be recommended to eliminate the toxicity of AFB1 and improve growth performance criteria in rabbits.

Enhancement of drought tolerance in diverse Vicia faba cultivars by inoculation with plant growth-promoting rhizobacteria under newly reclaimed soil conditions.

Water deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield-related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.

Isolation of diverse bioactive compounds from Euphorbia balsamifera: Cytotoxicity and antibacterial activity studies.

Antibacterial and cytotoxic activities of Euphorbia balsamifera, fractions and pure compounds were evaluated. The cytotoxic assays for HCT116, HePG2 and MCF7 showed a significant IC50: 54.7 and 76.2 µg/mL of non-polar fraction "n-hexane" against HCT116 and HePG2, respectively. Antibacterial results revealed that plant fractions exhibited significant potential against the tested pathogens than the total extract where n-butanol and ethyl acetate fractions showed significant antibacterial activity (P < 0.05) against tested bacterial strains. Isolation and structure determination of compounds from n-hexane and n-butanol fractions were performed. From n-hexane fraction, 29-nor-cycloartanol (1), lanost-8-en-3-ol (2a), cycloartanol (2b) and kampferol-3,4'-dimethyl ether (3) were isolated and structurally identified, along with 24 compounds were tentatively identified by GC-MS. From the polar n-butanol fraction, 4-O-ß-D-glucopyranosyl-2-hydroxy-6-methoxyacetophenone (4), 4-O-α-L-rhamnosyl-(1 â†’ 6)-ß-D-glucopyranosyl-2-hydroxy-6methoxy-acetophenone (5), quercetin-3-O-glucopyranoside (6) and isoorientin (7) were assigned. Structures of the obtained compounds were determined by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. Except compounds 1 and 5, all reported compounds announced antibacterial efficiency. Compound 2 showed selectively the highest activity against Enterococcus faecalis (22 ± 0.13 mm), meanwhile 4-O-ß-D-glucopyranosyl-2-hydroxy-6-methoxyacetophenone (4) showed broadly the highest antibacterial activity with MIC of 1.15-1.88 mg/mL against the test Gram-positive and Gram-negative bacteria. Cytotoxic assays indicated that kampferol-3,4'-dimethyl ether (3) exhibited the highest activity with matching IC50 values to doxorubicin; 111.46, 42.67 and 44.90 µM against HCT116, HePG2 and MCF7, respectively, however, it is toxic on retina normal cell line RPE1.

Plants: A natural solution to enhance raw milk cheese preservation?

Plants have been traditionnally used for centuries in cheese manufacturing, either for their aromatic properties or as technological auxiliaries (e.g. milk-clotting enzyme preparations, cheese wrappers). Some of these plants are known to have antimicrobial and/or antioxidant properties and could also act as natural preservatives for raw milk and derived dairy products. This review examined the traditional uses of plants in dairy processing, and then focuses on known antimicrobial and antioxidant properties of their extracts (e.g. maceration, decoction, essential oil). Known effects of theses plants on technological flora (starter cultures and microorganisms implicated in cheese ripening) were also summarized, and the potential for plant extracts used in combination with hurdle technologies was explored. Then, legal restriction and bioactivity variations from a culture media to a food matrix was reviewed: non-toxic bioactive molecules found in plants, extract preparation modes suitable with foodgrade processing restrictions, the role of the food matrix as a hindrance to the efficiency of bioactive compounds, and a review of food legislation. Finally, some commercial plant extracts for milk preservation were discussed.

Influences of stocking density and dietary probiotic supplementation on growing Japanese quail performance.

This study investigated the effects of stocking density and dietary supplementation of probiotic (Lactobacillus) on growth, traits of carcass, lymphoid organs and intestinal microbial count of Japanese quail. Quail chicks (one week old) were randomly allotted to 6 groups in a 2×3 factorial experiment included 2 levels of stocking density (100, and 75 cm2/bird) and 3 levels of probiotic (0.00, 0.02 and 0.04 g/kg diet). Quail reared at 100 cm2/ bird showed significantly the highest body weight and daily gain. Quail reared at 75 cm2/ bird had significantly the lower average of feed consumption and the best ratio of feed conversion. Increasing level of probiotic up to 0.04 g/kg led to a significant decrease in dressing percentage by about 2.7 % compared to the control. Interaction effect was insignificant on carcass traits studied except for liver percentage which was significantly higher for birds fed diet supplemented with probiotic at 0.04 g/kg of diet and reared at 100 cm2/bird. Rearing quail at 100 cm2/bird stocking density significantly increased bursa weight. Birds fed diet supplemented with probiotic at 0.02 g/kg of diet and reared at 100 cm2/bird showed significantly the highest (p = 0.043) spleen weight when compared with the other groups. In conclusion, the low (100 cm2/bird) stocking density was sufficient to give better performance of Japanese quail than the other group. Probiotic supplementation diminished the stressful effect of crowding on growing Japanese quail.

Inactivation of Listeria monocytogenes in ready-to-eat smoked turkey meat by combination with packaging atmosphere, oregano essential oil and cold temperature.

The effects of packaging atmosphere, storage temperature and oregano essential oil (EO) on growth of Listeria monocytogenes on ready-to-eat smoked turkey were studied. Smoked turkey slices were inoculated with a strain of Listeria monocytogenes Scott A (5.95, 5.28 and 5.26 log CFU/g) then vacuum packaged (VP), modified atmosphere packaging (MAP: 40% CO2 and 60% N2) and MAP with oregano essential oil (MAPEO), respectively. The treated slices were then stored at 0, 5, 10 and 15 °C for 179.88 days and the L. monocytogenes Scott A's growth and microbial shelf life were monitored. The combination of MAP or MAPEO and storage temperature did not allow growth of L. monocytogenes higher than log 1 CFU/g during all storage periods. While in VP temperature combinations, the multiplication of bacteria were ≥ 1 log CFU/g. In VP, MAP and MAPEO smoked turkey, the growth of L. monocytogenes increased regardless of storage temperature. In MAPEO samples the inoculum in the product was suppressed by ca. 5 log CFU/g at 0, 10 and 15 °C at 180, 117 and 81 days of storage, respectively. The inhibition of L. monocytogenes in ready-to-eat smoked turkey by the combinations of MAP and MAPEO was enhanced by storage at 0 or 5 °C. The MAPEO system can be used effectively to control growth of pathogen in processed food when maintaining fixed temperature measures is difficult.

Paulownia Leaves as A New Feed Resource: Chemical Composition and Effects on Growth, Carcasses, Digestibility, Blood Biochemistry, and Intestinal Bacterial Populations of Growing Rabbits.

This experiment was conducted to study the effects of paulownia leaf meal (PLM) as a nontraditional feed on the growth, carcasses, digestibility, blood chemistry, and intestinal microbiota of growing rabbits. Sixty rabbits (5-weeks old) were randomly allotted to three dietary treatments containing three amounts of PLM (0%, 15%, and 30%). The results showed that PLM has a higher content of ether extract, organic matter, methionine, tyrosine, histidine, manganese, and zinc than alfalfa hay. Body weight gain decreased when 30% PLM was provided. The best feed conversion ratio was recorded in the rabbits fed 15% PLM. A notable increase in high-density lipoprotein levels with a significant decrease in low-density lipoprotein was noted in the rabbits fed the PLM diets. Total fungi and Enterobacteriaceae and total bacterial count in the feed were significantly reduced because of PLM. In the cecum, coliforms, Enterobacteriaceae species, and total bacterial count declined in the rabbits fed the PLM diets. Conclusively, up to 15% PLM can be used in rabbit diets without any deleterious effects on the performance, nutrient digestibility, and blood constituents. In addition, dietary inclusion of PLM has the potential to reduce cecal pathogenic bacteria in rabbits.

Effects of clove (Syzygium aromaticum) oil on quail growth, carcass traits, blood components, meat quality, and intestinal microbiota.

To provide a safe growth promoter, the present study has investigated the effects of different levels of cold-pressed clove oil (CCPO) on growth performance, carcass traits, blood biochemistry, and intestinal microbial population of growing Japanese quails. A total of 300 quails (1-wk old) were randomly divided into 3 treatment groups: control basal diet, basal diet +0.75 mL oil/kg diet, and basal diet +1.5 mL oil/kg diet. Quails fed with 1.5 mL clove oil/kg diet showed a 3.43% improvement in live body weight vs. control group. Similar trend was observed for daily body weight gain. Feed intake gradually increased (P < 0.01) with an increase in clove oil level. The best feed conversion rate was reported for the control group, followed by the group treated with 1.5 mL CCPO/kg diet during the whole period (1 to 6 wk of age). Total globulin differed significantly in 1.5 mL CCPO/kg diet group. Antioxidant enzyme activities, lipid profile, and reduced glutathione concentrations significantly improved in a dose-dependent manner. Blood urea nitrogen, creatinine, malondialdehyde, 8-hydroxy-2΄-deoxyguanosine, and protein carbonyl levels significantly decreased in quails supplemented with 1.5 mL CCPO/kg diet vs. control group. Serum levels of insulin-like growth factor-1, insulin, growth hormone, and thyroxine significantly increased in quails supplemented with 1.5 mL CCPO/kg diet vs. control group. The intestinal bacterial population, coliforms, Escherichia coli, and Salmonella spp. in the ileal content were lower (P < 0.05) in groups treated with oil (1.5 mL/kg) vs. control group. Thus, dietary supplementation with antimicrobial CCPO (1.5 mL/kg diet) could enhance growth performance, improve health status, and reduce intestinal pathogens in Japanese quails.

Microalgae in modern cancer therapy: Current knowledge.

Cancer is an everyday medical concern which requires an appropriate treatment strategy. The malfunction of cell cycle is a well-established cause for cancer induction. Chemotherapy and radiation are the standard available therapeutic approach for cancer treatment; however severe side effects were reported in association to such treatments, for instance, the efficacy of patients' immune system is adversely affected in apart by radiation. These side effects may be minimized by providing novel remedial preparations. Complementary and alternative medicinal compounds, which were obtained from fresh or marine flora particularly micro and macro algae, were reported to its anti-cancerous activities. Several types of bioactive molecules are also present in microalgae, such as carotenoids, various forms of polysaccharides, vitamins, sterol, fibres, minerals…ect; the great unused biomass of microalgae and their excellent diversity of chemical constituents may introduce a major step in developing of anti-malignant drugs. Previously, such characteristic of microalgal bio-diversity was commercially exploited to make food supplements and gelling substances. However, recently, several investigations were designed to study the potential anti-carcinogenic effect of microalgal extracts, where they mostly concluded their ability to induce apoptotic cancer cell death via caspase dependent or independent pathways. In this review paper, we reported the various species of microalgae that possessed anti-tumor activity, the tumor cell lines altered through using microalgal extracts along with the levels of such extracts that reported to its inhibitor effect against cell cycle and proliferation.

Impact of Rosmarinus officinalis cold-pressed oil on health, growth performance, intestinal bacterial populations, and immunocompetence of Japanese quail.

This study was performed to study the impacts of rosemary cold-pressed oil (RCPO) for biostimulating health, growth performance, and intestinal bacterial populations of Japanese quail. The study included 300 growing 1-wk-old Japanese quails. Birds were divided into 3 groups in a complete randomized design experiment that involved 3 levels of RCPO (0, 1.00 and 2.00 mL/kg diet). Results revealed that the addition of rosemary oil numerically increased values of body weight and body weight gain when compared with the control group, particularly the highest level of RCPO (2.00 mL/kg diet). Birds fed diets supplemented with rosemary oil consumed more feed (P ≤ 0.01) compared with those fed the control diet. Feed conversion ratio tended to be improved in rosemary oil groups during the period 3 to 6 wk of age (P = 0.013). The highest level of rosemary oil (2.00 mL/kg diet) had the best impact on all carcass traits studied. RCPO supplementation showed an increase in serum total protein, metabolic hormones levels, while it reduced serum cholesterol and low-density lipoprotein cholesterol, 8-hydroxy-2'-deoxyguanosine, and protein carbonyl levels. Moreover, RCPO increased antioxidative enzymes, and reduced the lipid peroxidation in quail liver. The supplementation of 2 mL/RCPO kg diet showed significant reduction in populations of total cultural bacterial count, coliforms, Escherichia coli, and Salmonella spp. in the ileum when compared to the control. The current results showed that RCPO supplementation to Japanese quails diet could enhance the growth performance and reduce the intestinal pathogenic bacteria. Therefore, RCPO can be a beneficial antimicrobial and growth-promoting feed supplement for the Japanese quail.

Improving growth performance and health status of meat-type quail by supplementing the diet with black cumin cold-pressed oil as a natural alternative for antibiotics.

Using antibiotics in poultry diets as growth promoters was reported to have harmful effects on consumers, so the current study was done to monitor the impact of dietary supplementation of antimicrobial black cumin oil (BCO) on carcass traits, growth performance, biochemical components, and ileal microbial populations of growing Japanese quails. Three hundred growing Japanese quails were used with three different treatments (0, 0.50, and 1.0 g BCO/g diet). Birds fed diet supplemented with 0.5 g BCO/kg diet showed significant increase in body weight comparing with the control and other treatment group. The daily feed intake and feed conversion ratio were significantly increased side by side with increasing BCO level in the diet. The majority of carcass characteristics were maximized by supplementing the quail diet with 0.5 g BCO/kg. Moreover, liver functions, anti-oxidative capacity, lipid profile and anabolic hormones showed significant improvement in BCO-treated diets in a dose-dependent manner. The BCO showed highest antibacterial effect against Escherichia coli and Salmonella enterica. The ileal bacterial populations, i.e., total bacterial count (TBC), coliform, Salmonella species, and Escherichia coli were decreased in birds supplemented with BCO 0.5 and 1.0 BCO g/kg compared with the control diet. Based on the aforementioned results, conclusion could be drawn that supplementing quail with BCO in their diet could improve productive performance traits and enhance health aspect of the birds.

Impeding Bacillus spore germination in vitro and in milk by soy glycinin during long cold storage.

This paper presents a study of the magnitude and mechanism of impeding the emergent spore germination of Bacillus subtilis (non-hemolytic strain) and Bacillus licheniformis (hemolytic strain) under the action of soybean glycinin and its basic subunit (BS). Incubating B. licheniformis spores with 100 µg/ml of glycinin or BS at 35°C for 24 h totally prevented the hemolytic activity associated with the emergent vegetative cells on blood agar during 3-5 days of incubation at 35°C in contrast to the control. Glycinin and BS (100 µg/ml) also resulted in the leakage of 70 and 73% of the initially germinating spore contents of A260 absorbing materials of the two bacterial species after 2 h of incubation at 35°C, respectively. Increasing the concentration of glycinin and BS up to 400 µg/ml increased the germinating spore leakage to 83 and 88%, respectively. Spore germination in Muller Hinton Broth containing glycinin and BS (100 µg/ml) was practically nil after 4 days of incubation at 35°C. Supplementing milk preheated at 80°C/5 min with both glycinin and BS kept the final vegetative cell counts down to about 30 and 20% of the corresponding control, respectively, after 50 days of storage at 4°C. Both light, and transmission electron, microscopy images revealed significant morphological and structural distorting changes in BS-treated spores of B. licheniformis.

Soft cheese supplemented with black cumin oil: Impact on food borne pathogens and quality during storage.

Black cumin seed oil (BCSO) was tested for its inhibitory effect against some pathogenic bacteria (Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, Listeria monocytogenes Scott A and Salmonella enteritidis PT4) in Domiati cheese during cold storage. Physical, chemical and sensorial changes in cheese during storage were recorded. Pasteurized milk was inoculated before renneting with a mixed culture of bacteria at ca. 4 log CFU mL(-1). In vitro and in situ supplementation with BCSO showed antimicrobial impact on the growth of S. aureus, E. coli, L. monocytogenes and S. enteritidis inoculated into media and cheese samples. Supplementing of cheese with BCSO (0.1% or 0.2%, w/w) significantly reduced the counts of the inoculated pathogens by ca. 1.3 log and 1.5 log CFU g(-1) after 21 days of storage. In addition, BCSO controlled the development of titratable acidity, limited the changes in ripening indices, flavor components and kept considerable physicochemical and sensorial properties of cheese.

Preservative action of 11S (glycinin) and 7S (ß-conglycinin) soy globulin on bovine raw milk stored either at 4 or 25 °C.

Considerable inhibitory antibacterial actions were exerted by the soybean 11S subunit comparable with nisin on the proliferation of total viable count, Pseudomonas count and Enterobacteriaceae count in bovine milk stored at 4 or 25 °C for 30 d and 48 h, while 7S and lysozyme were much less effective. The maximum magnitudes of bacterial reduction by 11S and nisin were in the range 2-4 log CFU/ml. The proliferation of 3 pathogenic bacteria (Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7) artificially inoculated into raw milk stored at 4 or 25 °C were particularly and significantly (P<0.05) reduced by 11S subunit and nisin (0.5% w/v), but only slightly by 7S and moderately by lysozyme. Lactose consumption, acidity development and casein degradation during storage of bovine raw milk were attenuated during storage at 4 or 25 °C and sensorial traits were better maintained by supplementation with 11S (0.5% w/v). 11S subunit may be used a safely food preservative, if permitted.

In vitro and in situ antimicrobial action and mechanism of glycinin and its basic subunit.

Glycinin, basic subunit and ß-conglycinin were isolated from soybean protein isolate and tested for their antimicrobial action against pathogenic and spoilage bacteria as compared to penicillin. The three fractions exhibited antibacterial activities equivalent to or higher than penicillin in the next order; basic subunit>glycinin>ß-conglycinin with MIC of 50, 100 and 1000 µg/mL, respectively. The IC(50%) values of the basic subunit, glycinin and ß-conglycinin against Listeria\monocytogenes were 15, 16 and 695 µg/mL, against Bacillussubtilis were 17, 20, and 612 µg/mL, and against S. Enteritidis were 18, 21 and 526 µg/mL, respectively. Transmission electron microscopy images of L. monocytogenes and S. Enteritidis exhibited bigger sizes and separation of cell wall from cell membrane when treated with glycinin or basic subunit. Scanning electron microscopy of B. subtilis indicated signs of irregular wrinkled outer surface, fragmentation, adhesion and aggregation of damaged cells or cellular debris when treated with glycinin or the basic subunits but not with penicillin. All tested substances particularly the basic subunit showed increased concentration-dependent cell permeation assessed by crystal violet uptake. The antimicrobial action of glycinin and basic subunit was swifter than that of penicillin. The cell killing efficiency was in the following descending order; basic subunit>glycinin>penicillin>ß-conglycinin and the susceptibility of the bacteria to the antimicrobial agents was in the next order: L. monocytogenes>B. Subtilis>S. Enteritidis. Adding glycinin and the basic subunit to pasteurized milk inoculated with the three bacteria; L. monocytogenes, B. Subtilis and S. Enteritidis (ca. 5 log CFU/mL) could inhibit their propagation after 16-20 days storage at 4 °C by 2.42-2.98, 4.25-4.77 and 2.57-3.01 log and by 3.22-3.78, 5.65-6.27 and 3.35-3.72 log CFU/mL, respectively.