Allyl Alcohol Is the Sole Antiyeast Compound in Heated Garlic Extract

The principal antiyeast compound of heated garlic was isolated and identified by high‐performance liquid chromatography (HPLC) and gas chromatography‐mass spectrometry (GC‐MS) as allyl alcohol (2‐pro‐pene‐1‐ol). The generation of allyl alcohol was observed in heated garlic as well as in heated pure alliin solution. The pattern of growth inhibition of Candida utilis ATCC42416 by allyl alcohol was essentially the same as that seen with heated garlic and heated alliin solution. The minimum inhibitory concentrations of heated garlic, with an alliin content of 1.5% (w/v), and allyl alcohol were 0.6% (v/v) and 0.002% (v/v), respectively, against C. utilis ATCC42416. Yeasts were extremely sensitive to allyl alcohol, with minimum inhibitory concentration (MIC) ranging from 0.002% (v/v) to 0.014% (v/v), while bacteria were not very sensitive to allyl alcohol, with MIC ranging from 4% to 7%. Among yeasts, xerotolerant strains, including Zygosaccharomyces rouxii, were significantly less sensitive to allyl alcohol and heated garlic extract than others. Allyl alcohol is different from all other known antimicrobial compounds found in garlic in that it does not contain sulfur in its molecule.     

沙门氏菌污染豆腐干和牛肉干后代谢物的研究

鼠伤寒沙门氏菌可引发沙门氏菌病,且耐药性强,严重危害人畜健康。利用气相色谱-质谱法（Gas Chromatography - Mass Spectrometer,GC-MS）显示沙门氏菌接种于NB培养基、豆腐干和牛肉干培养基后的代谢物,采用主成分分析和正交偏最小二乘判别鉴别特征性和差异性代谢产物,结合沙门氏菌的基因注释分析特征性和差异性代谢产物可能的代谢路径。结果表明：沙门氏菌污染两种食品后有显著的生长,特征性和差异性代谢产物包括烷烃,酚类及小分子酸、醇等;沙门氏菌的基因注释表明存在大量的碳水化合物代谢基因,参与了1-丁醇的生成,因此1-丁醇是沙门氏菌污染豆腐干和牛肉干的典型代谢物。     

The mode of action of fumigants

Studies on the action of the widely used fumigants, hydrogen cyanide, phosphine, methyl bromide, carbon tetrachloride, ethylene dichloride, and ethylene dibromide, are reviewed with a view to establishing some of the biochemical lesions responsible for the toxicity of fumigants to insects. The modes of action of ethylene oxide, carbon disulphide, sulphuryl fluoride, and methyl chloroform are also briefly discussed.     

Antimicrobial Activity of Butylated Hydroxyanisole, Tertiary Butylhydroquinone, and Potassium Sorbate in Combination

Butylated hydroxyanisole (BHA), tertiary butylhydroquinone (TBHQ), and potassium sorbate, alone and in combination, were tested for antimicrobial activity against Staphylococcus aureus and Salmonella typhimurium in trypticase soy broth. Concentrations of the antimcrobials which resulted in 0-50% growth lnhibition of the test organisms after 72 hr at 32°C were used in combination. Sorbate-BHA and sorbate-TBHQ combinations caused a 12 hr delay in growth initiation of S. aureus. No delay in growth initiation was found with BHA-sorbate combinations against S. typhimurium, but all combinations had synergistic antimicrobial activity against the: microorganism. TBHQ showed little or no effect on growth of S. typhimurium.     

The toxicity of twelve fumigants to three species of mites infesting grain

Eggs of Tyrophagus longior, Acarus siro and Glycyphagus destructor were highly tolerant of each fumigant tested at 10°C while mobile stages were susceptible. Some eggs of T. longior survived the highest test dosages of methyl bromide, phosphine, ethylene oxide, ethyl formate, methallyl chloride and ethyl bromide. The ascending order of toxicity for the other fumigants, as judged by the ct product needed to kill all eggs, was methyl chloroform (MC), carbon tetrachloride (CTC), ethylene dichloride (EDC), methyl formate, ethylene dibromide and acrylonitrile. The toxicity of EDC was generally enhanced by the addition of MC or CTC, though dosages for control were still high, and a single fumigation can only be expected to provide a short-term absence of mobile stages. If complete control is required, this can be achieved by two treatments at a low dose if these are separated by an interval during which the surviving eggs hatch but do not reach the adult stage. The length of this interval depends on temperature and at 10°C is about 7 weeks, at 15°C 3 weeks and at 20°C 2 weeks.     

Reduction of Numbers of Salmonella typhimurium on Poultry Parts by Repeated Freeze-Thaw Treatments

Cells of Salmonella typhimurium suspended in 50 ml of 0.1% buffered peptone were subjected to five cycles of rapid or slow freezing and rapid or slow thawing. A five cycle rapid freeze-rapid thaw process was found to be an effective treatment resulting in 99% reduction in the numbers of S. typhimurium cells. Of the surviving cells after treatment, 75% was sublethally injured. The five cycle rapid freeze-rapid thaw process was investigated for its effectiveness in reducing numbers of S. typhimurium cells on experimentally inoculated chicken wings. The part of chicken wings consisting of ulna and radius with attached skin and muscle was inoculated with low (16–20 CFU/g) or high (ca 1,100 CFU/g) numbers of S. typhimurium and each wing was subjected to five cycles of the rapid freeze-rapid thaw process. There was over 90% reduction in the numbers of S. typhimurium cells on the chicken wings after the freeze-thaw treatment.     

Chemical Spray Conditions for Reducing Bacteria on Chicken Skins

Chemical spray parameters, including temperature, pressure and exposure time, were evaluated for their effects on reducing Salmonella typhimurium on chicken skins. Pre-chilled chicken carcass skins were inoculated with S. typhimurium and sprayed with 0.1% cetylpyridinium chloride (CPC), 10% trisodium phosphate (TSP), or 2% lactic acid (LA). In the CPC spray, the 40°C treatments resulted in the greatest bacterial reduction. The most effective spray temperatures for LA and TSP treatments were 40 to 55°C. All chemical spray treatments at 207–1034 kPa reduced S. typhimurium. The reduction of S. typhimurium was greatest in all treatments when sprayed with 90 sec spray and 90 sec setting time.     

射频杀菌条件下黑胡椒颗粒中沙门氏菌的替代菌研究

为探究热杀菌过程中屎肠球菌NRRL B-2354作为沙门氏菌ATCC 14028替代菌的可行性,通过等温实验测定黑胡椒颗粒中屎肠球菌NRRL B-2354和沙门氏菌ATCC 14028的耐热性参数,并对黑胡椒颗粒（A_w=0.65）开展射频杀菌实验验证。等温实验结果表明,黑胡椒颗粒中屎肠球菌的耐热性高于沙门氏菌。射频杀菌实验中,将2 g接种微生物的黑胡椒颗粒真空包装后置于45 g黑胡椒中心位置,在40.68 MHz射频场中加热15 min,黑胡椒颗粒中沙门氏菌的减少量相较于屎肠球菌更多,证明在射频加热中屎肠球菌的耐热性高于沙门氏菌,可作为黑胡椒颗粒杀菌过程中沙门氏菌的合适替代菌。     

Detection of Salmonella enteritidis and Salmonella typhimurium in foods using a rapid,multiplex real-time recombinase polymerase amplification assay

Salmonella has been recognized as a major foodborne pathogen for humans and animals. In this study, a multiplex real-time recombinase polymerase amplification (RPA) was developed for simultaneous detection of Salmonella enterica serovars, Salmonella enteritidis and Salmonella typhimurium, from chicken, eggs, lettuce, and papaya. The reaction was performed for 20 min at 35°C, and the detection limit of the assay was 10² CFU/ml for pure culture. In food application, the limit of detection (LOD) of S. enteritidis and S. typhimurium using multiplex real-time RPA without enrichment procedure was 10² CFU/25 g, respectively. After enrichment, the LOD of S. enteritidis and S. typhimurium was 10 CFU/25 g. Moreover, the result for Salmonella spp. was not significantly different from those obtained using a culture-based method. Additionally, the assay has a lower cross-reactivity with other pathogenic microorganisms and a good stability performance. Thus, the developed multiplex RPA assay could be used as a rapid tool for the detection of S. enteritidis and S. typhimurium in food.     

Trisodium Phosptiate (TSP) Treatment of Beef Surfaces to Reduce Escherichia coli O157:H7 and Salmonella typhimurium

Trisodium phosphate (TSP) was evaluated for removing attached E. coli O157:H7 and S. typhimurium from beef surfaces using microbiological plating and scanning electron microscopy (SEM). Both fat and fascia surfaces were exposed to 10⁹ CFU/mL of each inoculum for 15 min and rinsed with 10% TSP solution (10°C) for 15 sec. Compared to controls, the level of E. coli O157:H7 was 1.35 and 0.92-logs lower on TSP-treated fat and fascia surfaces, respectively by plating. .S. typhimurium was 0.91- and 0.51-logs lower, respectively. By SEM, TSP-treated fabcia surfaces showed 1.39-log and 0.86-log reductions in E. coli O157:H7 and S. typhimurium, respectively. Overall, TSP was more effective on removing E. coli O157:H7 than S. typhimutium and more efficient in removing both bacteria from fat surfaces than from fascia.     

Mutagenicity of Edible Palm Oil on the Ghanaian Market before and after Repeated Heating

Red palm oil produced in Ghana largely by village folks has never been tested for its mutagenic potential. The study aimed at determining the mutagenicity of high‐energy heated red palm oil (RRPO) and refined, bleached imported palm oil (PO) on the Ghanaian market. Samples of RRPO and PO were 1× and 5× heated for 10 min at 180 °C with a cooling period of 5 h in‐between. Unheated, together with heated samples, were tested for mutagenicity using Salmonella typhimurium TA 98 and TA 100 tester stains. Unheated PO was negative for the Ames mutagenicity test with TA 98 strain. However, 1× and 5× heated PO were mutagenic (P = 0.05, each). Testing PO, using TA 100 strain was negative. RRPO was mutagenic with TA 98 strain for heated oils (P = 0.05, each). Assays with TA 100 strain showed highly significant mutations (P = 0.001, each) that increased with increasing heating frequency. PO 1× and 5× heated samples caused significant frameshift mutation in the S. typhimurium TA 98 strain. RRPO caused highly significant point and frameshift mutations in heated samples. Furthermore, unheated RRPO mutagenic potential has serious health implications.     

Movement of halogenated fumigants through wheat

The movement of fumigants was studied by gas chromatography on columns of wheat coupled directly to a detector. The fumigants were methyl bromide, methylene dichloride, carbon tetrachloride, chloropicrin and ethylene dibromide. Their chromatographic behaviour was the same with carbon dioxide as carrier gas as with air or nitrogen. Improved distribution of fumigants added with carbon dioxide in silos is attributed to other factors and not to changes in the dynamics of adsorption of fumigant to wheat.     

Trisodium Phosphate Treatment of Pork Carcasses

Pork skin samples, naturally contaminated or inoculated with Salmonella typhimurium, were treated with varying levels of trisodium phosphate (TSP). Aerobic plate counts (APC) of the samples were unaffected by treatment; however, S. typhimurium was reduced (P < 0.05). Using levels most effective for reducing S. typhimurium on skin, TSP was investigated for use on whole pork carcasses during slaughter/processing and did not affect APC of pork carcasses. Due to a lack of detectable presence, any effects of TSP on native Salmonella contamination of pork carcass surfaces could not be determined. TSP had negligible effect on visual pork color, texture or odor.     

Growth of Enteropathogenic and Spoilage Bacteria in Sage-Containing Broth and Foods

Sensitivity of strains of S. aureus, B. cereus, Pseudomonas sp. and S. typhimurium to sage was studied in nutrient broth and in foods. Inhibition was highest in broth (MIC of 0.0–1.0%), and diminished in rice (MIC of 0.4 to >2.5%), and chicken and noodles (MIC of 1.0 to >2.5%). Little or no inhibition was seen in meat at ≤2.5% of sage. In each growth medium B. cereus strains displayed the least resistance, followed by S. aureus, Pseudomonas sp., and S. typhimurium. Growth from spores of B. cereus was inhibited in a manner similar to that seen in vegetative cells. While antimicrobial activity of sage increased with increase in the volatile oil fraction, essential oils alone had limited inhibitory effect in broth, and no effect in foods. Salt and water levels in the food increased bacterial sensitivity, whereas fat and protein decreased it.     

Antimutagenic and antigenotoxic effects of vegetable matrices on the activity of pesticides

Two in vitro tests, one to detect bacterial mutagenicity (Ames test) on Salmonella typhimurium TA98, TA100, and TA1535 and the other the primary DNA damage (SOS Chromotest) on Escherichia coli PQ37, were applied to determine the overall genotoxic activity of 12 pesticides (azinphos methyl, chlorothalonil, chlorphyriphos ethyl, chlorphyriphos methyl, λ-cyhalothrin, cypermethrin, cyprodinil, fenazaquin, fludioxonil, indoxacarb, iprodione and penconazol). These were detected by gas chromatography (GC) analysis with electron capture (ECD) and nitrogen phosphorus detection (NPD) in 18 samples of vegetables. Some extracts of vegetables, found positive for pesticides with GC, were subjected to the Ames test and SOS Chromotest to evaluate the possible antimutagenic and/or antigenotoxic effects of vegetable matrices. The same bioassays were also performed on the mixtures of pesticides found in these samples to evaluate whether interactions could occur between pesticides and be responsible for the possible antimutagenic and/or antigenotoxic effects of the contaminated matrices. Experiments were also carried out to compare the results found for contaminated vegetables with their content of antioxidant components. Significant differences in mutagenicity and genotoxicity were found among the pesticides selected for this study. Of the 12 pesticides tested, only azinphos methyl, cyprodinil, fludioxonil and iprodione were found to be positive for both S. typhimurium and E. coli. No mutagenic/genotoxic activity was found in the extracts of vegetables contaminated by pesticides. S. typhimurium TA1535 showed a strong positive mutagenic effect for the mixtures of pesticides while they were not able to induce the SOS system. The data concerning the content of polyphenols and the total reducing activity of the contaminated vegetables indicated high amounts of antioxidants that could explain the inhibitory effect on the activity of pesticides shown by vegetables.     

Reduction of Salmonella Contamination on Chicken Egg Shells by a Peroxidase-Catalyzed Sanitizer

A peroxidase-catalyzed compound (PCC) sanitizer was tested to determine its bactericidal activity on Salmonella typhimurium and Salmonella enteritidis inoculated on egg shell surfaces. Eggs with no treatment were compared to those immersed in either deionized distilled water, PCC or 200 ppm chlorine-treated water for 1, 3 or 5 min. Eggs immersed in PCC or chlorinated water solutions had lower (P < 0.05) S. typhimurium and S. enteritidis populations than those not exposed to treatments. No differences were detected among PCC and chlorine treatments except the S. typhimurium populations from PCC dipped eggs were significantly higher than those from eggs dipped in the chlorinated water for 1 min. Results indicate that PCC has potential as an effective shell egg sanitizer.     

Selective detection of Salmonella typhimurium in the presence of high concentrations of masking bacteria

This article presents the results of an investigation into the ability of a magnetoelastic biosensor to detect Salmonella typhimurium, with high specificity, even in the presence of high concentrations of masking bacteria. Magnetoelastic biosensors are mass sensitive devices comprised of a magnetoelastic material that serves as the transducer and bacteriophage as the bio-recognition element. The sensors were tested individually with several different genus bacteria (Salmonella typhimurium, Salmonella entertidis, Escherichia coli O157:H7 and Listeria monocytogenes) to compare the bioprobe’s affinity towards species other than the target analyte. The effect of the presence of one masking bacteria (E. coli) and two masking bacteria (E. coli and L. monocytogenes) in a mixture with S. typhimurium upon the response of the biosensor was studied. It was observed that the response of the sensors followed similar trends; however the sensitivity and the frequency changes were slightly lower for the mixtures. The sensitivity of the sensors exposed to only S. typhimurium was 161 Hz decade⁻¹ and in mixtures with one and two masking bacteria were 131 Hz decade⁻¹ and 127 Hz decade⁻¹, respectively. Binding kinetics studies show that the dissociation constant (K _d) and the binding valency (1/n _H) samples with only S. typhimurium are 149 cfu mL⁻¹ and 2.49, respectively.     

Screening for mutagens in norwegian foods by the ames test

Twelve Norwegian food products prepared in an ordinary domestic manner, were screened for mutagenic activity towards Salmonella typhimurium strains. Mutagenic activity towards the frameshift mutations strains (TA1538 and TA98) was observed in the basic organic extracts from fried fish cakes and fish pudding. Metabolic activation with rat liver homogenate (S9) was required. The ten other food items studied were found to be devoid of mutagenic activity.     

Quaternary Ammonium Compounds Inhibit and Reduce the Attachment of Viable Salmonella typhimurium to Poultry Tissues

Quaternary ammonium compounds (QAC) were studied to characterize their inhibition and reversal of S. typhimurium's strong attachment to chicken skin. An initial screening human buccal epithelial cell model and a novel, highly quantitative model using pieces of chicken skin in culture plates were used. Some QAC, particularly cetylpyridinium chlo ride (CPC), were extremely effective at both inhibiting and reversing attachment of viable S. typhinlurium to chicken skin. Pretreatment of chicken skin (room temperature, 10 min) with 0.1% CPC completely inhibited the attachment of S. typhimurium. CPC may be very beneficial in reducing S. typhimurium contamination of poultry carcasses during processing and especially in preventing cross-contamination.     

Synthesis of acetals and esters of propargyl,propenyl and propyl alcohols and the bioassay of these and related compounds as fumigants against Anastrepha suspensa (Loew) larvae

The synthesis of 36 compounds, acetals, ketals, esters or ethers of acetylenic, olefinic and aliphatic alcohols is described. These and 26 related compounds were tested as fumigants against Anastrepha suspensa (Loew) larvae. Twenty-three compounds showed fumigant activity. 3-Butyne-2-one killed all the larvae exposed at the rate 2.2 mg/1 for 3 h, as did the reference fumigant ethylene dibromide (EDB). Six compounds killed 100% of the larvae exposed to them at the rate of 2.2 mg/l for 24 h. Eight compounds, including propargyl alcohol, propargyl methacrylate and propargyl 3-methylcrotonate, did not kill A. svspensa larvae until a few days after exposure during which time the larvae apparently grew normally and underwent pre-pupariation wanderlust in synchrony with untreated larvae.