摘要:

ABSTRACTSalmonella typhimuriumwas inoculated into prepared dirt (moisture content 8.8%), sand (moisture content 0.06%) and phosphate buffer, and these menstrua were used to contaminate beef tissue. Fewer bacteria adhered to the tissue surface from the low moisture menstrua when compared to contamination by buffer. Determination of SRvalues, an estimate of the total population associated with the surface which was physically attached, indicated that more bacteria remained in the soil menstrum than adhered to the surface, when compared to buffer and sand menstrua. Contrary to expectations, bacteria which contaminated the surface from the low moisture menstrua were not more sensitive to organic acids than those which originated from the buffer.

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1991.tb00077.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTA method for predicting the depth of penetration of bacteria into various beef tissues was developed. Blue Lake, an insoluble dye, was used to simulate bacteria on the meat surface because movement of the Blue Lake into the meat tissue during spray washing could be easily visualized. The beef tissue surfaces studied were: (1) exterior lean, (2) exterior fat, (3) interior body cavity (peritoneum) and (4) cut tissue. The model indicated that many bacteria not removed during washing are driven into the beef tissue by the washing process. Interior body cavity tissue was most resistant to penetration followed by exterior lean and fat tissues, which were about equal in resistance. Cut surfaces were the most susceptible to Blue Lake penetration.

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1991.tb00078.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTA lactic acid bacterium (LK5) originally isolated from raw ground beef was characterized in relation to its ability to inhibit the growth ofListeria monocytogenes.The isolate, which was identified asCarnobacterium piscicola,inhibited the growth of 17 of 21 strains ofListeria (L. monocytogenes, L. innocua, L. ivanovii, L. welshimeri,andL. grayii).Its activity was not due to either acid or hydrogen peroxide production, but was related to the production of a heat stable bacteriocin. The isolate was most active againstL. monocytogenesat refrigeration temperatures due to the combined effect of the pathogen's increased susceptibility, LK5's rapid growth rate, and enhanced bacteriocin production at low temperatures. Examination of the effect of inoculum ratios in co‐cultures ofC. piscicolaLK5 andL. monocytogenesScott A indicated that the lactic acid bacterium was active againstL. monocytogeneseven when the initial level of the pathogen was 100‐fold greater. Evaluation of the impact of oxygen availability, initial pH, and sodium chloride content on the effectiveness of LK5 suggested that the isolate could be used to suppress the growth ofListeriain a variety of refrigerated fo

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1991.tb00079.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTThe potential for controlling the growth ofListeria monocytogenesin refrigerated foods usingCarnobacterium piscicolaLK5, a bacteriocin‐producing strain originally isolated from raw ground beef, was studied using co‐culture techniques. Eight foods, including UHT milk, canned “all‐beef”dog food (cooked meat), raw ground beef, irradiation‐sterilized raw ground beef, chicken roll, pasteurized crabmeat, canned creamed corn, and frankfurters, were inoculated with 103cfu/gL. monocytogenesScott A, with and without 104cfu/g LK5, and incubated at 5 and 19C. Samples were removed periodically and assayed for total aerobic plate count using Brain Heart Infusion Agar andL. monocytogenesusing Vogel‐Johnson Agar or Modified Vogel Johnson Agar. The growth ofL. monocytogeneswas suppressed in milk, dog food, crabmeat, creamed corn, and frankfurters stored at 5C. The microorganism was less inhibitory at 19C. In sterile raw ground beef, LK5 inactivated the pathogen at 5C and prevented its growth at 19C. No activity attributable to LK5 was observed in refrigerated nonsterile ground beef or chicken roll; however, these products did not support the psychrotrophic growth of the pathogen even in the absence of LK5. LK5 was most effective in products where the background microflora was reduced by either thermal processing or irradiation treatment. The results indicate thatC. piscicolaLK5 has potential as a means for preventing the growth ofL. monocytogenesin a variety of refrigerated

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1991.tb00080.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTClostridium perfringensType A is one of the most common causes of food‐borne disease in the USA. Diarrheal and cramping symptoms associated with this illness are caused by a protein enterotoxin (abbreviated as CPE). Recently, diagnosis ofC. perfringensfood poisoning has been improved by the development of direct assays to detect CPE in feces or CPE production by food or fecal isolates ofC. perfringens.The enterotoxin has a membrane‐active action which appears to involve four early steps: (1) binding of CPE to a mammalian receptor, (2) insertion of CPE into membranes, (3) formation of a complex between CPE and mammalian membrane proteins and (4) onset of toxin‐induced ion and water permeability changes. CPE has a unique amino acid sequence, and recent studies have indicated that the receptor‐binding region of enterotoxin is localized at the extreme C‐terminus. Further studies of the CPE structure versus function relationship may facilitate development of vaccines for human or veterin

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1991.tb00081.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTConsumer food safety concerns and interest in pesticide related information was measured by personal interviews with 479 consumers in 14 counties in California. Although concern about pesticide safety was noted by almost half of the respondents, nutritional considerations had the greatest impact on food selection criteria. Of those who volunteered pesticide safety concerns, 15% indicated they sought organic produce and 13% said they avoided or reduced produce purchases. In addition to information about the human health effects of pesticide use, consumers expressed high interest in the environmental effects of pesticide use. Consumers currently use television and newspapers as information sources and prefer these to other sources.

ISSN:0149-6085    

DOI:10.1111/j.1745-4565.1991.tb00082.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY