共查询到20条相似文献,搜索用时 31 毫秒
1.
Antoine FR Wei CI Otwell WS Sims CA Littell RC Hogle AD Marshall MR 《Journal of food protection》2004,67(10):2255-2262
Biogenic amines, total volatile base-nitrogen (TVB-N), and sensory evaluation are some of the indicators used for fish quality determination. Our objective was to evaluate the relationship among histamine, cadaverine, putrescine, TVB-N, and sensory evaluation as quality assessment tools. Two groups of six mahi-mahi fillets were refrigerated at 7 degrees C and sampled on days 0, 2, 4, 6, 8, and 10. On day 3, histamine, cadaverine, and putrescine levels reached 5, 3, and 0.5 mg/100 g, respectively, whereas TVB-N reached 30 mg/100 g. Sensory scores were 6 to 6.5 (10 very fresh and 1 very spoiled) for odor, appearance, texture, and color. Correlations were 0.78 and 0.72 between histamine and cadaverine and histamine and putrescine, 0.74 and 0.80 between TVB-N and cadaverine and TVB-N and putrescine, and 0.75 and 0.78 between odor and putrescine and odor and cadaverine. AromaMaps showed distinct trends for deteriorating mahi-mahi (Coryphaena hippurus) quality. 相似文献
2.
HAMEED M. AL-OBAIDY MAHMOOD A. KHAN HANS P. BLASCHEK BARBARA P. KLEIN 《Journal of Food Safety》1985,7(1):43-55
Growth, sporulation, and enterotoxin formation by Clostridium perfringens NCTC 8239 were determined in chicken thigh meat incubated at 45°C for 1.5 h and 37°C for up to 12.5 h. With an inoculum of 106 vegetative cells per g, the cell counts reached mean log 10 7.32/g after 6 h of incubation and remained in that range through 14 h. Heat-resistant spores (log10 2.48/g) were first detected at 4 h, and the number increased to log10 5.19/g at 14 h. Enterotoxin (0.19 μg/g) was first detected after 2 h of incubation (1.5 h at 45°C and 0.5 h at 37°C) in the absence of detectable sporulation, and the enterotoxin concentration increased to 0.76 μg/g after 14 h. Significant differences (p < 0.01) in the odor, color, and texture scores for inoculated versus uninoculated cooked chicken following 2 h incubation correlated with the production of enterotoxin and suggested that these parameters could be used as indices of chicken spoilage by C. perfringens. 相似文献
3.
Modeling the Growth Characteristics of Listeria monocytogenes and Native Microflora in Smoked Salmon
ABSTRACT: Smoked salmon contaminated with Listeria monocytogenes has been implicated in foodborne listeriosis. The objectives of this study were to model the growth characteristics and examine the growth relationship of L. monocytogenes and native microflora in smoked salmon. Smoked salmon samples with a native microflora count of 2.9 log10 CFU/g were inoculated with a 6-strain mixture of L. monocytogenes to levels of log10 1.6 and log10 2.8 CFU/g, and stored at 4, 8, 12, and 16 °C. Growth characteristics (lag phase duration [LPD, h], growth rate [GR, log10 CFU/h], and maximum population density [MPD, log10 CFU/g]) of L. monocytogenes and native microflora were determined. At 4 to 16 °C, the LPD, GR, and MPD were 254 to 35 h, 0.0109 to 0.0538 log10 CFU/h, and 4.9 to 6.9 log10 CFU/g for L. monocytogenes , respectively, and were 257 to 29 h, 0.0102 to 0.0565 log10 CFU/h, and 8.5 to 8.8 log10 CFU/g for native microflora. The growth characteristics of L. monocytogenes or the native microflora were not significantly different ( P > 0.05), regardless the initial levels of L. monocytogenes . Mathematical equations were developed to describe the LPD, GR, and MPD of L. monocytogenes and native microflora as a function of storage temperature. The growth relationship between L. monocytogenes and native microflora was modeled and showed that the LPD and GR of L. monocytogenes were similar to those of native microflora. These models can be used to estimate the growth characteristics of L. monocytogenes in smoked salmon, and thereby enhance the microbiological safety of the product. 相似文献
4.
Vijay K. Juneja Harshavardhan Thippareddi Latiful Bari Yasuhiro Inatsu Shinichi Kawamoto Mendel Friedman 《Journal of food science》2006,71(6):M236-M240
ABSTRACT: We investigated the inhibition of Clostridium perfringens spore germination and outgrowth by the biopolymer chitosan during abusive chilling of cooked ground beef (25% fat) and turkey (7% fat) obtained from a retail store. Chitosan was mixed into the thawed beef or turkey at concentrations of 0.5%, 1.0%, 2.0%, or 3.0% (w/w) along with a heat-activated 3-strain spore cocktail to obtain a final spore concentration of 2 to 3 log10 CFU/g. Samples (5 g) of the ground beef or turkey mixtures were then vacuum-packaged and cooked to 60 °C in 1 h in a temperature-controlled water bath. Thereafter, the products were cooled from 54.4 to 7.2 °C in 12, 15, 18, or 21 h, resulting in 4.21, 4.51, 5.03, and 4.70 log10 CFU/g increases, respectively, in C. perfringens populations in the ground beef control samples without chitosan. The corresponding increases for ground turkey were 5.27, 4.52, 5.11, and 5.38 log10 CFU/g. Addition of chitosan to beef or turkey resulted in concentration- and time-dependent inhibition in the C. perfringens spore germination and outgrowth. At 3%, chitosan reduced by 4 to 5 log10 CFU/g C. perfringens spore germination and outgrowth ( P ≤ 0.05) during exponential cooling of the cooked beef or turkey in 12, 15, or 18 h. The reduction was significantly lower ( P < 0.05) at a chilling time of 21 h, about 2 log10 CFU/g, that is, 7.56 log10 CFU/g (unsupplemented) compared with 5.59 log10 CFU/g (3% chitosan). The results suggest that incorporation of 3% chitosan into ground beef or turkey may reduce the potential risk of C. perfringens spore germination and outgrowth during abusive cooling from 54.4 to 7.2 °C in 12, 15, or 18 h. 相似文献
5.
J. Chantarachoti A.C.M. Oliveira B.H. Himelbloom C.A. Crapo D.G. McLachlan 《Journal of food science》2006,71(5):S414-S421
ABSTRACT: The ability of a portable hand-held electronic nose (EN) in detecting spoilage of whole Alaska pink salmon ( Oncorhynchus gorbuscha ) stored at 14 °C and in slush ice (1 °C) was investigated. Fish were sampled daily at 14 °C for up to 3 d, while fish stored in slush ice were sampled at various intervals up to 16 d. Sensory evaluations indicated that fish were rejected at day 3 when stored at 14 °C and at day 12 when stored in slush ice. Aerobic bacteria counts for fish skin at 14 °C ranged from 3.4 log10 colony-forming units (CFU)/cm2 (day 0) to 4.8 log10 CFU/cm2 (day 3) and for fish stored in slush ice ranged from 3.4 log10 CFU/cm2 (day 0) to 5.5 log10 CFU/cm2 (day 16). The correct classification rate using forward stepwise general discriminate analysis was 85% and 92% for EN analysis of belly cavity volatiles for fish held at 14 °C and in slush ice, respectively. A predictive model may be developed for spoilage of whole Alaska pink salmon by analyzing belly cavity odors using the EN. 相似文献
6.
W.-X. Du C.-M. Lin A.-T. Phu J.A. Cornell M.R. Marshall C.-I. Wei 《Journal of food science》2002,67(1):292-301
ABSTRACT: The effects of storage at 0,4,10, and 22°C for 0,1,3,5, and 9 d on the quality of yellowfin tuna fillets as determined by microbiological assessment, development of some biogenic amines, and sensory analysis were studied. Tuna fillets stored at 22 °C for 3 d, 10 °C for 5 d, and 4 °C for 9 d were rated unacceptable for consumption. Those stored at 22 °C for 3 d had total aerobic bacterial count of > 8 log10 CFU/g, a histamine-producing bacterial population of 7 log10 CFU/g, and 832 ppm of histamine, 35.8 ppm of putrescine, and 147 ppm of cadaverine. A comparison of the capillary electrophoresis, AOAC fluorometric method, and gas chromatography showed a very good correlation (r2 > 0.99) among these 3 methods for histamine quantitation in tuna samples. Morganella morganii, Enterobacter agglomerans, Enterobacter intermedium, Pseudomonas fluorescens, Proteins vulgaris , and Serratia liquefaciens were the decarboxylase-positive bacterial species isolated by using the Niven's medium and identified during storage, which were responsible for histamine production in test tuna fillets. 相似文献
7.
R. Capita C. Alonso-Calleja M.T. García-Arias B. Moreno M. Del Camino García-Fernández 《Journal of food science》2002,67(2):765-771
ABSTRACT: Contamination levels (cfu/g and cfu/cm2 ) of indicator microorganisms in retail broiler chicken carcasses in León (Spain) were investigated. Counts (log10 cfu/g) were 5.19, 3.04, 2.73, 3.38, and 3.16 for total aerobic counts ( TAC), Enterobacteriaceae , coliforms determined by the standard VRBA method (coliforms-VRBA), coliforms determined by the Hydrophobic Grid Membrane Filter method (coliforms-HGMF), and Escherichia coli (HGMF method), respectively. These values fit into the microbiological criteria for poultry meat consulted. A low correlation coefficient was found between TAC and Enterobacteriaceae counts (r = 0.308; P = 0.053) and between coliforms-VRBA and coliforms-HGMF counts ( r = 0.398; P = 0.048). The determination method had a significant influence on the coliform counts obtained. All broiler chicken carcasses harbored E. coli biotype I. E. coli biotype II was detected in 20% of the samples. The HGMF method was not completely specific for detecting E. coli since 11.25% of false positive colonies were found. 相似文献
8.
The microbiological status of beef carcass meat was investigated at a traditional and a semi-modern abattoir in Indonesia. Carcasses from the traditional abattoir were generally less contaminated than those from the semi-modern abattoir. The average total aerobic viable bacterial count of carcasses produced at the traditional abattoir, (log10 3.62/cm2 ) was found to be significantly lower (p = 0.02) at the semi-modern abattoir (log10 4.02/cm2 ). More than 70% of carcasses at both abattoirs were found to be positive for Escherichia coli (> 10 organisms/cm2 ), while Salmonellae were found on approximately 15% of carcasses at both locations. 相似文献
9.
REBECCA MONTVILLE SARAH SMITH PEDRO PERDOMO PETER J. NITZSCHE DONALD W. SCHAFFNER 《Journal of Food Safety》2003,23(3):159-166
Calabaza (Curcubita moschata) is a tropical squash which is gaining popularity as a specialty crop for agricultural producers in the Northeast United States. It is commonly marketed by being cut in half, wrapped in plastic and may be held unrefrigerated until sold. This method of display is essential for consumer acceptance, yet unrefrigerated storage means that some potential for food safety problems exists. Experiments were conducted to determine the potential for bacterial growth during storage of cut calabaza. Freshly cut calabaza contained between 1.3 and 4.7 log10 CFU/g aerobic mesophiles. By 10 h, duplicate counts from some samples exceeded 4 log10 CFU/g. After 24 h of room temperature storage, total aerobic plate counts ranged from 5.2 to 7.7 log10 CFU/g. Rapid bacterial growth on cut calabaza stored at room temperature indicates that these products are highly perishable, and may be able to support the growth of pathogenic bacteria, should they be introduced during the slicing process. 相似文献
10.
UFUK KAMBER 《International Journal of Dairy Technology》2008,61(2):146-150
This study was designed to investigate the microbiological and chemical characteristics of kurut, a dairy product obtained by drying yogurt under the sun in rural areas of Turkey. For this purpose, 50 randomly collected kurut samples from the Kars Region were analysed for determination of their microbiological and chemical characteristics. Analysis of kurut samples showed that kurut contained on average 4.52 log10 cfu/g of aerobic mesophilic bacteria, 2.78 log10 cfu/g of aerobic mesophyl spores, 3.60 log10 cfu/g of lactic acid bacteria, 3.60 log10 cfu/g of Lactococcus , 3.94 log10 cfu/g of mould and yeast, 2.13 log10 cfu/g of Enterobacteriaceae, l.51 log10 cfu/g of sulphite-reducing clostridia, and 1.81 log10 cfu/g of coagulase-positive s taphylococci . Coliform bacteria and enterococci bacteria were not detected in any of the kurut samples. Furthermore, chemical characteristics of the kurut were as follows: pH 4.2, acidity (lactic acid) 2.9, moisture 12.1%, fat 45.9% protein 25.5%, salt 6.7% and ash 10.0%. The quality characteristics of kurut presented here may help create a different perspective for new products to be produced in the dairy sector. 相似文献
11.
M BARBARA PISANO M ELISABETTA FADDA MAURA DEPLANO ARIANNA CORDA SOFIA COSENTINO 《International Journal of Dairy Technology》2006,59(3):171-179
The purpose of this study was to assess the chemical and microbial characteristics of 12 batches of artisanal Fiore Sardo, a protected designation of origin (PDO) hard cheese made from raw ewe's milk without addition of starters, during maturation. High standard deviations were observed for moisture percentage, total solids percentage and NaCl percentage content, possibly owing to differences in manufacturing processes and/or milk composition. Total mesophilic bacteria varied between 10 log10 cfu/g in 48-h-old cheese samples and 3 log10 cfu/g in 9-month-old samples. Total coliforms and staphylococci showed the highest counts at 48 h of ripening then decreased significantly, dropping to levels below 2 log10 cfu/g at 3 months of maturation. Lactic acid bacteria and enterococci were the dominant micro-organisms throughout maturation. They were mainly represented by the species Lactococcus lactis ssp. lactis, Enterococcus faecium, Lactobacillus plantarum and Lactobacillus casei group. Low levels of yeasts were detected throughout the maturation period of the cheese. Debaryomyces hansenii and Kluyveromyces lactis var. lactis were the prevalent yeast species isolated. 相似文献
12.
ABSTRACT: The purpose of this research was to develop empirical models that describe the amount and distribution of ground beef contaminated with Escherichia coli O157:H7 when a contaminated beef trim is introduced into a batch of uncontaminated beef before processing in a mid-size commercial grinder (34 g/s). A beef trim was inoculated with a rifampacin-resistant strain of E. coli O157:H7 and added to a batch of noncontaminated trims at the grinding step. To study the distribution of the E. coli O157:H7rif in the ground beef, 6 treatments with different inoculum levels (1 to 6 log10 colony-forming units [CFU]) were tested. Removal or pick up of the residual contamination with E. coli O157:H7rif left in the grinder was evaluated. E. coli O157:H7rif was detected in 9% to 86% of the total ground beef for the 1 to 6 log10 CFU inoculum levels, respectively. E. coli O157:H7rif contamination was detected in the collar that fixes the grinder's die and blade to the hub. An exponential algorithm described the relationship between the quantities of ground beef containing E. coli O157:H7rif and the inoculum level ( R 2 = 0.82). Distribution models based on a Chi-squared algorithm were developed for each inoculum level describing the contamination level as a function of the batch fraction processed ( R 2 = 0.81 to 0.99). The results of this study corroborate that when beef processors test for pathogenic contamination in a mid-scale grinder, they should test the beef residues in the collar that fixes the grinder's die and blade to the hub. 相似文献
13.
ABSTRACT: The objective of this study was to evaluate the effects of enhancement solutions containing sodium lactate or sodium lactate/sodium diacetate on E. coli K12 transmission to beef strip steaks and in purge. Solutions containing salt, phosphate, and shelf-life enhancers were injected to 10% over initial weight of the steaks. Lactate or lactate/diacetate addition to a solution inoculated with 6 log10 E. coli K12 CFU/mL was equally effective in limiting growth resulting in a 1-2 log10 CFU/g reduction when compared to salt/phosphate in steaks. When inoculation level was 3 log10 CFU/mL in the enhancement solution, microbial growth was detectable only in the purge of steaks enhanced with salt/phosphate only. Lactate increased CIE L* value and b* and decreased a* values when compared to the control. Lactate-/diacetate-containing solutions decreased L* values when compared to lactate alone. Lactate/diacetate also reduced purge loss from steaks compared to lactate and salt/phosphate solutions. 相似文献
14.
Vacuum-packaged fresh meat products held at refrigeration temperatures have limited shelf-life expectancies, often due to growth of anaerobic lactic acid-producing bacteria. Agents that can suppress the growth of this group are beneficial. Fresh pork sausage, formulated to contain 0%, 1%, 2%, or 3% sodium lactate (SL), was vacuum packaged and stored at 4C for 0, 10, 17, 24, and 31 days. A trained sensory panel evaluated pork, salty, sour, and bitter flavors. Aerobic total plate counts (APC), anaerobic total plate counts (AnPC), aerobic lactic acid producers (ALC), anaerobic lactic acid producers (AnLC), TBA values, and pH were determined. SL depressed APC, AnPC, and AnLC. Addition of 1% SL extended shelf-life of vacuum-packaged fresh pork sausage by 1 week compared to controls; samples containing 2% and 3% SL had not reached spoilage level (log10 7.0 CFU/g) at the conclusion of this study. Addition of SL increased salty taste and prevented loss of pork flavor over time, but had no effect on sour or bitter flavors. 相似文献
15.
The influence of chlorine or hydrogen peroxide treatment on populations of Escherichia coli 25922 on the external surface of inoculated cantaloupe was investigated. Surface treatment with 70% EtOH, followed by immersion in 108 CFU/mL E. coli inoculum deposited an average of 4.4 log10 CFU/cm2 cell population on the cantaloupe surface. The efficncy of washing inoculated cantaloupe was dependent on storage interval between inoculation and treatment. Dipping the cantaloupes in solutions containing 1000 mg/L chlorine or 5% peroxide for 5 min, within 24 h of inoculation, caused a 2 log10 CFU/cm2 reduction of the indigenous surface microflora and a 3–4.0 log10 CFU/cm2 reduction in E. coli. The efficacy was less when the interval between inoculation and treatment exceeded 24 h. Chlorine appeared in be a better antimicrobial agent than hydrogen peroxide against F. coli ATCC 25922 inoculated on cantaloupe surfaces while hydrogen peroxide was better in reducing surface microflora of cantaloupe. 相似文献
16.
ABSTRACT: Antibacterial activity of electrolyzed oxidizing (EO) water prepared from 0.05% or 0.10% (w/v) sodium chloride (NaCl) solutions against indigenous bacteria associated with fresh strawberries ( Fragaria × ananassa ) was evaluated. The efficacy of EO water and sodium hypochlorite (NaOCl) solution in eliminating and controlling the growth of Listeria monocytogenes and Escherichia coli O157:H7 inoculated onto strawberries stored at 4 ± 1 °C up to 15 d was investigated at exposure time of 1, 5, or 10 min. Posttreatment neutralization of fruit surfaces was also determined. More than 2 log10 CFU/g reductions of aerobic mesophiles were obtained in fruits washed for 10 or 15 min in EO water prepared from 0.10% (w/v) NaCl solution. Bactericidal activity of the disinfectants against L. monocytogenes and E. coli O157:H7 was not affected by posttreatment neutralization, and increasing exposure time did not significantly increase the antibacterial efficacy against both pathogens. While washing fruit surfaces with distilled water resulted in 1.90 and 1.27 log10 CFU/mL of rinse fluid reduction of L. monocytogenes and E. coli O157:H7, respectively, ≥ 2.60 log10 CFU/mL of rinse fluid reduction of L. monocytogenes and up to 2.35 and 3.12 log10 CFU/mL of rinse fluid reduction of E. coli O157:H7 were observed on fruit surfaces washed with EO water and NaOCl solution, respectively. Listeria monocytogenes and E. coli O157:H7 populations decreased over storage regardless of prior treatment. However, EO water and aqueous NaOCl did not show higher antimicrobial potential than water treatment during refrigeration storage. 相似文献
17.
ABSTRACT: Swordfish fillets, dry-salted and treated with liquid smoke, were sliced and packed in vacuum conditions and under modified atmosphere (MA) (5% O2 ,45% CO2 , 50% N2 ) and stored at chilled temperature (4°C) to determine the effect of different packaging on shelf-life. Sensory attributes, total volatile basic nitrogen (TVB-N), pH, lipid oxidation by thiobarbituric acid test, and microbiological counts were monitored during 45 d of storage. The TVB-N increased to levels recommended by European regulation at the time of sensory rejection, resulting as the most reliable parameter of quality decay. Lipid oxidation was low and microbial counts could not be correlated with quality decay. Sensory rejection (at least 50% of the assessors scoring =5 in a scale from 1 to 9) was sooner for MA-packed samples (12d) than for vacuum-packed ones (42d). 相似文献
18.
ABSTRACT: Small fruits are increasingly being implicated in outbreaks of foodborne illness, and fresh produce is now the 2nd leading cause of foodborne illness in the United States. Conventional methods of decontamination are not effective, and there is a need to evaluate novel technologies. Pulsed ultraviolet (UV)-light is one such technology. In this study, pulsed UV-light was applied to strawberries and raspberries at varying UV doses and times. On raspberries, maximum reductions of Escherichia coli O157:H7 and Salmonella were 3.9 and 3.4 log10 CFU/g at 72 and 59.2 J/cm2 , respectively. On the surfaces of strawberries, maximum reductions were 2.1 and 2.8 log10 CFU/g at 25.7 and 34.2 J/cm2 , respectively. There was no observable damage to the fruits at these UV doses. The results obtained in this study indicate that pulsed UV-light has the potential to be used as a decontamination method for raspberries and strawberries. 相似文献
19.
Sterile slices of cooked uncured turkey loaf were inoculated with 106 CFU of either Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Enterococcus faecalis, Citrobacter freundii, Klebsiella pneumoniae, or Enterobacter cloacae. Inoculated samples were vacuum-packaged and stored at 3 ± 1°C. Microorganisms were enumerated at 0, 3, 6, 9, 12, and 15 days on nonselective media . K. pneumoniae exhibited the least cold-tolerance with a log10 1.70 decrease in numbers. The coliforms E. cloacae, E. coli, and C. freundii had a survival pattern similar to that of S. typhimurium, with population decreases of log10 0.65, 0.82, 1.13, and 0.79, respectively . E. faecalis and L. monocytogenes were significantly more cold-resistant, with a decrease of log10 0.20 and no significant change in numbers, respectively. Survival of E. faecalis was not significantly (p < 0.01) different than that of L. monocytogenes, suggesting the use of enterococci as indicators of L. monocytogenes contamination of processed meats . 相似文献
20.
Various amounts of nisin (0, 103 and 5 × 103 IU/g) in combination with either potassium sorbate (0, 2, and 3%) or sodium benzoate (0, 0.06 and 0.12%) were tested for effectiveness in inhibiting growth of Staphylococcus aureus C10 and Bacillus cereus B7 inoculated on a vegetarian food. The strains used were isolated from vegetarian foods obtained commercially in Taiwan, and the test food, spice and dried bean curd, was selected for the study based on ability to support the growth of these organisms. After treatment with a preservative combination, the surfaces of sterilized food samples were inoculated, samples were stored in vacuum or nonvacuum packages at either 4C or 30C, and at appropriate times, tested for microbial growth. Growth of both isolates was unaffected by vacuum-packaging treatment; however, a bacteriostatic effect was found at 4C. Data indicated that during the 14-day storage at 4C, vacuum-packaged samples treated with 5 × 103 IU/g nisin and 0.12% sodium benzoate significantly (p < 0.05) decreased the counts of S. aureus C10 and B. cereus B7 by 2.61 and 3.02 log10 CFU/g, respectively. In the vacuum-packaged samples treated with 5 × 103 IU/g nisin and 3% potassium sorbate, counts for C10 and B7 were decreased by 2.35 and 2.64 log10 CFU/g, respectively. Thus, the combined treatment extended the shelf-life of the vegetarian food . 相似文献