Inhibition of Fusarium Growth and Mycotoxin Production in Culture Medium and in Maize Kernels by Natural Phenolic Acids

The possible role of natural phenolic compounds in inhibiting fungal growth and toxin production has been of recent interest as an alternative strategy to the use of chemical fungicides for the maintenance of food safety. Fusarium is a worldwide fungal genus mainly associated with cereal crops. The most important Fusarium mycotoxins are trichothecenes, zearalenone, and fumonisins. This study was conducted to evaluate the potential of four natural phenolic acids (caffeic, ferulic, p-coumaric, and chlorogenic) for the control of mycelial growth and mycotoxin production by six toxigenic species of Fusarium . The addition of phenolic acids to corn meal agar had a marked inhibitory effect on the radial growth of all Fusarium species at levels of 2.5 to 10 mM in a dose-response pattern, causing total inhibition (100%) in all species except F. sporotrichioides and F. langsethiae . However, the effects of phenolic acids on mycotoxin production in maize kernels were less evident than the effects on growth. The fungal species differed in their responses to the phenolic acid treatments, and significant reductions in toxin concentrations were observed only for T-2 and HT-2 (90% reduction) and zearalenone (48 to 77% reduction). These results provide data that could be used for developing pre- and postharvest strategies for controlling Fusarium infection and subsequent toxin production in cereal grains.

Biogenic Amines and Polyamines and Total Aerobic Count During Storage of Vacuum-Packaged Porcine Kidney, Liver and Spleen

Biogenic amines and polyamines (cadaverine, histamine, 2-phenylethylamine, putrescine, spermidine, spermine, tryptamine and tyramine) were analysed in vacuum-packaged porcine livers, kidneys and spleens stored at 3°C and 7°C (for up to 6 days) or 0°C (for up to 21 days). Total aerobic count, pH and sensory assessment were done in parallel. While histamine, 2-phenylethylamine and tryptamine concentrations were nearly constant, spermidine and spermine showed a moderately declining trend, irrespective of the storage temperature. Cadaverine, putrescine and tyramine concentrations increased with storage time and temperature. Maximum concentrations at day 21 at 0°C were: 122mg/kg for cadaverine, 207.35mg/kg for putrescine and 63.19mg/kg for tyramine. The correlation of concentrations of the latter three amines and the total aerobic count was ranging from r 0.54 to 0.89. A significant rise in amine concentrations was observed only when the total aerobic count exceeded 6 log10 cfu/g. Concentrations of cadaverine, putrescine and tyramine may be useful to confirm spoilage of vacuum-packaged inner organs. The fraction of the potential food-borne pathogen Aeromonas in high-pH organs (spleen, kidney) during storage was significantly higher than in liver, with low pH. It was observed that the spermine: spermidine ratio of spleen (3:2; weight base) was significantly different from that of liver and kidney (4:1).

Stability of Capsaicinoids and Antioxidants in Dry Hot Peppers under Different Packaging and Storage Temperatures

The maintenance of the quality and storage life of perishable fruits and vegetables is a major challenge for the food industry. In this study, the effects of different temperatures, packaging materials and storage time on the stability of capsaicinoids and antioxidants, such as total carotenoids, ascorbic acid and total phenolic compounds, were studied in three commercially cultivated hot pepper hybrids, namely Sky Red, Maha and Wonder King. For this purpose, dry whole pods were packed in jute bags and low-density polyethylene bags (LDPE), stored for five months under controlled conditions at 20, 25 or 30 ○C and analyzed on Day 0 and at 50-day intervals until Day 150. The three hot pepper hybrids differed significantly with respect to their capsaicinoids and antioxidant concentrations, but the results indicated that with the increase in storage temperature and time, a gradual and steady decrease in these levels was equally observed for all hybrids. Overall, mean concentrations after five months were significantly reduced by 22.6% for ascorbic acid, 19.0% for phenolic compounds, 17% for carotenoids and 12.7% for capsaicinoids. The trends of capsaicinoids and antioxidants evolution were decreasing gradually during storage until Day 150, this effect being more pronounced at higher temperature. Furthermore, the disappearance rates of capsaicinoids and antioxidants were higher in peppers packed in jute bags than in those wrapped with LDPE. In conclusion, despite the sensitivity of capsaicinoids and antioxidants to oxygen, light and moisture, the packaging in natural jute or synthetic LDPE plastic bags, as well as the storage at ambient temperature preserved between 77.4% and 87.3% of the initial amounts of these health- and nutrition-promoting compounds during five months' storage.

Aflatoxin M1 contamination in cow and buffalo milk samples from the North West Frontier Province (NWFP) and Punjab provinces of Pakistan

A total of 178 milk samples (94 of buffalo and 84 of cow) were randomly taken from Punjab and the North West Frontier Province (NWFP) of Pakistan (n = 89 in each province) and analysed for the presence of aflatoxin M1 (AFM1) by HPLC-FLD. From Punjab about 46% of buffalo's and 49% of cow's milks were contaminated with AFM1 as compared with 52% and 51% for milk samples from NWFP, respectively. Overall, the mean AFM1 concentration was 0.046 µg kg(-1) with a maximum of 0.350 µg kg(-1). All samples complied with the Codex Alimentarius limit of 0.50 µg kg(-1) for AFM1 in milk, but 16.3% of samples exceeded the European Union maximum level of 0.05 µg kg(-1). Another set of 415 buffalo's and cow's milk samples (213 morning milks and 202 evening milks) were analysed. Statistical analysis revealed significant differences (p < 0.05) between mean AFM1 concentrations in milk during the morning (0.043 µg kg(-1)) and the evening (0.028 µg kg(-1)) lactation times.

Characterization of capsaicinoids and antioxidants in hot peppers as influenced by hybrid and harvesting stage

Studies were conducted to investigate the accumulation pattern of capsaicinoids and antioxidants such as carotenoids, ascorbic acid and phenolic compounds in three hot pepper hybrids at five different harvesting stages: immature green, mature green, color break, red ripe and dried fruit. Capsaicin and dihydrocapsaicin contents were maximum at mature green stage in both Sky Red (61.30 and 43.76 mg/100 g) and Wonder King (43.93 and 26.16 mg/100 g) hybrids, whereas Maha hybrid reached top values at color break stage (39.13 and 24.20 mg/100 g). The accumulation of total carotenoids showed an 8-fold increase from red ripe (12 mg/100 g) to dried fruit stage (96 mg/100 g), while a noticeable decline by 76 % was observed for ascorbic acid at same harvesting stages (150 vs. 36 mg/100 g, respectively). The three hot pepper hybrids showed great variations in the evolution of total phenolic contents during harvesting stages. Overall, the mature green stage was ideal to acquire maximum pungency due to capsaicinoids, while peppers at red ripe stage were best sources of ascorbic acid and dried fruits contained higher levels of total carotenoids.

Mold and aflatoxin reduction by gamma radiation of packed hot peppers and their evolution during storage

The effect of gamma radiation on moisture content, total mold counts, Aspergillus counts, and aflatoxins of three hot pepper hybrids (Sky Red, Maha, and Wonder King) was investigated. Whole dried peppers packed in polyethylene bags were gamma irradiated at 0 (control), 2, 4, and 6 kGy and stored at 25°C for 90 days. Gamma radiation proved to be effective in reducing total mold and Aspergillus counts in a dose-dependent relationship. Total mold counts in irradiated peppers immediately after treatments were significantly lowered compared with those in nonirradiated samples, achieving 90 and 99% reduction at 2- and 4-kGy doses, respectively. Aspergillus counts were significantly reduced, by 93 and 97%, immediately after irradiation at doses of 2 and 4 kGy, respectively. A radiation dose of 6 kGy completely eliminated the population of total molds and Aspergillus fungi. The evolution of total molds in control and irradiated samples indicated no further fungal proliferation during 3 months of storage at 25°C. Aflatoxin levels were slightly affected by radiation doses of 2 and 4 kGy and showed a nonsignificant reduction of 6% at the highest radiation dose of 6 kGy. The distinct effectiveness of gamma radiation in molds and aflatoxins can be explained by the target theory of food irradiation, which states that the likelihood of a microorganism or a molecule being inactivated by gamma rays increases as its size increases.

Assessment of hot peppers for aflatoxin and mold proliferation during storage

Aflatoxin contamination and mold proliferation in three hot pepper hybrids (Sky Red, Maha, and Wonder King) were studied during 5 months of storage at three temperatures (20, 25, and 30°C) and under different packaging conditions (low-density polyethylene bags and jute bags). The presence of aflatoxins in hot pepper samples was determined by high-performance liquid chromatography with a UV-Vis detector. Sampling for analysis of aflatoxins, total mold counts, and Aspergillus counts was carried out at 0, 50, 100, and 150 days of storage. Hot peppers packed in jute bags were more susceptible to aflatoxin contamination than those packed in polyethylene bags; aflatoxin concentrations were 75% higher in peppers stored in jute bags. The effect of storage temperature resulted in aflatoxin concentrations that were 61% higher in hot peppers stored at 25 and 30°C than in those stored at 20°C. Of the three pepper hybrids, Wonder King was more susceptible to aflatoxin contamination, with a maximum of 1.50 μg/kg when packed in jute bags and stored at 25°C for 150 days. However, no sample exceeded the maximum permitted level for total aflatoxins in spices established by European Union regulations (10 μg/kg). Total mold counts and Aspergillus counts increased with storage duration, but all counts were significantly lower in peppers stored in polyethylene bags. A gradual increase in temperature during prolonged storage of hot peppers in combination with aeration may be the main reasons for increases in fungal biomass and Aspergillus proliferation with the subsequent aflatoxin production.

Influence of agricultural practices on the contamination of maize by fumonisin mycotoxins

The objective of the present work was to investigate the effect of different agricultural practices on the contamination of maize by fumonisin mycotoxins. Corn samples were collected from 16 maize fields located in Aragón (northeastern Spain) during the 2007 crop year. Corn samples were collected from each field five times at different maturation stages: F1, day 0 (milky corn); F2, day 15; F3, day 30 (yellow corn); F4, day 45; and F5, ripe corn at harvest. The agricultural practices evaluated were type of seed (conventional and transgenic), planting method (dry and wet planting), tillage system (plowing and minimum tillage), type of irrigation (flood and sprinkler), residue management of preceding crop (removal and burial), nitrogen fertilization level (kg N per ha), and harvest date. Mycotoxin analysis was carried out with the ROSA Fumonisin test, which measures both fumonisin B1 and B2 by lateral flow immunoassay. No fumonisins were detected in milky corn (F1 and F2 stages). Only one field had fumonisins in F3 yellow corn (1,037 microg/kg); this field was part of the only farm affected by borer insects. One-third of fields had fumonisins at the F4 stage (363 microg/kg), and 62.5% of the fields were positive for fumonisins at the F5 harvest stage (520 microg/kg). Wet planting and the removal of debris from the previous crop significantly lowered the risk of fumonisin in corn. The use of insect-resistant maize seeds tended to reduce fumonisin levels. However, higher levels of nitrogen fertilizer had a tendency to increase fumonisin levels in corn. Tillage system, type of irrigation, and harvest date had no clear effect on fumonisin levels.

Ochratoxin A in liquorice as affected by processing methods

A study of the effect of several processing methods on the concentration of ochratoxin A (OTA) in liquorice and derived products was carried out. The effect of the sorting, washing and peeling of fresh liquorice roots was investigated; as well as the production at a laboratory scale of liquorice extract and block liquorice from dry roots. Finally, the thermal stability of OTA was assessed. The OTA content was analysed by high-performance liquid chromatography-fluorescence and confirmed by methyl ester formation. The OTA level in liquorice extract was stable to heat treatment at 150 degrees C for 60 min. The OTA concentration was unaffected by sorting or washing, but it was much reduced by peeling (a 53.1% reduction). A great reduction in the OTA level was found during the production of liquorice extract (78.6%) and block liquorice (91.8%).

High levels of ochratoxin A in licorice and derived products

The ochratoxin A (OTA) content of 30 samples of licorice root and derived products (licorice-confectionery, licorice block, and licorice extract) was analyzed by a standard HPLC-fluorescence technique and confirmed by methyl-ester formation. All analyzed samples of licorice and derived products were found to contain ochratoxin A, and some of them showed extremely high concentrations up to 252.8 ng/g of OTA. Highest levels of ochratoxin A were found in dry licorice root, averaging 63.6 ng/g, while mean contents in fresh licorice root were 9.2 ng/g. Licorice-confectionery (sweets) contained 3.8 ng/g of OTA. Ochratoxin A was also abundant in two licorice derivatives, liquid licorice extract (16.0 ng/g) and solid licorice block (39.5 ng/g). The ochratoxin levels found in licorice and derived products are higher than those reported in the literature for other food commodities. The experiments of OTA transfer into the tea beverages showed that almost 5% of the OTA present in dry licorice root is transferred to the corresponding decoction tea, whereas only 1% of OTA remains in infusion tea. The significance of the levels of ochratoxin A in licorice and its derivatives is discussed in the context of existing data on ochratoxin contamination in foods.

Determination of pesticides and PCBs in honey by solid-phase extraction cleanup followed by gas chromatography with electron-capture and nitrogen?phosphorus detection

A multiresidue method for determination of 15 organochlorine pesticides (OCPs), six polychlorinated biphenyls (PCBs), and seven organophosphorus pesticides (OPPs) is implemented for routine determinations of residues in honey. The method involves solid-phase extraction cleanup and determination by GC-ECD/NPD. Quantitation limits ranged from 0.1 to 0.6 microg kg-1 honey for OCPs and PCBs, and from 5.0 to 25.0 microg kg-1 honey for OPPs. Recoveries of OCPs ranged between 77.4 and 94.0%; for PCBs they were from 63.8 to 73.5%. Recovery assays for OPPs varied from 66.7 to 98.1%. The method was applied to the analysis of 111 honey samples from Aragon, Spain. The results obtained indicated a low level of contamination by pesticide residues and PCBs, which can contribute to ensuring the consumer has a safe wholesome supply of honey.

Anthropometric measurements in both sides of the body in the assessment of nutritional status in prepubertal children

OBJECTIVE

To analyze the impact of choosing the left or the right side of the body on the anthropometric measurements and derived nutritional indices, in prepubertal children.

DESIGN

Cross-sectional pilot nutrition survey.

SETTING

General prepubertal school-age population.

SUBJECTS

One-hundred and sixty-four children (97 boys and 67 girls) aged 7-9 y.

INTERVENTIONS

None.

RESULTS

The agreement between anthropometric measurements in both sides of the body showed that in males and in females, suprailiac skinfold thickness and arm circumference were significantly higher in the left than in the right side of the body. The agreement between body composition assessed by anthropometric measurements in both sides of the body showed that only in males was arm muscle area significantly higher in the left than in the right side, and arm fat percentage was higher in the right than in the left side of the body. Total body fat percentage calculated from skinfold thickness did not show statistically significant differences when skinfolds were obtained in the both sides of the body, either in boys and in girls.

CONCLUSIONS

Our results show that differences between the sides of the body were lower than the technical error of measurement of the anthropometric measurements obtained and seem not to be biologically significant in this age group. It is necessary to standardize the method of anthropometric assessment of the nutritional status in terms of body side.

Multiresidue determination of organochlorine pesticides and polychlorinated biphenyls in milk by gas chromatography with electron-capture detection after extraction by matrix solid-phase dispersion

A multiresidue analytical method based on matrix solid-phase dispersion was developed to analyze liquid milk for 22 organochlorine pesticides (OCPs) and 6 polychlorinated biphenyls (PCBs). Initial extraction is performed by loading 3 mL milk onto a 2.0 g octadecyl (C18)-bonded silica cartridge with n-hexane as the eluant. Neutral alumina column chromatography with sodium sulfate as the drying agent is used for further cleanup. The eluate is concentrated to 0.5 mL, and target analytes are determined by capillary gas chromatography with electron-capture detection. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of milk samples fortified at 10 and 1 microg/L levels. Average recoveries were between 74 and 106% for all residues except beta-HCH, beta-endosulfan, and endosulfan sulfate. Both repeatability and reproducibility relative standard deviation values were < 22% for all residues. Detection limits ranged from 0.02 to 0.12 microg/L and quantitation limits were between 0.02 and 0.62 microg/L. The proposed analytical method may be used as a fast and simple procedure in routine determinations of OCPs and PCBs in milk.

Red-legged partridges (Alectoris rufa) as bioindicators for persistent chlorinated chemicals in Spain

Persistent organochlorine residues such as hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlorocyclodienes, and the DDT group (DDTs) were determined in fat and muscle samples of resident red-legged partridges (Alectoris rufa) hunted in Spain. Chlorinated contamination pattern varied largely depending on geographical distribution. Birds collected from the northern part of Spain contained greater concentrations of lindane (34.4 ng/g fat basis) than those from central or southern Spain. In contrast, red-legged partridges collected in southern locations exhibited elevated levels of p,p-DDE (62.3 ng/g fat basis) as compared with central (31.2 ng/g fat basis) and northern areas (5.6 ng/g fat basis). The only cyclodiene detected, dieldrin, showed higher amounts (3.4 ng/g fat basis) in partridges collected in central Spain. The sex differences in pollutant occurrence and concentrations were negligible. One-year-old birds accumulated greater concentrations of beta-HCH, and dieldrin than older birds. Global comparison of organochlorine concentrations indicated that northern partridges are more contaminated by compounds of industrial origin, whereas southern birds contained greater amounts of agricultural chemicals. Estimates of hazards associated with organochlorine levels in resident red-legged partridges in Spain suggested that southern birds may be at risk from exposure to DDTs, and northern birds may be affected by excessive concentrations of lindane. The use of red-legged partridge as bioindicator for OCP contamination is discussed.

Kinetic mechanism of cytochrome P450 reductase from the house fly (Musca domestica)

Recombinant house fly (Musca domestica) cytochrome P450 reductase has been purified by anion exchange and affinity chromatography. Steady-state kinetics of cytochrome c reductase activity revealed a random Bi-Bi mechanism with formation of a ternary P450 reductase-NADPH-electron acceptor complex as catalytic intermediate. NADP(H) binding is essential for fast hydride ion transfer to FAD, as well as for electron transfer from FMN to cytochrome c. Reduced cytochrome c had no effect on the enzyme activity, while NADP+ and 2'-AMP inhibited P450 reductase competitively with respect to NADPH and noncompetitively with respect to cytochrome c. The affinity of the P450 reductase to NADPH is 10 times higher than to NADP+ (Kd of 0.31 and 3.3 microM, respectively). Such an affinity change during catalysis could account for a +30 mV shift of the redox potential of FAD. Cys560 was substituted for Tyr by site-directed mutagenesis. This mutation decreased enzyme affinity to NADPH 35-fold by decreasing the bimolecular rate constant of nucleotide binding with no detectable effect on the kinetic mechanism. The affinity of the C560Y mutant enzyme to NADP+ decreased 9-fold compared to the wild-type enzyme, while the affinity to 2'-AMP was not significantly affected, suggesting that Cys560 is located in the nicotinamide binding site of the active, full-size enzyme in solution.

Salmonella Incidence and Distribution of Serotypes throughout Processing in a Spanish Poultry Slaughterhouse

A survey of contamination with Salmonella spp. was done at 11 sampling sites in a poultry slaughter establishment in Spain for a total of 192 samples. Samples included fecal material, utensils, water, and poultry carcasses and livers at several stages of processing. Salmonella incidence rates increased from 30% in fecal material collected from incoming birds to 60% in air-chilled carcasses and 80% in cold-stored livers, indicating that cross-contamination occurred. The rate of incidence of Salmonella organisms on carcasses averaged 56.7% through post-picking to post-air chilling and reached a maximum of 70% on carcasses at the post-spray wash site. Poultry livers were more heavily contaminated with salmonellae, as 55% and 80% samples after evisceration and cold storage, respectively, were positive for those pathogenic bacteria. From a total of 112 strains isolated, 87 (77.6%) were S. enteritidis , 7 (6.2%) Salmonella serotype 4,5,12:b:-(II), and 6 (5.4%) Salmonella serotype 4,12:b:-(II), and the remaining 12 strains were equally distributed among S. typhimurium . S. virchow , and S. blockley (3.6% each). Serotypes isolated from feces were later detected in matched carcasses and livers indicating a cross-contamination of carcasses by endogenous microflora in bird feces. The incidence of Salmonella serotype 4,5, 12:b:-(II) and that of S. typhimurium were significantly higher (P < 0.05) in samples obtained prior to evisceration than in those collected after that particular step. The situation with S. enteritidis was quite the reverse, since this serotype was more frequently detected in samples taken after the evisceration step (P < 0.01).

Physico-chemical Characterization of "Bone Taint" in Spanish Dry-cured Hams

Samples of Spanish dry-cured hams were analyzed using several physico-chemical parameters (moisture content, chlorides, water activity, nitrate, nitrite, total volatile basic nitrogen [TVBN], pH, and oxidation-reduction potential [E_h]). The samples (n = 76) were taken from three basic types of dry-cured hams produced in Spain: slow-cured hams from white pigs (n = 39), fast-cured hams from white pigs (n = 15), and hams from black-skinned Iberian pigs (n = 22). Overall, 56 samples (73.7%) showed the "bone taint" condition, and the remaining 20 hams (26.3%) were normal, and therefore considered as a control group. The objective of this research was to establish the possible circumstances that determine the alteration by means of the differences found in the values of the analyzed measurements in both groups of samples (altered versus normal ones). The hams with "bone taint" were, in general terms, those with a higher TVBN content, a greater pH, and a lower E_h, attributable to an anomalous development of the proteolytic phenomena. The conjunction of a lower concentration of chlorides, greater moisture content, and a higher a_w in the affected hams may have created the conditions favorable for tissue enzyme and/or microbial activity.

High Prevalence of Multiple Resistance to Antibiotics in 144 Listeria Isolates from Spanish Dairy and Meat Products

The resistance to 12 commonly used antimicrobial agents of 144 foodborne isolates belonging to the genus Listeria (23 L. monocytogenes , 54 L. innocua , 66 L. seeligeri , and 1 L. welshimeri ) was tested by using the agar disc-diffusion assay. The Listeria strains were isolated from dairy products (different varieties of unripened fresh and bacteria-ripened hard cheeses made from ewe's, cow's, and goat's milk) and meat products ( longaniza , a type of pork sausage). A total of 84 (93%) and 54 (100%) Listeria strains isolated from cheese and pork sausage, respectively, were resistant to multiple antimicrobial agents. More than 80% of the Listeria strains of both food origins were found to be susceptible to penicillin G and ampicillin, whereas the proportion of isolates resistant to the cephalosporins cefotaxime and cefoxitin was nearly 100%. The prevalence of resistance was much higher for isolates from pork sausage (73.8% on average) than for isolates from cheese (20.9%). This marked difference was statistically significant (P < 0.05; chi-square test) for all antibiotics except ampicillin, cefotaxime, and cefoxitin. The strains of the foodborne pathogen L. monocytogenes isolated from cheese were all susceptible to 9 of the 12 antimicrobial agents evaluated. In contrast, more than 80% of the L. monocytogenes strains isolated from pork sausage exhibited resistance to cefotaxime, cefoxitin, tobramycin, amikacin, chloramphenicol, tetracycline, and erythromycin. The appearance of substantial resistance to antibiotics in foodborne Listeria isolates suggests the need for more prudent use of antibiotics by farmers, veterinarians, and physicians.

The effect of commercial processing on incurred residues of DDE in meat products

The influence of processing on the degradation of DDE in meat products was investigated. First, the current level of contamination in six different types of Spanish meat products was determined. Analysis were carried out by capillary gas chromatography with electron capture detector. Of the three residues analysed (both o,p' and p,p' isomers of DDT, DDD, and DDE), only p,p'-DDE was found above the detection limit of 4 micrograms/kg fat. The frequency of p,p'-DDE detection for the various products investigated varied between 78 and 100% of the 129 samples analysed, although mean levels were very low, in the range within 6-16 micrograms/kg. No sample contained DDE residues above the EC maximum residue limit of 1 mg/kg for DDT and metabolites on meat products. Mean concentrations of DDE in Spanish meat products have declined since 1980 by more than 10-fold as compared with previously reported data. Meat products following three commercial processes were analysed to compare the levels of DDE in the finished products with those obtained in the starting material. The average levels of DDE remained unchanged after 30 days of curing in 26 samples of pork sausage. Similarly, mean DDE concentrations were essentially constant throughout the ripening process to which 30 hams were subjected. Finally, cooking in an oven (80-82 degrees C for 100 min) of 20 pork bologna samples produced an apparent increase of 12.5% in mean p,p'-DDE levels that was not statistically significant (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of an Excision Surface Sampling Method for Microbiological Analysis of Lamb Liver

Reproducibility of an excision surface sampling method for the microbiological analysis of 204 samples of spoiled and nonspoiled lamb liver was studied. The procedure consisted of removing a 5-cm² area from the liver (1-2 mm in thickness) with sterile scalpel and metal templates. Since variation was observed in the thickness of the excised portions taken from different livers, all excised samples were weighed and results for microbiological analysis (aerobic Plate counts at 30 and 7°C, Enterobacteriaceae , Pseudomonas , and lactic acid bacteria counts) were expressed as both log CFU/cm² and log CFU/g. For all groups of microorganisms studied, in both spoiled and nonspoiled samples, a highly significant correlation was found (r ≥ 0.996, p < 0.0001) between results expressed as log CFU/cm² and log CFU/g.