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ThesisItem Open Access Microbial quality assurance of curd during production and storage(Department of Veterinary Public Health, College of Veterinary and Animal Science, Mannuthy, 2005) Praseeda, R; KAU; Nanu, EIn the present investigation, a total of 180 freshly prepared curd samples belonging to 10 batches were collected on the day of production. Two samples from each batch were selected at random and examined on zero day and the remaining samples were stored under refrigeration and duplicate samples examined on day 3, 5, 7, 9, 12, 15, 18 and 21 of storage. A total of 80 curd samples belonging to four brands viz. A, B, C and D were also collected from retail outlets in and around Thrissur Corporation. All samples of curd were tested to evaluate the microbial quality by estimating the total viable count (TVC), coliform count (CC), faecal streptococcal count (FSC), psychrotrophic count (PC) and yeast and mould count (YMC). Isolation and identification of Escherichia coli, Staphylococcus aureus, Salmonellae, Pseudomonas aeruginosa and Bacillus species were also carried out. The organoleptic qualities of curd such as colour and appearance, flavour, body and texture and product acidity and physico-chemical parameters such as pH and titratable acidity were also assessed. Microbial quality assurance of curd during its production and critical control points of microbial contamination in the production line were also evaluated during the study. Paired‘t’ test of the data revealed that mean TVC of the samples increased at a highly significant (p<0.01) level from zero day to fifth day of storage, after which it decreased gradually. The mean CC of curd samples showed a gradual decreasing trend till the 12th day of storage. Coliforms were not detected in 90 per cent of the fresh curd samples. The mean FSC of curd samples also decreased significantly through out the storage period. On 18th and 21st day, 70 per cent of the samples did not reveal the presence of faecal streptococci. The mean PC decreased subsequently during storage till 12th day, after which it slightly increased. The mean YMC of fresh curd was 3.91 ± 0.11 log10cfu/g and it increased gradually from third day of storage compared to the count of the fresh sample. The count increased by 1.5log10cfu/g on the 12th day of storage and the increase was highly significant (p<0.01). A highly significant (p<0.01) and positive association was observed between the mean TVC and FSC on 21st day of storage. A significant (p<0.05) and negative association was observed between the mean TVC and PC on day nine of storage. A similar association was observed between mean CC and PC of samples on 12th day of storage and mean YMC and PC of samples on 15th day of storage. E. coli was not detected from any of the fresh and refrigerated samples of curd. Staphylococcus aureus was isolated from 35 per cent of fresh curd samples. On day 3, 5 and 7 of storage, 25, 20 and 10 per cent of the samples revealed the presence of the organism and all isolates were coagulase and TNase positive. None of the curd samples revealed the presence of Salmonellae and Pseudomonas aeruginosa. Bacillus species were present in 70 per cent of the fresh samples and 20 per cent each of the samples tested on day 15 and 18. Bacillus cereus was not detected in any of the curd samples and among the isolates, 55.4 and 25.67 per cent were B. subtilis and B. coagulans. The mean titratable acidity showed an increase till ninth day of storage and then decreased throughout the storage period. The pH of fresh curd samples decreased on storage and after 15th day, it increased gradually. Analysis revealed that flavour scores decreased during storage. Body and texture score remained almost the same throughout the storage period except a slight decrease on the third day. Colour and appearance score decreased significantly during the storage period and product acidity score also got reduced during storage. Of the 80 samples collected from the four brands, 42.5, 37.5 and 20 per cent had mean TVC at the level of 109, 108 and 107 cfu/g, respectively. Highly significant (p<0.01) difference was observed in mean CC of the samples of the different brands. Coliforms were not detected in the samples of brand B and 80 and 70 per cent samples of the brands C and D, respectively. A highly significant (p<0.01) difference was observed between the mean FSC count of samples from the four brands. Of the samples, 40 per cent did not reveal the presence of the organism and the count in 50 per cent samples from brand A was at the level of 103cfu/g. E. coli was not detected in the samples of brands B and D. The organism was isolated from 5 and 15 per cent of samples of brand A and C and the four isolates belonged to the serotype O157, O5, O148 and rough type. None of the samples from the four brands revealed the presence of Salmonellae. Pseudomonas aeruginosa was present in 2.5 per cent of the samples from the four brands. Staphylococcus aureus was detected in two of the curd samples, one (5%) each from brand A and C. Bacillus species was isolated from 62.5 per cent of the samples and among the isolates, 14.14 per cent was B. cereus. Analysis of variance test revealed a highly significant (p<0.01) difference in the mean titratable acidity and pH of the samples from the various brands. Organoleptic score analysed by Kruskal-Wallis test revealed that the product acidity score of the market curds varied significantly (p<0.01). Air samples collected from the various areas of curd production revealed highest bacterial count at the area of thermal treatment and lowest at the area of cream separation. The mean YMC was higher at the pasteurisation room. Hand washings of the personnel had the highest mean TVC and CC. E. coli was detected only in hand washings of personnel. Samples collected from the cream separator had the highest mean TVC and least in packaging material. Faecal streptococci were detected in all the samples tested and highest count was observed in the case of storage can. Samples from the double jacketed vat had the highest CC. Coliforms were not detected in the washings of the packaging material. Heat treated skim milk was free of coliforms and the mean FSC was significantly (p<0.05) lower than that of starter inoculated milk after one and six h of incubation. Yeast and moulds were not detected in heat treated skim milk, but present in starter inoculated one and six h milk samples. The mean pH of fresh curd samples was significantly (p<0.01) lower than that of heat treated skim milk. The starter culture was free of coliforms and faecal streptococci. The present study reflects the importance of quality assurance during every step of production and storage of curd to avoid early spoilage and to safeguard consumer health. Presence of pathogenic organisms in curd is of great public health significance as it is consumed as such paving way to food poisoning.ThesisItem Open Access Microbial quality assurance of milk in its production, processing and storage(Department of Veterinary Public Health, College of Veterinary and Animal Science, Mannuthy, 2005) Prejit; KAU; Nanu, EIn the present study 296 milk samples were collected from dairy farm, processing plant and retail shops and analysed for the microbial quality by estimating various microbial counts and assessing the presence of certain bacteria of public health importance. The microbial, physico-chemical and organoleptic qualities of pasteurized milk samples stored under refrigeration were evaluated. The critical points of bacterial contamination of milk at various stages of production, pasteurization, packaging and storage were also assessed during the investigation. Out of 60 samples of raw milk from individual animal, pooled milk and chilled milk analysed, 46.7 and 36.6 per cent samples were graded as very good and good based on BIS (IS 1977). However only 25 per cent samples were only considered satisfactory based on coliform count with none of the pooled milk samples meeting the standards. Pooled milk samples revealed maximum contamination with highly significant (p0.01) difference between mean TVC and CC and significant (p0.05) difference between mean PC and FSC of milk from individual animal. However mean E.coli count was more in individual animal milk sample when compared with pooled milk. The pooled milk sample was kept under chilled condition for 17 hours. The chilled milk had higher mean TVC, ECC and PC however the increase was not statistically significant. Pasteurization of milk was effective in reducing the microbial population of raw milk and there was highly significant (p0.01) reduction in TVC, CC, PC, FSC and YMC. From the sample of milk collected immediately after heating, after pasteurization and after packaging the mean TVC was high in packaged milk sample (4.76±0.15 log10 cfu/ml). Coliform was absent in cent percent of heated milk. However, 60 per cent of packaged milk had the organism with the mean count of 0.98±0.36 log10 cfu/ml. Only 40 per cent of packaged milk was graded satisfactory based on coliform standards prescribed by BIS (Indian Standards, 1992). E.coli could not be detected from milk collected after heating section and immediately after pasteurization. Maximum microbial contamination was seen in packaged milk. This indicates that contamination of milk occur in the storage tank or packaging section. Hence proper cleaning and sanitation of storage tank and packaging machine will reduce the microbial contamination to a considerable extent. The microbial analysis of the retail milk sample (56) of the brands A, B, C and D revealed that the samples of the brand B had highest mean TVC (5.91 ± 0.01 log10 cfu/ml) and FSC (1.52 ± 0.22 log10 cfu/ml). The highest mean coliform (3.08 ± 0.29 log10 cfu/ml), E. coli, (2.35 ± 0.38 log10 cfu/ml), psychrotrophic counts (5.68 ± 0.25 log10 cfu/ml) were seen in the samples of brand C. Brand A had highest mean YMC (1.21 ± 0.22 log10 cfu/ml). Only 23.2 and 26.8 per cent retail samples met the TVC and CC standards prescribed by BIS (IS-1992). However, 57.14 per cent of the samples of the brand A met the standard. On comparison of freshly packed milk obtained from dairy plant with the retail brands revealed that freshly packed milk sample had highly significant (p0.01) difference and lesser TVC, CC and PC in comparison with the brands B, C and D. Thus the microbial quality of retail milk available in the locality varied among different brands hence strict hygienic measures should be adopted to minimize microbial contamination. Pasteurized milk stored under refrigeration (4±1°C) showed an increase in TVC, CC, ECC, PC, FSC and YMC throughout the storage period. However, the initial growth rate of microorganism was slow due to sub lethal injury of microorganism during pasteurization and storage of milk under refrigerated condition. The increase in TVC, CC, ECC, PC, FSC and YMC between zero day and 12th day was 3.96, 1.76, 0.16, 3.76 and 2.37 log10 cfu/ml, respectively. The increase in the count of organism during storage may present the problem of shelf life deterioration of milk. The public health impact on the consumers was assessed by isolation and identification of E.coli, S. aureus and L. monocytogenes, the organisms of public health importance. Escherichia coli contamination of milk occurs through unhygienic handling of milk. The organism was detected in four samples (20 per cent) of the samples of raw pooled milk and was of serotypes 05 (2 samples), 0141 and 0172. Ten per cent of freshly packaged and refrigerated milk samples revealed the presence of the organism and all isolates were of serotypes 0148. A total of 38 E.coli isolates were obtained from retail milk samples. S. aureus was isolated from 60, 5, 12.5 per cent of the samples of raw, freshly pasteurized and retail milk, respectively. The organism was isolated from 5 per cent of the samples stored on sixth day and from 10 per cent samples stored on the eight day. L. monocytogenes was not isolated from milk samples. Sensory analysis of refrigerated milk samples showed an overall reduction in the score of colour and appearance, flavour, odour and body as the storage period increased. Development of off odour, salty or stale flavour and presence of clotted particles indicated the sensory spoilage and the maximum shelf life obtained was eight days. There was reduction in mean pH value throughout the storage period. All the samples showed positive to clot on boiling test on the day 12 of storage but the sample showed sensory unacceptability earlier. The various critical points of bacterial contamination of milk was evaluated by collecting samples of air, water, rinse samples from utensils, equipments, hand washing of milker/personnel in the processing line, strainer and packaging material and were subjected to estimation of various bacterial counts. The mean total viable count and yeast and mold count of air samples were found to increase after the milking process or processing. Among the water samples, coliform and E. coli was detected more in the samples obtained from dairy farm. High microbial count was recorded for milk pail, milkers hand washings and package machine wash indicating an important sources of contamination. Strict hygienic practices followed by health education will minimize the microbial contamination to a considerable extent.ThesisItem Open Access Evaluation of bacteriological quality of beef carcasses in meat processing plant(Department of Veterinary Public Health, College of Veterinary and Animal Sciences, Mannuthy, 2003) Sethulekshmi, C; KAU; Nanu, EDuring the present study, 40 beef carcasses were randomly selected from a meat processing plant located at Kochi in Kerala. The plant procures beef carcasses from two slaughtering units, viz., Source A and B, located in Tamil Nadu. From each carcass surface 500-cm2 area was swabbed which consisted of 100 cm2 each from neck, brisket, loin, flank and outer round. The samples from each carcass were examined for the bacterial quality by estimating the total viable count (TVC), coliforms count (CC), Escherichia coli count (ECC) and faecal streptococcal count (FSC). All samples were also subjected to the isolation and identification of Escherichia coli, Staphylococcus aureus, Salmonella and Listeria monocytogenes. The samples of air, water, equipment and hand wash of personnel were also collected and estimated the various bacterial loads of these samples. Analysis of variance test of the data did not reveal significant difference between the mean total viable count of the samples from two sources. The samples had an overall mean total viable count of 7.40 ± 0.17 10glO cfu/cm/. The mean count of samples from source B was slightly higher than that from source A. The count of the samples belonging to source A ranged from 106 to 109 cfu/cm2 while the count of the samples from source B varied between 106 and 108 cfu/cm/. Of the 40 carcass samples examined, 45 per cent had count at the level of 106 cfu/crrr', The counts in 30 per cent and 22.5 per cent were at the level of 108 cfulcm2 and 107 cfu/cnr', resp~ctively. Analysis of variance' test of the data revealed a significant (P<0.05) difference between the mean coliforms count of the samples from the two sources. The samples from source A had a higher mean count. The overall mean coliforms count of the samples was 3.41 ± 0.13 10glO cfu/cm". The count of the samples from both the sources varied from 102 to 104 cfu/cm/. The count in 21 (52.5 per cent) carcass samples was at the level of 103 cfu/crn", In 17.5 per cent carcasses the count was at the level of 104 cfu/crrr' and in 30 per cent carcass samples the count was at the level of 102 cfu/crrr'. Analysis of variance test of the Escherichia coli count revealed a significant (P<0.05) difference between the mean count of samples from the two sources. The samples belonging to source A had a higher mean count. The overall mean Escherichia coli count of the samples was 1.83 ± 0.22 10glO cfu/crrr'. The Escherichia coli count of the samples from both the sources varied from 101 to 103 cfu/cm2. The count in 16 (40 per cent) of carcass samples was at the level of 102 cfu/cm", In 17.5 per cent samples each had count at the levels of 101 and 103 cfu/cm", Analysis of variance test of the faecal streptococcal count revealed significant (P<0.05) difference between the mean counts of samples from the two sources. Source A had higher mean count. The overall mean count of samples was 3.27 ± 0.10 10glO cfu/cm". The count on the carcasses from the source A ranged between 102 to 104 cfu/crrr' whereas the count on the carcasses belonging to source B varied between 102 to 103 cfu/crrr'. Out of 40 carcasses, 18 (45 per cent) had count at the level of 103 cfu/crrr'. The counts on 40 and 15 per cent of the carcasses were at the levels of 102 to 104 cfu/cm/, respectively. A significant (P<0.05) positive correlation was observed between the mean CC and FSC of the carcasses belonging to source A. The association between the mean TVC and FSC in source B was significant (P<0.05). Escherichia coli was isolated from 10 carcasses belonging to source A and 5 carcasses from source B. Out of the 15 isolates, 14 were serotyped and were grouped under nine serotypes and one isolate was untypeable. The serotype 0157 was isolated from two of the carcass samples belonging to source A. Four isolates from this source belonged to serotype 036. The serotypes 036, 0156, 0157 and 0172 were isolated only from the samples obtained from the source A. The serotype 08 was isolated from both the sources. However, the serotypes 013,065,069 and 075 were isolated only from samples of source B. Staphylococcus aureus was isolated from two (5 per cent) carcasses belonging to source A and one (2.5 per cent) of the carcasses belonging to the source B. Of-the 40 carcass samples tested, salmonellae were isolated from one sample each from the source A and B. Listeria monocytogenes could not be isolated from any of the samples belonging to both the sources. The mean total viable counts on meat-cutting board and meat-cutting table were 4.94 ± 0.87 and 4.28 ± 0.87 10glO cfu/cm/, respectively. The mean coliforms count on the former was 1.24 ± 0.94 10glO cfu/crrr' and the latter was at the level of 1.26 ± 0.83 10glO cfu/crrr'. The mean faecal streptococcal count was at the level of 1.38 and 1.29 10glO cfulcm2 on meat cutting board and meat cutting table, respectively. Ice samples had a mean total viable count of 3.20 ± 0.11 10glO cfu/ml. The coli forms count in ice, pond, and tap water were 2.30 ± 0.08, 1.39 ± 0.77 and 0.50 ± 0.21 10glO cfu/ml, respectively. The mean total viable count, coliforms count, Escherichia coli count and faecal streptococcal count observed per ml of the hand wash of the personnel engaged in various operations were 4.96 ± 0.82, 1.26 ± 0.78, 0.80 ± 0.24 and 1.48 ± 0.77 IOglO cfu/ml, respectively. The mean bacterial load in the air samples of slaughter hall and chilling room obtained in the present study was 100.7 ± 8.17 and 8.75 ± 1.19 cfu/min, respectively.ThesisItem Open Access Evaluation of bacteriological quality of processed chicken(Department of Veterinary Public Health, College of Veterinary and Animal Sciences, Mannuthy, 2003) Raji Rose, Jacob; Nanu, EAn investigation was carried out to evaluate the bacterial quality of chicken carcasses collected at two steps on the dressing line of a meat processing plant. During the study a total of 60 dressed chicken carcasses consisting of 3 0 each were randomly collected after the removal of head and feet (ARHF) and after evisceration (AB) from a meat processing plant located at Cochin. The bacterial quality was evaluated by estimating the total viable count (TVC), coliforms count (CC), Escherichia coli count (ECC) and faecal streptococcal count (FSC). All the samples were examined for the presence of Escherichia coli, salmonellae, Staphylococcus aureus and Listeria monocytogenes. Bacterial quality of environmental samples and processing equipmerits were also evaluated. The study revealed a significant (P<0.05) difference between the mean total viable count of the samples taken ARHF and AB. A higher mean count (5.88 ± 0.13 10glO cfulml) was observed in the former group of carcasses. The count of the carcasses taken after the removal of head and feet ranged between 104 and 107 cfulml while that of eviscerated carcasses vary from 104 to 106 cfulml. A higher mean coliforms count (3.92 ± 0.12 10glO cfulml) was observed in the samples taken from the carcasses after evisceration. The count of the carcasses in both groups varied between 102 and 1 O~ cfulml. Analysis of variance test of ' the mean Escherichia coli count revealed significant (P<0.05) difference between the count of the samples taken from the carcasses ARHF and AB. The eviscerated carcasses had higher count (2.15 ± 0.24 10glO cfulml) .. The mean Escherichia coli count of the carcasses taken ARHF was 0.89 ± 0.23 10glO cfulml. In both groups, the counts ranged from 102 to 103 cfulml. Escherichia coli was not detected in 63.33 per cent of carcasses taken after the removal of head and feet and 23.33 per cent of eviscerated carcasses. All samples collected from the carcasses after the removal of head and feet and after evisceration had faecal streptococci but the mean count of the samples belong to both groups did not differ significantly. !\ higher mean count (3. I) I :l.: 0.07 10glO cfu/ml) was obtained in the samples collected from the eviscerated carcasses. The samples taken after the removal of head and feet had a mean count of3.89 ± 0.0610glO cfulml. Correlation coefficient of the data revealed a significant (P<0.05) and positive association between the mean TVC and FSC, CC and ECC, CC and FSC and ECC and FSC of the samples taken from the carcasses after the removal of head and feet. A similar relationship was observed between the mean CC and ECC \ and ECC and FSC of the eviscerated carcasses. Escherichia coli was isolated from 36.67 per cent of carcasses taken after the removal of head and feet and 76.67 per cent of eviscerated carcasses. A total of 40 Escherichia coli isolated from both the groups were serotyped and grouped under 15 serotypes, two rough strains and one untypable. The serotypes consisted of 02, 05, 08, 016, 021, 051, 060, 064, 069, 078, 081, 0101, 0119, 0123 and 0140. Salmonella enteritidis was isolated from three (10 per cent) carcasses taken after the removal of head and feet. Eleven (36.67 per cent) samples taken from the carcasses after evisceration revealed the presence of Staphylococcus aureus. Listeria monocytogenes could not be isolated from both the groups of carcasses. The mean total viable count of air samples from the processing hall was high (1.99 ± 0.83 10g1O cfu/min) followed by sticking and bleeding area (1.63 ± 0.98 10glO cfu/min) and scalding area (1.54 ± 0.01 10g1O cfu/min). The water samples from the scalding tank had TVC, CC, ECC and FSC but pond and tap water samples, defeathered carcass wash and fmal carcass wash did not reveal the presence of Escherichia coli and faecal streptococci. Among the equipments, samples from the eviscerating table had TVC, CC and FSC but the samples from the defeathering machine and knife swab had only TVC and Cc.ThesisItem Open Access Evaluation of bacteriological quality of pork carcasses in a processing plant(Department of Veterinary Public Health, College of Veterinary and Animal Sciences, Mannuthy, 2003) Shiny John; KAU; Nanu, EDuring the present study, 25 pork carcasses were randomly selected from the dressing line of a pork processing plant, in order to evaluate the hygienic status of the carcasses produced in the plant. From each carcass, after evisceration and also after final washing, 500 Clll2 area was swabbed, which consisted of 100 cm2 each from jowl, shoulder, bacon, loin and ham areas. Samples collected, after evisceration were pooled into 500 1111 diluent, which formed the initial test samples. Similarly, the initial test sample was also prepared with the samples collected from the finally washed carcasses. This sample was tested to evaluate the bacterial quality of carcasses by estimating total viable count, coliforms count, Escherichia coli count and faecal streptocoecal count. The sample was also used for the isolation and identification Escherichia coli, Staphylococcus aureus, Salmonella and Listeria monocytogenes. Samples from environment, processing equipment, hand wash of personnel, scalding tank water and HOPE pouches were also tested to estimate the bacterial load. Analysis of variance test revealed signi ficunt (Peviscerated and finally washed carcasses. The mean count in the former and latter groups or carcasses was 5.14 L O.I() and 5.31 :L 0.16 loglo cfu/cm", respectively. In ()4,20 and le) per cent or the eviscerated carcasses the count was at levels 105, 104 and 10.1 cfu/cm", respectively. III tile latter group or carcasses, eight, 56,32 and four per cent had the count at the level of 10(1, 105, 104 and io' cfu/crn", respectively. The mean coli forms count of eviscerated carcasses was 1.89 ± 0.17 10g\O cfu/cm ' and the count in the finally washed carcasses was 1.99 ± 0.23 10glO cfu/crn". night and 24 per cent ni' samples bclongiru; to both groups had tile count at the level of 102 cfu/cm". The count ill 52 ami 24 per cent or eviscerated and finally washed carcass samples was at the level or lolcru/C\\l2. Eviscerated carcasses had a mean Escherichia coli count of 1.19 ± 0.08 loglo cfu/cm ' and the count ill finnl ly washed carcasses was 1.29 :I: 0.12 loglo cfu/cm", The organism was not detected in RO and R4 per cent or eviscerated and finally washed carcasses, respectively. Tile count in I () and four per cent of the former group or carcasses was at levels I {)2 and I ()I Cl'U/CI1l2. respectively. In eight per cent each of finally washed carcasses, the count was at the level of 102 and 101 cfu/cm2. '~he eviscerated and finally wash cd carcasses had a mean faecal streptococcal count of 3.19 ± 0.20 and 3.28 ±O.20 loglo cfu/cm, respectively. The count on 12 per cent of carcasses in each of the above groups, did not reveal the organism. However, in both the groups 01' carcasses, 20 pCI' cent or samples each had the count at 103 cfu/crrr'. The count in 52 pCI' cent of the eviscerated and 60 pCI' cent of the finally washed carcasses was ut the level or 102 cf'U/CIl12. The count at the level of 101 cfu/cm2 was observed in I () pCI' cent or the eviscerated and eight pCI' cent of the finally washed carcasses. Analysis 01' the data revealed positive and significant (P<0.05) association between CC and ECC in eviscerated and finally washed carcasses. However, a negative but signi ficant (P 0.05) correlation was observed between TVC and CC and TVC and ECC in the finally washed carcasses. Escherichia coli was isolated from 20 per cent of eviscerated carcasses and 16 per cent of finally washed carcasses. Out of 18 isolates recovered from both the groups, 15 fell into 12 scrotypcs and three were untypablc. The serotypes include 05,08,011, 025,060,064,078,088, OlOl, 0119, 0123 and 0140. Staphylococcus aureus was isolated from eight and 24 per cent of samples belonging to eviscerated and finally washed carcasses, respectively. None of the carcass samples in both the groups revealed the presence of Salmonella and Listeria monocytogenes. Air samples at the evisceration area had the highest bacterial count and the lowest was observed at the chilling room. Pond water samples had the highest mean total viable count and coli forms population was seen highest in scalding tank water. Escherichia coli count was highest in hand washing of personnel. None of the pond and tank water samples revealed presence of the organism. Samples collected from the bell semper had the highest mean total viable count and least in packaging material. Samples obtained from carcass splitter had the highest coliforms count. None of the processing cquipmcnts revealed the presence of Escherichia coli. Cutting board samples showed the highest faecal streptococcal, count.ThesisItem Open Access Bacteria of public health significance in broiler dressed chicken(Department of Veterinary Public Health, College of Veterinary and Animal Sciences, Mannuthy, 2002) Bindu Raj, R; KAU; Nanu, EIn the present investigation, 60 chicken carcasses, consisting of 20 each, collected from retail shops selling dressed birds which were brought from outside the state (A), shops selling locally reared dressed birds (B) and dressed chicken from the Kerala Agricultural University Poultry Farm (C). The bacterial quality of each carcass was evaluated by estimating the total viable count (TVC), coliforms count (CC), Escherichia coli count (ECC) and faecal streptococcal count (FSC). All samples were also tested for the presence of bacterial pathogens such as Escherichia coli, salmonellae, Staphylococcus aureus and Listeria monocytogenes. Analysis of variance test of the mean TVC revealed significant (P<0.05) difference between the count of the samples from source Band C. The overall mean TVC of the samples was 7.89 ± 0.07 10glO cfulml of the carcass rinse. The samples from source B had the highest mean TVC (8.06 ± 0.11 log., cfulml) and lowest mean count was seen in the samples belonging to the source C (7.69 ± 0.13 log., cfulml). The samples from source A had a mean TVC of7.94 ± 0.08 log., cfulml. The count at the level of 109 cfulml was observed in one of the samples belonging to the source B. The count in three (5%), 34 (56.67%) and 22 (36.67%) samples was at the level of 106, 107 and 108 cfulml, respectively. Analysis of variance test showed significant (P<0.05) difference between the mean CC of the samples from source A and C and Band C. The overall mean CC of the carcass rinse was 4.97 ± 0.1 0 log., cfulml. The samples from the source A had the highest mean count (5.30 ± 0.10 log}o cfulml) and lowest in the samples from source C (4.37 ± 0.17 log., cfulml). The mean CC of samples from source B was 5.23 ± 0.13 log}o cfulml. The count in l.67 per cent and five per cent of the samples was at the level of 102 and 106 cfulml, respectively. The count in 1l.67, 3l.67 and 50 per cent samples was at the level of 103, 104 and 105 cfulml, respectively. Analysis of variance test revealed significant (P<0.05) difference between mean ECC of the samples belonging to the source A and C and Band C. The overall mean ECC of samples from the three sources was 2.20 ± 0.27 log}o cfulml. The mean count of the samples belonging to the source A, Band C was 2.83 ± 0.48, 2.66 ± 0.46, 1.08 ± 0.35 10glO cfulml, respectively. The count in five, 20 and 26.67 per cent of the carcasses was at the level of 102, 103 and 104 cfulml, respectively. Analysis of variance test revealed highly significant (Pdifference between FSC of samples from source A and B, A and C and B and C. The overall mean FSC of the samples was 4.32 ± 0.09 log., cfulml. The highest mean count was observed in samples from source A (4.99 ± 0.10 log., cfulml) and the lowest mean count in samples from source C (3.75 ± 0.l0 10glO cfulml). The mean FSC in samples from source B was 4.20 ± 0.10 10glO cfulml. The count in 38.33, 46.67 and 15 per cent samples were at the level of 103, 104 and 105 cfu/ml, respectively. Correlation coefficient test of the data revealed significant (P<0.05) association between the mean CC and FSC. A positive and non- significant correlation existed between mean TVC and CC, TVC and ECC, TVC and FSC, CC and ECC and ECC and FSC. Escherichia coli was isolated from 51.67% of the samples. The 44 E. coli isolated from the samples were serotyped and fell into 21 serotypes, six rough strains and two .untypables. The serotypes consisted of 05,08, 014, 025,033,041,049,066,078,081,084,085,091,0116, 0121, 0131, 0132, 0146, 0150, 0157 and 0161. Salmonellae were isolated from two samples. Staphylococci were isolated from 30% of the samples, but none of them were coagulase positive. All samples were found free from Listeria monocytogenes.ThesisItem Open Access Bacterial profile of market beef and It`s public health significance(Department of Veterinary Public Health,College of Veterinary and Animal Sciences, Mannuthy, 2000) Deepa, Jolly; KAU; Nanu, ETbe bacterial quality of75 market beef samples, collected from four different areas, in and around Thrissur was evaluated. The samples were collected from East Fort (EF), Mannuthy (MN), Shakthanthampuran market (SM) and West Fort (WF), areas. Of the samples, 25 belonged to EF, 21 to MN, 17 to SM arid 12 to WF, areas. All samples were subjected to estimate the total viable-count, coliform, Escherichia coli. faecal streptococcal and Staphylococcus aureus counts and efforts were also made to isolate and identify Escherichia coli, Salmonellae and Staphylococcus aureus. Analysis of variance test of the data en total viable count revealed no significant difference between the mean count of the samples from the four areas. The overall mean total viable count was 7.39 ± 0.06 log to cfu/g. Samples from the MN area had the highest mean count (7.57 ± 0.11 log to cfu/g) , while samples from WF area had the lowest mean count (7.19 ± 0.15 log-Io cfu/g). The mean count of the samples from EF and SM areas were 7.29 ± 0.10 Iogto cfu/g and 7.45 ± 0.12 log to cfu/g, respectively. Of the total samples examined, 60.00,25.33 and 14.67 per cent of samples had the count at the level of 107, 106 and 108 cfu/g, respectively. A highly significant (p<0.01) difference was observed between the mean coliform count of samples from the four areas. Critical difference test of the count revealed significant difference between the mean count of samples from EF and MN, EF and SM, and WF and SM, areas. The overall mean coliform count of the samples was 4.62 ±0.06 logto cfu/g. The mean coliform count of the samples from EF, WF, SM and MN, areas was 4.35 ± 0.10, 4.50 ± 0.15~ 4.95 ± 0.12 and 4.76 ± 0.11 logto cfu/g, respectively. The level of coliform count in 54.67 per cent of samples was 10" cfu/g. The count in 29.33 per cent samples was 105 cfu/g and in 16 per cent it was 103 cfu/g. No significant difference was observed between the mean Escherichia coli count of samples from the four areas. The overall mean E. coli count of the samples , was 3.52 ± 0.09 10glO cfu/g. The highest mean count (3.67 ± 0.19 10glO cfu/g) was observed in samples from the SM area, while the lowest (3.28 ± 0.23 10glO cfu/g) was observed in samples from the WF area. The mean counts of samples from EF and MN areas were 3.41 ± 0.16 10glO cfu/g and 3.65 ± 0.17 10glO cfu/g, respectively. Of the , samples examined, 53.33 per cent had a count at the level of 103 cfu/g. In 26.67 per cent samples, the count was at the level of 104 cfu/g and in 16 per cent samples, the count was at the level of 102 cfu/g. Highly significant (p<0.01) difference was observed between the mean faecal streptococcal count of samples from the four areas. Critical difference test of the data revealed significant difference between the mean count of samples of EF and MN, WF and MN, and WF and SM, areas. The overall mean count of the samples was 4.11 , ± 0.07 10glO cfu/g. The highest mean count (4.38 ± 0.12 10glO cfu/g) was observed in the samples from MN area, whereas the lowest (3.75 ± 0.16 10glO cfu/g) was s-een in the samples belonging to WF area. The mean count of samples from EF and.Slvl areas was 3.93 ± 0.11 10glO cfu/g and 4.28 ± 0.13 10glO cfuig, respectively. The count in 49.33 per cent of the samples was at the level of 103 cfu/g. The count in 42.67 per ceru and 8 per cent samples was at the level of 104 &.i1d 105 cfuig, respectively. A significant (pviable count and faecal streptococcal count, coliform and Escherichia coli counts and coliform and faecal streptococcal counts. A positive but non-significant correlation was observed between total viable count and coliform count, and between E. coli and faecal streptococcal counts. The correlation between total viable count and E. coli count was negative and non-significant. Of the 75 samples, 98.67 per cent showed the presence of Escherichia coli. From these samples, a total of 185 isolates were identified as E. coli. Of these, 91.35 per cent were identified as E. coli biotype I and 8.65 per cent as biotype 11. Salmonella and Staphylococcus aureus could not be isolated from any of the samples. Cent per cent of the samples examined in the study, conformed to the standards prescribed for Salmonella, by the International Corrunission on , Microbiological Specifications for Foods, while only 25.33 per cent met the total viable count limit.ThesisItem Open Access Effect of refrigeration on the quality of beef frankfurter and chicken pepperoni(Department of Veterinary Public Health, College of Veterinary and Animal Sciences, Mannuthy, 2004) Ambili, V S; KAU; Latha, CThe present study was conducted to assess the microbial, physico- chemical and organoleptic qualities of beef frankfurter and chicken pepperoni at chilled and frozen storage. Effect of storage on these products was studied by estimating various microbial counts, assessing the presence of certain pathogenic and spoilage bacteria and studying the changes in pH and TBARS number and organoleptic qualities like color, odor and presence of sliminess. In chilled samples (4-7°C) the mean total viable count, faecal streptococcal count, psychrotrophic count and yeast and mold count were found to increase significantly as storage period progressed. In both the products, coliforms reached a detectable level by second day of chilled storage and thereafter the count increased. E. coli were detected only from samples of chilled beef frankfurter from fourth day onwards and the count remained at 101 cfu/g level. Aeromonas hydrophila, A. sobria and A. caviae were the three species of Aeromonas isolated from the chilled samples of both the products. Hemolytic and hemagglutination assays of these isolates were also carried out which is indicative of enteropathogenic effects. Escherichia coli were isolated from beef frankfurter samples. Among the isolates 84.62 per cent belonged to the serotype O2 ( Enterohaemorrhagic E. coli.). Salomonellae could not be detected from any of the samples. A number of samples revealed the presence of Pseudomonas aeruginosa. Important species of lactobacilli isolated were Lactobacillus brevis, Lactobacillus curvatus, Lactobacillus fermentum and Lactobacillus sake. The mean pH and TBARS values were increased during chilled storage, indicating the progress of development of acidity and rancidity. Color and odor scores gradually increased from fourth day onwards and slight discoloration was noticed on 10th day in both the products. Surface slime was developed on fourth day in beef frankfurter samples and from sixth day onwards in chicken pepperoni samples. Thus, the shelf life was found to be four days for beef frankfurter and less than six days for chicken pepperoni stored at 4-7° C. When samples were stored at –20°C, it was observed that mean total viable counts of fresh and frozen beef frankfurter samples did not differ significantly. Frozen samples of chicken pepperoni had the total viable count significantly (P<0.05) lower than that of fresh samples. Aeromonas hydrophila, A. sobria and A. caviae were isolated from frozen samples of both the products. Many of the isolates were hemolytic and hemagglutinating. Pseudomonas aeruginosa were also detected. E. coli , salmonellae, and lactobacilli were not isolated from any of the frozen samples. Frozen sausage samples had lower mean pH values when compared to fresh samples and mean TBARS values were found to decrease gradually during the frozen storage. Color and odor scores remained the same during frozen storage and slime formation was not observed in frozen samples. Study revealed that frozen samples of both products had a shelf-life of 90 days. In order to identify various critical points of bacterial contamination, samples of air, water, rinse samples from equipment, hand washing of personnel in the processing line and packaging material were examined for their hygienic quality. The mean total viable count and yeast and mold count of air samples were found to increase after processing. Among the water samples, the high microbial count was recorded for hand washings, reflecting unsanitary working practices. Among the equipment, sausage filler was found to contribute maximum to the total microbial load of the product. Among the raw ingredients, samples of beef used for preparation of beef frankfurter and samples of pork used for chicken pepperoni were found to possess high bacterial load. Coliforms were present at 2 log cfu/g level in all the ingredients. Faecal streptococci were detected in all the ingredients except beef. E. coli were present only in samples of spices. Study reflects the importance of quality assurance during every step of preparation of ready-to-cook meat products to avoid the early spoilage and to safe guard consumer health. Presence of pathogenic organisms in these products is of great public health significance as improper cooking can cause outbreaks of food borne diseases.ThesisItem Open Access Isolation and identification of certain bacteria of public health importance from market beef(Department of Veterinary Public Health, College of Veterinary and Animal Sciences, Mannuthy, 2001) Binsy, Mathew; KAU; Nanu, EIn the present investigation, 100 retail beef samples were collected from retail shops located at East Fort (EF), West Fort (WF) Sakthanthampuran Market (SM) and Mannuthy (MN) areas. From each area 25 samples were collected and were brought to the laboratory in a thermocool container. All samples were subjected to estimate Total Viable Count (TVC), Coliforms count (CC), Faecal streptococcal count (FSC) and Escherichia coli count (ECC) and also for the isolation and identification of Escherichia coli, salmonellae Staphylococcus aureus, and Listeria monocytogenes. The overall mean total viable count of the samples belonging to four areas was 6.66 ± 0.08 10glOcfu/g. The mean total viable count of EF, WF, MN and SM areas was 6.61 ± 0.15, 6.68 ± 0.17, 6.49 ± 0.15 and 6.84 ± 0.1910glOcfu/g respectively. One, 13 and 23 per cent had counts at the level of 109, 108 and 107 cfu/g respectively and 46 per cent and 17 per cent of the samples had counts at the level of 106 and 105 cfu/g. The overall mean coliforms count was 2.73 ± 0.09 log.scfu/ g. The mean coliforms counts obtained from the samples of EF, WF, MN and SM areas were 2.78 ± 0.16, 2.84 ± 0.14, 2.62 ± 0.22 and 2.70 ± 0.18 10glOcfu/g respectively. The percentage of sample that had counts at the level of 104, 103 and 102 were two, 46 and 45 respectively. The overall mean Escherichia coli count was 3.56 ± 0.17 10glOcfu/g. The mean Escherichia coli counts of EF, WF, MN and SM areas were 3.11 ± 0.38,4.00 ± 0.27; 3.52 ± 0.37 and 3.60 ± 0.34 10glOcfu/g respectively. One, 19, 45 and 17 per cent of samples had counts at the level of 104, 103, 102 and 10 cfu/g respectively. The overall faecal streptococcal count was 3.04 ± 0.09 10gIOcfu/g. The mean faecal streptococcal counts of EF, WF, MN and SM areas were 3.06 ± 0.16, 3.16 ± 0.08, 2.77 ± 0.28 and 3.18 ± 0.17 10gIOcfu/g respectively. Eleven, 53 and 30 per cent samples had counts at the level of 104, 103 and 102 cfu/g respectively. There was no significant difference in all the four counts between the four areas. The overall correlation between the 100 samples collected from the four areas showed a highly significant (P~O.O I) and positive correlation between TVC and FSC, CC and ECC, CC and FSC and ECC and FSC. A significant (P~0.05) and positive correlation was observed between TVC and CC. Only 18 per cent samples met the standards prescribed by Government of India and 63 and 61 per cent samples met the standards prescribed by ICMSF and Oregon state respectively for total viable count. Twenty and 34 per cent samples met the standards prescribed by Government of India .and Oregon state for Escherichia coli count respecti vely. None of the samples yielded Listeria monocytogenes and salmonellae, but 82 per cent samples had Escherichia coli. The serotypes obtained were 03, 019, 022, 025, 029, 034, 036, 042, 050, 051, 053, 055, 065, 066, 073,079,0105,0109,0115,0139,0140,0147,0152,0163, 0164 and 0173. Two per cent of the samples had coagulase positive staphylococci.