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Subject: Livestock Product Technology × Author: KAU × End date: 2006 × Start date: 2006 × Type: Thesis × Thesis Type: M.V.Sc. ×
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    ThesisItemOpen Access
    Tenderisation of buffalo meat by calcium chloride marination
    (Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Kavitha, Rajagopal; KAU; George, T Oommen
    The present study on the tenderisation of buffalo meat by calcium chloride marination was designed to assess the effect of marination on tenderness and other organoleptic qualities of meat and to compare the effects with those of natural ageing. Samples of longissimus dorsi muscle between 9th and 12th thoracic vertebrae from 14 healthy crossbred Murrah buffaloes of 4 – 8 years old were collected. They were assorted for three treatments, viz., samples neither aged nor calcium chloride marinated; and stored at room temperature for 6 h postmortem (NAM), samples aged only (A), samples which are marinated (AM). Samples of A and AM were stored at 2-4o C. The aerobically packaged samples for the treatment AM after 24 h of storage were marinated by injection with 200 mM calcium chloride solution (5% w/w) at multiple sites. The pH, WHC, cooking loss, color, MFI, WBSF and sensory quality attributes such as juiciness, ease of fragmentation, amount of connective tissue, overall tenderness, flavour intensity and colour of the steaks were assessed. The samples for the treatment NAM were subjected to the study at 1 h and 6 h and the steaks from A and AM at 1 h, 6 h and on days 1, 2, 4, 6 and 8. The pH of the steaks was not affected by CaCl2 marination. It followed the normal postmortem pattern, with a pH of 6.7 ± 0.01 at 1 h in all treatments. The ultimate pH of 5.6 reached on day 1 was significantly lower (P < 0.05) than on all days, which gradually increased until day 8 in treatments A and AM. The samples followed a normal rigor with sufficient amount of m-calpain and the increase in pH was due to the accumulation of products of proteolysis. The WHC at 1 h was 0.37 ± 0.021 which declined to a significantly lower (P < 0.05) value of 0.31± 0.021 at the ultimate pH on day 1. This remained almost static till day 8 in both treatments A and AM. On day 1 the pH and calcium induced shrinkage caused loss of water. Later changes in the cytoskeleton improved WHC by removing rigor induced shrinkage of myofibrils. WHC was not significantly affected by calcium chloride marination. The percentage of cooking loss increased significantly (P < 0.05) on da 1 and thereafter it remained static till day 8. Calcium chloride was not found to affect the percentage of cooking loss. The comparatively higher loss observed in the study could be attributed to the lack of external fat covering and marbling in the buffalo LD steaks. Ageing is found to improve the colour of fresh meat from day 1 onwards. But calcium chloride marination did not have any additional effect on the colour of aged meat. The decline in postmortem pH to 5.6 on day 1 contributed to higher L, a, b values which increased the light scattering properties. On subsequent days, L, a, b values remained without significant changes. This could be due to the antioxidant action of amino acids and dipeptides formed during postmortem proteolysis, which preserve the methmyoglobin reducing activity. In treatments A and AM the MFI followed a gradual significant decrease (P < 0.01) from 768.0 ± 40.52 to 541.78 ± 34.63 on day 1 and day 8, respectively in aged steaks. While in marinated it declined to 465.28 ± 29.79 on day 8. Significantly lower (P < 0.01) value of 630 ± 42.88 on day 2 in marinated samples was comparable to that in the aged samples on day 4, indicating the early achievement of tenderness in marinated samples. MFI varied little with ultimate pH. MFI is deemed as a very useful indicator of meat tenderness particularly when sample size is smaller for the determination of shear force or sensory evaluation. Significantly highest (P < 0.01) WBSF value of 11.37 ± 0.61 obtained on day 1 could be attributed to rigor induced shortening. The values declined significantly in treatments A and AM. The values obtained for the marinated steaks were significantly lower (P < 0.01) than the aged samples on all days postmortem. It reduced from 10.48 ± 0.48 at 1 h postmortem to 4.88 ± 0.45 in a course of 8 days. This indicated a 53.44% reduction in values from 1 h to day 8, while in aged sample only a 35.59% reduction was noticed in a course of 8 days. The sensory panel evaluation of organoleptic qualities showed that calcium chloride marinated steaks significantly improved (P < 0.01) in the scores for the different attributes studied on each day of ageing. No flavor problems or alterations in cooked color were noticed at 200mM CaCl2. Correlation studies in between MFI and WBSF revealed a significant positive correlation (P < 0.01) with r = 0.85 in A and 0.84 in AM on all days from 1 to 8. This indicates that MFI could be used as an indicator of tenderness of fresh meat rather than cooked. WBSF and MFI were strongly correlated with the overall tenderness measured by taste panel evaluation. The overall tenderness was more negatively correlated with SF (r = 0.70) rather than MFI (r = 0.65). The tenderness and other organoleptic qualities of buffalo longissimus steaks could be improved significantly by post-rigor marination with 200mM CaCl2 (5 % w/w) on day 1 and subsequent ageing at 2 – 4o C for 4 – 8 days. The tenderness improved by 53.44 per cent in marinated steaks as against 35.59 per cent in those aged without marination. The improvement in tenderness could be attributed to the activation of μ- and m-calpain by calcium ions and the autolysis of calpastain at 2 - 4o C of ageing.
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    ThesisItemOpen Access
    Effects of preslaughter stress and irradiation on physicochemical qualities of meat
    (Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Vivek, A K; KAU; Kuttinarayanan, P (Guide)
    The effect of stress on the blood parameters and physicochemical qualities of meat as well as effect of irradiation on the qualities of fresh meat from stressed cattle were investigated in the present study. A total of 27 culled adult cattle from different farms were grouped into three, having nine animals in each group. Group I animals were considered as control while group II animals were transported for 2 h and slaughtered immediately after transport. Group III animals were transported for 6 to 7 h and given rest for 18 h before slaughter. Blood samples were collected prior to transport in all the animals, immediately after transport in group II and III and after 18 hours rest, before slaughter, in group III animals. Meat samples were collected from all the animals in which half of the samples were subjected to irradiation at 2.0kGy with gamma irradiation, as Cobalt 60 as source. The samples were stored at 40C for further studies. Animals in all the groups were having homogenous blood values prior to transport in cortisol, CK, BUN, creatinine and PCV. After transport, group II had a significant increase in cortisol (P<0.01), CK (P<0.01) and BUN (P<0.05), while group III had a significant increase in cortisol (P<0.01), CK(P<0.01), BUN (P<0.05) and creatinine (P<0.05) except PCV, in which the increase in cortisol and CK were significantly (P<0.01) greater than that in group II. By giving rest, even though there was significant (P<0.01) reduction in cortisol and CK values, the after rest values of cortisol (P<0.01), CK (P<0.01) and BUN (P<0.05) were significantly higher than that of the before transport values. In the case of pH and WHC, the trend was almost similar, with a higher value at zero hour and the decline was drastic in zero to 6 h, followed by 6 to 12 and 12 to 24 h and the control and irradiated samples did not show any significant difference in the decline. Cooking loss of the control and irradiated samples did not have a significant difference at zero hour storage, while the 24h storage brought a significant (P<0.01) increase in cooking loss in all the samples and irradiated samples had a significantly (P<0.05) higher cooking loss at 24h. Shear force values were significantly (P<0.01) less for irradiated samples while storage significantly (P<0.01) increased the values of all the samples. The Hunterlab colour values, L, a, b, C and hue angle, were significantly (P<0.01) higher in irradiated samples at zero hour storage. At 24h storage, the values were significantly (P<0.01) higher than that at zero hour, and only the hue angle values were significantly (P<0.05) higher in irradiated samples. Even though there existed a slight difference between control and irradiated samples in various organoleptic qualities like colour, flavour, juiciness and tenderness, there was no significant difference in overall acceptability between control and irradiated samples. In the present study, the differential response due to irradiation for the stress given to the animals, found to be statistically non significant leading to the result that irradiation conditions did not have an impact on the meat obtained from stressed animal.
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    ThesisItemOpen Access
    Determination of residues of carbofuran and its metabolites in tissues of buffaloes and ducks
    (Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Poulson Joseph; KAU; George T, Oommen
    A research work on the determination of residues of carbofuran and its metabolites in tissues of buffaloes (Bubalus bubalis) and ducks (Anas platyrhynchos) was under taken. The objectives were to develop and standardise a suitable simple method of extraction of residues of carbofuran and its metabolite from meat, liver, kidney and fat of buffaloes and ducks for reversed phase HPLC analysis and to apply this method for further screening of animal tissues for monitoring these residues Fifteen samples of each tissue of buffaloes and ducks were randomly collected from different lots of slaughtered animals in Kerala. Different solvents, viz., acetonitrile (ACN), acetone, methanol, hexane and 2-propanol were used for the extraction of carbofuran residues and its metabolite from tissues. The extracted samples were cleaned up by liquid-liquid partitioning for HPLC analysis using Schimadzu LC-10 AVP series with UV/VIS detector at 211 nm in a mobile phase of acetonitrile (35): water (65). Certified standard references of carbofuran and its metabolites, viz., 3-hydroxy carbofuran, 3-keto carbofuran, 3-hydroxy 7-phenol carbofuran, 3-keto 7-phenol carbofuran and carbofuran phenol were analysed in HPLC to identify the chromatogram peaks of respective compounds. Excellent linearity was observed for carbofuran and 3-hydroxy carbofuran at 1, 10 and 100 ppm. Based on the highest percentage of recovery, ACN was chosen as the best solvent for extraction of residues from meat, liver and kidney and hexane for fat. This solvent system was applied for the extraction of residues in a further HPLC residue monitoring programme in the tissues of buffaloes and ducks. In buffalo meat, liver, kidney and fat the residues of carbofuran and its metabolites could not be detected and hence denoted as below detection limit (BDL). Residues could not be detected in all duck tissue samples, except in one sample, wherein 3-hydroxy carbofuran was detected at 2 ppm and 0.9 ppm in meat and kidney, respectively which is above the MRL. An appropriate method is developed for the screening of animal tissues to detect the presence of residues of carbofuran and its metabolites. This would enable in monitoring and surveillance of residues of carbofuran in animal tissues, hazard analysis and determining the critical control points.
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    ThesisItemOpen Access
    Effect of low dose gamma radiation on the quality of intermediary moisture pet food
    (Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2006) Rana Raj, V R; KAU; Kuttinarayanan, P
    The effect of low dose gamma irradiation on the quality of intermediary moisture pet food was assessed in the present study. Dog biscuits were prepared using meat cum bone meal, plain flour (Maida), blood, rendered fat, eggs, wheat bran and black gram flour. The mix was baked at different time temperature combinations to attain three different moisture levels of 10, 15 and 25 per cent. The samples were separately packed in High Density Polyethylene (HDPE) packets at a rate of 200g each and then subjected to gamma irradiation using Gamma Chamber 5000 at various doses of zero, 2.0 kGy, 3.0 kGy, 4.0 kGy, 6.0 kGy and 8.0 kGy. After irradiation the samples were kept in ambient temperature for further analysis like proximate composition, development of rancidity, microbiological quality and palatability/ acceptability attributes on the day of preparation and then on 7, 15, 30, 45, 60, 75, 90, 120, 150 and 180 days of storage or till spoilage which ever was earlier. The proximate compositions of the dog biscuits of all moisture levels were not significantly affected by various doses of irradiation and days of storage. The TBARS values were shown a significant (P<0.05) increase with the increase in the doses of irradiation. The days of storage were also affected the TBARS values significantly (P<0.05). The samples irradiated at 6.0 and 8.0 kGy of all moisture level dog biscuits were spoiled between 120 to 150 days where as the samples irradiated at 4.0 kGy showed a higher shelf life in the absence of any developed rancidity changes. The aerobic plate count was shown a significant reduction as the dose of irradiation increased, also a significant (P<0.05) increase was noticed with the days of storage. In 10 per cent moisture level dog biscuits, the samples irradiated at 6.0 and 8.0 kGy revealed 100 per cent reduction of aerobic organisms, where as the same result was obtained for the samples irradiated at 8.0 kGy in case of 15 per cent moisture level dog biscuits. Coliforms and staphylococcal organisms were present only in 25 per cent moisture level dog biscuits and they were completely destroyed at an irradiation dose of 4.0 kGy and above. All the samples under study were found free from E. coli, Salmonella, Clostridium and faecal streptococcal organisms. The yeast and mould count also showed the same trend as aerobic organisms. The samples of 10 and 15 per cent moisture level dog biscuits were found free from yeast and mould when irradiated at 4.0 kGy and above, while the same result was obtained for 25 per cent moisture level samples on irradiation at 6.0 and 8.0 kGy. The palatability/ acceptability studies were conducted using the dog biscuits of 5, 10, 15 and 25 per cent moisture levels irradiated at 4.0 kGy. The dogs preferred intermediary moisture dog biscuits of 15 and 25 per cent moisture levels when compared with dry dog biscuits having 5 and 10 per cent moisture. It was observed that gamma irradiation of dog biscuits significantly reduced the microbial load with out affecting their proximate compositions. But higher doses of irradiation induced the production of oxidative rancidity. The palatability studies revealed that intermediary moisture level food was more preferred by the dogs than dry food. This study also found that the dog biscuits containing 10 per cent moisture and irradiated at 4.0 kGy had got the highest shelf life of more than 180 days.