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ThesisItem Open Access Effect of rice beer and phyto-ingredients on certain quality characteristics of duck meat product(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2023) Boro, Pompi Rani; Laskar, S KThe study was conducted in the Department of Livestock Products Technology, Assam Agricultural University, Khanapara, Guwahati-22 to develop a duck meat product incorporating rice beer, phyto-ingredients and spices as marinating ingredients along with control without affecting the physico-chemical, microbial, organoleptic qualities and shelf life of the meat. A total of five batches of marinated duck meat comprising of 4 different treatments in each batch were prepared. Ducks were collected and slaughtered hygienically and marinated. The marinades were prepared by using rice beer, spice paste and phyto-ingredients. The marinated samples are grouped into following treatments for control (meat and spice paste), Treatment 1 (meat and rice beer), Treatment 2 (meat, phyto-ingredients and spice paste) and Treatment 3 (meat, spice paste, rice beer and phyto-ingredients). The marinated samples were vacuum and aerobically packed and stored in refrigeration temperature for 24 hrs. After these periods, the samples were subjected to various quality assessments. Shelf life studies conducted at interval of 5 days for vacuum packed samples, whereas, aerobically packed samples were assessed for shelf-life studies at an interval of 3 days. The results of the investigation are as follows: The alcohol content (%) of rice beer found to have 6.02±0.2. The pH value was 3.58±0.09 and the antioxidant activity (%) was found to have 16.12±0.13. The results with respect to pH, tyrosine and TBA of marinated duck meat were found to be significantly (P<0.01) higher when compared to control samples. Mean cooking yield was found to be higher in control samples as compared to the treated samples. The cooking yield was significantly lower in treated samples as compared to that of control samples. The mean percent of proximate composition of products showed similar trend for both aerobic and vacuum packaging systems. Moisture was high in the Treatment 3 samples as compared to that of control samples, whereas, crude protein, ether extract and total ash was high in control samples. The mean values of moisture, crude protein, ether extract and total ash showed significant differences among the control and treated samples but no significant effect could be seen in both the packaging conditions. The mean values of colour profile showed no significant differences between the control and treated samples and also no significant effect in both the packaging conditions. The data generated for aerobic packaging method revealed marginally higher L* values. The L* value was lower for treated products than that of control products. Redness (a*) followed a decreasing trend in all the treated products as well in control products. Slight decrease in yellowness in vacuum packaged duck meat products. ii The mean values of texture profile also showed similar trend in both the packaging systems. The hardness values showed a decreasing trend in treatment 3 as compared to control samples in both the packaging systems. However hardness values were marginally lower in vacuum packaged samples when compared to aerobically packaged samples. Significant differences (P<0.01) could be observed in the control and treated samples for springiness and chewiness, whereas, cohesiveness followed an increasing and decreasing trend and no significant (p>0.05) differences among all the treated samples. The resilience followed uniformly decreasing trend from control to T3 samples The sensory evaluation showed no significant differences (Appearance, colour, flavour and tenderness), whereas, significant differences were observed for juiciness and overall acceptability. The microscopic study in both (scanning electron microscope and light microscope ) revealed swelling of muscle fiber and decrease in inter fibrillar spacing between the muscle fibers and disruption of connective tissue membranes due to use of marinating ingredients. The microbiological quality studies revealed that there is a significant increase (P<0.01) in control samples compared to treated samples during the entire storage periods in both the packaging systems, whereas, total psychrophilic count could not be detected on 1stand 5th day of storage in vacuum packaging but on 10th and 15th day it increases in the storage periods. Similarly for aerobically packaging systems, TVPBC were not detected on 1st day of storage but on 3rd, 5th and 7th day of storage it increases in the storage periods. The Yeast and Mould count and Coliform count were absent in all the storage periods in both the packaging systems. The Sulphite Reducing Clostridial organisms and salmonella were also found to be absent in all the samples for both the packaging systems. The shelf life studies of marinated duck meat were studied on the basis of pH, tyrosine, TBARS value, microbiological quality and visible colour and odour changes of the products at refrigeration temperature. Vacuum packaging system was found to be better than the aerobic packaging system. Based on the investigation, it can be concluded that an acceptable marinated duck meat product can be developed for future commercial exploitation.ThesisItem Open Access Interaction studies of microbial enzymes and phytochemicals of Bael (Aegle marmelos) in flavour enhancement cow's milk ghee(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Saikia, Rashmi Rekha; Borpuzari, TrishnaA study was conducted to develop flavour and colour enhanced cow’s milk ghee using starter cultures as a source of microbial enzymes and phytochemicals of bael (Aegle marmelos) fruit pulp extract. The experiment was conducted in the laboratories of the Department of Livestock Products Technology, the All India Coordinated Research Project on Post-Harvest Engineering and Technology, the Department of Livestock Production and Management, the Department of Veterinary Biochemistry, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati–781 022; and the Central Analytical Instrumentation Facility, Guwahati Biotech Park Incubation Centre of the Indian Institute of Technology, Amingaon, Kamrup, Guwahati-781 031 during the period from August 2020 to April 2022. Lactococcus lactis ssp. lactis var. diacetylactis and yoghurt cultures of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus were used @ 3% (v/v) in the study. Bael pulp extract was added @ 1% (v/v) to the treatment groups. Cow’s milk ghee was prepared by the heat clarification method. The flavour and colour qualities, FFA contents, antioxidant compounds, sensory attributes, proximate composition and shelf-life of the cow’s milk ghee thus prepared were studied. The ghee was stored at ambient temperature to study the shelf-life. A total of 34 flavour compounds were detected in the samples of the treatment groups as well as the reference sample by GC-MS studies. Identical numbers of FFA were also detected in the ghee samples. The flavour of the ghee was attributed by the FFA along with the other flavouring compounds like the alcohol, hydrocarbons, ketones, terpenoids, organic acids and 9 other compounds identified in the ghee samples. Ascorbic acid, thymol, phytol and β-sitosterol were the four antioxidant compounds detected by GC-MS. The maximum radical scavenging activity (60.160±0.541%) was observed in the sample of T4. Bael pulp extract added ghee samples had higher DPPH inhibition activity as compared to the other groups and the reference sample. Colour component b* was found in higher values in bael pulp extract added ghee samples. Highly significant positive correlation was found between the sensory evaluation scores for colour and the colorimetric assessment of the colour components (b* value). Higher panel ratings for flavour and colour of the samples of T4 group indicated that bael pulp extract indeed had a positive effect on the flavour and the colour characteristics of cow’s milk ghee. The moisture and ash contents of the ghee were highly significantly influenced by the starter cultures and addition of bael pulp extract while only significant difference could be found in their protein content. Shelf-life study was done based on the FFA and peroxide values. Correlation studies revealed a highly significant difference between FFA and PV while a negative correlation existed between the FFA x antioxidant activity and PV. A gradual increase in FFA and PV along with the increase during the storage period was found in all the treatment groups. Even after 6mon of storage, FFA and PV were found to be much lower than those recommended by the FSSAI (2016). From the study it was found that the starter culture Lc. lactis ssp. lactis biovar diacetylactis used in the study in combination with the bael pulp extract produced cow’s milk ghee with improved flavour and colour attributes and had an extended shelf-life at room temperature.ThesisItem Open Access Detection and deactivation of antimicrobial residues in pork(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-09) Debbarma, Param; Laskar, S KThe present study aims to detect antimicrobial residues in collected pork samples, isolation and in-vitro study of the resistance pattern of meat-borne pathogens (Escherichia coli, Salmonella spp. and Staphylococcus aureus) against 12 commonly used antimicrobials in pig husbandry and effect of different cooking methods (viz, boiling, roasting and microwaving) on deactivation/inactivation of antimicrobial residues. The preliminary screening of 261 pork samples by microbial inhibition assay using endospores of Bacillus subtilis MTCC 441 as test organism revealed that none of the samples were positive for antimicrobial residues except 3 (three) which were doubtful to have traces of antimicrobial residues. A total of 80 pork samples were further screened by Ultra-Fast Liquid Chromatography system (Model: Shimadzu Prominence LC-20AD, Detector-SPD-20AUV/ Vis; C18 Column: BDS Premium, 250 mm x 4.6 mm, 5 m) to detect OTC, TTC, CIP and GEN residues. OTC and CIP residues were detected in 2.5% and 1.25% of the samples, while none of the samples detected TTC and GEN residues. The overall recovery rate of Escherichia coli, Salmonella spp. and Staphylococcus aureus from the pork samples were 28.75%, 9.09% and 31.25%, respectively. All the isolates showed variable ranges of resistance against the tested antimicrobials. Highest resistance was recorded against ampicillin (75-100%), followed by trimethoprim (37.5-100%), cefepime (25-75%), nalidixic acid (12.5-62.5%), sulfafurazole (0-37.5%), ciprofloxacin (0-37.5%), chloramphenicol (0-37.5%), ceftriaxone (0-25%) and amoxiclav (0-12.5%). All the isolates however, recorded 100% sensitivity against amikacin, gentamicin and tetracycline. The effect of cooking viz. boiling, roasting and microwaving revealed significant reduction (p˂0.001) in the residual concentration of antimicrobials (OTC, TTC, CIP and GEN). Cooking by microwaving recorded highest reduction (44.48-91.06%) followed by roasting (32.11-85.92%) and boiling (22.02-73.33%). Thus, cooking temperature and time can have a significant effect on the losses of antimicrobial residues and provides an additional safety margin to the consumers.ThesisItem Open Access Effects of different methods of smoking and levels of fat on certain quality characteristics of buffalo meat sausages(College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022) Mali, Anindita; Laskar, S KBuffalo meat sausages were developed employing different methods of smoking and levels of fat to obtain a healthy product with good shelf-life properties and economic feasibility. Three primary treatment groups were prepared, namely- T1 (20% fat), T2 (10% fat + 10% inulin), T3 (7.5% fat + 12.5% inulin), which were subjected to three subgroup A (Conventional smoking), B (3% Liquid smoke), C (7% Liquid smoke). The control was prepared with 20% fat without any sub-treatments. 5 batches of buffalo meat sausages were prepared and evaluated for various important qualitative parameters on the 1st, 7th, 14th, 21st and 28th day of refrigerated storage, including estimation of PAH and cost of production. The ES and CY were seen to significantly increase with the replacement of fat with inulin and the highest was observed in the treatment group T3. The pH value decreased significantly (P<0.05) in all the treatments in comparison to the control, the lowest of them being T2A (5.69 ± 0.09). With higher inclusion of inulin, the aw, and WHC significantly (P<0.05) increased in the treatment. The TBARS values were significantly (P<0.05) lower in the treatment group T3, ranging (from 0.30 ± 0.02 to 0.34 ± 0.03). The tyrosine value did not vary significantly among the control and treatments. However, T3B (10.14 ± 0.38) and T3C (10.10 ± 0.44) were significantly lower. The proximate analysis depicted treatment T3C to have the highest moisture content of 68.62 ± 0.45. The protein content did not vary significantly between the control and treatment and ranged from 19.05 to 19.72%. The fat content reduced from 19.12± 0.46 to 8.08± 0.33 when inulin was substituted for fat. The highest fat per cent was observed in T1A (19.12 ± 0.46) and the lowest inT3C (8.08 ± 0.33). The ash content increased from 1.04 ± 0.07(control) to 2.63 ± 0.06 (T3C) with the addition of inulin at higher percentages. The lowest calorific value was obtained in T3C (155.79 ± 1.42), corresponding to the lowest level of added fat. The mean log10 cfu for total plate count showed significant (P<0.05) differences between the control and other treatments, without any significant difference among the treatments. The buffalo meat sausages were not detected for E. coli, yeast and mould, Salmonella and Staphylococcus. The TPA results showed that with higher inclusion of inulin as a fat replacer, the hardness, springiness, chewiness and resilience significantly increased. However, cohesiveness was not significantly affected. The colour profile study depicted a significant increase in the L* value, with higher inclusion of inulin (54.95 ± 0.22) in T3B; however, the a* values were inversely co-related to L*. The b* did not vary between treatments and control, except for treatment T3C. The estimation of PAH depicted that the potent carcinogen Benzo(a)pyrene was absent in control and all the treated samples. However, the PAH compounds, Fluoranthene and Chrysene, were observed in the samples in both conventionally smoked and liquid smoke added products. The concentration of Fluoranthene differed significantly and was found to be the lowest in T1B (15.10 ± 0.00) and the highest in T2C (53.47 ± 9.04), while Chrysene content did not vary significantly and ranged from (32.27 ± 0.97 to 38.37 ± 1.77). Considering the above parameters, T2 was found to be better than other treatment groups, and therefore the sausage samples of T2, along with the control, were subjected to the organoleptic evaluation. The subjective evaluation revealed that the conventional smoking treatment T2A had the highest scores for appearance, colour, flavour, texture and overall acceptability.The developed buffalo meat sausages were found to be stable for up to 21 days under vacuum packaging at a refrigeration temperature (4 ± 10C), after which the microbial counts exceeded the FSSAI standards. The cost of production was calculated based on the market prices of the raw materials. The highest was observed for T3C (Rs. 763.45/kg), while the lowest was for control (Rs. 518.00/kg). Based on the findings of the present study, treatment group T2, in particular, T2A, was the best among all the treatments.ThesisItem Open Access DEVELOPMENT AND QUALITY ASSESSMENT OF SOLAR AND OVEN DRIED SPENT HEN MEAT POWDER(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2019-06) SARKAR, BIJOY KUMAR; Hazarika, MineswarChicken occupies one of the important constituents of Indian non-vegetarian diet due to cost competitiveness, nutritional quality, universal availability and absence of religious taboos. Spent hen meat represents hardiness, poor acceptability and lowers remunerative prices in spite of its good nutritional quality, because of its higher collagen content and toughness of meat compared to those of broilers and roasters. To overcome the problems of toughness of spent hen meat, perishability of fresh meat, high cost involvement in maintaining refrigeration, lack of cold storage facility, energy deficiency in NER, disadvantages of traditional drying etc. a study was undertaken to develop spent hen meat powder with better shelf life at ambient temperature without affecting its quality. Keeping in view the above facts, the proposed study was undertaken with the following objectives viz. development of technology for preparation of spent hen meat powder by using oven and solar dryer and by incorporating phytochemicals; determination of physico-chemical, microbiological and sensory qualities of spent hen meat powder; selection of an effective and suitable packaging method; and determination of shelf life and cost of production. A total of five batches of spent hen meat powder were prepared with different formulations with or without addition of the phytoingredients in solar dryer (60-70°C for 30- 32h) and oven dryer (70°C for 18-20h). Control of solar dried spent hen meat powder was packaged with LDPE (150μm) under aerobic (A) and vacuum packaging (B); similarly treatment was packaged under aerobic (C) and vacuum packaging (D) for assessment of quality and identifies shelf stability. At the same time control of oven dried spent hen meat powder was packaged under aerobic (E) and vacuum packaging (F) and treatment was packaged under aerobic (G) and vacuum packaging (H). The results of the investigation are as follows- Yield decreased in treatments, whereas hygroscopicity, water hydration capacity, bulk density and solubility do not very. Water activity, pH and TBARS value increased during storage. Treated sample show lower pH and TBARS value than control. TBARS values of meat powder under vacuum packaging were lower than aerobic packaging during storage. Tyrosine values were higher in oven dried sample compared to solar dried sample. Lightness and yellowness values shows an increasing trend, whereas redness shows decreasing trend during storage period. Increasing trends in moisture content were observed during the storage periods. Crude protein, crude fat, total ash and carbohydrate content of spent hen meat powder did not differ much between samples and during storage. Decreasing trends of calorific value of samples were observed during storage period kept under aerobic packaging. All the samples were microbiologically safe throughout the storage period. All the samples were acceptable up to 150 days with good sensory scores. Spent hen meat powder can store up to five months at room temperature under both aerobic and vacuum packaging. Main antioxidant compounds present in phytoingredients extract were identified by LC-MS and large numbers of antioxidant compounds were found to be present in the phytoingredients. Solar drying is economical over oven drying for preparation of spent hen meat powder with similar product quality. Vacuum packaging is better to preserve product quality. Addition of phytoingredients increases the cost of production but provides better product quality and shelf stability. Based on the above study it can be concluded that chemically, microbiologically and organoleptically acceptable spent hen meat powder can be prepared with the use of low cost solar dryer.ThesisItem Open Access CERTAIN ASPECTS OF CARCASS AND MEAT QUALITY CHARACTERISTICS OF SWAMP BUFFALOES OF ASSAM(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2019-07) RAHMAN, ZIAUR; Hazarika, MineswarThe swamp buffaloes of Assam play an important role in the socio-economic as well as socio-cultural life of the people of Assam. Swamp buffaloes are poor in milk production but yield excellent source of meat. It is widely recognized that meat is an excellent source of good quality protein provides all essential amino acids and several micro-nutrients in proper proportion to support human health. As some people have wrong conception towards the consumption of red meat that it causes cardiovascular diseases, but in present day situation the best alternative red meat is carabeef, a rich source of hypocholesterolemic fatty acids. Buffalo is the only potential animal that can boost meat industry in India. A study on the carcass characteristics and meat quality traits including viz. pH, Water Holding Capacity (WHC), Extract Release Volume (ERV), Drip loss, Cooking loss, TBARS, Tyrosine value, Muscle fibre diameter, MFI, Hydroxyproline content, Proximate Composition, Texture and Colour profile analysis along with organoleptic, shelf-life and microbial qualities of meat of swamp buffaloes of the age groups 2-4 years and above 4 years of either sexes were carried out. Twenty buffaloes were slaughtered in service type of slaughterhouses. Their live weight, carcass weight, dressing percentage, carcass length, loin eye area, weight of different wholesale cuts and by-products were recorded. The physico-chemical qualities were assessed on 1st, 2nd, 4th and 6th day. The representative meat samples (L. dorsi) were kept at refrigerated temperature (4 ± 1°C) up to 6th day for quality assessment. Significant (P < 0.01) and progressive increase in live weight, carcass weight, carcass length, loin eye area and dressing percentages were recorded along with increase in age and irrespective of sexes although these were recorded more pronounced in male than female. A progressive increase in by-products yields were recorded as age advanced and were found to be more in female than in male. The weight of fore quarter was more than the hind quarters, round followed by chuck were the heaviest among the wholesale cuts. The meat pH did not show significant differences. Although there was significant (P < 0.01) increase in the overall mean values of pH and WHC (sq cm) during the refrigerated storage. Yet, there were no significant differences in overall mean pH and WHC values with increasing age of buffaloes of either sexes. The overall mean ERV (ml/100gm) and shear force values (kg/cm2) were higher on 1st day as compared to 6th day of refrigerated storage. There was significant (P < 0.01) increase in the overall mean of shear force along with increase in the age of both the sexes of buffaloes but no significant differences were observed in overall mean ERV values. TBARS (mg malonaldehyde/kg) and Tyrosine (mg tyrosine/100gm) values increased significantly (P < 0.01) with the increase in the refrigerated storage period from 1st to 6th day. No significant differences were observed in overall mean TBARS and Tyrosine values with the increasing age of either sex of swamp buffaloes. A significant (P < 0.01) decrease in the overall mean values of per cent MFI was recorded with increase in the age of both the sexes of buffaloes. The overall mean per cent MFI values increased significantly (P < 0.01) along with the increase in the storage periods from 1st to 6th day. Muscle fibre diameter (μ) and per cent Hydroxyproline content were higher on 1st day as compared to 6th day of storage in refrigeration temperature. The overall mean Muscle fibre diameter and per cent Hydroxyproline content increased significantly (P < 0.01) on increase in the age of buffaloes of both sexes. On Texture Profile Analysis, the overall mean values of hardness (g), springiness (mm), cohesiveness, chewiness and resilience were found to be significantly (P < 0.05) decreased from 1st to 6th day of storage. There was no significant differences in the overall mean values of hardness (g), springiness (mm), cohesiveness, chewiness and resilience on increase in the age of both sexes of buffaloes. On colour profile analysis, significant (P < 0.05) decrease in the overall mean values of lightness (L*) with the increase in the age of either sexes of buffaloes. The overall mean values of lightness (L*) increased significantly (P < 0.01) with the increase in the storage period from 1st to 6th day and significant (P < 0.01) increase in overall mean values of redness (a*) with the increase in the age of both the sexes of buffaloes. The overall mean values of redness (a*) decreased significantly (P < 0.01) with the increase in storage period from 1st to 6th day. There was significant (P < 0.01) decrease in the overall mean values of yellowness (b*) with the increase in the age of both the sexes of buffaloes. The overall mean values of yellowness (b*) increased but non significantly with the increase in the storage period from 1st to 6th day. A significant (P < 0.01) decreasing trend in the overall mean values of per cent moisture was observed on increase in the age of buffaloes irrespective of sexes. However, increase in storage days showed no significant differences. A significant increase in the overall mean values of per cent crude protein, per cent ether extract and per cent total ash were recorded along with increase in the age of buffaloes of either sex. The overall mean values of per cent crude protein, per cent ether extract and per cent total ash showed no significant differences with the increase in storage periods from 1st to 6th day. Per cent drip loss showed significant (P < 0.01) decrease in the overall mean values on increase in age of both the sexes of buffaloes. The mean per cent drip loss increased significantly (P < 0.05) with the increase in storage periods from 24 to 48 hours. The overall mean values of per cent cooking loss decreased significantly (P < 0.01) with increase in the age of both the sexes of buffaloes during storage periods. Microbial studies revealed that the Psychrophillic, Mesophillic, Coliform, Yeast and Mould counts increased significantly (P < 0.01) with increase in storage period from 1st day to 6th day and the counts were in acceptable range up to 3rd day. Staphylococcus aureus were detected only on 6th day of storage. Five meat samples out of twenty were found to be positive for Salmonella. Organoleptic evaluation of meat revealed that panelist preferred meat of 2-4 years age group of buffaloes. The above study leads to the conclusion that the meat of 2-4 years of age group of buffaloes of either sex were more tender and juicy and could be stored safely at refrigerated temperature (4 ± 1ºC) up to 3rd day. To reduce the initial bacterial load for slaughtering and dressing of buffaloes, should be done on hanging the carcass to enhance the shelf-life of meat. Since swamp buffaloes are considered as meat animals in draft policy of Assam, data obtained in present study would be quite useful for Government to take progressive steps in the processing and marketing of buffalo meat both for domestic and export purpose.ThesisItem Open Access INFLUENCE OF COAGULATING ENZYMES, IRON FORTIFICATION AND PACKAGING METHODS ON THE QUALITY CHARACTERISTICS AND SHELF-LIFE OF MOZZARELLA CHEESE(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2019-01) RAQUIB, MASUK; Borpuzari, TrishnaA study was carried out to develop iron fortified mozzarella cheese from cow’s milk, goat’s milk and mixed milk using kiwifruit crude extract. The experiment was conducted in the laboratories of Department of Livestock Products Technology, All India Coordinated Research Project on Post- Harvest Engineering and Technology and Department of Veterinary Microbiology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati -781 022. Kiwifruit crude extract was prepared from fresh kiwi fruits (Actinidia chinensis). The proteolytic enzyme present in the crude extract identified through SDS-PAGE was actinidin having an apparent molecular mass of 24.5 kDa. Optimum level of kiwifruit extract can be used @ 150μg/ml of milk for complete coagulation within 27min for preparation of iron fortified mozzarella cheese. Mozzarella cheese can be efficiently fortified with ferric chloride safely without giving rise to off-flavour in the product at an optimum level of 1g/lts of milk. Maximum retention of iron (51.29mg/kg) was recorded in mixed milk iron fortified mozzarella cheese samples. Effect of enzymes and different types of milk were studied on the physico-chemical properties (pH, acidity), proximate composition, water activity, meltability, colour profile, texture analysis, yield, organoleptic properties and microbiological quality of iron fortified mozzarella cheese. Proximate composition revealed highest values for total solid and ash content for goat’s milk iron and fat in mixed milk iron fortified mozzarella cheese, while lowest moisture and fat content were recorded in goat’s milk iron fortified mozzarella cheese in the treatment group. Texture profile analysis of goat’s milk iron fortified mozzarella cheese samples showed higher values for hardness, springiness, cohesiveness and chewiness while cow’s milk iron fortified mozzarella cheese samples recorded higher value for adhesiveness and mixed milk iron fortified mozzarella cheese for gumminess parameters. There was a gradual increase in curd syneresis with advancement of time. Curd syneresis was noted to be highest in cow’s milk followed by goat milk and least was observed in mixed milk over a period of 120min. Mixed milk iron fortified mozzarella cheese enjoyed superior ratings for all the sensory attributes, viz., appearance, colour, body and texture, flavour, saltiness and overall acceptability. The TVC increased gradually from 0d till 15d of refrigerated storage for all the samples of iron fortified mozzarella cheese under both aerobic and vacuum packaging conditions irrespective of the types of milk and enzymes used. Under aerobic packaging condition, higher TVC were observed for goat’s milk sample in both control and treatment group all throughout the storage period. Mixed milk iron fortified mozzarella cheese exhibited least count in both the groups. The TVC of all the cheese samples were higher in aerobic packaging compared to vacuum packing. Nil counts for Yeast and moulds, E. coli, Coliform, Staph. aureus, Salmonella, Shigella, Listeria monocytogenes and anaerobic spore counts were noted for all the types of cheese samples under both the packaging conditions, all throughout the storage period, under refrigerated condition Best before use of mixed milk iron fortified mozzarella cheese samples was found to be 15d under both the packaging conditions with lesser TVC in the vacuum packaged samples. Based on proximate composition, meltability, sensory attributes microbiological quality and cost of production, the technology developed under treatment group for mixed milk mozzarella cheese is recommended and a suitable protocol for commercial production of iron fortified mozzarella cheese has been proposed.ThesisItem Open Access TECHNOLOGY UPSCALING OF CERTAIN TRADITIONAL PORK PRODUCTS OF NAGALAND(College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 2018-12) SANGTAM, H. MOAAKUM; Laskar, S. K.Traditional pork products of Nagaland prepared with locally available plant based ingredients viz. Anishi, Silam and FDS (Fermented dried soya) were evaluated in the present study. Based on the popularity, a purposive survey was conducted in field level to evaluate the level of ingredients used and with an aim to refine and upscale the processing steps and to extend the shelf life of the products. Three formulations were prepared using pork with Anishi, Silam and FDS along with a control, prepared without adding the above ingredients. On the basis of pilot study, the level of incorporation for Anishi, Silam and FDS were selected as 5, 10 and 5 percent, respectively. The cooked products were packaged under two different systems viz. retort pouch and vacuum packaging. The retort pouched products were subjected to physicochemical, microbiological and sensory evaluation at ambient temperature (25-32oC) for 6 months whereas, the vacuum packaged products were evaluated at refrigeration temperature (4±1oC) for 15 days. The economics of products were also calculated. Under retort processing, the total heating time (min) was recorded to be highest in pork with FDS compared to control, pork with Anishi and Silam. The proximate composition i.e. percent moisture, crude protein, ether extract and total ash in retort pouch and vacuum packaging revealed highly significant (p<0.01) differences in control and the treated products. The pork with FDS revealed highest protein content in both retort and vacuum packaging. However, no significant differences were observed for different storage periods. For mean scores of pH, TBARS and tyrosine values highly significant (p<0.01) differences were observed among control and different product formulations and also during different storage periods. The TPC, coliform and yeast and mould were absent under retort pouch packaging during the entire storage period, conversely under vacuum packaging highly significant differences (p<0.01) were recorded in respect of TPC and psychrophilic count among control and all the treated products and at different storage periods. Coliform count was <3 and yeast and mould were absent in vacuum packaged products. The amino acid content in control and treated products were decreased with the increase in storage period. Highly significant (p<0.01) differences were observed in texture profile among control and the treated products as well as during different storage periods under retort pouch packaging. In respect of vacuum packaging significant (p<0.05) differences were observed during different storage periods among control and the treated products. Highly significant (p<0.01) differences were observed in colour profile under retort pouch and vacuum packaging in control and among the treated products and during storage period. The sensory evaluation showed highly significant (p<0.01) differences in appearance, flavour, juiciness, tenderness and overall acceptability in control and treated products and during storage period under retort pouch and vacuum packaging and revealed higher scores in pork with Silam and FDS compared to Anishi and control. The costs of productions were lower in all treated products compared to control under retort pouch and vacuum packaging. Based on the results obtained in the study it might be concluded that traditional pork products could be prepared economically by incorporating traditional ingredients like Anishi, Silam and FDS at 5, 10 and 5 percent levels using vacuum and retort packaging without any appreciable depreciation in nutritive values and sensory qualities till 15 days for vacuum packaging with refrigeration storage and for retort packaging till 180 days under ambient temperature.ThesisItem Open Access DEVELOPMENT OF READY-TO-COOK SOLAR AND MECHANICALLY DRIED PORK PRODUCTS(Assam Agricultural University, Khanapara, Guwahati, 2017-07) CHOWDHURY, SADHANA; Hazarika, MineswarPork is one of the most popular meats in North Eastern Region (NER) and there is a growing demand for Ready-to-Cook meat products in recent years in the country including NER. Because of highly perishable nature of fresh meat at room temperature, high cost involved in maintaining refrigeration, necessity of cold storage facility, presence of energy deficient areas in NER, disadvantages of traditional drying methods to increase the shelf-life etc. an approach was undertaken to develop dry Ready-to-Cook pork products, which could be stored at room temperature for a considerable period without affecting its quality. Keeping in view the above facts, the proposed study was undertaken with the following objectives viz. to develop ready to cook solar and mechanically dried pork products with the addition of phytoingredients viz. amla, carrot, mint, round lemon and pomegranate and to study their different physico-chemical, microbiological, oganoleptic qualities by storing with two packaging methods along with their shelf-life and cost of production. A total of five batches of meat cube and meat balls were prepared with different formulations with or without addition of the phytoingredients. A control group was there for each treatment group. The raw pork were collected from nearby local market and separated in two parts for meat cubes and balls. Meat was cut into small pieces and cured overnight and then marinated with non meat ingredients containing phytoingredients and dried in solar and mechanical dryers. The control group was also dried along with the treated group which contained only cured meat. The meat balls were prepared by curing the minced meat overnight and then bowl chopped with other non meat ingredients and then shape was given as meat balls. They were also dried in solar and mechanical dryers along with the control group. The temperature of the mechanical dryer was maintained at 60° C, whereas in solar dryer it was fluctuating between 50-60°C. The products were packed in food grade High Density Polyethylene (HDPE) and stored at room temperature. The same packaging material was used for both aerobic and vacuum packaging of the products. For sensory evaluation of the products they were rehydrated to a certain period till saturation. The results of the investigation are as follows- The mean percent of proximate composition of products showed similar trend for both the products as well as in both aerobic and vacuum packaging. Moisture and total ash percent showed an increasing trend during storage, whereas crude protein and ether extract showed a deceasing tend during storage. For moisture and crude protein there were no significant differences between control and treated groups but the mean values of ether extract and total ash showed significant differences among control and treated groups. There were significant differences (p<0.01) during the storage period up to 180 days for moisture, crude protein, ether extract and total ash in all the samples and in both the drying methods. But no significant difference could be seen in the vacuum packaged products. The amino acid profile study reveals that the amino acid content was higher in solar dried products than mechanically dried products and control samples had higher values than treated groups. This trend was similar for both meat cubes and balls, whereas meat cubes showed higher values than meat balls and it was observed in both the drying methods. After storage period of 180 days there were changes in all the amino acids and this was not similar for all the amino acids for both the products. The vacuum packaged products showed lesser changes than the aerobically stored products. The mean values of texture profiles also showed similar trend for both meat cubes and meat balls. The drying methods did not show any difference in texture profiles of the products. Significant differences (p<0.01) could be observed in the control and treated groups for hardness, fracturability, cohesiveness and springiness. There were significant (p<0.01) decrease for hardness, fracturability and cohesiveness during the storage period whereas significant (p<0.01) increase was observed for springiness in storage period. In vacuum packaging, during storage differences were non-significant. The mean values of colour profile showed significant differences (p<0.01) among control and treated groups for both meat balls and meat cubes. Similar trend could be observed for both the products as well as in both the drying methods. The L٭ and b٭ value showed a significantly (p<0.01) increasing trend during storage for all the samples, whereas a٭ value showed a significantly (p<0.01) decreasing trend. There were significant difference (p<0.01) between the control and treated groups. In vacuum packaging, during storage significant differences were not observed. The shelf-life studies of meat balls and cubes were studied on the basis of water activity, TBARS value and their microbiological studies (TPC, Yeast and Mould count, Presence of Sulphide reducing Clostridium). The mean value of water activity showed a significant (p<0.01) increasing trend during the storage period in acerbic packaging. It was similar for both meat balls and meat cubes in both the drying methods. There were significant differences (p<0.01) between control and treated groups. In vacuum packaging the increase during storage was non-significant. As the storage period was increasing a significant (p<0.01) increasing trend was observed for all the products in all the storage periods. There were significant (p<0.01) differences among the control and treated groups i.e. mean values of treatment groups were lower than control groups. In vacuum packaging, the increase was non-significant during storage. The trend of the results was similar for both meat cubes and balls and for both the drying methods. The microbiological quality studies revealed that in TPC and Yeast and Mould counts were absent in all the storage periods. It was seen in all the samples of meat cubes and balls under both the packaging methods and for both the drying methods also. The Sulphide Reducing Clostridial organisms were also found to be absent in all the samples in all storage periods. The results were similar in both the packaging methods. However, after 150 days of storage periods, problems of yeasts and moulds were observed in the meat cubes in aerobic packaging. The shelf-life of meat cubes and balls were six months at both aerobic and vacuum packaging method of storage. It was similar for both the drying methods. The dry products were rehydrated until a point of saturation was observed and for meat cubes it took one and half hour to two hours whereas meat balls took three to three and a half hour for saturation. The rehydrated products absorbed 60-65% water until saturation. The dry products were rehydrated in order to study the physico-chemical and sensory qualities of the rehydrated products. There were no significant differences for cooking loss and rehydration capacity (percent) for control and treated groups for both meat cubes and balls. The drying method had also no effect on these two parameters but the meat cubes showed a higher rehydration capacity (percent) than meat balls. Significant differences (p<0.01) were observed for pH and aw between control and treated groups for meat cubes and balls. The proximate composition (moisture, crude protein, ether extract and total ash) of the rehydrated products revealed that there were significant differences between control and treated groups for both cubes and balls. The texture profile (hardness, fracturability, cohesiveness and springiness) study showed significant differences (p<0.01) between the treated groups in both cubes and balls. The colour profile (L٭, a٭ and b٭) study also showed significant differences (p<0.01) between the samples at both drying methods. The sensory evaluation studies (appearance, flavour, juiciness, tenderness and overall acceptability) of rehydrated meat cubes showed no significant differences between the samples whereas for meat balls significant differences (p<0.05) were observed for juiciness, and overall acceptability. However, the sensory scores were higher for meat cubes than meat balls. The yield of dried products was found to be 18-20% and after drying one kg of fresh product it could be served upto 8-10 persons. The dry products can be served deepending on method of preparation such as soup, curry etc. Cost of production studies for meat cubes and balls at both drying methods revealed that solar dried products were cheaper than mechanically dried products. The cost of control products per kg were Rs. 1310.81 for solar dried products whereas Rs. 1449.54 for mechanically dried products. The cost of meat cubes were Rs. 1432.22 (solar dried), Rs. 1603.33 (mechanically dried) and the cost of meat balls were Rs. 1410.28 (solar dried), Rs. 1725.57 (mechanically dried). From the above study, between the products solar dried treated group was cheaper than mechanically dried products. Based on the above study, it can be concluded that microbiologically and organoleptically acceptable dry pork products can be prepared economically with the use of low cost solar dryer.
