1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Cryoconservation of koovalam (Aegle marmelos L.Corr.) by encapsulation-dehydration technique(Department of Plant Biotechnology, College of Agriculture, Vellayani, 2018) Deepa, E; Deepa S NairThe study entitled “Cryoconservation of Koovalam (Aegle marmelos L. Corr.) by encapsulation-dehydration technique,” was carried out in the Department of Plant Biotechnology, College of Agriculture, Vellayani during 2015-2017. The objectives of the present study were to standardize a cryopreservation protocol for Aegle marmelos using encapsulation and dehydration technique and to assess the genetic fidelity of plantlets regenerated from encapsulated axillary buds after cryostorage, using molecular markers. Investigation was carried out in three phases viz., enhancement of multiplication rate, standardization of in vitro conservation using the encapsulation-dehydration technique and assessment of genetic fidelity of the regenerated plantlets using ISSR markers. Single node segments with axillary buds from in vitro maintained cultures were used as the explants in all the experiments. Among the twelve combinations of auxins and cytokinins were tried, MS (Murashige and Skoog, 1962) medium supplemented with BA 2 mg L-1 + IBA 0.5 mg L-1 was found to be the best treatment with respect to shoot multiplication (9.33 shoots per explant). The additives chitosan (CH), thidiazuron (TDZ) and adenine sulphate (AdS) at different concentrations were supplemented in two different media i.e. 1) hormone free MS medium and 2) MS + BA 2 mg L-1 + IBA 0.5 mg L-1 to study their effect on shoot proliferation. The best shoot proliferation response obtained for each additives were MS + BA 2 mg L-1 + IBA 0.5 mg L-1 + chitosan 10 mg L-1 (35.66 shoots per explant), MS + AdS 60mg L-1 (5.33 shoots per explant) and MS + BA 2 mg L-1 + IBA 0.5 mg L-1 + TDZ 0.02 mg L-1 (20.00 shoots per explant). Even though higher shoot proliferation was observed in CH and TDZ supplemented media, they exhibited morphological abnormalities. Normal shoots were obtained with AdS supplemented medium, but shoot proliferation was less compared to MS + BA 2 mg L-1 + IBA 0.5 mg L-1. Hence MS + BA 2 mg L-1 + IBA 0.5 mg L-1 was used as basal medium for cryopreservation studies. Encapsulation-dehydration technique of cryopreservation involved various steps like preconditioning, encapsulation, pre-culture, dehydration (desiccation), thawing and recovery. Nodal segments with single axillary buds were used as the explant. In preconditioning experiment, PC2 (sucrose 0.1M in semi solid MS for 7 days) was selected as the best preconditioning treatment, which produced maximum shoot proliferation (5.50 shoots per culture) when cultured on basal medium. Among different encapsulation treatments, maximum shoot proliferation of (6.66 shoots per culture) was obtained in the beads formed with sodium alginate 3.5 per cent in modified MS medium and calcium chloride 100 mM, when cultured on modified basal medium (½ MS + BA 2 mg L-1 + IBA 0.5 mg L-1). Pre-culture experiments were conducted using preconditioned and encapsulated explants. The pre-culture treatment selected was liquid MS medium supplemented with sucrose 0.5 M and DMSO 3 per cent for 3 days, which gave maximum shoot proliferation (3.66 shoots per explant) in modified basal medium. The preconditioned, encapsulated and pre-cultured beads were subjected to 0 to 7 h of desiccation under laminar airflow. The moisture content declined from 82 per cent to 12.60 percent on 7 h of desiccation. The desiccated beads were then cryopreserved in liquid nitrogen for 2h, followed by thawing for 30-60s at 40oC and inoculated on to recovery medium ½ MS + BA 2 mg L-1 + IBA 0.5 mg L-1. Survival (66.67 per cent) and regeneration (50 per cent) could be obtained only at 6h of desiccation when the moisture content was 19.50 per cent. The beads when stored in liquid nitrogen for different duration did not show any significant variation with respect to survival and regeneration. The genetic fidelity of plantlets regenerated from encapsulated axillary buds subjected to cryostorage were analysed using ISSR markers. Among the nine primers tried, four primers UBC 807 (AGAGAGAGAGAGAGAGT), UBC 840 (GAG AGA GAG AGA GAG AYT), UBC 847 (CACACACACACACACART) and UBC 826 (ACACACACACACACACC) that gave scorable (5-7) bands were selected for the study. The ISSR banding patterns of the cryoregenerated plantlets and control plants were identical, which indicated the genetic stability. This study was successful in developing a protocol for cryopreservation using encapsulation-dehydration technique in A. marmelos with 50 per cent regeneration efficiency.Item Potential of the narural bio polymers, chitin and chitosan in pest management(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2017) Archana, N H; Reji Rani, O PItem Effect of hurdle technology, chitosan and gamma radiation on quality parameters of chicken fry(Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2008) Shijin, A; Kuttinarayanan, PThe study on the effect of low dose gamma radiation and chitosan coating on shelf-life and quality changes of ready-to-eat chicken fry under vacuum packaging was conducted in the Department of Livestock Products Technology, Mannuthy. Half of the prepared chicken fry was coated with 0.5 per cent chitosan in one per cent glacial acetic acid. The other half was coated with equal quantity one per cent glacial acetic acid. The whole samples were packed under vacuum in PA-PE pouches. Half of the packets from each treatments were irradiated at 2.5 kGy employing Gamma Chamber 5000. Sufficient numbers of packets from each treatment were stored under room temperature (25-30°C) and in chiller (1-4°C). Samples were analysed for proximate composition on the day of preparation and for TBARS, TV, microbiological and organoleptic qualities on day 0, 5, 10, 15, 20, 30, 40, 50, 60 and 70 of chiller storage, while those at room temperature on day 0, 5, 10 and 15 or until spoilage, whichever was earlier. Shelf life of chicken fry was assessed based on the physical signs of spoilage. The spoiled samples were not subjected to any further analysis. The non-irradiated control samples had a shelf life of 5.33±0.23 days at room temperature and 28.16±0.33 days in chiller. The shelf life was extended to 7.33, 8 and 10 days for CH-NIR, IR and CH-IR samples respectively at room temperature. In chiller storage, the samples were consumable up to 67 days (IR) and 73 days (CH-IR). The proximate composition of the product analysed on the day of preparation was not significantly affected due to irradiation or chitosan coating. The TV showed a decreasing trend due to irradiation whereas the TBARS values were increased and it was controlled by chitosan coating. Storage had a significant effect in increasing both these physicochemical qualities. Aerobic plate count, psychrotrophic plate count and yeast and mould count were significantly reduced due to irradiation, chitosan coating and their combination. Whereas the extend of reduction due to chitosan coating alone was not up to the combined effect of chitosan coating and irradiation. As storage period enhanced the counts increased. The increase was rapid in room temperature stored samples and it was slow and steady in chiller samples. As the storage period enhanced, in the chiller stored products, the survived bacteria might have multiplied and count has gone up beyond the initial count as evidenced by the higher count in terminal end of the storage period. The organoleptic qualities were assessed with help of nine point Hedonic scale. The colour, juiciness, tenderness and overall acceptability of the product were improved by irradiation, chitosan coating and their combination. But flavour showed a decrease in score. A gradual decrease in organoleptic qualities was observed due to storage. Even after 60 and 70 days of chiller storage, the samples had an overall acceptability score of above 7 indicating the samples are preferred by the consumers. The cost of chicken fry was Rs. 109.83 per kg and addition of chitosan at a level of 0.5 per cent increased the cost of the same by Rs. 4.38 per kilogram. The irradiation preservation of ready-to-eat chicken fry was beneficial for enhancing the keeping quality of the product under chiller conditions without affecting the qualities. Some of the bad effects of irradiation like increase in fat rancidity can be controlled by the beneficial coating with natural antioxidants like chitosan. Microbial count like aerobic plate count, psychrotrophic count, yeast and mould count were significantly (P<0.05) reduced due to irradiation at 2.5 kGy, the lowest limit prescribed by PFA. The hurdle technology combined with irradiation and chitosan coating has significantly increased the keeping quality of the product. Considering the extended shelf life, wholesomeness of the product, reduced microbial load and energy saving aspects, chitosan coating followed by irradiation can be advocated as a suitable method for preservation of ready-to-eat value added meat products.