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2020 - 20212
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Author: Pawandeep Kaur × Start date: 1998 × Thesis Type: M.Tech. ×
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    ThesisItemOpen Access
    Shelf life enhancement of kinnow through active packaging
    (Punjab Agricultural University, Ludhiana, 2021) Pawandeep Kaur; Kanojia, Varsha
    Kinnow comes in “Mandarin” group of citrus fruits, which produced prominently in India and Pakistan and being perishable in nature. It has the shortest shelf life among all other citrus fruits. The present study was carried out to enhance the shelf life of kinnow by active packaging. RSM with BBD for 3 independent variables at 3 levels viz. dose of scavenger (35grams), fungicide concentration (3-7%) and polythene thickness (100-200guage) was used to optimize the process parameters to maintain the quality of fruit with respect to selected responses i.e., gas composition, physiological loss in weight, firmness, total soluble solids, titrable acidity, ascorbic acid, color difference, microbial load and shelf life. The samples treated with fungicide was packed in LDPE wrapped carton box with O2, CO2 and C2H4 scavenger and stored in cold chamber (5-7°C and 90-95% RH) and were monitored at regular intervals. It was observed that physiochemical properties of kinnow fruit were significantly affected by active packaging (p< 0.05). Optimization was done aiming at minimize O2, CO2, physiological loss in weight, total soluble solids, color difference, microbial load and maximize firmness, titrable acidity, ascorbic acid, shelf life while the process parameters should be within range. The optimized conditions for active packaging of kinnow fruit was 5 grams dose of scavenger, 6.83% fungicide concentration and 192.12 guage of polythene thickness. Corresponding to these variables, the values of O2, CO2, physiological loss in weight, firmness, total soluble solids, titrable acidity, ascorbic acid, color difference, microbial load and shelf life were 12.84%, 3.75%, 7.34%, 4.44 kgf, 9.2°Brix, 1.72%, 35.28 mg/100ml, 0.55, 4.87x103 cfu/ml and 69 days respectively. The overall desirability was 0.812. Value of percentage deviation for validation was less than 5% for all the responses which indicating the precision and reliability of the study.
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    ThesisItemOpen Access
    Characterization and testing of metakaolin based geopolymer mortar containing corn cob ash along with carbon nano tubes
    (Punjab Agricultural University, Ludhiana, 2020) Pawandeep Kaur; Jaspal Singh
    Geopolymer is a new concept in the construction technology which is synthesized by mixing the alumino-silicate sources with alkaline activating solution. It is an eco-friendly technique which utilized various materials as an alternative to Ordinary Portland Cement. Metakaolin (an alumino- silicate material) used as a source material, as it is suitable for geopolymerization. In this study, effect of corn cob ash and multi walled carbon nano tubes on metakaolin based geopolymer has been investigated. Seventy five mixes of geopolymer mortar were prepared with three different molar concentrations of alkaline activator (8M, 10M and 12M) and different proportions of corn cob ash (0% to10% @2.5% increment) as well as with the addition of multi walled carbon nano tubes at proportions of 0%, 0.25%, 0.50%, 0.75% and 1%. The compressive strength of geopolymer mortar was tested after 3, 7and 28 days of curing. Scanning electron microscope test was performed on powdered sample of mixes M1, M13 & M23. The powdered samples were collected from remnants of geopolymer after 28 days of compressive strength testing. Test results depicts that the compressive strength of geopolymer mortar increases at all ages of curing when the molar concentration of alkaline activator is enhanced from 8M to 12M but the proportion of corn cob ash and multi walled carbon nano tubes increases the strength up to a certain limit. Beyond that, there was reduction in the compressive strength of geopolymer mortar. The geopolymer mortar prepared using 12M concentration of alkaline activator and 5% proportion of corn cob ash including 0.50% of multi walled carbon nano tubes is recommended for the maximum compressive strength.