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2011 - 20186
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Subject: Post Harvest Technology × Author: KAU × End date: 2018 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Portion packaging and storage of jackfruit (Artocarpus heterophyllus Lam.)
    (Department of Post Harvest Technology, College of Agriculture, Vellayani, 2018) Gana, K R; KAU; Mini, C
    The investigation entitled “Portion packaging and storage of jackfruit (Artocarpus heterophyllus Lam.)” was conducted at the Department of Post Harvest Technology, College of Agriculture, Vellayani, during the year 2016-2018, with the objective to standardize portion packaging and storage techniques for extending shelf life of jackfruit types. Experiment was carried out independently for mature varikka, ripe varikka and mature koozha jack fruit types. Good quality jackfruit types were harvested, cleaned, outer spiny rind removed, cut in to portions of 200-250 g weight, pre-treated using 0.5% potassium meta bisulphite (KMS) and citric acid, surface drained and subjected to seven different packaging conditions, and stored under ambient and refrigerated storage conditions. The seven different packaging systems included use of polypropylene film with 5% ventilation, cling film wrapping, shrink wrapping, vacuum packaging in laminated pouches, modified atmospheric packaging (MAP) in laminated pouches with KMnO4, MAP with silica gel and unwrapped portions. Based on efficiency in maintaining physiological parameters, organoletic quality and marketability, portions under vacuum packaging in laminated pouches of PP/LDPE under refrigeration was selected as best treatment for further quality evaluation. MAP in laminated pouches with silica gel sachet was considered as the second best packaging treatment. Jackfruit portions stored under ambient condition were spoilt within a day in all types. Quality evaluation of jackfruit portions stored under refrigeration after vacuum packaging in laminated pouches of PP/LDPE revealed that mature varikka portions had 21 days shelf life with 2.34% physiological loss in weight and 80% marketability. Vacuum packed mature koozha portions under refrigeration exhibited 15.71 days shelf life with 2.89% PLW and 75% marketability. Ripe varikka portions had 12.28 days shelf life with 3.42% PLW and 70% marketability under similar packaging and storage. Unwrapped jack fruit portions under refrigeration were spoilt within 3 days after storage. Oxygen concentration gradually decreased and CO2 concentration gradually increased in all the vacuum packaged jackfruit portions, indicating high respiration rate of the fresh cut commodity. TSS, reducing sugars and total sugars increased during storage, where as vitamin C and acidity showed a decrease during storage. Vacuum packed refrigerated jackfruit portions had good sensory acceptability even at the end of shelf life, though there was reduction in firmness. Despite an increase in the carotenoid content, vacuum packed refrigerated jack fruit bulbs retained their natural colour, which stayed even during the storage period. The mature varikka bulbs held a cream colour while the ripe varikka ones were a deep yellow, and the mature koozha bulbs remained yellow even at the end of storage. Cost of production of vacuum packed jack fruit portion was calculated and the BC ratio was found to be 1.37. Vacuum packaging in laminated pouches of PP/LDPE and storage under refrigeration was standardized as the best packaging and storage treatment for all jack fruit portions. Adoption of the standardized technology may help to transform the current trend of total unhygienic marketing system into a totally different style, where hygienically packed quality jackfruit portions with sufficient prolonged shelf life can be marketed through the current retail outlets having refrigerated storage facility. The system has to be properly modified in future to suit the ambient storage system so as to reduce the cost of production.
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    ThesisItemOpen Access
    Postharvest treatments for delayed ripening in nendran banana (Musa spp.)
    (Department of Post Harvest Technology, College of Agriculture, Vellayani, 2018) Athira, M Nair; KAU; Geetha Lekshmi, P R
    The investigation entitled “Postharvest treatments for delayed ripening in Nendran banana (Musa spp.)” was conducted at the Department of Post Harvest Technology, College of Agriculture, Vellayani, during 2016-2018. The objective of the programme was to study the effect of postharvest application of different ethylene inhibitors and to standardize the optimum concentration for delayed ripening and extended shelf life of Nendran banana. Nendran banana bunches of uniform maturity were selected from Instructional Farm, College of Agriculture, Vellayani. De-handed banana fruits were treated with different ethylene inhibitors at various concentration viz. Benzyl Adenine (BA) (30 ppm, 50 ppm, 80 ppm - dipping for 10 minutes), Hexanal (0.5%, 1.0%, 1.5% - dipping for 10 minutes), Nitric Oxide (NO) (0.25 mM, 0.5 mM, 0.75 mM - dipping for 5 minutes), Salicylic Acid (SA) (1 mM, 1.5 mM, 2 mM - dipping for 10 minutes) along with distilled water, ethanol and absolute control (without any treatment). Treated banana fruits were air dried and stored under room temperature (30+20C, RH 80-85%) in Corrugated Fiber Board boxes till the end of shelf life. Effectiveness of different ethylene inhibitors for delayed ripening of Nendran banana was evaluated by analyzing physiological, biochemical, physical and sensory qualities. Nendran banana fruits treated with 50 ppm BA recorded a pulp percentage of 69.38%, peel percentage of 30.62% and pulp to peel ratio of 2.26 with the lowest physiological loss in weight (PLW) (13.01%) and respiration rate (97.55 mL CO2 kg-1 h-1) after 15 days of storage. Total sugar (20.82%), reducing sugar (17.55%), TSS (24.25 0B) and acidity (0.45%) increased with storage and highest retention of vitamin C (10.74 mg 100g-1) content and antioxidant activity (78.46%) were also observed at the end of storage. When fruit firmness, colour and sensory parameters were analyzed, BA 50 ppm treated banana fruits exhibited maximum fruit firmness of 10.55 N after 15 days of storage with optimum ripening (Stage VI). It also exhibited maximum mean score for sensory parameters viz. appearance, colour, flavour, taste, texture and overall acceptability and recorded a shelf life of 16.75 days. Nendran banana fruits treated with SA (2 mM) recorded a shelf life of 15.75 days next to BA (50 ppm) with 13.82 % PLW and respiration rate of 106.23 mL CO2 kg-1 h-1. When biochemical parameters were analyzed, SA 2 mM recorded a total sugar content of 21.50%, reducing sugar (18.05%), TSS (25.45 0B), acidity (0.48%), carotenoid (0.30 mg 100g-1), ascorbic acid content (9.84 mg 100g-1) and antioxidant activity (76.55%) after 15 days of storage with good fruit firmness, colour and sensory qualities. Nendran banana fruits without any postharvest treatment (absolute control) had a shelf life of 11.58 days with higher rate of physiological, biochemical and physical changes. They also exhibited the highest PLW of 19.94% and high rate of respiration (128.11 mL kg-1 h-1) which lead to short shelf life and lowest mean score for sensory attributes after 12 days of storage. Application of ethylene inhibitors as postharvest treatments reduced the rate of physiological activities and extended the shelf life of Nendran banana. Based on physiological, biochemical, physical and sensory analysis, dipping of Nendran banana hands in 50 ppm Benzyl Adenine for 10 minutes was standardized as the best postharvest treatment for delayed ripening and extended shelf life up to 16.75 days whereas Nendran banana without any treatment (absolute control) recorded a shelf life of 11.58 days under room temperature storage. Dipping of Nendran banana in 2 mM Salicylic Acid for 10 minutes recorded a shelf life of 15.75 days and was found cost effective as compared to BA (50 ppm).
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    ThesisItemOpen Access
    Development of novel value added products from tender coconut (cocos nucifera L.)
    (Department of Post Harvest Technology, College of Horticulture, Vellanikkara, 2018) Archana Unnikrishnan; KAU; Saji Gomez
    The study titled ‘Development of novel value added products from tender coconut (Cocos nucifera L.)’ was carried out in the Department of Post Harvest Technology, College of Horticulture, Vellanikkara during 2016-2018. The immature nut known as tender coconut, contains a sterile liquid which is the endosperm and it has got many health benefits and medicinal values. But the popularisation of tender coconut based products is limited because of the loss in natural freshness unless treated scientifically. Therefore, an attempt was made to prepare some novel value added products from tender coconut and to evaluate their quality and shelf life. Fresh tender coconut of about 7 months maturity (cv. COD) was procured from different localities of Thrissur district. In the first experiment, RTS beverage was prepared with tender coconut and the beverage was added with 100 ppm ascorbic or malic acid in combination with one of the three preservatives, viz. potassium metabisulphite, sodium benzoate and potassium sorbate at a concentration of 100 ppm. The RTS beverage stored under refrigerated condition gave significantly longer shelf life as compared to samples stored under ambient condition. The treatment T1 (tender coconut RTS beverage added with 100 ppm ascorbic acid and 100 ppm potassium metabisulphite) gave the maximum shelf life of 25 days under ambient condition and 50 days under refrigerated storage. The same treatment was also superior with regard to titratable acidity (0.217 %), ascorbic acid (53.00 mg 100g-1), protein content (0.053 %), non-enzymatic browning (0.03), overall acceptability score (7.4) and microbial load among the treatments under refrigerated condition. Tender coconut was blended with fruit juice/pulp of guava, pineapple and sweet orange in different proportions (90:10, 80:20, 70:30, 60:40, 50:50 v/v) and based on the organoleptic score obtained for each blend, best type of tender coconut- fruit juice blend was identified. Tender coconut blended with guava pulp in 80:20, tender coconut and pineapple in 50:50 and tender coconut with sweet orange in 60:40 proportion was selected for storage studies. Tender coconut RTS beverage blended with pineapple (T2) gave significantly longer shelf life (40 and 73 days) under ambient and refrigerated storage conditions respectively. The biochemical parameters such as highest TSS (14.23o brix) and total sugar content (14.58 %), lowest non-enzymatic browning (0.03) was observed in T2 (tender coconut RTS beverage blended with pineapple) and T3 (tender coconut RTS beverage blended with sweet orange) retained highest vitamin C content (47.66 mg 100 g-1), 30 days after storage, under refrigerated condition when compared to ambient condition. Sixty days after storage, the biochemical parameters such as TSS, sugars, pH, protein and overall acceptability score was highest in T2 (tender coconut RTS beverage blended with pineapple) under refrigerated condition. Tender coconut jelly was preapared from tender coconut by incorporating jellifying agents such as agaropectin, banana peel pectin, guava pectin and nutmeg rind pectin at different concentrations (0.5 %, 1.0 %, 1.5 % and 2 %). Treatments such as C3 (1.5 % agaropectin), C4 (2 % banana peel pectin), C3 (1.5 % guava pectin) and C4 (2 % nutmeg rind pectin) showed highest overall acceptability score of 7.5, 7.5, 7.2 and 7.5 respectively. Tender coconut jelly could be stored for 73 days under ambient condition whereas under refrigerated condition, the shelf life beyond 90 days. T4 (tender coconut jelly prepared from nutmeg rind pectin) showed lowest (0.75) water activity Highest vitamin C (11.93 mg 100 g-1) was observed in T3 (tender coconut from guava pectin) under both refrigerated storage conditions. Tender coconut jelly from nutmeg rind pectin (T4) showed highest overall acceptability value of 7.7 and 7.4, 2 months after storage under ambient condition and 3 months after storage under refrigerated condition respectively. The results of the study indicated that through scientific handling along with addition of preservatives, the tender coconut can be utilized as a potential source for the production of many novel value added and processed products.
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    ThesisItemOpen Access
    Standardisation of packaging and storage techniques for green chillies (capsicum spp.)
    (Department of Post Harvest Technology, College of Horticulture, Vellanikkara, 2018) Geethu, M; KAU; Sheela, K B
    The study entitled ‘Standardisation of packaging and storage techniques for green chillies (Capsicum spp.)’ was carried out in the Department of Post Harvest Technology, College of Horticulture, Vellanikkara during 2016-2018. The objectives of the study were standardisation of pre-storage treatments, packaging and storage methods for green chillies. Six accessions of green chillies belonging to three species of Capsicum viz C. annuum, C. frutescens and C. chinense were selected for the study. Variety Ujwala, belonging to the species Capsicum annuum was selected for the surface sanitisation studies. The fruits were surface sanitised with tap water, brine solution (2%), Veggie Wash (1%), sodium hypochlorite (100ppm) and ozone (2 ppm). Fruits sanitised with sodium hypochlorite (100 ppm) recorded the longest shelf life (15days) and lowest microbial load. Lowest Physiological Loss in Weight (PLW %) was observed in fruits sanitised with 2 ppm ozone, followed by sodium hypochlorite. Hence sodium hypochlorite was selected as the best surface sanitisation treatment for further studies. The effect of clipping of pedicel on shelf life of fruits was studied in six accessions of chillies. The accessions selected were Ujwala and Vellayani Athulya (Capsicum annuum) Vellayani Samrudhi and local accession Green Chuna (C. frutescens) and Vellayani Thejus and local accession CC65 (C. chinense). Significant differences were not observed for PLW between the clipped and non clipped fruits. Non clipped fruits in C. annuum accessions registered higher microbial count, comparatively lower shelf life and poor appearance. Packaging and storage studies were conducted in six chilli accessions by subjecting fruits to five methods of packaging viz. control (T0), packaging in micro ventilated polythene cover (T1), polystyrene tray overwrapped with cling film (T2), polypropylene punnets (T3) and shrink wrapping in polystyrene tray (T4). The storage conditions were, ambient (28-36 0C), refrigeration (4-7 0C) and cold storage (10-12 0C). In the varieties belonging to C. annuum and C. frutescens, shelf life could be extended to more than 30 days in shrink wrapped fruits under cold storage. Shelf life was longer in accessions of C. chinense (Vellayani Thejus and CC65) under refrigerated storage. Changes in respiration rate were not pronounced under ambient storage. The physiological loss in weight (PLW %) in all the accessions increased during storage irrespective of treatments and storage conditions and it was higher in unwrapped fruits. Unwrapped fruits had higher TSS under the three storage conditions in all the varieties, one week after storage. Significant variation was not observed in titrable acidity among the treatments except in Vellayani Samrudhi. Fruits of Vellayani Athulya and Vellayani Samrudhi packaged in polythene cover under refrigerated storage and shrink wrapped fruits of Ujwala and Vellayani Thejus under cold storage had high ascorbic acid content. Fruits of Vellayani Athulya and CC65 packaged in polypropylene punnets recorded high β carotene content under ambient conditions and Green Chuna under cold storage. Fruits under cold storage recorded higher capsaicin content in Ujwala, Vellayani Samrudhi, Green Chuna and Vellayani Thejus. Unwrapped fruits had highest total phenols in the three storage conditions in the varieties Vellayani Samrudhi and Green Chuna. Microbial load was analysed by recording the population of bacteria, yeast and fungi. Microbial load was found to increase towards the end of storage. Bacterial population was comparatively low under refrigeration and cold storage. Yeast population was not significant during the storage of green chillies. Population of fungi was found to be lesser under refrigerated conditions. Organoleptic scores were found to decrease in all the varieties, during storage, however the fruits were acceptable for consumption. Shrink wrapped fruits and fruits packaged in polythene cover had higher overall acceptability in all the varieties.
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    ThesisItemOpen Access
    Development of osmodehydrated bilimbi (Averrhoa bilimbi L.) and assessment of bioactive compounds
    (Department of Post Harvest Technology, College of Agriculture, Vellayani, 2017) Aparna, G S; KAU; Geetha Lekshmi, P R
    The present study entitled “Development of osmodehydrated bilimbi (Averroha bilimbi L.) and assessment of bioactive compounds” was carried out in the Department of Post Harvest Technology, College of Agriculture, Vellayani during 2015-17 with the objective to standardize the process variables for osmodehydrated bilimbi and to assess the retention of bioactive compounds. Harvested mature bilimbi fruits of uniform size were washed, surface dried, pricked and blanched in hot water for one minute. Blanched fruits were subjected to osmotic treatment, with sucrose solution of 40, 60 and 80⁰B for 60, 120 and 180 minutes. The osmodehydrated bilimbi fruits were analyzed for mass transfer, biochemical and sensory qualities. Mass transfer characters viz., solid gain, water loss, percentage weight reduction, yield and biochemical parameters such as reducing sugar and total sugar increased with increase in osmotic concentration and immersion time whereas free acids, ascorbic acid and antioxidant activity were decreased. The osmotic treatment of 80 0B for 180 minutes recorded the highest value for solid gain (5.10 %), water loss (16.72%), weight reduction (22.57%), ratio of water loss to solid gain (3.25%) and yield (21.13%) with a free acid content of 2.32 %, 21.66 mg/100g vitamin C, 47.81% antioxidant activity, 8.24% reducing sugar and 18.53% total sugar which exhibited superior sensory scores for taste (8.43), flavor (8.27), texture (8.46) and overall acceptability (8.43). The best three treatments selected based on sensory analysis (80 0B for 180 minutes, 80 0B for 120 minutes and 60 0B for 180 minutes) were subjected to storage stability studies under room temperature for four months. The stored osmodehydrated bilimbi fruits were analyzed for biochemical, sensory and microbial qualities at monthly intervals. During storage, reducing sugar and total sugar increased while ascorbic acid, antioxidant activity and free acids decreased. Osmodehydrated bilimbi in 800B for an immersion time of 180 minutes recorded 2.06 % free acid content, 19.55% total sugar, 8.75% reducing sugar, 19.29% vitamin C and 44.59% antioxidant activity at the end of four month storage with highest sensory score. All the osmodehydrated bilimbi fruits were microbiologically safe till the end of storage. Bioactive compounds viz. vitamin C, phenols, total flavonoids, antioxidant activity, carotenoids, free acids, and oxalate content of osmodehydrated, dried, hot water blanched, steam blanched and fresh bilimbi fruits were assessed. Osmodehydrated bilimbi fruits recorded the highest TSS (19.32 0B), total sugar (18.73 %), reducing sugar (8.22%), carotenoids (0.46 mg/100g) and lowest oxalate content (24.34 mg/g) whereas dried bilimbi showed highest ascorbic acid (43.18 mg/100g), total phenols (694.60 mg/100g), antioxidant activity (56.23%), total flavonoid content (338.03 µg g-1) and highest oxalate content of 31.78 mg/g. Blanching treatments was found to reduce TSS, free acids, vitamin C and oxalate content of fruits. Hot water blanched fruits exhibited lowest oxalate content (8.08 mg/g) and TSS (3.82 0B) whereas steam blanching recorded the highest antioxidant activity (74.83%) total phenol (1067.31 mg/100g) and total flavanoid (198.32 µg g-1) whereas fresh bilimbi recorded 975.67 mg/100g phenols, 134.38 µg g-1 total flavanoid with 68.35% antioxidant activity. Osmotic treatment at 80 0B for 180 minutes was found as the best treatment for development of osmodehydrated bilimbi. Bioactive compounds in primary processed bilimbi are greatly influenced by the processing methods.
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    ThesisItemOpen Access
    Development and evaluation of a seed extractor for ash gourd and cucumber
    (Department of Post harvest technology and agricultural processing,Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2011) Aneesh, Mohan; KAU; Santhi, Mary Mathew
    A seed extractor was developed for ash gourd and cucumber. The important part of the machine is the extraction tool whose diameter can be varied (52 -160 mm) according to the placental diameter of the fruit and it can be maintained at that diameter for the required time. The principle of operation is to penetrate the rotating tool with handle, into the placental region after adjusting its diameter which helps in scraping out the seeds along with the pulp from the centre and surrounding mesocarp portion. The experiment was conducted as a completely randomized design with three factors. Two blade shapes (round edged and pointed edged), three blade thicknesses (1, 2 and 3 mm) and four rotational speeds (50, 80, 120 and 160 rpm) were chosen. For each experiment, the number of replications were three. Before loading the vegetables to the holder for seed extraction the top and bottom ends which do not contain the seeds were cut and removed for easy penetration of the tool. By adjusting the blade diameter to required size, the rotating tool is lowered through the central portion of the vegetable and it scraps out the seeds from the surrounding mesocarp. The seeds are discharged into the chute. The seed extraction of ash gourd was achieved by a mean time of 10.6 s/kg and that of cucumber with 16.6 s/kg. The seed extraction efficiencies of both these vegetables were in the range of 99 to 100%. The germination rates were 95% for ash gourd seeds and 96% for cucumber seeds. The capacity of the extractor for ash gourd is 350 kg/h and that of cucumber is 219 kg/h. The average energy consumption at loaded condition for seed extraction of ash gourd is 0.105 kWh and for cucumber is 0.102 kWh. The cost of seed extraction per kilogram for ash gourd is ` 0.15/- and for cucumber is ` 0.24/-. The cost of seed production per kilogram for ash gourd is ` 10.3 /- and for cucumber is ` 3.0/-.