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2011 - 20143
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Subject: Processing and Food Engineering × Author: KAU × End date: 2015 × Start date: 2011 ×
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    ThesisItemOpen Access
    Postharvest management practices in papaya (carica papaya L) for improving shelf life
    (Department of Processing Technology, College of Agriculture,Vellayani, 2014) Jayasheela, D S; KAU; Sreekala, G S
    The present investigation entitled “postharvest management practices in papaya (carica papaya L) for improving shelf life” was conducted at department of processing technology, College of Agriculture, Vellayani to determine the stage of harvest maturity of papaya for local and distant market and to standardize postharvest practices for improved shelf life with minimum nutritional loss. The study was carried out in three different continuous experiments. For local market, papaya fruits harvested at ¼ yellow (144.37 DFFB – Days From Full Bloom) and ½ yellow (146.12 DFFB) stages revealed ¼ maturity as the best stage of harvest due to increased shelf life. For distant market, the fruits were harvested at one stripe yellow (142.00 DFFB) and fully mature green (139.38 DFFB) and fruits harvested at fully mature green stage had more shelf life and hence selected as best stage of harvest for distant market. Investigation on the efficacy of different sanitizing agents on surface decontamination revealed that papaya fruits harvested at ¼ yellow for local market and fully mature green fruits for distant market, washed and treated with hot water at 50% C for 20 minutes and warm sodium hypochloride at 150 ppm was effective in reducing bacterial and fungal population. The effect of waxing and ethylene absorbent was studied on papaya fruits harvested for local and distant markets, sanitized with the two best sanitising agents. For local market, fruits harvested at ¼ maturity and sanitised with hot water at 500 C for 20 minutes followed by cooling, waxing and packing with ethylene absorbent (KMnO4 – Potassium permanganate) 8.0/kg fruit as sachet in corrugated fibre board boxes recorded highest shelf life (11.00 days), lowest physiological loss in weight (1.84 per cent ), lowest loss in membrane integrity (58.18 percent leakage), lowest respiration rate (30.33 mg CO2 /kg/hr), highest total soluble solids (12.660 Brix), least microbial population and less mechanical damage. For distant market, fruits harvested at fully mature green stage sanitised with hot water at 500C for 20 minutes followed by cooling , waxing and packed in corrugated fibre board boxes with ethylene absorbent in sachet (KMnO4 8.0g/kg fruit) improved the shelf life (12.33 days) of fruits and showed lowest physiological loss in weight (2.08 per cent), lowest loss in membrane integrity (57.82 percent leakage), lowest respiration rate (35.00 mgCO2/kg/hr) higher total soluble solids (11.330 Brix), microbial population and less mechanical damage. Further studies are required for the refinement of the technology for reducing postharvest losses in papaya fruits for transport to distant market.
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    ThesisItemOpen Access
    Evaluation of postharvest quality attributes of cabbage and cauliflower grown in plains and higher altitude
    (Department of Processing Technology,College of Horticulture,Vellanikkara, 2011) Elavarasan, K A; KAU; Pushpalatha, P B
    The studies on “Evaluation of postharvest quality attributes of cabbage and cauliflower grown in plains and higher altitude” was carried out in the Department of Processing Technology, College of Horticulture, Vellanikkara during 2009 - 2011. The study was undertaken with the objective of evaluating the postharvest quality attributes and shelf life of cabbage and cauliflower grown in plains and higher altitude. The study was conducted at ARS, Mannuthy (plains) and Orange and Vegetable farm, Nelliyampathy (hill station). Four genotypes each in cabbage (NS183, NS160, NS 35 and Tropical Sun Plus) and cauliflower (NS 60 N, NS133, Pusa Meghna and Basant) were evaluated both in plains and higher altitude. Significant differences were observed in yield of cabbage which ranged from 22.6 – 29.3 kg /16m2 in hills and 1.27 – 22.06 kg /16m2 in plains. Among the cabbage genotypes, NS 183 was found to be the best for hilly region in earliness, yield and yield attributes. The cabbage genotype Tropical Sun Plus exhibited better performance in plains in terms of high head yield (22.06 Kg /162m), head weight (729.6 g) and head height (11.1 cm). Harvest maturity was delayed by 39 – 45 days in the plains as compared to higher altitudes. The cauliflower genotypes NS 60N took lesser days to attain harvest maturity in hills (83.88 days) and Pusa Meghna in the plains (128.16 days). Significant variation was observed in curd yield of cauliflower which ranged from 21 – 26.4 kg /16 m2 in hills and 0.78 – 1.43 kg /16 m2 in plains. NS 133 was found to be the best among the cauliflower genotypes in high altitude region as it recorded high curd yield (26.4 Kg /162m), curd weight (800g), curd height (13.93 cm), curd solidity, early maturity and better adaptability. Cauliflower genotypes NS 60 N, NS133, Pusa Meghna and Basant produced firm and uniform curds in hilly region, but in plains, curds were thicker and non uniform. In the case of cabbage, no significant difference was noticed in terms of head solidity for both the regions. The cabbage and cauliflower genotypes which exhibited superior performance in hills and plains were selected for further sensory, biochemical and storage studies. The cabbage genotype Tropical Sun Plus recorded superior organoleptic qualities (colour, taste, flavour, texture and overall acceptability) when grown in plains than hilly region. However in the case of genotype NS 183, the differences in sensory qualities between produce from hills and plains were not significant. The biochemical constituents (moisture, acidity, ascorbic acid, protein and minerals) of the best performing genotypes identified from hills and plains both in cabbage and cauliflower were analysed. The cabbage genotype NS 183 recorded comparatively higher values for biochemical constituents like acidity (0.144%), ascorbic acid (51.8 mg/100g), protein (0.73 g/100g), phosphorus (26 mg/100g) and potassium (200 mg/100g). Significant variation was noticed in biochemical constituents between the cauliflower genotypes and higher values were recorded in NS 133 for acidity (0.119%), ascorbic acid (38.85 mg/100g), protein (0.89 g/100g) and potassium (320 mg/100g). The whole cabbage and cauliflower were wrapped with cling film and stored under three different temperature regimes (0 to -1oC, 4 to 6oC and ambient condition). Longest shelf life in cabbage genotypes Tropical Sun Plus (21 days) and cauliflower genotype NS 60N (22.5 days) was obtained in cling film pack stored at 0 to -1o C. PLW% was highest and shelf life the shortest under ambient condition in unpackaged produce of cabbage and cauliflower. The influence of packaging material (high density polyethylene, semi rigid metallised aluminum tray over wrapped with cling film and polypropylene) and storage conditions (0 to -1oC, 4 to 6oC and ambient condition) on minimally processed produce of cabbage and cauliflower were evaluated. The shelf life was significantly extended in HDPE packaged produce stored at 0 to -1oC in cabbage genotype Tropical Sun Plus (20.75 days) and cauliflower genotype NS 60N (22.5 days).
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    ThesisItemOpen Access
    Effect of pre treatments and curing methods on the quality characters of processed cardamom (Elettaria cardamom (L) Maton
    (Department of processing technology, College of horticulture, Vellayani, 2012) Sonia, V; KAU; Sreekala, G S
    The research on “Effect of pre treatments and curing methods on the quality characters of processed cardamom (Elettaria cardmomum (L.)Maton” was undertaken at Department of Processing Technology, College of Agriculture, Vellayani with the objective of developing a pre treatment for cardamom which can retain good quality green colour having better flavour, texture, appearance and acceptability. The experiment was done at Cardamom Research Station Pampadumpara and the analysis was carried out at Department of Processing Technology, College of Agriculture, Vellayani. The experiment was laid out in factorial completely randomised design with three replications. The cardamom capsules were treated with different chemicals and dried under two curing methods. Pre treatments consisted of 1% of sodium carbonate, potassium carbonate, sodium hydroxide, sodium bicarbonate, magnesium sulphate, copper acetate and 0.1% of ascorbic acid, citric acid, polyethylene glycol and 500 ppm of naphthalene acetic acid. An untreated control was also included in the experiment. These cardamom capsules were then dried under conventional and modern drier and evaluated for physical, chemical and sensory qualities. The effect of pre treatments and curing methods on physical qualities of cardamom was evaluated. The boldness, bulk density and instrumental measurement of texture were not affected by the pre treatments as well as by curing methods. The greenness and total colour difference were influenced by the pre treatments. The cardamom capsules treated with 1% sodium hydroxide and sodium carbonate were superior in imparting greenness to the capsule colour. The result of total colour difference also substantiates this. The chemical parameters such as moisture, chlorophyll and essential oil content were significantly influenced by different pre treatments. The curing methods did not influence the chlorophyll and essential oil content of cardamom capsules. Flavour profiles of essential oil content of small cardamom were analysed using Gas Chromatography Mass Spectrometry. The major ten chemical components (1,8-cineole, α -terpinyl acetate, limonene, linalool, sabinene, trans nerolidol, α-terpineol, linalyl acetate, myrcene, α- pinene) present in essential oil of small cardamom were statistically analyzed. Cardamom capsules treated with 1% sodium hydroxide and 1% sodium carbonate showed better flavour profile with respect to α-terpinyl acetate, linalool and linalyl acetate in essential oil of small cardamom compared to other chemical pre treatments. The moderate content of 1,8-cineole with higher α -terpinyl acetate, linalool and linalyl acetate might have resulted in better flavour as noticed by sensory evaluation of cardamom capsules pre treated with 1% sodium hydroxide and 1% sodium carbonate. Conventionally cured cardamom capsules showed better retention of flavour compared to modern curing method with respect to 1,8-cineole, α - terpinyl acetate, limonene, linalool, α-terpineol and linalyl acetate. The pre treated cardamom capsules were analysed to find the residue content of the pre treated chemicals. The residue of sodium, potassium, magnesium, ascorbic acid and citric acid analysed were below the toxic level and would not cause any harm since they are needed in trace amounts in human body. The presence of heavy metal copper was also below the maximum residual level. The naphthalene acetic acid (NAA) content was a bit slightly above the normal level recommended for apple, pear, quince and pineapple. A significant level of residue of polyethylene glycol (PEG) was noted compared to control. The sensory tests carried out revealed better colour, flavour, texture, appearance and overall acceptability for the cardamom capsules treated with 1% of sodium carbonate and sodium hydroxide compared to other pre treated capsules as well as control. The flavour, texture and overall acceptability was superior in cardamom capsules dried under conventional curing compared to modern curing. The study concludes that the pre treating cardamom capsules with 1% sodium carbonate or 1% sodium hydroxide for two minutes gave better colour, flavour and overall good acceptability of cardamom. Both curing methods were ideal with regard to the general colour and texture as indicated by instrumental measurements. However the flavour profile of essential oil of small cardamom and sensory qualities were scored in favour of conventional curing method.