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Subject: Post Harvest Technology × Author: KAU × End date: 2021 × Start date: 2021 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Technology refinement for wine production from under exploited fruits
    (Department of Post Harvest Technology, College of Agriculture, Vellayani, 2021) Aiswarya, S; KAU; Mini, C
    The present study entitled “Technology refinement for wine production from under exploited fruits” was conducted at Department of Post Harvest Technology, Kerala Agricultural University, College of Agriculture, Vellayani during the year 2019-2021 with the objective for technology refinement for wine production from under exploited fruits based on quality parameters and storage stability. Fruit wines were prepared from three under exploited fruits viz., jamun, papaya and rose apple independently by varying the process parameters viz., fruit: water ratio, fruit: sugar ratio, nitrogen source and clarification methods. Fruit: water ratio was tried at 1:1, 1:2 and 1.0.07; fruit: sugar ratio at 1:1, 24° brix and at 20% sugar, with or without nitrogen source and subjected to clarification by pectinase enzyme and by settling, thus forming 36 different wines under each fruit and were analysed for physical, chemical, nutritional and sensory quality parameters. The study was conducted as four continuous steps viz., fruit wine preparation, quality analysis, selection of superior wines and evaluation of storage stability. Jamun wines were attractive dark purple, had good flavour with 71.8 to 95.4 per cent yield. Papaya wines were light yellowish, papaya flavoured and had 42.2 to 90.7 per cent yield. Rose apple wines were creamy white with 82.24 to 93.33 per cent yield. Three wines with high yield, antioxidant activity and total sensory score with low alcohol content (<7%) were selected from each fruit. Jamun wine prepared using 1:1 fruit: water ratio, 1:1 fruit: sugar ratio, without nitrogen source and clarified by pectinase had 3.52% alcohol, 93.03% antioxidant activity and 253.29 mgg-1 polyphenol content with the highest total sensory score (18.5). When nitrogen source was added, the wine had highest (95.4%) yield, 3.52% alcohol content and high antioxidant activity (92.5%). The highest antioxidant activity (95.64%) was obtained for the wine produced using 1:2 fruit: water ratio, 1:1 fruit: sugar ratio, with nitrogen source and clarified by pectinase. This wine had 92.8% yield, 5.85% alcohol content and 125.92mgg-1 polyphenol content. Papaya wine produced with 1:1 fruit: water ratio, 1:1 fruit: sugar ratio, with nitrogen source and clarified by settling had 87% yield, 4.39% alcohol, 50.19mgg-1 polyphenol and 86.93% antioxidant activity. Addition of nitrogen source and clarification by pectinase had resulted in wine with highest total mean sensory score (17), 3.52% alcohol, 83.65mgg-1 polyphenol and 86.54% antioxidant activity. Wine prepared with 1:2 fruit: water ratio, 1:1 fruit: sugar, with nitrogen source and clarified by pectinase had high yield (90.7%), 5.13% alcohol, 56.55mgg-1 polyphenol and 82.95% antioxidant activity. 186 Rose apple wine prepared with 1:1 fruit: water ratio, 1:1 fruit: sugar, without nitrogen source and clarified by settling had 92.33% yield, 3.52% alcohol, 112.34mgg-1 polyphenol and 75.12% antioxidant activity with highest total mean sensory score (16). Preparation of wine with 1:1 fruit: water ratio, 1:1 fruit: sugar, with nitrogen source and clarified by pectinase had resulted in wine with 91.33% yield, 3.52% alcohol, 151.65mgg-1 polyphenol and 80.13% antioxidant activity. The wine produced using 1:2 fruit: water ratio, 1:1 fruit; sugar ratio, without nitrogen source and clarified by settling had 93.33% yield, 4.39% alcohol, 108.66mgg-1 polyphenol, high antioxidant activity (83.33%) and highest total sensory score (16). When the superior wines selected from each fruit were stored in amber coloured glass bottles and analysed for storage stability, it was seen that the polyphenol content decreased during storage. All the wines were microbiologically safe till the end of two moth storage. In general, utilization of pectinase for clarification, addition of nitrogen source and clarification by pectinase or by doubling the water content in addition to nitrogen source and use of pectinase can improve yield, antioxidant property and sensory score of jamun wine. Addition of nitrogen source, use of pectinase and nitrogen source or doubling the water content with nitrogen source and use of pectinase can improve yield and sensory score of papaya wine. But alcohol content and antioxidant activity were significantly reduced by doubling water in addition to use of nitrogen source and pectinase. By doubling the water content or usage of a nitrogen source and pectinase enzyme, no significant improvement could be made in yield or alcohol content of rose apple wine; instead the antioxidant activity could be significantly improved. The study clearly points out the relevance of selecting process parameters based on the quality of raw material used for wine making.
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    Determination of optimum maturity stage in mango (Mangifera indica L.) for fruit quality
    (Department of Post Harvest Technology, College Of Agriculture, Vellanikkara, 2021) Janmitha Shetty; KAU; Meagle Joseph, P
    Mango (Mangifera indica L.), the national fruit of India is nutritionally rich in carbohydrates, proteins, vitamins and minerals such as calcium, iron, and phosphorus and hence known as the “King of fruits”. Mangoes are popular in markets worldwide because of unique flavour, appealing aroma, colour and taste (Arauz, 2000). In Indian subcontinent flowering of mango starts from November in Kerala and extends to February – March in Northern India. Mangoes from Kerala fetch higher price in the main markets at other parts of the country due to earliness. But commercial cultivation of mango in Kerala is limited to a few pockets in Palakkad district and the national varieties such as Alphonso, Banganapalli, Amrapali, Ratna and Mallika are occasional. The adaptation of different varieties to the climatic conditions prevailing fruiting and yielding behaviour of the varieties, production and post-harvest management practices followed by the growers, prevailing marketing system, are some of the problems of mango cultivation in Kerala. Mango fruits gain acceptance and popularity among consumers when it is served with the correct ripeness. Mangoes harvested at full maturity had a shorter shelf life, but those harvested early had a higher weight loss but improved storability (Shahjahan et al., 1994). Maturity standards in relation to the quality of important commercial varieties have not been studied when grown under humid tropical conditions of Kerala. Hence a study on the “Determination of optimum maturity stage in mango (Mangifera indica L.) for fruit quality” was carried out at the Department of Post-Harvest Technology, College of Agriculture, Vellanikkara, Thrissur, Kerala during 2019- 21 with the objective to find out the ideal harvesting stage of two important mango varieties viz. Ratna and Mallika for good organoleptic qualities and shelf life. The varieties of mango grown in the college orchard were utilized for the study. Flowers were tagged at the time of fruit set and observations on external appearance, peel, pulp colour, stone characters and biochemical changes were taken at 90, 100,110 120 and 140 days after fruit set (DAFS) as per the IPGRI descriptor. Heat unit requirements for maturity were also studied, for determining optimum days for maturity. In case of mango cv. Ratna, 90, 100 and 110 DAFS are the three stages of growth and in cv. Mallika, 90, 110,120 and 140 DAFS are four stages of growth. Physical and biochemical characters were studied at different stages of growth. In mango cv. Ratna fruits harvested 110 DAFS with accumulation of 1107.75 HU recorded good quality attributes. Fruits harvested at this stage had attractive length (10.44 cm), diameter (26.1 cm), weight (358.8 g), firmness (1.40 kg/cm2 ), specific gravity (1.03), stone length (7.49 cm), stone weight (10.68 g), TSS (21.12 ⁰brix), acidity (0.30 %), ascorbic acid (33.48 mg/100g), total sugar (19.04 %), total phenol (32.06 mg/100g), total carotenoid (14.65 mg/100g), β-carotene (0.88 mg/100g), crude fibre (2.59 %) and total chlorophyll (0.01 mg/100g) with a score of 8.00 in overall acceptability in sensory evaluation. In mango cv. Mallika fruits harvested 140 DAFS with accumulation of 1507.00 HU was found to be good in quality attributes. Fruits harvested 140 DAFS had good length (14.80 cm), diameter (28.03 cm), weight (623.95 g), firmness (0.73 kg/cm2 ), specific gravity (1.05), stone length (11.83 cm), stone diameter (12.63 cm), stone weight (66.73 g), TSS (20.18 ⁰brix), acidity (0.73%), ascorbic acid (61.21 mg/100g), total sugar (17.00 %), total phenol (47.5 mg/100g), total carotenoid (7.56 mg/100g), β-carotene (0.03 mg/100g), crude fibre (3.44 %) and total chlorophyll (0.01 mg/100g) with a score of 8.25 in overall acceptability in sensory evaluation. Study on effect of maturity on ripening was done in the variety cv. Ratna at their mature stage. Fruits harvested at the optimum maturity stage (100 DAFS) and ten days prior to maturity stage (90 DAFS) were kept for ripening after giving five different pre-treatments, viz., control (T1), ethrel spray (T2), hot water dip with ethrel spray (T3), sanitization with ethrel spray (T4) and ozonisation with ethrel spray (T5). Treated fruits packed in ventilated CFB boxes were kept under ambient condition and observations were recorded at 3 days interval. PLW increased with increase in storage period resulted in decrease in shelf life because of more loss in weight but the TSS and sugar increased however storability was less. High ethylene evolution on 3 days after storage indicates that it is tending towards maturity and it lowers after 6 days of storage resulting in complete ripened stage. Thus it can be concluded that the fruits of mango cv. Ratna harvested 10 and 20 days prior to ripe mature stage can be stored for 6 days under ambient conditions after giving pre-treatment consisting of Ozonization @ 200 ppm and ethrel spray @ 200 ppm.