MSc

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.
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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.