‘Thompson seedless’ grapes (Vitis vinifera) possessing < 13° brix and > 1.0% acidity were used in the preparation of beverages with and without carbonation. Sour grape juice was extracted, bottled and clarified by racking for three months. Palatable blended grape beverages were also prepared using sour grape juice with phalsa / purple grape juice. Process parameters such as quantity of juice, blending proportions and brix / acid ratio for different beverages were optimized. Squashes were prepared by maintaining brix at 45° and acidity 0.75%. Readyto-serve (RTS) beverages were standardized with brix 15° and acidity 0.14%.
The appearance, color and flavor characteristics of sour grape beverages were improved by blending with purple grape juice and phalsa juice at 2:1 and 1:1 ratios respectively. A set of carbonated beverages in the above combinations were also prepared to check their compatibility and acceptability. A marginal rise in total sugars and decrease in acidity were observed in all beverages after 6 months of storage. Sensory evaluation indicated that carbonated beverages were highly acceptable than plain beverages throughout the storage period. Highest scores of 7.4 and 7.5 were recorded for blended grape beverages with purple grape and phalsa juice respectively even after a storage period of 6 months.
Keywords: Sour grapes; Phalsa; Purple grapes; Blended beverages; Carbonated beverages
Fruit beverages are well relished by all age groups of the society. Sour grapes (Vitis vinifera) ‘Thompson seedless’ are grown in some parts of Punjab, Haryana, and Tamil Nadu possess low total soluble solids (< 13° brix) with higher titratable acidity (>1%) which are not suitable for consumption as table variety. Recently, sour grapes were explored in our laboratory for the production of various shelf stable products such as raisins, jam, spread, sweet chutney and canned grapes . It was reported that consumption of grape products at moderate level helps in prevention of aging related diseases . Since higher acidity is a major obstacle in fruits for consumption, fruit juices were subjected to de-acidification by electro dialysis , and palatable raisins were produced from sour grapes by osmo-air dehydration . Literature review revealed various combinations of fruit juice, sugar and citric acid in preparation of ready – to – serve (RTS) beverages such as mango-papaya nectar, guava-lemon and papaya-passion fruit juice blends etc [5-7].
Blending of fruit juices is practiced to overcome the high cost of some exotic fruit juices, scarcity or seasonal availability, balancing of strong flavors, high acidity, astringency, or bitterness, improving total soluble solids, bland flavor, improving and stabilizing color. Nutritional or phytochemical properties can be improved by blending which offers to adjust sugar/acid ratios and compensate undesirable juice consistency .
Comminuted guava drinks were prepared maintaining the ratio of fruit bases to water at 100:200 and sugar to acid ratio at 450:7.6 to obtain superior organoleptic properties . Guava beverages were prepared using 5, 10% peeled fruit pulp, with 12.5% total soluble solids and 0.25% acidity. The beverages were preserved using 70 ppm SO2, 120 ppm sodium benzoate, and pasteurization at 85°C for 15 min . The juices were also assessed for retention of vitamin C and flavor in presence of carbonated water. The effect of potassium metabisulfite (100 ppm) was studied in non-pasteurized muscadine grape juice during storage at 3°C for 9 weeks.
It was observed that sulfitation J Food Process Technol
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lightened the red color and lowered microbial levels . Processes for extraction of lime juice and preparation of carbonated beverages were well documented in the literature . Preservation of a carbonated lime drink in glass bottles prepared using a base in sugar syrup diluted with chilled carbonated water was described . Blended muscadine grape beverages were prepared using 25% juice and addition of other juice namely, commercial grape juice, orange juice, and pineapple juice maintaining a brix/acid ratio of 30 . Higher overall acceptability and enhanced vitamin C content was achieved by blending gooseberry juice with grape juice at 20:80 ratios . Antioxidant capacity of soybased beverages was enhanced by blending with strawberry or grape fruit juices .
A method of preparation of carbonated RTS beverages using pomegranate syrup was described . The pomegranate syrup consisted of 100% fruit juice, 0.5% citric acid and brix was maintained at 65%. The syrup was diluted to 5 times and then carbonated. Carbonated RTS beverage from acidic tamarind pulp was developed by exposing the pulp to mixture of food enzymes . Tamarind RTS beverage was prepared using 12.5% tamarind extract, 0.4% acidity and adjusting to 16° brix. It was demonstrated that carbonated coconut beverages packed in glass bottles with crown cork seal can be safely preserved for 6 months period at an ambient temperature range of 2832°C . In the present study, products such as squash and ready to serve (RTS) beverages were prepared from grapes possessing low total soluble solids and high acidity which are hitherto not reported. Blended grape
*Corresponding author: Akula Satyanarayana, Central Food Technological Research Institute (Council of Scientific and Industrial Research), Resource Centre, Habshiguda, Uppal Road, Hyderabad-500 007, India, E-mail: [email protected] res.in
Received April 23, 2011; Accepted June 10, 2011; Published July 12, 2011 Citation: Balaswamy K, Rao PP, Nagender A, Satyanarayana A (2011) Preparation of Sour Grape (Vitis Vinifera) Beverages and Evaluation of their Storage Stability. J Food Process Technol 2:116. doi:10.4172/2157-7110.1000116
Copyright: © 2011 Balaswamy K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Volume 2 • Issue 3 • 1000116
Citation: Balaswamy K, Rao PP, Nagender A, Satyanarayana A (2011) Preparation of Sour Grape (Vitis Vinifera) Beverages and Evaluation of their Storage Stability. J Food Process Technol 2:116. doi:10.4172/2157-7110.1000116
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RTS beverages were prepared with purple grape and phalsa juices to improve the organoleptic attributes. Carbonated RTS beverages were also prepared for comparison with non-carbonated RTS beverages during storage.
Materials and Methods
‘Thompson seedless’ sour grapes with less than 13° brix and acidity more than 1.0 % were procured directly from grape orchards, Theni, Tamil Nadu, India. Purple grapes were purchased from the local fruit market, Hyderabad. Fully ripe and fresh phalsa (Grewia asiatica L.) fruits were procured from orchards situated at Acharya N.G. Ranga Agricultural University, Hyderabad. Carbonated water (Bisleri, Mumbai, India) was procured from a local market for use in preparing carbonated RTS beverages. Chemicals of laboratory grade were procured from S.d. fine Chemicals, Mumbai, India. Glass bottles of 200 and 750 ml capacities were collected from M/s Associated Glass Works, Hyderabad.