Journal of AgriSearch, 6(4):161-165 1 2 3 JJ JANKAR , VN PAWAR AND AJAY KUMAR SHARMA ISSN : 2348-8808 (Print), 2348-8867 (Online) https://doi.org/10.21921/jas.v6i04.16896 An Open Access International Peer Reviewed Quarterly Effect of Alpha-tocopherol with guar gum coating on the shelf life of thompson seedless grape 1, 2 MIT College of Food Technology, MITADT University, Pune, Maharashtra, India 3 ICAR-National Research for Grapes, Pune, Maharashtra, India *Corresponding author email: jankjagruti@gmail.com The search for biodegradable, non-toxic, healthy and eco-friendly treatments to increase the shelf life of fruits results in the use of edible, biodegradable films, or surface coatings. Under tropical conditions prevailing high temperatures coupled with low humidity severely affect the grape quality and reduce shelf life. Guar gum (0.25 %) with different levels of alpha tocopherols viz.; 0.2, 0.4 and 0.6 percent were applied on bunches of Thompson Seedless with objective to improve quality for extended shelf life. Treated bunches of Thompson Seedless were placed at 10℃ and 60-65 percent RH for 28 days. Observations showed that the application of guargum with alpha-tocopherol improved overall appearance, delayed pattern of TSS and acidity changes, increased antioxidant activities and total phenol content. A combination of alpha-tocopherol (0.6 %) with guar gum (0.25%) was found more effective over other combinations. KEYWORDS Grapes, Guar gum, Alpha-tocopherol, Shelf life, Postharvest Losses ABSTRACT INTRODUCTION 161 G rape is well adapted in the tropical climatic conditions of India. Maharashtra and Karnataka states contributed about 95% of total grape production ( ). India is mainly producing grapes for fresh Sharma et al., 2017 consumption (72%) and about 27% of the total output is dried for raisin making. Grapes are mainly harvested during February and March in these regions. After harvesting, grape bunches face high temperature and low humidity conditions and these conditions lead to faster deterioration in quality with higher postharvest losses. ( ) stated that postharvest loss in grapes is recorded within Sharma et al. 2018 the range of 8.23 to 16 percent under Indian conditions. Time of harvesting, the current temperature at the harvesting, presence of moisture on the berries and handling of grape bunches during harvesting are major regulating factors for deciding the quantum of losses. Physiological loss in weight, berry shattering, rachis, and skin browning are the leading causes of high-level quality deterioration in grapes. It is found that the application of the edible coating on berries works as a barrier during the process of handling, grading, packing, and storage. It retards quality deterioration and improves appearance as well as nutritional values and maintain Physico-chemical and sensory attributes ( ). Different Sanchez et al., 2011 types of coatings are found beneficial by retarding dehydration, suppressing respiration and improved textural quality of perishable foods to retain volatile flavor compounds and reducing microbial growth ( ; Debeaufort et al., 1998 Ozdemir et al., 2010). Various materials based on lipids, proteins, and carbohydrates are used to coat the food materials. Among polysaccharide materials, Guar Gum is one of the most economical and useful ingredients available for coating formulations. As guar gum possesses superior water-binding capacity, it affects high viscosity at low usage levels as it is soluble in cold water.Coatings create thin layers of material which act as a barrier against different agents (water vapor, oxygen, and moisture) and it helps in enhancing the quality and increases the storage period of fresh and processed foods. The addition of active compounds such as antioxidants to these films and coatings improves their functional properties and makes them potentially applicable in food preservation (Sanchez et al.,2011). Free radicals can be bounded by antioxidants to defend materials against oxidation processes, regardless of the action mechanism ( ). Alpha- Pokorny, 2007 tocopherol is found good radical scavenger and thereby stops the propagation of radical chain reactions. ( ) revealed that due to strong Mahoney and Graf 1986 hydrophobicity, the alpha-tocopherol is a significant antioxidant, especially in fat systems. ( ) have studied the effect of tocopherol added films in the Wu et al. 2001 packaging of precooked ground beef patties. They found that the tocopherol- treated stearic-acid films were more effective in inhibiting lipid oxidation than non- tocopherol films. Tocopherols have been incorporated into gelatin films, starch-alginate, or acetylated monoglyceride (AMG) coatings and used to protect margarine from lipid oxidation ( ). Delayed oxidative rancidity in walnuts was Guilbert, 1988 recorded by ( ). Besides these properties, tocopherols Mate and Krochta 1997 provide several benefits, preventing chronic diseases associated with oxidative stress and also are known to have a vascular smooth muscle cell signaling function ( ; ). Considering the applicability of guar gum in Liang et al., 2011 Montero et al., 1999 coatings, benefits of tocopherols and shelf-life issues of grapes under the tropical conditions of India, the present study was conducted to study the effects of coatings on the shelf life of Thompson Seedless grapes. ARTICLE INFO Received on Accepted on Published online 19-08-2019 12-10-2019 03-12-2019 : : :