~ 249 ~ The Pharma Innovation Journal 2017; 6(9): 249-255 ISSN (E): 2277- 7695 ISSN (P): 2349-8242 NAAS Rating 2017: 5.03 TPI 2017; 6(9): 249-255 © 2017 TPI www.thepharmajournal.com Received: 13-07-2017 Accepted: 15-08-2017 Ninja Begum Assistant Professor (Food Science and Technology), Department of Applied Biology, University of Science & Technology, Meghalaya (USTM), Meghalaya, India Sanjib K Paul Examiner of Patents & Designs, Biotechnology Group, the Patent Office Kolkata, India Prasanna Kumar GV Associate Professor, Department of Agricultural Engineering, Assam University, Silchar, Assam, India Jatindra K Sahu Assistant Professor, Centre for Rural Development & Technology, IIT-Delhi, Delhi, India Saiyyad Alamdar Husain Assistant Professor (Food Science and Technology), Department of Applied Biology, University of Science & Technology, Meghalaya (USTM), Meghalaya, India- Correspondence Ninja Begum Assistant Professor (Food Science and Technology), Department of Applied Biology, University of Science & Technology, Meghalaya (USTM), Meghalaya, India Development of tulsi impregnated starch-based edible coating to extend the shelf-life of tomatoes Ninja Begum, Sanjib K Paul, Prasanna Kumar GV, Jatindra K Sahu and Saiyyad Alamdar Husain Abstract An investigation study was undertaken to identify the optimum formulation of starch based edible coating and determine the effect of addition of Tulsi extract to optimized formulation of starch based edible coating on storage quality of tomatoes. The coating solutions were prepared by completely gelatinizing 1, 1.25, 1.5, 1.75 and 2 g/100 mL starch slurry in water at 95ºC for 30 minutes and adding glycerol (0.4, 0.5 and 0.6 mL) as plasticizer. The moisture loss, percent solubility of the coated film, TA and TSS of tomatoes after 10 days of coating were determined. Non-dominated sorting technique was applied to identify the optimum levels of starch and glycerol in the coating solution that minimized all the four storage attributes. The solution containing 1.5% starch and 0.5 mL glycerol was found to be best formulation for coating of tomatoes. The extract of Tulsi at 1%, 2% and 3% by volume was added to the optimized formulation and the effect of coating on weight loss, TSS, TA, pH and moisture content of tomatoes in every five days interval upto 20 days were studied. The weight loss, TSS and TA increased with increase in storage period for both coated and uncoated tomatoes. The moisture content and pH of tomato decreased with increase in storage period. The rate of increase and decrease of these parameters was found to be lowest for the optimized coating solution added with 3% Tulsi extract. Therefore, in order to increase the shelf life of tomatoes, coating using the starch based edible coating of 1.5% starch and 0.5 mL glycerol added with Tulsi extract upto 3% may be recommended. Keywords: Starch, edible coating, tomatoes, tulsi, shelf-life Introduction Starch is a central component of human diet which is the major dietary source of carbohydrates and is the most abundant storage polysaccharide in plants. Starch is a polymeric carbohydrate composed of anhydroglucose units. Starch is composed of glucose polymers: a linear chain molecule termed amylose and a branched polymer of glucose termed amylopectin which is linked together by α-D-(1-4) and/or α-D-(1-6) glycosidic bonds. Starch is the predominant food reserve substance in plants. Edible coating and/or film is a thin layer not exceeding 0.3 mm in thickness, made-up of eatable material covering any food item to extend their shelf-life and to introduce additional value to the item. Edible Coating can also be used on the surface of food to control the diffusion rate of preservative substances from the surface to the interior of the food [1, 2] . Edible coatings may be composed of polysaccharides, proteins, lipids or a blend of these compounds [2, 3, 4, 5] . Coating can act as a barrier to moisture and oxygen during processing handling and storage [6] . Additionally, edible coating can act as carriers of functional ingredients such as antimicrobial and antioxidant agents, nutraceuticals and color and flavor ingredients [7] . Food products are usually coated by dipping or spraying, forming a thin layer on the food surface that acts as a semi-permeable membrane, which in turn control the moisture loss and/or suppress the gas transfer [8] . The coatings also function as carriers for antimicrobial and antioxidant agents [9] . Edible coating can also be safely eaten as part of the product and do not add unfavourable properties to the foodstuff [10] . Starch-based coatings or films exhibit physical characteristics similar to plastic films in that they are odorless, tasteless, colorless, non-toxic, biologically absorbable, semi-permeable to carbon dioxide, and resistant to passage of oxygen. Since the water activity is critical for microbial, chemical, and enzymatic activities, edible starch based films can retard microbial growth by lowering the water activity within the package. Amylose is responsible for the film-forming capacity of starch [9] . Glycerol is a plasticizer and is included in the edible coating formulation with the purpose of modifying the mechanical properties of the base edible components producing more flexible coatings [11, 12] .