IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 __________________________________________________________________________________________ Volume: 03 Issue: 01 | Jan-2014, Available @ http://www.ijret.org 223 STORAGE STUDIES ON BITTER GOURD JUICE PRESERVED WITH DIFFERENT CHEMICAL PRESERVATIVES Gurpreet Kaur 1 , Poonam Aggarwal 2 1 PhD Scholar, 2 Senior Vegetable Technologist, Department of Food Science and Technology Punjab Agricultural University, Ludhiana, Punjab, India Abstract Bitter gourd (Momordica charantia) is one of the most popular vegetables in Southeast Asia. It is a member of the cucurbit family and is also known as bitter melon or balsam pear. It is a good source of ascorbic acid and is used in the treatment of infectious diseases. It is anti-diabetic, stimulant, stomachic, laxative, blood purifier and control diabetes. This seasonal vegetable can be made available for the consumers in off seasons also in the form of juice. The juice can be made shelf stable by using various chemical additives. Therefore, the aim of the experiment was to compare the effect of different chemical additives namely Sodium benzoate, Potassium metabisulfite (KMS) and their combination, on the physicochemical and phytochemical parameters and antioxidant activity of Bitter gourd juice. The storage was done for 6 months at room temperature and the analysis was conducted at the interval of one month. For the physicochemical parameters like TS, TSS, acidity and Total Phenols, very slight but non-significant change was observed. Color values (Lab), Vitamin C and antioxidant activity changed significantly (p≤0.05). The variation was found in the color of different samples. Considering all the parameters, samples treated with potassium metabisulfite (KMS) maintained the maximum nutrient stability. Keywords: Antioxidant activity, Chemical additives, Bitter gourd, Phytochemicals ---------------------------------------------------------------------***----------------------------------------------------------------------- 1. INTRODUCTION Bitter gourd is one of the most popular vegetables in Southeast Asia. It is a member of the cucurbit family along with cucumber, squash, watermelon and muskmelon. Native to China or India, the fast growing vine is grown throughout Asia and is becoming popular worldwide. Depending on location, bitter gourd is also known as bitter melon or balsam pear [1]. The vegetable is a good source of ascorbic acid [2]. The medicinal value of bitter gourd in the treatment of infectious diseases and diabetes is attracting the attention of scientists worldwide. Bitter gourd is anti-diabetic, stimulant, stomachic, laxative, blood purifier and control diabetes [3]. As it is a seasonal vegetable, so steps should be taken to preserve them to make them available for consumption in off season as well. This could be achieved by extending the shelf life in fresh form or in the processed form [4]. Much of the work is done for preservation of bitter gourd by different methods such as steeping preservation, processing of bitter gourd into rings [5], sun drying and dehydration of bitter gourd [6], hot air drying of bitter gourd slices[7]etc. But the excellent medicinal virtues of bitter gourd can benefit the consumers equally in the form of juice also. However, information on the processing of bitter gourd into juice and its preservation by chemical additives is scanty. Keeping this in view, the current study was focused on assessing the effect of different preservation methods on the shelf stability of the processed Bitter gourd juice. 2. MATERIALS AND METHODS 2.1. Raw Materials The study was conducted in the Department of Food Science and Technology, Punjab Agricultural University, Ludhiana. Bitter gourd was procured from the local market. 2.2. Extraction Process of Bitter Gourd Juice Fresh bitter gourds were washed thoroughly and cut off from the top and were not peeled. The Bitter gourd juice was extracted in a juicer extractor (Kalsi: 9001-2008). The juice was pasteurized at 83°C for 3 min and citric acid @ 0.15% was added, followed by chemical preservatives. Dose distribution of chemical additives Sample Chemical additives Dose(ppm) T 2 Na-benzoate 3000 T 3 KMS 3000 T 4 Na-benzoate+ KMS 1500+1500 The pre-sterilized glass bottles were filled with the hot juice and corked. T 1 sample was given the pasteurization treatment followed by processing at 100°C for 20 min in boiling water bath and gradually cooled to a low temperature under running