International Journal of Scientific and Research Publications, Volume 4, Issue 10, October 2014 1 ISSN 2250-3153 www.ijsrp.org Production and Evaluation of Set type Yogurt Incorporated with Water melon (Citrallus lanatus) S.T.S.K. Warakaulle*, W.A.D.V. Weerathilake* and N.R. Abeynayake** * Department of Livestock and Avian Sciences, Faculty of Livestock, Fisheries and Nutrition, Wayamba University of Sri Lanka, Makandura, Gonawila 60170, Sri Lanka. ** Department of Agribusiness Management, Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, Gonawila 60170, Sri Lanka. Abstract- Yogurt is an increasingly popular cultured dairy product in most of the countries. Popularity of yogurt has increased due to its perceived health benefits. Health-promoting attributes of yogurt containing live and active cultures are well documented. Yogurt is easily digested, has high nutritional value, and is a rich source of carbohydrates, protein, fat, vitamin, calcium, and phosphorus. Main objectives of this research were to find out the ability of producing yogurt incorporated with Water melon and to evaluate the consumer preference for yogurt incorporated with Water melon. Prepared yogurts were analyzed for moisture, ash, total solid, fat, and vitamin C content. Titrable acidity, pH, and microbial quality (Total plate count, Coliform and yeast/mold) have been investigated on 1 st , 7 th , 14 th and 21 st days of refrigerated storage. The addition of Water melon juice into the yogurt showed an increase in vitamin C content when compared to the plain yogurt. In addition, decreased levels in the fat, total solids, and titratable acidity were observed comparatively to the plain yogurt. Coliform and yeast/moulds count was less than 10cfu/g in both the control and the experimental yogurt. The addition of 25% Water melon juice into milk in order to produce yogurt, improved the yogurt in terms of color, appearance, odor and overall acceptability of yogurt. Index Terms- Yogurt, Fruit yogurt, Water melon, Milk, Vitamin C I. INTRODUCTION ogurt can be defined as a fermented dairy product manufactured from fermentation of milk [1]. It is a semi solid fermented product made from heat-treated and standardized milk mixed by the activity of a symbiotic blend of Streptococcus thermophilus and Lactobacillus delbruckii subsp. bulgaricus [2]. According to the Code of Federal Regulations of the Food and Drug Administration (1996c) (FDA) yogurt can defined as the “food produced by cultur ing one or more of the optional dairy ingredients (cream, milk, partially skimmed milk, and skim milk) with a characterizing bacteria culture that contains the lactic acid-producing bacteria, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus” [3]. On the other hand, Codex Alimentarius (2003) defines yogurt as a milk produced with. Streptococcus thermophilus in conjugation with any Lactobacillus species [2]. Milk fermentation with Lactic Acid Bacteria (LAB) also results in products with distinctive tastes and aromas [1]. Milk of various mammals is used for yogurt making in various parts of the world. However, most of the industrialized production of yogurt uses cow’s milk [4]. Since yogurt is a safer product with a unique flavor which has a higher consumer preference, consideration is being given by nutritionists to incorporate inexpensive source of nutrients to make it an almost complete food [5]. Yogurt has some curative characters also. It has been reported that yogurt can lower the blood cholesterol level [6] and helps to control some intestinal disorders like constipation, dysentery etc., [7]. Yogurt is one of the fastest growing cultured dairy products throughout the world [6]. Yogurt and related products continue to increase in popularity in many countries around the world. Consumers, especially children are demanding novel yogurt formulations more than traditional plain yogurt. Few of the novel yogurt formulations are non-fat yogurt, whipped yogurt, yogurt smoothies, organic yogurt and minimally processed fruit yogurt [8]. An increasing demand can be seen for fruit yogurts. Introduction of various fruit-flavored yogurts has significantly contributed to the consumption of yogurt among all ages [9]. There could be many reasons behind this. Incorporation of fruits endorses the healthy image of yogurt. Bardale (1986), reported that the addition of fruit preparations, fruit flavors, fruit purees, and flavor extracts enhances versatility of taste, color, and texture for the consumer [10]. However fruit-flavored yogurts require an appropriate balance of sweetness, sourness and therefore sufficient flavor intensity should be involved in the flavored yogurt to mask the plain yogurt base [11]. There have been many attempts to produce a range of fruit yogurts in Sri Lanka, recently. However, use of Water melon to produce of fruit yogurt has not yet been done so far. Finding the plausibility of producing a yogurt incorporated with Water melon is important since Water melon is a very popular and abundant tropical fruit. Therefore, the aim of this study was to formulate a Water melon incorporated yogurt with higher consumer acceptability. Another objective of this study was to evaluate the effect of Water melon additive on physical, chemical, sensory, and microbiological properties of the yogurt. II. MATERIALS AND METHODS Yogurt preparation Y