Junaid et al., J. Anim. Plant Sci. 23(5):2013 1342 DEVELOPMENT AND QUALITY ASSESSMENT OF FLAVORED PROBIOTIC ACIDOPHILUS MILK M. Junaid, I. Javed, M. Abdullah * , M. Gulzar, U. Younas * , J. Nasir ** and N. Ahmad * Department of Dairy Technology, University of Veterinary & Animal Sciences, Lahore, Pakistan * Department of Livestock Management, University of Veterinary & Animal Sciences, Lahore, Pakistan ** Department of Meat Technology, University of Veterinary & Animal Sciences, Lahore, Pakistan Corresponding author’s email address: mjunaid@uvas.edu.pk ABSTRACT Functional foods containing probiotic bacteria (lactic acid bacteria and bifidobacteria) are getting popularity in the world, due to tremendous health benefits conferred by these bacteria. However, the total viable count of bacteria in the final product and the sensory attributes of the product are of higher importance for its consumer acceptability. In this study, flavored (strawberry, pineapple, and mango) probiotic acidophilus milk (from buffalo) using probiotic starter culture (Lactobacillus acidophilus) was prepared and its microbiological, physicochemical and sensory quality studies were carried out up to 6 days of storage. A slight increase in acidity of the milk was observed after 6 days of storage resulting in a decrease of pH (from pH 4.5 to 4.3). Total viable count of L. acidophilus bacteria was decreased after 6 days of storage due to increase in acidity but it was still within acceptable range (>10 6 ). Sensory evaluation data shows that the quality of sensory attributes (color, taste, aroma, appearance and overall acceptability) was slightly decreased after 6 days of storage but still had considerable acceptability. Key words: Functional foods, Probiotics, Lactobacillus Acidophilus, Acidophilus milk, Sensory evaluation, Keeping quality, Buffalo milk INTRODUCTION In recent years, there has been an increasing trend about incorporation of the health promoting bacterial species; Lactobacillus acidophilus and Bifidobacterium longum, into fermented milk products. In fact, these bacteria having prescribed population of viable cells, when administered orally as supplement or through food products impart a variety of beneficial health effects (Azlin et al., 1997; Anderson and Gilliland 1999; Andrade and Borges 2009). A number of Lactobacillus acidophilus strains are used in the processing of various dairy products such as acidophilus yoghurt and sweet acidophilus milk. The nutritional and therapeutic benefits derived through the consumption of dairy products containing viable Lactobacillus acidophilus as a food or supplement have been the focus of studies for the last two decades (Walker and Gilliland, 1993; Salminen et al. 1996; Azlin et al. 1997; Anderson and Gilliland 1999; Andrade and Borges 2009;). However, the production of high-quality fermented milk products containing these probiotic bacteria is a major challenge (Yeung et al., 2002) due to particular attributes of the bacteria such as rapid acid production from lactose and development of suitable quantities of the volatile compounds such as diacetyl and acetaldehyde etc. These compounds must not be over or under produced nor should they be accompanied by off- flavoring compounds. A lot of information has been accumulated relating to starter culture for milk fermentation (Marshall, 1987) and now even the efforts are going on to use the mixed cultures of bacterial species to produce specific flavor. Although significant attention has been placed towards the organoleptic characteristics of the product, enriched with probiotic bacteria but still most of the publications concerning probiotic bacteria have not paid much attention on the consumer acceptability and preference of the finished product. For enhancing the consumption of functional probiotic products, the consumer satisfaction must be achieved keeping in view the cost effectiveness and health perspectives (Hilde et al., 2003). Presently in Pakistan none of the dairy company is producing value added flavored acidophilus milk. Keeping in mind the need for value added products and the beneficial and , flavored (strawberry, pineapple, and mango) probiotic acidophilus milk (from buffalo) using probiotic starter culture (Lactobacillus acidophilus) was prepared for its microbiological, physicochemical and sensory quality studies up to 6 days of storage. pH was decreased as a consequence of increase acidity in milk after 6 days of storage. Total viable count of L. acidophilus bacteria was also decreased although within acceptable range (>10 6 ). Similarly, satisfactory results were found regarding sensory attributes (color, taste, aroma, appearance and overall acceptability) that showed slight decrease after 6 days of storage similar to the findings of Lehtoranta (2013). The Journal of Animal & Plant Sciences, 23(5): 2013, Page: 1342-1346 ISSN: 1018-7081