AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com *Corresponding author’s e-mail: sudhasreenivas2005@gmail.com. 1 Dept. of Home Science, Sri Sathya Sai Institute of Higher Learning, Anantapuramu. Asian J. Dairy & Food Res, 35(1) 2016: 37-40 Print ISSN:0971-4456 / Online ISSN:0976-0563 Effect of inulin, fructooligosaccharides and L. acidophilus in formulating a synbiotic yoghurt K. Sudha Rani* and N. Srividya 1 Research Associate (Home Science) Krishi Vigyan Kendra, Reddipalli, Ananthapuramu-515 701, India. Received: 22-04-2015 Accepted: 16-02-2016 DOI: 10.18805/ajdfr.v35i1.9250 ABSTRACT The objective of the present investigation is to develop a suitable protocol for low fat synbiotic yoghurt with inclusion of L. acidophilus (probiotic), Inulin and Fructo oligosaccharides (prebiotics). The prebiotic yoghurts were prepared by using control yoghurt and addition of prebiotics. The nutritional profile of control yoghurt (CY), prebiotic yoghurt (PY) and Synbiotic yoghurt(SY) were studied. The nutritional profile of the products studied includes mineral composition, carbohydrate and in vitro calcium availability. The carbohydrate profiles determined were the total soluble sugars, reducing and non-reducing sugars. The prebiotics (which are fructose polymers) containing yoghurt exhibited a high sugar profile. The prebiotic yoghurt showed high mineral profile of Ca, Mg, and P followed by synbiotic yoghurt. In vitro calcium availability was found higher in samples containing inulin and/ FOS. Prebiotic yoghurt samples showed higher sensory acceptability scores than other samples. Texture profile analysis further confirmed improvement in textural parameters in samples containing prebiotics. Thus, the present investigation resulted in the development of low fat prebiotic and synbiotic yoghurts with improved functionality and enhanced therapeutic benefits, suitable for infants and elderly owing to its better digestibility and high nutrient availability, for boosting the immune system and for producing beneficial clinical and systemic effects. Key words : FOS, Inulin, Nutritional profile, Synbiotic yoghurt. INTRODUCTION Yoghurt is a fermented milk product produced by using thermophilic and lactic bacteria consisting of Streptococcus thermophillus and Lactobacillus bulgaricus. The cultures produce lactic acid from lactose during fermentation reducing the pH of milk and cause milk protein to coagulate thickening the product. From the nutritional point of view, milk and yoghurt are similar products. However, reports have confirmed that mineral availability especially, Ca, phosphorus, Mg and Zn to be improved in yoghurt over milk (Blanc, 1981; Balasubramanyam et al., 1984). Nutritional quality of proteins in fermented milk such as yoghurt has been reported to have higher in vitro digestibility (Breslaw and Kleyn, 1973) . To enhance and extend the functionality of yoghurt, friendly / ‘probiotic’ bacteria such as Lactobacillus acidophilus are being added. Probiotic yoghurt thus have live cultures which can survive the gastrointestinal passage unlike the yoghurt starter cultures. Probiotic cultures and dairy form a good combination package as milk provides lactose as energy source for the growth of the bacteria in the intestine and milk proteins protect the bacteria during passage through the stomach (Chartiers et al., 1998). The concept of prebiotics and probiotics, has led to a newer interesting ‘synbiotic approach’. This approach combines the synergistic benefits of both prebiotics and probiotics (Gibson and Roberfroid, 1995). Such synbiotic products would boost the market potential of yoghurt in the Indian market. This approach would widen the therapeutic and nutritional benefits of yoghurt and would cater to the requirements of children to aged people. Keeping in view the above points, the study aimed at the development of a low-fat synbiotic yoghurt. MATERIALS AND METHODS The milk product selected for the present study was ‘set yoghurt’. The product was prepared using double toned milk (Fat = 1.5%; SNF = 9%) obtained from the local dairy. The prebiotic substances – Fructo-oligosaccharide / Raftilose and Inulin / Raftiline (Orafti, Belgium) procured through S.A. Pharmachemical Pvt. Ltd., Mumbai. Sugar (local market) and skim milk powder (sagar brand) were obtained in one lot from the local market Low-fat milk cultured with the ‘yoghurt’ starter cultures – S. thermophilus and L.bulgaricus at 1% level each (ST + LB = ‘CY’) was treated as control. Prebiotic yoghurts were prepared by adding either inulin (IY) or fructooligosaccharides (FY) to the milk cultured with S. thermophilus (ST) and L. bulgaricus (LB). The range of prebiotic addition was based upon tolerance