International Journal of Scientific and Research Publications, Volume 2, Issue 5, May 2012 1 ISSN 2250-3153 www.ijsrp.org The Effect of Arrowroot (Maranta arundinacea) Extract on the Survival of Probiotic Bacteria in Set Yoghurt Nishani Abesinghe, Janak Vidanarachchi, Saliya Silva Department of Animal Science, Faculty of Agriculture, University of Peradeniya, Peradeniya Abstract- The objective of this study was to determine the effect of Arrowroot carbohydrates on the survival of lactobacilli in bio-yoghurts. There were four treatments; probiotic yoghurt (control), probiotic yoghurt with 3% Arrowroot extract, probiotic yoghurt with 1.65% Raftilose ® and yoghurt without probiotics or prebiotics. Lactobacilli population of control was 4.82 log CFU/mL at 11 st day of refrigerated storage whereas Arrowroot carbohydrates and Raftilose ® increased (P<0.05) it by 1.44 log CFU/mL and 1.17 log CFU/mL respectively compared to the control. These results support the conclusion that Arrowroot carbohydrates can be used to enhance the Lactobacilli population in bio-yoghurt during refrigerated storage. Index Terms- arrowroot, bio-yoghurt, prebiotics, probiotics I. INTRODUCTION he therapeutic properties of fermented milk are widely known and the contribution of yoghurt bacteria to the improvement of intestinal microflora has been widely recognized. Lactobacillus bulgaricus and Streptococcus thermophilus (yoghurt starter culture) are not bile acid resistant and do not survive the passage through the intestinal tract. However, L. acidophilus and B. bifidum (probiotic bacteria) incorporated into a yoghurt starter culture results in a milk product “of excellent therapeutic value” due to the ability of these species establish themselves amongst gut microflora (Tamime and Robinson, 2007). In recent years, there has been growing interest in using probiotic microorganisms as dietary adjuncts in the dairy industry. To produce the desired benefits, probiotic bacteria should be presented in the product in sufficient quantities during its whole shelf-life. Shah (2000) recommended that the minimum dose able to assure therapeutic effect should 6 log CFU mL-1. However, the survival of bacteria in yoghurt is quite low because the pH of yoghurt ranges from 4.2 to 4.6. Lankaputhra et al. (1996) reported the survival of 3 out of 9 bacterial strains in the pH range of 3.7 to 4.3. Further, he found that 14 out of 17 strains lost their viability in fermented milk in the first week of storage. Therefore, the strict strain dependence and poor survival of probiotics under adverse processing conditions including low pH, oxygen tension and nutrient depletion are some of the problems faced by the fermented milk industry. Many recent studies have shown that incorporation of prebiotic ingredients in probiotic yoghurt would probably leads to enhancement of the survival of those microorganisms. Prebiotics are selectively fermented ingredients that allow specific changes, both in the composition and/or activity in the gastrointestinal microbiota which confer benefits upon host well- being and health (Gibson et al., 2004). A range of oligosaccharides has been tested so far, with inulin and oligofructoses most frequently assessed and commercially incorporated in different products. Arrowroot (Maranta arundinacea) is a locally available rhizomatous herbaceous plant. Arrowroot rhizomes have high level of fructo-oligosaccharides which may possess prebiotic properties and may be useful in manufacturing bio-yoghurt. This study was carried out to assess the effect of incorporating water- soluble carbohydrate extracted from Arrowroot rhizomes on the sensory properties and the survival of lactobacilli and lactic acid bacteria in set-type yoghurt during refrigerated storage. II. MATERIALS AND METHODS Extraction of Arrowroot (Maranta arundinacea) carbohydrates Arrowroot carbohydrates were extracted as outlined in Figure 1. T Fresh rhizomes of Arrow root Sundry the precipitate (moisture content 9.9%) Filtering Decanting Store in an air tight bottle Water soluble carbohydrates Settling the filtrate (30 mins) Mixing Grinding Pulp Water Fibrous residue Figure 1: Extraction of carbohydrates from Arrowroot rhizomes