PREBIOTIC INFLUENCE OF PLANTAGO OVATA ON FREE AND MICROENCAPSULATED L. CASEI–GROWTH KINETICS, ANTIMICROBIAL ACTIVITY AND MICROCAPSULES STABILITY

Objective: To study the enhancement of antimicrobial effects of probiotic Lactobacillus casei (L. casei) both in free and immobilized form and in the presence of a natural prebiotic-Psyllium seed husk.Methods: Arabinoxylan was isolated from Psyllium seed husk. The isolated arabinoxylan was characterized using FTIR, TLC and HPTLC method. The growth kinetics of L. casei has been studied with and without arabinoxylan extracted from Psyllium husk. The antimicrobial activity of L. casei against Escherichia coli has been determined using glucose and arabinoxylan as substrates. Zone of inhibition in the presence of arabinoxylan has been observed. The probiotic has been immobilized through microencapsulation technique and the size distribution of the microcapsules has been microscopically determined. Effects of centrifugal force and high temperature stress on the stability of microcapsules have been studied.Results: The values of kinetic parameters, µmax and ks have been determined to be 0.379/h, 0.3942 g/l and 0.08127/h, 0.3094 g/l for glucose in MMRS and Basal media respectively. In the case of arabinoxylan the zone of inhibition was 14.5 mm and for glucose it was observed 13 mm. 15 g of microcapsules have been obtained from 5 ml of cellular broth. The size of microcapsules was in the range of 0.1 mm-0.55 mm in which 0.25 mm of diameter were maximum size.Conclusion: The presence of arabinoxylan enhances the growth and antimicrobial activity of L. casei both in free and immobilized forms. The retention of probiotic cells in fortified milk under freezing condition increases in presence of arabinoxylan. The size of microcapsules follows a normal distribution

STUDIES ON PREBIOTIC FOOD ADDITIVE (INULIN) IN INDIAN DIETARY FIBRE SOURCES - GARLIC (ALLIUM SATIVUM), WHEAT (TRITICUM SPP.), OAT (AVENA SATIVA) AND DALIA (BULGUR)

Objective: In the present investigation inulin has been extracted from dietary fibre rich Indian food stuffs, namely, garlic, wheat, oat and dalia. Inulin in the raw food stuff and in the extract has been assessed qualitatively and quantitatively. Methods: Inulin has been extracted from each food source using a combination of lab-scale chemical processes and unit operations. Qualitative assessment of inulin in different food samples and their extracts has been done using FTIR and TLC and quantitative assessment has been done using high performance liquid chromatography (HPLC) and also through combination of TLC and spectro-photometry. Results: The concentration (on dry weight basis) of inulin in natural prebiotic sources has been determined to be 16.60%, 13.07%, 8.94%, 14.95% for garlic, wheat, oat and dalia respectively. The extraction of inulin from garlic, wheat, oat and dalia was possible up to the extent of 99.46%, 77.94%, 53.31% and 89.15% respectively. Conclusion:  It may be concluded that all the food samples, investigated under the study, may serve as potential sources for extraction of prebiotic inulin. The present extraction procedure may be escalated to commercial scale for the production of inulin particularly from garlic for which the efficiency is as high as 99.46%