SUBMERGED FERMENTATION OF JERUSALEM ARTICHOKE PULP AND EXTRACT BY LACTOBACILLUS

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 1065-1070 pp, DOI: 10.5593/sgem2017/61/S25.139

ABSTRACT

Prebiotics are one of most common components of functional food. Jerusalem artichoke tubers contain up to 20 % of inulin and oligofructose (OF) well known as probiotic substances. In agriculture Jerusalem artichoke (JA) has a number of advantages while it is used. It is zoned in temperate climates like the northern regions of China and Russia. Due to its acceptable organoleptic properties (sweetish taste without bitterness) compared with chicory (commonly used as source of probiotic), JA tubers can be used in functional food directly. On the other hand the term of “prebiotic” is strongly bounded with “probiotic”. The products fermented by lactic acid bacteria (LAB) are referred to functional food also. So, three kinds of drink products based on milk whey were studied. The sources of prebiotics were extract of JA tubers (sample 2) and pulp of JA tubers (sample 3), while the control sample 1 didn’t containe prebiotics. Two strains of LAB Lactobacillus plantarum and Lactobacillus fermentum were selected for fermentation. The count of Lactobacillus plantarum after fermentation (24 h) was varied from 4.6×10 8 CFU/ml to 7.4×10 8 CFU/ml in different samples, and was maximal in sample 2. Greatest count of Lactobacillus fermentum (2.4×10 8 CFU/ml) was observed in sample 3. The final pH was about 4.0 in all cases. The survival of LAB was studied during 6 weak at 6 °C. Presumably the presence of JA tubers pulp ensured the best stability of Lactobacillus fermentum due to adhesion of LAB cells at solid particles. Final amount of cells decreased at about 20 times (1.2×10 7 CFU/ml) in sample 3, and about 500 times (2.9×10 5 CFU/ml) in sample 1. The suspensions of LAB cells were treated with CTAB (0.02 μg/ml) to confirm their adhesion on JA tubers particles. The variation of LAB count in sample 3 was detected after 3 week of storage. The value mentioned was greater at 2.7 times (3.3×10 7 CFU/ml) in treated suspension. There was not significant difference between treated and not-treated suspensions in samples 1 and 2.

Keywords: prebiotics, Jerusalem artichoke, functional food, lactic acid bacteria, fermented product