Application of some insensitive probiotic lactic acid bacteria and ginger as functional dairy products

Abstract

The use of dairy-based functional foods has increased markedly over the last fewyears. Ginger is believed to exert a wide range of therapeutic properties. This study aimed toevaluate probiotic properties of twenty Lactic acid bacteria to apply in functional fermented milkfortified with fresh ginger juice to increase the therapeutic and nutritional effects of the product.Ginger juice was prepared from ginger rhizomes through sorting, washing, peeling, crushing andcrude juice extraction. It was assayed for antibacterial activity by minimal inhibitoryconcentration against antibiotic resistant pathogenic bacteria (E. coli BA 12296, Bacillus subtilisDB100, Klebsiella pneumoniaa ATCC12296, Salmonella senftenberg ATCC 8400,Staphylococcus aureus NCTC 10788, Staphylococcus epidermidis ATCC 35984). Total phenol,total flavonoids and antioxidant activity were determined, ginger juice showed an antibacterialactivity and antioxidant activity. Twelve strains out of twenty were resistant to bile saltsconcentrations (0.2, 0.3 and 0.4 w/v), to acid conditions (pH 2.0, 3.0 and 4.0) and were able togrow in the presence of 0.2 and 0.4 w/v of phenol. Seven strains (Lactobacillus delbrueckiisubsp. delbrueckii KT615, Lb. brevis KP653, Lb. delbrueckii subsp. lactis KP645, Lb. plantarumKP623, Lb. paracasei subsp. tolerans WT631, Enterococcus faecalis BM711, Enterococcusfaecium BT734) had the ability to adhere to rabbit intestinal epithelial cells in-vitro, and wereresistant to ginger juice. Ginger juice concentration showed indirect relationship with the milkcoagulation time and direct with syneresis of fermented milk. It was showed that used 2% ofginger juice concentrations was the best results on fermented milk products.