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

Document Type : Original Article

Authors

Department of Food Science, Faculty of Agriculture, Saba Basha, Alexandria University, Saba Basha, Alexandria 21527, Egypt

Abstract

The use of dairy-based functional foods has increased markedly over the last few
years. Ginger is believed to exert a wide range of therapeutic properties. This study aimed to
evaluate probiotic properties of twenty Lactic acid bacteria to apply in functional fermented milk
fortified 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 and
crude juice extraction. It was assayed for antibacterial activity by minimal inhibitory
concentration against antibiotic resistant pathogenic bacteria (E. coli BA 12296, Bacillus subtilis
DB100, 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 antibacterial
activity and antioxidant activity. Twelve strains out of twenty were resistant to bile salts
concentrations (0.2, 0.3 and 0.4 w/v), to acid conditions (pH 2.0, 3.0 and 4.0) and were able to
grow in the presence of 0.2 and 0.4 w/v of phenol. Seven strains (Lactobacillus delbrueckii
subsp. delbrueckii KT615, Lb. brevis KP653, Lb. delbrueckii subsp. lactis KP645, Lb. plantarum
KP623, Lb. paracasei subsp. tolerans WT631, Enterococcus faecalis BM711, Enterococcus
faecium BT734) had the ability to adhere to rabbit intestinal epithelial cells in-vitro, and were
resistant to ginger juice. Ginger juice concentration showed indirect relationship with the milk
coagulation time and direct with syneresis of fermented milk. It was showed that used 2% of
ginger juice concentrations was the best results on fermented milk products.

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