Screening of biogenic amine production by lactobacillus SPP. And development of functional food, tea curd

Abstract

Biogenic amines are natural toxins and produced by decarboxylase enzyme through the removal of α-carboxyl group from an amino acid. Consumption of higher levels of biogenic amines will result in various pathophysiological effects such as hypotension or hypertension, cardiac palpitation, and even death. Lactic acid bacteria (LAB) produce decarboxylase enzymes to synthesize amino acids and are reported to form biogenic amines. The present work was aimed to screen the LAB isolated from locally available curd for biogenic amine formation and to utilize non-biogenic amine forming LAB to prepare black tea and green tea curd. LAB was isolated using MRS agar and biogenic amine formation was checked in decarboxylase media with amino acids like ornithine, lysine, histidine, tyrosine and without amino acids as control. Five LAB were isolated and morphological identification was made through simple staining. Out of five strains, two were found to produce biogenic amines from all the amino acids tested and three strains were found to be negative. Tea curd was prepared by inoculating LAB which are not producing biogenic amines in 2% green tea and black tea decoction prepared with milk. The preparation was incubated at 45°C for 12 hours. Lactic acid content and pH of green tea curd black tea curd were found to be around 1.40 and 3.60, respectively. Viable count of LAB in black tea curd was found to be higher (1.7 X 1012 CFU/mL) than in green tea curd (1 X 1012 CFU/mL).