Effect of indigenous lactic acid bacteria isolated from goat milk and cheeses on folate and riboflavin content of fermented goat milk

Abstract

The aim of the present study was to isolate riboflavin- and folate-producing lactic acid bacteria (LAB) from raw goat milk and cheeses, identify them and evaluate their capability to increase the content of these vitamins in fermented goat milk, envisaging potential application for development of novel bioenriched goat milk products. From 179 LAB isolates obtained, 151 (84%) were capable to produce at least one of these vitamins. The average production of total folate and riboflavin in vitamin-free media was 138 ng/ml and 364 ng/ml, respectively. Based on RAPD-PCR and 16S rDNA sequencing, 19 different genetic profiles were obtained and 7 species were identified, with predominance of Streptococcus thermophilus (7), Weissella paramensenteroides (6), and Lactococcus lactis (4). Seven isolates that produced folate and riboflavin above the average were tested for vitamins production in UHT goat milk. Five isolates were capable to increase four to six fold the original amount of folate in the milk in 24 h. Folate content in milk fermented with Lc. lactis FP368 for 24 h was 313 ng/ml that could provide 19% of the recommended daily intake of this vitamin. In addition, St. thermophilus FP268 increased the folate concentration in the milk almost four fold in only 6 h.