Streptococcus thermophilus and lactobacillus spp. may increase the folate content of soymilk containing passion fruit by-product and fructooligosaccharides

LEBLANC, JEAN GUY; ALBUQUERQUE, M.A.C.; SAAD, S.M.I.; BEDANI, R.

San Miguel de Tucuman

Simposio; V Simposio Internacional de Bacterias Lácticas; 2016

CERELA

Folate is an important B-group vitamin that plays a crucial role in human metabolism since it is involved in the biosynthesis of DNA, RNA and some amino acids and prevents neural tubes defects. In order to prevent folate deficiencies, the bio-enrichment of foods with natural folates produced by lactic acid bacteria has become a promising alternative to mandatory fortification with synthetic folic acid. Additionally, the potential of the use of fruit by-products as a bacterial substrate for folate production is interesting since these are rich in several bioactive compounds. Therefore, the ability of four strains of Lactobacillus spp. (Lb. acidophilus LA-5, Lb. rhamnosus LGG, Lb. fermentum PCC and Lb. reuteri RC-14) in producing natural folates from fermentation of fruits by-products (passion fruit, orange, acerola and mango) was investigated. A phenol red modified MRS broth (mMRS) was supplemented with 1% (m/v) of each by-product and inoculated with 4-5 log cfu of each strain. Inoculated mMRS broths were incubated statically at 37ºC and samples were taken at 0 and 24 h for folate quantification using a microbiological assay. Folate content of mMRS was determined and subtracted from the final values. All the strains were able to produce folate in mMRS supplemented with passion fruit (8±2 ng/mL) and orange (38±11 ng/mL). Strain RC-14 was the best producer in both passion fruit and orange by-products (594±48 and 782±7 ng/mL) and LGG (76±6 ng/mL) and LA-5 (66±1 ng/mL) produced the lowest amount in the presence of passion fruit and orange by-products, respectively. In the presence of acerola, only LGG consumed the vitamin (-11±4 ng/mL) and PCC produced the highest amount (516±68 ng/mL). Regarding mango by-product, both LA-5 (-14±1 ng/mL) and LGG (-15±6 ng/mL) consumed the available folate and RC-14 was the best producer (168±5 ng/mL). These results show that folate production is not only strain-dependent, but also can be influenced by the type of fruit substrate. Additionally, the production of folate by LA-5 is an interesting result since this strain does not possess the folate biosynthesis genes in its published genome.