Optimization of the growth of Lactobacillus in skim milk added with green banana flour and determination functional properties

Abstract

Purpose

This paper aims to study the effect of addition of green banana flour (GBF) in skim milk, provides a nutritional and functional contribution to this matrix when added. They have biological compounds like resistant starch, phenolic compounds, antioxidant compounds and others. The skim milk containing 1.08 per cent of GBF was chosen after a central composite rotational design and response surface methodology. The response variable was the growth of Lactobacillus plantarum (LP) and Lactobacillus helveticus (LH).

Design/methodology/approach

During the fermentation process, the antioxidant activity, plasmid DNA protection capacity, proteolytic activity and inhibitory activity of angiotensin-converting enzyme (ACE) of the fermented milk was determined.

Findings

All variables were influenced by the fermentation time. The antioxidant activity evaluated by the ABTS radical presented values of 0.83 ± 0.04 µM Trolox.mL−1 and 0.79 ± 0.02 µM Trolox.mL−1, respectively, for the fermented LP and LH. The extracts fermented by L. plantarum and L. helveticus were able to inhibit the oxidation of plasmidial DNA. The proteolytic activity was higher in the fermented with LH (1.16 ± 0.03) than in the fermented with LP (0.71 ± 0.02). The ACE inhibitory activity was higher in the fermented LH (59.01 per cent) than in the fermented LP (54.45 per cent).

Originality/value

Fermented milk with 1.08 per cent GBF presented positive results in the analyzed variables and could be studied commercially as a functional food alternative.

Citation

Busanello, M., De Moraes Filho, M.L., Guergoletto, K.B. and Garcia, S. (2019), "Optimization of the growth of Lactobacillus in skim milk added with green banana flour and determination functional properties", Nutrition & Food Science, Vol. 49 No. 2, pp. 249-261. https://doi.org/10.1108/NFS-03-2018-0098