Abstract
This study aimed to evaluate the γ-aminobutyric acid (GABA) production and antioxidant activity during fresh cheese processing with single and co-fermentation processes of the high-GABA producing strain, Lactobacillus plantarum L10-11. For a mini-batch of fresh cheese, milk with 0.1% monosodium glutamate was fermented for 18 h and GABA production was monitored by thin layer chromatography and ion chromatography. GABA could be detected in co-L10-11 at 12 h of fermentation and at greater amounts after 18 h. The 18 h fermented milk of co-L10-11 and single-L10-11 contained GABA at 11.30 and 1.21 mg/100 mL, respectively, while GABA was not detected in the control. After whey separation, GABA remained in the cheese curd portion, resulting in 14.91 mg/100 g being found in the co-L10-11 cheese curd. ABTS antioxidant and metal chelating activities significantly increased during 18 h of fermentation and were retained in the cheese curd in the range of 783.11-922.00 μmol TE/kg and 216.71-266.98 μmol EDTA equivalents/kg cheese, respectively. Moreover, there were no significant difference in the textural characteristic between co-L10-11 and the control cheese curd. These results suggested that Lb plantarum L10-11 could be exploited as adjunct to improve health-promoting effects of the GABA in fresh cheese.
Keywords:
Lb plantarum; GABA; antioxidant activity; co-fermentation; cheese curd