High temperature lacto-fermentation improves antioxidant and antidiabetic potentials of Lithuanian red beetroot

Abstract

Diabetes is becoming a global pandemic and therefore calls for diverse therapeutic strategies for mitigating the disease. In this study, lactic acid bacteria isolated from Lithuanian traditional fermented foods were screened for β-Glucosidase activity and were used to ferment beetroot to develop an antidiabetic product. After fermentation, LAB PN39MY (also referred to as PN39) fermented samples demonstrated the strongest DPP-IV and α-Glucosidase inhibitory abilities of 50.0 ± 3.5% and 80.5 ± 5% respectively as well as the highest antioxidant capacity of 0.69 ± 0.04 mmol/L relative to all the other samples. Varying the fermentation conditions revealed that fermenting beetroot with PN39 at 45 °C for 72 h yielded the strongest DPP-IV and α-Glucosidase inhibition of 87.45% and 80.5 ± 5.3% respectively and increased the antioxidant capacity to 1.46 ± 0.01 mmol/L. Whole genome sequencing analysis of PN39 revealed the strain to be Latilactobacillus curvatus. HPLC-MS analysis of PN39 fermented samples showed that the fermentation process generated high levels of dihydromyricetin (an antidiabetic flavonoid) which was absent in unfermented beetroot. Results from this study indicate that fermenting beetroot with Latilactobacillus curvatus PN39 at 45 °C for 72 h would be an effective method for developing antidiabetic functional foods.