Enhancements of antioxidant activity and mineral solubility of germinated wrinkled lentils during fermentation in kefir

- Germination and fermentation improve the nutritional and functional value of low-quality “wrinkled” lentils.
- The total phenolic content and antioxidant activity of low-quality “wrinkled” lentils improved with germination.
- Germinated wrinkled lentil kefir samples showed higher antioxidant activity and mineral solubility after fermentation.
- The percent soluble minerals can be used as a marker of prebiotic activity of legumes/grains during fermentation.

The aims of this study were to (1) compare dietary fibers (soluble and insoluble), phenolic contents and antioxidant activity (AA) in germinated (GL) and non-germinated wrinkled lentils (NGL) and (2) evaluate phenolic contents, AA and mineral solubility in kefir beverage supplemented with GL and NGL during fermentation. Total dietary fiber (TDF) in NGL (28.0 ± 2.6 g/100 g) was significantly (P < 0.05) higher than GL (17.4 ± 0.4 g/100 g). Both GL and NGL contained more insoluble dietary fiber than soluble dietary fiber. The AA of GL was ∼13% higher than NGL. Kefirs with GL and NGL had more bacterial activity and acidity (1.22 ± 0.06% and 1.18 ± 0.05%, respectively). Fermentation of kefir supplemented with GL or soluble or insoluble dietary fiber from GL increased calcium solubility up to 10%. These findings suggest that germination and fermentation enhance the nutritional and functional value of low-quality “wrinkled” lentils that are otherwise considered waste.