Natural and induced fermentation by

Natural and induced fermentation by L. plantarum are sufficient to improve the concentration of phenolic compounds in fermented cowpea flour; complex polyphenols are hydrolysed to simpler and more biologically active compounds during fermentation (Dueñas, Fernández, Hernández, Estrella, & Muñoz, 2005). p-Coumaric, caf- feic, ferulic and m-coumaric acids are also metabolised by L. plan- tarum (Rodríguez et al., 2009). L. plantarum growth in fresh olive mill wastewaters leads to phenolic hydrolysis and depolymeriza- tion (Lamia & Moktar, 2003). There is higher antioxidative activity in samples fermented with L. rhamnosus compared with samples fermented with Saccharomyces cerevisiae. For example, the per- centage of lipid peroxidation inhibition in liposomes is 50.8% in unfermented barley, 52.4% in barley fermented with S. cerevisiae, and 60.9% in barley fermented with Lactobacillus rhamnosus (Ðord-evic ́ et al., 2010). The effects of lactic acid bacteria on antiox- idative activity could be explained by the liberation of simple phenolic compounds after acid and enzymatic hydrolysis of polymerised phenolic compounds during fermentation.