Fermentation with lactic acid bacteria enhances the bioavailability of bioactive compounds of whole wheat flour
Shariful Islam, Md. Abdus Satter Miah, Md. Faridul Islam, Khurshida Jahan Tisa, Md. Habibur Rahman Bhuiyan, Md Nazrul Islam Bhuiyan, Sadia Afrin, Khandoker Shahin Ahmed, Hemayet Hossain
Abstract
• Solid-state fermentation (SSF) of wheat and whole wheat flour via lactobacillus plantarum . • Extraction of free and bound phenolic fractions and their in vitro antioxidant and HPLC analysis. • Individual phenolics increased significantly especially for free phenolic fractions. • Both free and bound phenolic extracts DPPH • , ABTS •+ , H 2 O 2 and ferric reducing power became stronger after SSF. • SSF is an effective bioprocessing technique to enhance the health benefit and utilization of whole wheat flour. This study aimed to examine how lactic acid bacteria (LAB) Lactobacillus plantarum mediated solid-state fermentation (SSF) of whole wheat flour (WWF) affected the release of phenolic fractions and their in vitro antioxidant (DPPH • , ABTS •+ , H 2 O 2 , and ferric reducing power) activities as well as phenolic acids. Results revealed that fermentation techniques successfully released the bound phenolic fractions into free form of the treated wheat and considerably increased the free/bound ration of phenolic fractions. The free and bound phenolic fractions total phenolic, flavonoid and antioxidant (TPC, TFC and TAC) contents were found increased 284.87 % and 39.60 %; 339.92 % and 105.86 %; 157.13 % and 52.43 %, respectively for SSFWG whereas 399.59 % and 103.24 %; 522.18 % and 102.72 %; 226.35 % and 95.67 %, respectively for SSFWF until 72hr and then found decreased. In HPLC analysis, individual phenolics were found increased significantly ( P ≤ 0.05) for free phenolic fractions and decreased for bound phenolic fractions. For free phenolics, 3,4 -dihydroxy benzoic acid was found increased enormously (164.54 % and 220.47 %, respectively for SSFWG and SSFWF) among the other individual phenolics. After SSF, both free and bound phenolic extracts DPPH • , ABTS •+ , H 2 O 2 and ferric reducing power of wheat became stronger. Principal component analysis and correlation matrix showed TPC are strongly correlated with the in vitro antioxidant activities and individual phenolics. The results of this experiment suggest that SSF is an effective bioprocessing technique to improve the phenolic release and antioxidant activities of wheat, which may further enhance the health benefits and utilization of fermented whole wheat flour. Consequently, the food and nutraceutical industries may get inspiration for the utilization of fermented whole wheat flour for future food production to get benefit from the release of phenolics found in fermented wheat and minimize the losses of raw material by-products.