[Fermentation of sheep bone enzymatic hydrolysates by Lactobacillus plantarum]

In order to improve the nutritional value and bio-availability of sheep bone enzymatic hydrolysates, we tried to ferment the hydrolysates with lactic acid bacteria (LAB) to enhance free Ca²⁺, to generate oligopeptide and antioxidative activity. First, we isolated 7 LAB strains from commercial starters and selected Lactobacillus plantarum as the starter for its highest protease-producing ability. The content of released Ca²⁺ was evaluated when the fermenting conditions were optimized by the method of responsive surface design. When supplemented with 1% maltose and inoculated 4% L. plantarum, at initial pH 5.5 and 37 ℃ for 14 h, Ca²⁺ content in the hydrolysates increased significantly (P<0.05), as well as the generation oligopeptide (P<0.01), and the content of hydroxyproline (P<0.01). The count of L. plantarum in the fermented hydrolysates reached to 94.6×10⁸ CFU/mL. L. plantarum fermentation significantly enhanced the ability to scavenge free radicals DPPH, ·OH and O₂⁻· (P<0.01, P<0.05). Therefore, fermenting sheep bone hydrolysates by L. plantarum can increase free Ca²⁺, oligopeptide and antioxidative ability.