Peanut meal (PM) is limited in practical use (feed or food) from imbalance of amino acid profile and denaturation of protein. Fermentation was used to promote its nutritional and functional properties by single-factor experiments and orthogonal experiments. Results showed that the nutritional properties of fermented peanut meal (crude protein content, dry matter content, ash content, acid soluble oligopeptides content, in vitro digestibility, and content of organic acids) had a significant increase (P < 0.05 or P < 0.01) and more importantly, the content of amino acids was balanced by fermentation. In addition, fermented peanut meal possessed better antioxidant activities in the areas of reducing power, 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging activity, hydroxyl radical scavenging activity, and metal chelating activity (P < 0.05 or P < 0.01). These results implied that the nutritional and antioxidant properties of peanut meal were improved effectively by biological modification, which could be valuable in terms of nutrition and protein resources. It is great of importance to meet requirement of raw materials for husbandry in China when facing a huge lacking of feedstuff, especially for protein feed with an over 80 % import amount depending from other countries yearly.
Keywords: Antioxidant activity; Bacillus licheniformis; Bio-modification; Nutritional property; Peanut meal; Solid-state fermentation optimization.