Protein fractions and amino acid profile of Aspergillus niger-fermented Terminalia catappa seed meal

The effect of solid state fermentation, using Aspergillus niger, on the protein fractions and amino acid profile of Terminalia catappa seed meal was investigated. A 5 ml A. niger spore suspension, containing 2.21 x 10(4) spores per ml, was used to inoculate 25 g of milled T. catappa seed meal. The inoculated samples were then incubated at room temperature (25 - 30 degrees C) for 1, 2 or 3 weeks. Levels of albumin, globulin, gliadin and glutelin, as well as the essential and non-essential amino acids profile were determined in both the raw and the fermented samples. The results showed that glutelin and gliadin are the predominant protein fractions (74.07%) in T. catappa seed meal, while albumin and globulin are less prominent (25.93%). Fermentation with A. niger, however, significantly increased the albumin and globulin content of the T. catappa seed meal to 38.83%, while it significantly reduced the gliadin fraction. The glutelin fraction was, however, not significantly (p>0.05) affected by the treatment. There were significant reductions (p<0.05) in some of the essential amino acids (like leucine, isoleucine and methionine), while the non-essential amino acids like glutamic acid was significantly increased (p<0.05). It is considered that fermentation using A. niger could improve the nutritive protein fractions of T. catappa seed meal. However, there may be need for essential amino acid supplementation when such fermented seed meal is used in formulating feed for poultry and livestock animals.