Production of value-added product from pineapple peels using solid state fermentation

Pineapple (Ananas comosus) peels are agricultural plant residues that contribute to waste disposal problem and there is little information on their conversion to useful products. Solid state fermentation (SSF) of pineapple peels (with and without ammonium sulphate) was done with a view to increase their protein content using Trichoderma viride ATCC 36316 for 96 h at 30 °C. The study was carried out using conical flasks and on-farm solid state fermenter. Chemical composition (fat, crude and true proteins, carbohydrate and ash) of the unfermented and fermented peels were determined using standard methods. Unfermented pineapple peel had low values of 4.5, 2.84, 0.6, 6.8% for crude protein, true protein, fat and ash contents, respectively. The SSF using T. viride with or without the addition of (NH4)2SO4 increased the chemical compositions of the pineapple peels. Higher protein yields were recorded when (NH4)2SO4 was used as nitrogen source. T. viride and (NH4)2SO4 increased the crude protein content from 4.5 to 14.9% when fermentation was done using conical flask. With on-farm scale fermenter, protein yields increased further. SSF of pineapple peels with T. viride produced high protein fungal biomass and may be recommended as suitable for animal feed.