Enhancing the nutritional values of tiger nut meal through solid-state fermentation

Tiger nut (Cyperus esculentus L.) is widely recognized as both an oil crop and a high-quality forage. However, the comprehensive utilization of tiger nut meal (TNM) remains underexplored. This study investigates the potential of solid-state fermentation with selected microorganisms to convert TNM into a high-nutritional-value animal feed. After evaluation, fermentation of TNM with Saccharomyces cerevisiae GLLB−3, or the mixture of S. cerevisiae GLLB−3 and Lactiplantibacillus plantarum SCTM−1 (EMIX group) improves the nutrient profiles of TNM. Post-fermentation, the contents of crude protein, crude fiber, total phosphorus, and amino acids increased. Especially, the crude protein content in TNM fermented with S. cerevisiae GLLB−3 increased by 34.71%, whereas TNM fermented with EMIX exhibited a 27.77% increase. Additionally, essential amino acids except histidine showed significant increases, ranging from 6.82% to 119.49%. The fermentation not only enhances TNM’s nutritional values but also contributes to a more balanced amino acid composition suitable for animal feed production. Simultaneously, fermentation of TNM with two Aspergillus strains changes amino acid and other nutrient profiles. The analysis of the fermented products revealed significant increases in the contents of crude protein, crude fiber, total phosphorus, and amino acids. Notably, the levels of eight essential amino acids were substantially elevated, indicating a marked improvement in the nutritional quality of the fermented products as compared to the raw materials. This study demonstrates probiotic fermentation can effectively enhance the nutritional profile of TNM, highlighting it as a promising approach for the comprehensive utilization of tiger nut by-products.