Effects of mixed fungal fermentation in improving the nutritional value of maize (Zee Mays) cobs

Background: Fungal fermentation could provide a key opportunity for achieving great benefits of biomass utilization through bioconversion into the simple digestible nutrients and greatly improve nutritive value.Objective: Mixed fungal fermentation of maize cobs was carried out to determine the effects on nutrients and antinutrients compositions.Methods: Maize cobs samples were pretreated with sodium hydroxide and solid-state fermentation (SSF) was carried with single and a consortium of four fungi; Lachnocladium flavidum Aspergillus niger, Trichoderma reesei, and Lenzites betulina for 7 days under standard conditions. Proximate composition, amino acid, mineral and antinutrient analysis were conducted on fermented and unfermented cobs. Differences and variabilities in groups were analyzed with the aid of Statistical software Package for the social sciences (SPSS) version 24.Results: Fermentation of cobs was found to have significantly increased the protein (9.10±0.85g/100g) and ash contents (5.60±0.05g/100g), while decreasing the fiber content (21.00± 0.10g/100g). The mineral levels were significantly (p<0.05) increased in potassium, sodium and calcium ions. The levels of some antinutrients were significantly reduced (p<0.05); phytate (8.91±0.50mg/100g), saponin (1.84±0.26mg/100g) and flavonoids (1.99±0.12mg/100g). The total amino acid content increased in most fermented cultures, with mixed culture of L. flavidum/ T. reesei having the most significant increase. Amino acid analysis revealed significant increases in essential amino acids Histidine, Leucine and Valine while Alanine, Aspartic and Glutamic acid were among the noticeable increases in non-essential amino acids.Conclusion: The effects of fermentation on the nutrient and antinutrient composition of maize cobs have been demonstrated. With further studies, maize cobs can serve as a good addition in animal feed production.