Solid-state fermentation in cereal grains on chemical properties, gas and methane production in vitro

Resumen

Objective: to evaluate the effect of solid-state fermentation, in vitro with Aspegillus oryzae, on the chemical properties, gas production, and methane in maize, oats, barley, and sorghum grains.

Design/ Methodology/ Approach: maize and sorghum grains were fermented in solid for 5 days, and oats and barley for 7 days with Aspergillus oryzae and neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), flavonoids and in vitro production of gas at 3, 6, 9, 12, 24, 48, 72 and 96 h; and methane at 24 h.

Results: in general terms, solid-state fermentation (SSF) decreased neutral detergent fiber and increased flavonoid content in grains. Methane production in sorghum grains also decreased with five days of fermentation (5DF sorghum). Regarding gas production, SSF improved fermentation parameters by reducing lag time (A) and increasing gas production rate (k). There was, however, lower gas production due to partial consumption of soluble carbohydrates during solid-state fermentation.

Limitations / Implications of the study: results obtained in this study were in vitro, therefore, they are not yet applicable in vivo. They provided, however, a proper notion of compound degradation in the rumen, and on which of the fermented grains would help to reduce methane production.

Findings/ Conclusions: solid-state fermentation improved grain structure, increased flavonoid content, and decreased methane production.