The effects of different heating periods and exclusion of some fermentation conditions on bioethanol production from plantain pseudo-stem waste using the digestive juice of Archachatina marginata, garlic and Saccharomyces cerevisiae

ABSTRACT

Lignocellulosic biomass represents the largest renewable reservoir of potentially fermentable carbohydrates on earth, and its utilization for ethanol production continues to be a subject of worldwide interest. The present study evaluated the effect of 0, 30, 60 and 90 min heating periods on fermentation setups containing a mixture of 100 g plantain pseudo-stem waste, 250 ml of digestive juice of African land snail (Archachatina marginata), 4 g garlic and 200 ml of yeast slurry. On exclusion of some fermentation conditions, the yield of ethanol was evaluated for fermentation setups excluding yeast and garlic, yeast only, digestive juice of African land snail and garlic, digestive juice of African land snail only, and garlic. From the results, the best yield of ethanol at 76.0 ml ± 3.5 of distillate containing 21.7% ± 2.1 (w/v) ethanol composition was obtained at 60 min heating period, which declined continuously as the heating period increased to 90 min. No significant change (p $>0.05$) in the ethanol yield was observed between the fermentation setups excluding the digestive juice of snail and garlic, and yeast only. The ethanol yield obtained from the fermentation setup excluding garlic alone was 79.7 ml ± 2.5 distillate containing 9.7% ± 1.5 ethanol by volume and the formation of acetic acid. This result suggests that the optimum heating period to enable the accessibility of cellulose degrading enzymes from the digestive juice of the African land snail is 60 min, and that constituents of garlic can promote the inhibition of acetic acid synthesis from fermentation.

KEYWORDS:

• African land snail
• digestive juice
• acetic acid
• yeast
• plantain pseudo-stem

Disclosure statement

No potential conflict of interest was reported by the authors.