Bioethanol production from cashew (<i>Anacardium occidentale L.</i>) apple juice by batch fermentation using <i>Saccharomyces cerevisiae</i> E450

Abstract

Large amounts of cashew apples from Côte d'Ivoire are left over as waste in the plantations after nut separation, while it can be transformed into bioethanol. This study aimed at producing bioethanol from cashew apple juice by Saccharomyces cerevisiae E450 yeast. S. cerevisiae E450 was used as ferment at 10 7 CFU/mL in anaerobic and aerobic conditions at temperatures of 30 °C and 33 °C. The fermentation was carried out in batch mode with sampling every 24 hours. The determination of ethanol and glycerol was performed by Gas Phase Chromatography and sugars (glucose, fructose and sucrose) by HPLC. The amounts of ethanol obtained at 30 °C and 33 °C respectively were of 65.10 and 73.17 g/L in anaerobic conditions and 62.05 and 75.79 g/L aerobic conditions. The fermentations carried out at 33 °C gave the highest ethanol concentrations with the maximum in aerobic which was 75.79 g/L. The fermentation carried out at 30 °C in anaerobic yields the lowest value of 62.05 g/L. This study showed the influence of temperature on the growth of cells and the synthesis of ethanol marked by the presence of oxygen which decreases fermentation time and thus improves productivity. It also revealed that cashew apple has great potential as a biofuel feedstock for bioethanol production.

Assessment of biofuel potential of the red variety of cashew apple

“…They obtained an ethanol content of (19.82-37.83 g/L) from cashew apple juice in Brazil. The fermentations carried out at 33 °C gave the highest ethanol concentrations with the maximum in aerobic which was 75.79 g/L [10] . Karuppaiya et al [35] had obtained in India, under optimal conditions (pH 6.5 and at 32 °C with a fermentation time of 37 hours) an alcoholic strength of 15.64 g/L.…”

“…In total, sampling was carried out in ten (10) communes spread over four (04) agro-ecological zones (ZAE) of Benin (…”

“…Then the valorization of cashew apple, a resource of low market value, will help in bring to the local and international market a new generation of products with high added value such as first-generation bioethanol [9] . Indeed, Touré et al [10] reported that cashew apple has great potential as biofuel feedstock for bioethanol production.…”

Fermented Parkia biglobosa seeds as a nitrogen source supplementation for bioethanol production from cashew apple juice

“…Its fermentation substrate is cashew apple juice (Anacardium occidentale L.), a potential source of fermentable sugars (3.85-4.63% (w/v) of glucose, 3.90-4.52% (w/v) of fructose) which is very poorly valued because of its astringency due to the presence of tannins (Deenanath et al, 2013;Padonou et al, 2015;Gbohaïda et al, 2016;Soro et al, 2017). Previous evaluation of the chemical composition and nutritional profile of the cashew apple juice showed its richness in vitamin C (104.0-293.5% (w/v)) and mineral elements (3609.93-4361.28 mg/L of potassium, 121.60-413.44 mg/L of magnesium, 218.03-234.01 mg/L of sodium, 120.24-601.20 mg/L of calcium, 35.10-44.80 mg/L of iron, 3.55-4.47 mg/L of zinc, 3.16-19.75 mg/L of manganese, 6.25-22.00 mg/L of iodine), which makes it a good substrate for use in agro-resource bioconversion into bioethanol by fermentation (Dedehou et al, 2015;Padonou et al, 2015;Soro et al, 2017;Agbagnan Dossa et al, 2018;Toure et al, 2019). The aim of this research was to investigate the effect of natural yeast nutrients from fermented P. biglobosa seeds on bioethanol production from cashew apple juice by S. cerevisiae.…”