Lactic Acid Fermentation from Coffee Ground Waste Hydrolysate by Lactobacillus rhamnosus

초록

Lactic acid is an important organic acid that is widely used in the food, pharmaceutical, and cosmetic industries. Lactic acid was produced from coffee ground waste which contains fermentable sugars and is increasingly generated from our daily dietary life. Among 114 strains of Lactobacillus species, Lactobacillus rhamnosus ATCC 10863 was selected for the production of lactic acid from coffee ground waste. Through alkali pretreatment and saccharification, cellulose and hemicellulose in coffee ground waste were converted into fermentable sugars. Pretreatment experiments were conducted at various alkali solution, concentrations, and times. Alkali pretreatment with 35 g/L of KOH at 121 degrees C for 60 min, the highest concentration of fermentable sugars was produced. The optimum concentration of Viscozyme L was 2% when saccharification was proceeded at 55 degrees C for 7 days. The productivity of lactic acid fermentation was the highest (0.59 g/L/h) at 100 g of coffee ground waste (1x concentration), whereas the lactic acid concentration was the highest at 600 g of coffee ground waste (6x concentration). As the concentration of coffee ground increased, the lactic acid concentration was also increased, however, the amount was not proportional to the coffee ground waste used. In this study, it was found that coffee ground waste could be used as a culture medium for Lactobacillus rhamnosus ATCC 10863 through pretreatment and saccharification for the production of lactic acid.

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