Effect of Fermentation Conditions (Dilution Ratio, Medium pH, Total Soluble Solids, and Saccharomyces cerevisiae Yeast Ratio) on the Ability to Ferment Cider from Tamarillo (Solanum betaceum) Fruit

Abstract

Tamarillo (Solanum betaceum) is a nutrition-rich product containing antioxidant components and preventive properties against cancer risk. However, there is currently a scarcity of research on processing techniques to diversify products and extend the preservation time of the active compounds in tamarillo. In this study, we focused on developing a cider processing procedure from tamarillo by fermentation with Saccharomyces cerevisiae (Angel RV002). Fermentation conditions, such as the dilution ratio (66 : 34–34 : 66%, $w/w$), medium pH (3.5–5), total soluble solids (TSS 10–26°Brix), and yeast ratio (0.6–1.2 g/L) were investigated. Ethanol concentration, pH, TSS, titratable acidity, total sugar content, and reducing sugar content were evaluated from day 0 to day 5 of fermentation. At a 50 : 50 (%, $w/w$) dilution ratio of the tamarillo juice with water, pH 4.5, TSS of 22°Brix, and the addition of yeast 0.6 g/L to the fermentation process, the ethanol concentration reached $7.54\pm 0.11$ (%, $v/v$) after 4 days of fermentation. Additionally, the product maintained a moderately low pH (pH 4.16). The final product exhibited a high sugar content and dissolved nutrients. The results of this study are expected to serve as a basis for the production of tamarillo cider, contributing to the diversification of the product, enhancing the value of tamarillo, and promoting economic development in the region of cultivation.