Effect of Inoculum Size in Fermentation of Cocoa Beans Using Candida tropicalis

Abstract

Cocoa fermentation is a crucial step in determining the quality, yet spontaneous fermentation often yields inconsistent results. This study aimed to evaluate the effectiveness of Candida tropicalis as a starter culture to improve fermentation performance and bean quality at a semi-pilot scale (10 kg). Fermentation trials were conducted using five treatments (control and C. tropicalis at 10³, 10⁴, 10⁵, and 10⁶ cells/g) on 10 kg of fresh cocoa beans, with samples collection every 24 hours for six (6) days. Key parameters measured included fermentation index (FI), pH and acidity of pulp and cotyledon, and reducing and total sugars in both bean pulp and cotyledon. The results showed that inoculation with C. tropicalis, particularly at 10⁵ and 10⁶ cells/g, significantly improved the speed and quality of fermentation. FI values (≥1) and brown bean percentages (≥60%) were achieved after 72 hours and 96 hours respectively in these treatments, compared to 144 hours in the control. The pH, acidity, sugars content also showed considerable improvement with best strains. These findings suggest that C. tropicalis, especially at 10⁵ cells/g, can enhance fermentation efficiency, reduce processing time by up to 50%, and improve bean quality. Future research should explore the sensory impact of this yeast on chocolate flavor, optimize fermentation protocols, and assess scalability for industrial applications.