Study of Fermented Cacao Beans using Aspergillus oryzae Isolated from Pea Coffee Leaves

Abstract

Background: Chocolate is commercially made from the nut of Theobroma cacao. It has a bitter nutty taste, therefore many additives such as sucrose, milk, butter, etc are added to improve its taste and quality. The processing of cacao is an important step in the production of chocolate. It includes the fermentation of cacao beans using various microorganisms. In present study Aspergillus oryzae isolated from pea coffee leaves was characterised and was used to ferment cacao beans and the resulting change in its properties was studied. Methods: In this study, we aimed to use Aspergillus oryzae isolated from pea coffee leaves, characterized and used to ferment cacao beans, to improve the flavour and quality. The changes in the flavour and qualities such as reducing sugar, protein, polyphenols, calcium, potassium, and iron content of cacao beans before and after fermentation were compared. The results were further compared with that of the cacao beans fermented with yeast and unfermented cacao beans to analyse the differences. Results: The colour, smell, pH, and taste of fermented cacao beans have considerably changed after fermentation. Quantitative analysis revealed that the sugar, protein, and polyphenols contents have decreased, while those of nutrients such as iron, calcium, and potassium increased after fermentation.