245 The Effect of Cacao (Theobroma cacao L.) Pulp on Final Flavour N.A. Ali 1,a , G.S.H. Baccus-Taylor 2 , D.A. Sukha 1 and P. Umaharan 1 1 Cocoa Research Centre, The University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies 2 Food Science and Technology Unit, Faculty of Engineering, the University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies Keywords: fermentation, cocoa quality, cocoa liquor, passion fruit, temperature progression Abstract The first stage of cacao (Theobroma cacao L.) postharvest processing consists of microbial fermentation of pulp surrounding the beans. Previous studies have revealed that permeability of the cacao seed coat plays a significant role in final flavour and that acidification by entrance of acetic acid starts through the micropyle and hilum of the seed. The main objective of this study was to further understand the effects of pulp on final flavour which was accomplished by the following experiments to test: 1) the effect of fermentation mass size (pulp quantity) on flavour, by fermenting selected fine or flavour clones individually as batch insert micro-fermentations and in small styrofoam coolers; 2) the effect of pulp quality on flavour, by fermenting a composite of selected bulk types with an aromatic fruit pulp viz., passion fruit pulp (Passiflora edulis). Results of this investigation provided preliminary information about the fermentation process (i.e., physicochemical changes and implications on flavour perceived) and determined the impact of the fermentation mass (quality and quantity) on final flavour. Results further revealed that pulp quantity during fermentation affected final flavour. Floral, fruity and acid flavours were more pronounced in batch insert micro-fermentations than in styrofoam cooler fermentations. The clone × fermentation method interaction was only significant for the floral attribute of clones fermented as inserts (P≤0.05), but multiple attributes in the case of styrofoam cooler fermentations. Typically fine or flavour clones exhibit acid, fruity and floral flavour notes. Therefore the batch insert micro-fermentation method allowed better formation and expression of these attributes. The pulp quality also affected final flavour; fermentations with passion fruit pulp had a more pronounced fruity, acid and floral flavour. INTRODUCTION Among the countries producing well-fermented cocoa beans, Trinidad and Tobago has gained a worldwide reputation for its high quality and strong chocolate-flavoured beans with ancillary fruity and floral notes (Ostovar and Keeney, 1973). Fermentation is still not thoroughly understood and fermented cocoa beans may not always be of consistent, predictable quality (Lihrian, 1984; Lanaud, 1999). Generally, cacao pulp is a rich medium for microbial growth. The pulp consists of water (82-87%), sugar (10-15%), pentosans (2-3%), citric acid (1-3%) and pectin (1-1.5%). Proteins, amino acids, vitamins (mainly vitamin C), and minerals are also present. The concentration of glucose, sucrose and fructose is a function of fruit age (Schwan and Wheals, 2004). Though changes in the local climatic conditions influence the sequence of microorganims involved in cacao fermentation, a similar succession of groups of organisms has often been reported (Schwan and Wheals, 2004). Early in the fermentation, several genera of yeasts proliferate, leading to ethanol production and secretion of pectinolytic enzymes. This activity is followed by a phase in which bacteria grow, principally lactic-acid bacteria and acetic-acid bacteria, followed aerobic spore-forming bacteria. Finally, some moulds may appear on the surface (Schwan and Wheals, 2004). a Naailah.Ali@sta.uwi.edu Proc. III rd Int. Conf. on Postharvest and Quality Management of Horticultural Products of Interest for Tropical Regions Eds.: M. Mohammed and J.A. Francis Acta Hort. 1047, ISHS 2014