Sensory profile, visual and aromatic instrumental analysis of African tamarillo (Solanum betaceum L.) fruit drinks

Tamarillo (Solanum betaceum L.), also known as “tree tomato”, is a subtropical plant native of the Andean regions, also found in Southern Europe and Africa. These fruits are of great interest in some regions of the world as they can also be processed into juice or wine and contain functional compounds such as phenolic molecules, vitamins, minerals, and carotenoids. The objective of this study was to characterize, through sensory and instrumental analyses, two tamarillo fruit drinks produced in Kenya, named TJ and BTJ (the latter a variant of the first one through enrichment with mulberry leaf extract), formulated without added sugars and two common Italian juices (a red fruit juice and an orange juice), these last used for a comparison. The sensory analysis (Flash Profile) identified 23 distinctive sensory descriptors. TJ was characterized by bitter, herbal, and moldy notes, while BTJ exhibited turbidity, exotic fruit aroma, and balsamic notes. The volatile profile (SPME-GC-MS) revealed the presence of terpenic compounds, namely, limonene, linalool, and terpinen-4-ol. Furthermore, image analysis (IRIS electronic eye) identified the specific red tones of the tamarillo fruit drinks. The combined analysis of sensory and instrumental data (Multiple Factor Analysis) highlighted relationships between specific volatile molecules and olfactory descriptors, as well as registered red tones and visual descriptors. This work provides elements for the characterization of tamarillo fruit drinks, useful for improving their formulation, acceptability and enhancing their commercial potential at a global level, or considering specific needs of sugar reduction and dietary food fortification.