Physicochemical properties and toxicity of cocoa powder-like product from roasted seeds of fermented rambutan (Nephelium lappaceum L.) fruit

Abstract

A novel way to fully utilize rambutan fruit and seed is to ferment peeled fruits followed by drying and roasting, and use the seeds to produce seed powder similar to that of cocoa powder. Hence, the objective of this study was to optimize the roasting time and temperature of rambutan fruit post-fermentation and drying, and to produce a cocoa-like powder product from the seeds. Parameters monitored during roasting were colour and total phenolic content, while seed powder obtained using optimized roasting conditions was analyzed for its physicochemical properties and toxicity. The latter was examined using the brine shrimp lethality assay. Results showed that the roasted seed powder possessed colour and key volatile compounds similar to that of cocoa powder. Besides, the brine shrimp lethality assay indicated that the roasted seed powder was non-toxic. Thus, the fruit, including its seed could be fully utilized and subsequently, wastage could be reduced.

A Critical Review on Tropical Fruits Seeds as Prospective Sources of Nutritional and Bioactive Compounds for Functional Foods Development: A Case of Indonesian Exotic Fruits

“…Even though having slightly different physical characteristics, these lipids were reported to be a suitable substitute to cocoa butter for confectionery products [72]. Based on the brine shrimp lethality test, Chai et al [73] confirmed that the roasted rambutan seed powder is not toxic and is safe for human consumption. A blend of 30% mass of rambutan lipid and 70% mass of cocoa butter can result in characteristics similar to cocoa butter but with a higher viscosity [74].…”

Effects of drying methods on the characteristics of rambutan (Nephelium lappaceum L.) seed fat: An optimisation approach

“…Recently, many researchers reported that the physicochemical properties of RSF from either fermented or nonfermented rambutan seeds are suitable as cocoa butter alternatives . Chai et al produced a cocoa powder‐like product from the roasted seeds of fermented rambutan fruit. Thus, optimising the extraction of fat from rambutan seed is crucial in achieving the highest yield.…”

Comparative Study of Table Margarine Prepared from Moringa oleifera Seed Oil‐Palm Stearin Blend and Commercial Margarines: Composition, Thermal, and Textural Properties

“…The triacylglycerol (TAG) profiles of the oil samples were determined by using the same instrument (HPLC connected to a refractive index detector) and method as described by Chai et al. [ 15–17 ] with slight modifications where the oven temperature was set at 35 °C and the total run time was 100 min. The TAG peaks were identified based on the retention time of commercially available TAG standards and the results of Chen et al.…”