Comparative evaluation of encapsulation using β-cyclodextrin versus freeze-drying for better retention and stabilizing of black Perigord truffle (Tuber melanosporum) aroma

This study aimed to develop a novel technique to retain and stabilize compounds contributing to truffle aroma by encapsulation using beta-cyclodextrin. Two experiments were conducted. In the first experiment, the key volatile profile and microbial population of products resulting from three different encapsulation methods, namely direct mixing method (M1), direct mixing followed by ethanol addition method (M2), and paste method (M3), were compared with untreated truffles (positive control) over a 90-day period. The M2-derived product was the least optimal for retaining key volatile compounds despite showing the lowest microbial population. There was no significant difference in the volatile profile of products derived from M1 and M3 on day 0. However, it was observed that the M3-derived product could retain its volatile profile better than the M1-derived product by day 90. M3 was compared with freeze-drying in the second experiment. Freeze-dried truffles showed an overall higher relative percentage of volatiles than the M3-derived product on day 0. However, by day 90, some volatile changes occurred in the freeze-dried truffles but not in the M3-derived product. The findings indicate that while freeze-drying could adequately conserve truffle volatiles, the encapsulation of volatile compounds in beta-cyclodextrin could improve the volatile stability of truffle products and allow for longer storage times. Microbes were found in all encapsulated truffle products and freeze-dried truffles on days 0 and 90, suggesting the need to explore the possibility of incorporating a decontamination step in the process prior to either encapsulation or freeze-drying.

Automated summary

This study aimed to develop a novel technique using beta-cyclodextrin encapsulation to retain and stabilize compounds contributing to truffle aroma. The findings suggest that encapsulation of volatile compounds in beta-cyclodextrin can improve the volatile stability of truffle products and allow for longer storage times, while considering the potential microbial contamination in the encapsulation process.