Assessment of aroma release in filled chocolate wafers through electronic nose analysis

Abstract

The present research sought to evaluate the detection capacity of the electronic nose for the hazelnut aroma in a filled chocolate wafer, measuring its release and physical–chemical, thermal, and microbiological properties during 60 days where the product was stored at 25 °C and 40 °C. It was found that moisture, Aw, pH, thermal resistivity, and diffusivity remained stable during storage at both temperatures, with no significant difference (p > 0.05). While there was variation in color (L*, a*, b*, and ΔE) and in thermal conductivity. The microbiological analyses of mesophilic bacteria, Escherichia coli, Salmonella spp., and coagulase-positive staphylococci were maintained in accordance with the standards established by current legislation. The results obtained with the sensors array showed good sensitivity and a high limit of detection (> 0.001 mg/mL) for hazelnut aroma. The electronic nose was able to discriminate between the release of volatiles from chocolates stored at 25 and 40 °C, with a greater response observed at high temperature (40 °C) at the beginning of storage. Through the application of the Arrhenius model, we successfully determined the activation energy for key color components (L*, a*, b*) and thermal conductivity. Additionally, our findings revealed a good fit of volatile component release to the zero-order model, characterized by a high correlation coefficient (> 0.9). These findings underscore the importance of considering storage temperature when preserving the quality of products such as chocolates. Furthermore, the study validates the use of the electronic nose as a viable technique for analyzing volatiles in food, providing valuable insights for the food industry.

Graphical abstract