Investigation into the production process and storage stability of spray-dried whole bitter almond powder

The demand for bitter almonds is increasing worldwide due to their high nutritional value and health benefits. In this study, whole bitter almond powder was prepared by spray drying (SD) at five inlet temperatures (160-240 °C). The physicochemical properties of the bitter almond powder were investigated, as well as the changes in the surface chemistry associated with rehydration characteristics of the spray-dried bitter almond powder over a 12-week period under accelerated storage conditions (RH60%, 40 °C). The results showed that SD samples at higher inlet temperatures (220-240 °C) had lower moisture content and faster moisture migration rates compared to lower temperatures. With the increase of inlet temperature, the protein structure of the powder shifted to a disordered structure, and the particle size showed a trend of decreasing and then increasing, with increasing zeta potential. During storage, the thermal stability of the powder did not change significantly, and the peroxide value, protein content and solubility decreased with the extension of storage time, which was related to the migration of lipids to the outside. And the number of volatile compounds of bitter almond powder decreased significantly at the end of storage.