Non-thermal technologies for the conservation of açai pulp and derived products: A comprehensive review

Acai (Euterpe oleracea) is one of the main sustainable extractive crops in the Amazon region, widely consumed by the local population and a significant export product. This review presents the current knowledge regarding nonthermal technologies employed in acai processing. This review aims to discuss and compare the main results attained by the application of HPP, ultrasound, ozone, UV light, cold plasma, and pulsed electric field on microbial inactivation, enzymatic inhibition, and the content of anthocyanin and other bioactive compounds after acai pulp processing. The discussion compares these technologies with pasteurization, the current main technology applied to acai sanitization. This review shows that there are still many gaps to be filled concerning acai processing in thermal and non-thermal technologies. Data analysis allowed the conclusion that pasteurization and HPP are, up to now, the only technologies that enable a 5-log CFU reduction of yeasts, molds, and some bacteria in acai. However, no study has reported the inactivation of Trypanosoma cruzi, which is the major gap found in current knowledge. Other technologies, such as pulsed electric field, cold plasma, and ultrasound, require further development and process intensification studies to be as successful as HPP and pasteurization.

Automated summary

This review presents nonthermal technologies employed in acai processing, such as HPP, ultrasound, ozone, etc. The results show that pasteurization and HPP are the only technologies that effectively reduce yeasts, molds, and bacteria in acai, but there is a gap in the knowledge regarding the inactivation of Trypanosoma cruzi, and further research is needed for other technologies.