Ultrasound combined with mild heat improves short-term quality of frozen avocado puree

• Ultrasound combined with mild heat improved frozen avocado puree quality. • Combined treatment reduced PPO activity and slowed enzymatic browning. • Total phenolics and antioxidant capacity were better retained after treatment. • Antioxidant enzymes (CAT, APX) were maintained more effectively than controls. • This approach supports improved short-term cryopreservation of avocado puree. Avocado puree, a nutrient-rich product, is susceptible to enzymatic browning, leading to challenges in maintaining quality during processing and storage. This study aims to enhance the quality attributes, focusing on physicochemical properties, browning enzyme activities and antioxidant activity through the combination method between ultrasound and mild heat treatment. Frozen avocado puree samples were treated with ultrasound, mild heat and their combination. The integration of ultrasound and mild heat treatment presents a promising method for improving the quality in short-term storage at -18±2°C for three months. The results demonstrated significant improvement in enzymatic browning enzyme activities, antioxidant activities and related antioxidant enzymes. Furthermore, the combined treatment reduced PPO activity and better maintained total phenolics, FRAP, DPPH and antioxidant enzymes (CAT, APX) compared with single treatment and control. These findings provide new insights into how ultrasound and mild heat may act complementarily through cell wall disruption, enhanced diffusion of bioactive compounds, and partial enzyme inactivation. Such mechanisms contribute to improving the short-term cryopreservation of avocado puree. This approach represents a promising and testable strategy for the processing of frozen pureed fruits and vegetables.