Pulsed vacuum impregnated trehalose to improve the physicochemical quality of frozen-thawed kiwifruit was investigated. Kiwifruits were treated by pulsed vacuum impregnation (PVI) with 10%, 20% and 30% trehalose, then frozen and stored at −20 °C. The results showed that PVI with 30% trehalose treatment exhibited minimum drip loss (11.21%), maximum ascorbic acid content (0.93 g kg −1 ) and firmness (12.3 N), and retained the flavour and taste as well as improved water distribution for frozen-thawed kiwifruit as compared with other treatments: control, PVI with 10% and 20% of trehalose. Therefore, the results illustrated that pulsed vacuum impregnated trehalose could be used as an effective method to improve the quality of frozen-thawed kiwifruit.

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The influence of ultrasound (US) treatment in combination with modified atmosphere packaging on microbial loads and quality attributes of fresh-cut lettuce was investigated during storage at 4 °C for up to 15 days. Fresh-cut lettuces were sonicated for different durations (0, 5, 10 and 15 min) by US (20 kHz, 226 W cm −2 ) and then packed in active modified atmosphere packaging (MAP). Results showed that US treatment combined with modified atmosphere effectively inhibited growth of bacteria, mold and yeast during storage. The US treatment for 10 min combined with MAP reduces mass losses and colour change, inhibits POD and PPO activities, conserves ascorbic acid and chlorophyll contents and maintains water distribution in fresh-cut lettuce. These results illustrated that US treatment combined with modified atmosphere was an effective preservation method to improve storage quality of fresh-cut lettuce.