This study focused on developing a Pickering emulsion fresh-keeping paper that contained clove essential oil (CEO). Cherry tomatoes served as the test material for assessing the preservative efficacy of fresh-keeping paper. The results showed that Pickering emulsion had strong stability. Additionally, the fresh-keeping paper had a good antioxidant activity and sustained-release effect on CEO. In terms of the preservation effect, 0.75 wt% CEO Pickering emulsion paper reduced the decay incidence and weight loss of cherry tomatoes during 12-day storage. Fresh-keeping paper could also play a positive role in protecting the sensory index and color difference of tomatoes. It slowed the decline rate of soluble solid concentration (SSC) and titrable acid (TA). The vitamin C (Vc) and hardness of preserved tomatoes using fresh-keeping paper were maintained at a high level. The paper also inhibited the growth of microorganisms significantly. Therefore, 0.75 wt% CEO Pickering emulsion fresh-keeping paper displayed considerable potential for application in the preservation of postharvest fruits and vegetables. It is a novel fruit and vegetable preservation material worthy of development.

Postharvest cherry tomatoes are prone to senescence, decay and nutrient loss during the storage period owing to microbial invasion and their own metabolism. In this work, postharvest cherry tomatoes were treated with a composite coating of 1% chitosan and 1% curdlan, and the characteristics of postharvest cherry tomatoes during storage were investigated. Compared to control samples, after 21 d of storage under ambient conditions, the cherry tomatoes treated with the chitosan and curdlan coatings showed less rottenness, less weight loss, a lower respiration rate, reduced ethylene production, lower malonaldehyde (MDA) content and reduced membrane permeability. After the samples were treated with the composite coating, the activities of free radical scavenging enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were maintained at higher levels; the activities of related disease-resistant enzymes such as chitinase (CHI) and glucanase (GLU) were also maintained at higher levels. The soluble solids, titratable acidity, firmness, vitamin C content, lycopene content and antioxidant activities of postharvest cherry tomatoes treated with the composite coating exhibited higher levels as well. The composite coating of chitosan and curdlan might be a potentially promising method for preserving postharvest cherry tomatoes and other fruits.