Vegetable freshness is very important both for the catering business and domestic consumption. Supermarkets often spray water on leaf vegetables to make them look fresh and, most of all, to make it impossible to assess how long they've been on the shelf for. Nonetheless, it's not possible to store these vegetables for too long as they can rot quickly. It is therefore important to use quick and easy monitoring tools that can assess freshness.
Researchers at Jiangnan University (China) analysed the degree of freshness of spinach, cabbage and lettuce after a few days on display. They measured chlorophyll fluorescence every half hour for three days. The data was then analysed and the correlation of ChlF parameters with freshness and storage time was found.
Researchers identified some indexes that can be used as early detection tools to verify the freshness of leaf vegetables. The water sprayed on them makes it difficult to initially assess freshness but these indexes make it possible to assess it after 2-2.5 days on the shelves.
Research will continue to assess the freshness of leaf vegetables in different sale conditions (i.e. temperature and wetting method) and will also test it on new varieties.
