With the development of technology and the continuous improvement of cultivation techniques and transportation capabilities, people can now enjoy almost all kinds of vegetables and fruits year-round. However, nutrition experts recommend that people should eat seasonal vegetables and fruits whenever possible. This is because off-season fruits and vegetables are not only expensive, but more importantly, their nutritional value is not as high as that of seasonal produce.
Research has found that the nutritional value of most fruits and vegetables often changes significantly with the seasons. For example, the vitamin C content per 100 grams of edible parts of cucumbers, tomatoes, watermelons, and strawberries purchased in the summer is generally twice that of those purchased in winter. Meanwhile, the beta-carotene content in carrots purchased in the summer is often 1.5 times that of those purchased in winter. Furthermore, the beta-carotene content in fruits and vegetables like tomatoes and oranges also increases significantly when they are in season. However, there are exceptions. Studies have shown that the vitamin C and beta-carotene content in green peppers does not show a significant seasonal difference. Additionally, research has found that spinach is the vegetable with the most significant seasonal variation among common vegetables. Compared to winter and spring, its nutritional value in summer and autumn is nearly 8 times different.
Therefore, nutrition experts particularly remind us that the content of nutrients in vegetables and fruits is usually most abundant during their peak season. At this time, the produce is not only the cheapest but also the most nutritious. When purchasing fruits and vegetables, it is also important to buy them as you need them and eat them fresh, as each vegetable or fruit has its own optimal storage temperature and shelf life. In general, the longer they are stored, the worse their nutritional value and taste tend to become.