The nutritional value of many fruits and vegetables changes significantly with the seasons. For example, the vitamin C content in 100 grams of edible tomatoes bought in July is twice that of January; the vitamin C content in cucumbers in summer is also about twice that in winter.
Vegetables should be picked when they are most nutritious.
The beta-carotene content in carrots is 1.5 times higher in June than in the depths of winter. The beta-carotene content in vegetables like tomatoes also increases significantly in the summer. However, there is no significant seasonal difference in the vitamin C and beta-carotene content in green peppers.
Spinach is the vegetable with the greatest variation in value due to seasonal changes. Compared to winter, its nutritional value varies by nearly 8 times between May and October. Vegetables like spinach, which are on the market in winter, are exposed to not very intense sunlight throughout the winter, and the nutrients related to photosynthesis gradually increase. After entering summer, their water content increases significantly, and the solid content is reduced by about half.
With the continuous improvement of cultivation technology and transportation capabilities, almost all vegetables can appear on people's dining tables all year round, and people's concept of the season when a certain vegetable is on the market has become blurred. In this regard, nutritionists especially remind that for vegetables whose main purpose is to intake nutrients, the content of vitamin C, etc., is usually richest during the peak season. Because most frozen foods are processed during the peak season, their nutritional value is also higher than that of varieties grown in greenhouses.