The nutritional value of foods can be affected by several factors. For example, a fruit's nutritional content is affected when it is picked before ripeness or is mishandled post-harvest. Storing foods at the wrong temperature can also alter nutritional value. For the best nutrition, choose foods that have spent the least amount of time being transported and processed and favor locally produced fruits and vegetables.
Before Being Harvested
Soil conditions influence the nutritional value of foods. The most preferred soil conditions have been treated with composted manure as fertilizer and cover crops. Organic or composted manure fertilizers release nutrients more slowly and over longer periods than synthetic fertilizers. Crop roots grown in soil that is organic or has been managed in an Integrated Pest Management system have longer roots and are able to take up nutrients efficiently.
After Being Harvested
Foods have the best nutritional value when harvested at their peak maturity. Once harvested, nutritional degradation occurs rapidly and daily. It is very likely your produce has spent five days in transit following harvest before arriving at a distribution center, according to Diane Barrett, director of the Center for Excellence in Fruit and Vegetable Quality, University of California. Many foods are harvested by hand, but some, such as tubers, are mechanically separated from the source. Mechanical separation of foods causes more stress and loss of nutrients. If the food is picked before ripening, then it may be less vulnerable to damage caused by post harvest handling.
Handling
Mishandling can alter the chemical makeup and plant tissue of fruits and vegetables, causing loss of nutrients. This is apparent in off-color and bruised, overripe produce. Nutritional values are best when fruits and vegetables are harvested when ripe, are stored in high-humidity conditions and are refrigerated. Pears and apples can be stored under controlled temperatures for at least 12 months. Cut and chopped fruits and vegetables at home are susceptible to nutritional value losses.
Best Fruits and Vegetables
Farmers markets, community supported agriculture and local grocers are good sources for local foods. These foods will have higher nutritional value than other foods because the farmer has most likely prioritized taste and nutritional quality than durability or shelf life, according to a report from Harvard University about locally produced foods. However, regardless of whether the food is fresh, frozen or canned, fruits and vegetables should be a part of a healthy diet.
