What's in Your Fruits and Vegetables
March 28, 2013
Interest in the nutritional value of fruits and vegetables has been growing, due in part to new findings regarding the dramatic increase of obesity, diabetes, heart disease, and other diet-related health problems in both children and adults, across the nation.
Vegetables and fruits that are grown in the United States, may spend up to 5 days in transit after harvest before arriving at grocery stores. Shipping times for fruits and vegetables grown in the southern hemisphere for winter and spring consumption in the United States range from as little as a few days to several weeks. This includes fresh, canned, or frozen fruits and vegetables. Fruits and vegetables may be on display 1–3 days before being bought by customers who may store them for up to a week prior to eating. This means that fresh fruits and vegetables may not be eaten for a significant length of time after being harvested. During this time nutrient degradation may happen. Most fruits and vegetables once separated from the plant undergo higher rates of respiration, resulting in water loss, quality, and nutrient degradation, and spoilage.
Fruits and vegetables are often more healthy when harvested at their peak maturity, but most Americans do not have home gardens that produce the required nutrition year round. Commercially grown fruits and vegetables are usually harvested immature to reduce mechanical damage during harvesting and shipping. Temperature must be carefully maintained for low respiration rates and to reduce moisture loss, and enhance eating quality.
Vitamin C degrades rapidly after harvest, and this degradation continues during storage. Vitamin C loss in vegetables stored at 4°C for 7 days ranges from 15% for green peas to 77% for green beans. Refrigerated storage of green beans for 14-16 days results in a 10% loss of beta-carotene content. The B vitamins, thiamin and vitamin B-6 in particular, are quite sensitive to heat and light. Polyphenolics, which are in the skin of fruits like peaches, pears, and apples, generally decline with storage. Carotenoids and lycopene appear to be relatively stable during processing, storage, and cooking.
Loss of nutrients during fresh storage may be more substantial than consumers realize, so consumers should be educated about proper storage. Fruits and vegetables should be consumed soon after harvest, or post-harvest handling conditions must be controlled such that nutrient degradation is minimized. A good diet should include a variety of fruits and vegetables, whether they are fresh, frozen, canned, dried, or otherwise preserved.
There are two solutions to getting the maximum nutrients in your food. The best solution is to grow your own produce and eat it fresh from the garden each day. There are many vegetables that will grow year round or stay alive in the soil during the winter. Fruits need to be picked and dried or frozen to preserve them. Apples store quite well fresh when refrigerated or in a cool place through the winter and spring. Berries are best frozen. Pears, plumbs, peaches, apricots, nectarines, and similar fruits are best dried. It is best to keep vegetables fresh and eat what is available. Good winter crops are kale, collards, cabbage, kohlrabi, swiss chard, green onions, broccoli, and others. Good crops to grow during the summer and store in the ground for winter use are potatoes, carrots, and other root crops.
The other solution is to purchase freeze-dried or dehydrated fruits and vegetables that have no sugar or preservatives added.
A small amount of nutrients may be lost during the processing of freeze-dried vegetables. Actually, these vegetables usually retain more nutrients than frozen, dried, or canned vegetables. Freeze-dried vegetables have the same amount of fiber, carbohydrates and protein after processing as they do before processing.
The way the freeze-dry process works is the farmer arranges with a major freeze-dry company to come onsite and setup mobile production of produce when the fruit and vegetables are at their peak of maturity. Within a short period of time, a crop can be harvested and freeze-dried preserving the flavor and nutrients. One study on freeze dried blueberries found some nutrients, such as ascorbic acid, were reduced in the freeze drying process, yet the blueberries still had pretty much the same antioxidant abilities. According to NASA, freeze dried food retains 98% of its nutritional value while weighing only 20% of its original weight.
Whatever you plan to do, remember that healthcare costs are very high as is health insurance. It has been said that, "an ounce of prevention is worth a pound of cure".