Did you ever wonder if fresh food contains the same nutrients as its dried counterpart? Let’s examine what happens when food is dried. These four steps are involved in preserving food by drying:
- Harvesting
- Storing
- Processing
- Drying
From the moment it’s harvested or picked, raw food contains the highest content of nutrients. The nutrients decline as the food gets exposed to light and air during handling and transport. Additional nutrient loss occurs when the food undergoes processing (peeling, slicing, chopping) and declines further once exposed to heat for either cooking, preservation, or storage. Maximum nutrient retention occurs when raw food is dried immediately after harvest.
- Nutrient loss occurs when fresh food is cut open and exposed to the elements. For instance, beta-carotene (a precursor to vitamin A) and vitamin C (ascorbic acid) diminish when exposed to air and heat (i.e., cooking and drying). Thiamin, riboflavin, and niacin have a minimal loss during drying. Iron and fiber are not affected by heating or drying.
- The nutrient loss for commercially-dried foods varies between 30 – 80% for vitamin C and 10 – 50% for vitamin A. Loss depends on many factors, including storage time, drying temperature, and dry time. The variation is much higher for fresh food purchased from the store and preserved at home. Pre-treatment before the drying process can help retain some vitamins but destroy others. Chemical pre-treatments, such as sulfur dioxide, protect vitamins A and C but destroy vitamin B1 (thiamine), a nutrient needed for converting carbohydrates into energy. Note: organic food does not allow the use of sulfur. Natural pre-treatment methods, such as hot water blanching, help preserve carotene and thiamine but depletes vitamin C. Dipping foods in citrus juice or citric acid before drying can counteract some of the vitamin C loss.
Drying technology
The amount of nutrient loss also depends on the drying technology used for drying food – solar, controlled air dehydration, or freeze-drying.
- Sun-drying causes the most nutrient loss, indoor dehydration (using low heat) causes some loss (mostly vitamin C), and freeze-drying causes the least amount of nutrient loss.
- No method of drying can prevent nutrient loss in food. If you will be relying on dried foods for an extended time (thru-hiking), it’s a good idea to supplement with a multivitamin or (vitamin drink mix).
Why is vitamin C so important?
Citric acid naturally found in citrus fruits bonds to metals in the body, a process called chelation. This helps detoxify poisonous metal agents, often present in waterways and food sources, such as mercury, arsenic, cadmium, and lead, by converting them to a chemically inert form. The metals can then be excreted without impairing the body. Citrus packets that you add to your water such as True Lemon contain citric acid.
How to supplement with Vitamin C on the Trail
- Add powdered vitamin C (ascorbic acid) such as Emergen-C to your daily water. The original formula of Emergen-C is vegan; a few specialty products contain animal-derived ingredients. If you prefer natural, plant-based options, add a small amount of freeze-dried or cold-processed Peruvian Camu Camu, Acerola Cherry Powder, or Rosehip Powder to your drinking water or morning oats.
- Look for foods that contain a rich source of vitamin C ingredients. Lemon and other citrus fruits are commonly recognized sources but are not the highest. Chili peppers, red bell pepper, and parsley are some of the best food sources of vitamin C. Also, spices such as garlic and various peppers (paprika, chili powder, and cayenne) are reputable sources. Freeze-dried fruits are not heated when preserved, so they retain more vitamin C than dehydrated. Outdoor Herbivore incorporates organic freeze-dried fruits like apples and blueberries to minimize vitamin C losses. In addition, we use lemon powder to replace vitamin C losses. 1 tsp of dried organic lemon peel contains 70 % of DV for vitamin C!
- If you forage for food, look for foods high in vitamin C, such as wild garlic, berries, dandelion greens, and rose hips. Also, sprouting (especially alfalfa and red clover) is a good source of vitamins & minerals, including vitamin C.
Further exploring the importance of Vitamin A & Vitamin C
Beta-carotene (precursor to Vitamin A) is the red-orange pigment found in many plants and is a member of the carotenoid family of plant nutrients. Carotenoids are believed to interact with other nutrients – such as phytochemicals – to prevent disease and promote health. In particular, beta-carotene is a provitamin A carotenoid: it converts into vitamin A by the liver. Vitamin A plays a role in a variety of functions throughout the body, including the vision to prevent night blindness and other eye problems; immune function to protect against colds, flu, and infections of the kidney, bladder, and lungs; embryonic development and reproduction; the formation of bones and teeth; help prevent acne, reduce wrinkles, and lighten skin if applied topically; metabolize protein.
- Plant sources of vitamin A include sweet potato, carrot, and spinach.
Vitamin C, or ascorbic acid, is a water-soluble vitamin needed by the body for at least 300 metabolic functions, including tissue repair and growth, healthy gums, adrenal gland function, and immune system function. Vitamin C acts as an antioxidant in the body, protecting cells from the damaging effects of free radicals. Free radicals contain an unshared electron and appear to promote heart disease and cancer. We are exposed to free radicals in the environment from air pollution, cigarette smoke, and UV radiation from the sun. Also, vitamin C is needed to make collagen, a protein required to help wounds heal. It also improves the absorption of iron from plant-based foods.
7 thoughts on “Nutrient Loss Is In Dried Foods”
I’m glad that you talked extensively about the different vitamins and minerals aside from what happens during food dehydration. It’ll definitely help many households that are into drying foods.
I like drying foods but is also concerned about the amount of nutrients retained. I’m glad I’ve been doing it indoors because it has less loss compared to outdoor drying.
Again, thanks for sharing this.
References for nutritional information would be greatly appreciated!
Thanks for this post, I think is really interesting.
You are great. I am very thankful to you because you have shared your experience and valuable information with us. Thanks for all.
Don’t forget edible evergreens like spruce, fir, and pine are a great winter vitamin c source.
Thanks for this article, glad to see your emphasis is on whole foods.
I like the intense flavor of dried vegetables and meat in winter soups. I collect wild chenopodium seeds and grow microgreens and sprouts all winter. A spoon of chopped microgreens sprinkled on top of winter soup is a nutrient booster.