Food enrichments

Enrichment, a term often used interchangeably with fortification, is the addition of nutrients to achieve concentration specified in standards of identity.

In foods, enrichment refers to the addition of vitamins, minerals and/or protein to raise the nutritive value.

Because of the vital role vitamins and minerals play in the body’s processes, many foods are enriched or fortified with additional vitamins and minerals. Many foods have a diminished nutritive content as a result of loss in refining or processing and can benefit from the enrichment.

Also, some foods provide effective vehicles for distribution of a nutrient. Enrichment of cereal grain products with iron, thiamin, riboflavin and niacin has been a remarkably effective and efficient means of enhancing the nutrient quality of the food supply and is a classic example of an effective well-designed public health approach to providing needed nutrients.

Cereal grains were selected for enrichment because they are eaten frequently by virtually all populations groups.

The decision to fortify with a particular nutrient is a complex one. It starts with the realization that a significant number of people are not obtaining desirable levels of a specific nutrient and the determination that the food to be fortified makes an appreciable contribution to the diet.

It must be further ascertained that the fortification will:
*not result in an essential nutrient imbalance
*the nutrient is stable under storage
*capable of being absorbed from the food
*that toxicity from excessive intakes will generally not occur.
Food enrichments 

Losses of tocopherol during food processing

Naturally occurring vitamin E comprises tocopherols and tocotrienols. Processing and storage of foods can result in substantial tocopherol losses. Cooking of porridges of rolled oats and rye meal implies only minor effects on their tocopherol and tocotrienols contents.

Studies of alpha-tocopherol in UHT processed milk suggest that the processing conditions affect the subsequent losses, but that in all cases increased storage temperature led to increased rate of loss.

There was a loss of tocopherol reported in the study of potato chips. After only two weeks’ storage of the chips at room temperature, nearly half of the tocopherol was lost.

The losses were only slightly smaller during storage at freezer temperature.

Deep fat frying of fresh vegetable oil causes losses of about 10% but storage of fried foods, even at low temperature, may cause large losses.  The low content of alpha-tocopherol in frozen foods is surprising and indicates serious degradation even at 12 °C.

Boling of vegetables in water for up 30 minutes results in only minor losses of tocopherol.

Baking of white bread (200 °C, 30 minutes) destroyed of about 5% of the tocopherol in the crumb.

Tocopherol losses during microwave cooking are mainly caused by the effect of high temperature and not by microwaves as such. When sunflower oil was subjected to microwaves discontinuously for 120 min at two constant temperatures: namely 170 °C and less than 40 °C, tocopherol losses were 72% and 21%, respectively.
Losses of tocopherol during food processing 

Effect of processing on minerals

Effect of processing on minerals
When food is cooked, processed, or stored, minerals may combine with other food components and may become unavailable for digestion. Also, as with vitamins, natural variations in the raw food products and cooking methods result in variations in the final mineral contents of foods.

Minerals are generally not sensitive to heat during processing, but are susceptible to leaching into the processing or cooking water. More than 50% if the manganese, cobalt, and zinc may be lost during canning of spinach, beans, and tomatoes, if the liquid is not consumed.

Mineral losses during leaching can be minimized by use of a minimum amount of water and use if the cooking water in preparation of the food for consumption, such as in gravies, soups, and sauces. Losses in manganese, iron, copper, phosphorus, zinc, calcium, and manganese during the cooking of pasta may be as great as 86.5 – 100 %. Use of hard water for processing and cooking can result in an increase in the calcium or magnesium content of foods, while use of softened water can result in an increase in the sodium content. Mineral losses may also occur as a result of physical separation from the product during milling of grains, refining of sugar, and processing of legumes or seeds into oils. For example, significant losses of magnesium, zinc, iron, copper, and cobalt have been reported during milling of wheat to flour. However, nutrients can be added back to foods by restoration or fortification. Grain milling has positive nutritive benefits, as well. Phytate and fiber, which are present in the bran portion of the grain, are removed during this process, and they are no longer able to bind to minerals and render them unavailable. Therefore, iron and zinc deficiencies are not common in the U.S, whereas they may occur in populations which subsist on unmilled grains. Minerals are also susceptible to changes in bioavailability due to interactions with other food components. For, examples, oxalates may inhibit calcium bioavailability; while vitamin C enhances iron bioavailability.
Effect of processing on minerals