Foods fortifying with amino acids

Table IV presents the RBV for the iron of three breakfast cereals not fortified with iron. The two ready-to-eat cereals were sources of highly bioavailable iron, but the instant cereal was significantly lower in bioavailability than the reference salt. We have not studied the chemical nature of iron in commercially available wheat based foods. The iron that remains in the residue of 1.2 M ammonium acetate extracted wheat bran was only 71 as bioavailable as the extracted monoferric phytate (6j, but the iron of enzymatically dephytinized wheat bran, which may be complexed with amino acids, is highly bioavailable (11).

It may be more expeditious at the community, state, or national levels to enrich and fortify foods of low nutrient quality with amino acids, minerals, and vitamins, than to try to supply foods which naturally contain the optimal quantities of nutrients. This is particularly applicable to situations where foods, which are rich in the desired nutrients, are rejected by the population to be fed. Lor example, there is a high rejection rate for broccoli, carrots, and other vegetable sources of vitamin A in the US. School Lunch Program. Therefore, food technologists have proposed the development of a snack food, like a potato chip, which would contain spinach powder and be fortified with minerals and vitamins. 

These techniques have been used successfully in the micro-Zdman degradation of the enzyme mouse sarcoma dihydrofolate reductase to obtain the amino acid sequence of the first 25 amino acids 455). Similarly, RPC has been used in coqjunction with the automated Edman technique for sequencing 32 residues of myoglobin 456). Methionine and its oxidation products, methionine sulfoxide and methionine sulfone, in methionine fortified foods have been analyzed as their dansyl derivatives 457). Lysine has been determined as its dansyl derivative in a study in which the stability of lysine in fortified wheat flour was evaluated (458). 

Vitamins B6, B12, and folate An elevated plasma homocysteine level is associated with increased cardiovascular risk (see p. 263). Homocysteine, which is thought to be toxic to the vascular endothelium, is converted into harmless amino acids by the action of enzymes that require the B vitamins—folate, B6 (pyridoxine), and B12 (cobalamin). Ingesting foods rich in these vitamins can lower homocysteine levels and possibly decrease the risk of car diovascular disease. Folate and B6 are found in leafy green veg etables, whole grains, some fruits, and fortified breakfast cereals. B12 comes from animal food, for example, meat, fish, and eggs. 

Several essential amino acids have been shown to be the limiting factor of nutrition in plant proteins. In advanced countries, the ratio of vegetable proteins to animal proteins in foods is 1.4 1. In underdeveloped nations, the ratio is 3.5 1. which means that people in underdeveloped areas depend upon vegetable proteins. Among vegetable staple foods, wheat easily can be fortified. It is used as flour all over the world. L-Lysine hydrochloride (0,2% ) is added to the flour. Wheat bread fortified with lysine is used in several areas of the woilcl in Japan it is supplied as a school ration. 

Daniel, V. A., Urs, T. S. S. R., Desai, B. L. M., Rao, S. V., Rajalakshmi, D., Swaminathan, M., and Parpia, H. A. B. (1967). Studies on lost cost balanced foods suitable for feeding weaned infants in developing countries. The proteins efficiency ratio of low cost balanced foods based of ragi or maize groundnut, Bengalgram, soya and Sesame flours and fortified with limiting amino acids. J. Nutr. Diet. 4,183-188. 

Methionine is an essential amino acid in the diet, but interestingly enough is toxic in excess. In normal foods this may not be a problem however, in some fortified foods, methionine is added because many of the plant proteins are low in sulfur amino acids. This may also be a problem for vegetarians who wish to increase their sulfur amino-acid intake and overdose with methionine tablets available at health food stores. 

As a more enlightened public becomes increasingly aware of the need for adequate nutrition, the field of foods enriched or fortified with vitamins and amino acids will assume still greater importance in the years to come. It is conceivable that as these markets grow and as public education in nutrition progresses, there will be a consumer demand for foods with guaranteed, standardized nutritional value. 

This beverage contains everything needed to keep us alive for months to years, even when no other food is consumed. Where else can you find such a natural supply of the following (1) fluids, which are important for maintaining the right concentrations of electrolytes, such as sodium and potassium, for the electricity that flows in your brain and the right water pressure across cell membranes (2) calcium, which is critical for the release of the neurotransmitters needed for communication from one neuron in your brain to the next and (3) whole protein, which contains all the essential amino acids plus the fat-soluble vitamins A and D with which it s routinely fortified ... 

ENRICHED FOODS. Consumers will find a variety of enriched foods, and at times it is difficult to differentiate between the use of a nutrient for enrichment or as an additive. Indeed, nutrients—minerals, vitamins, and amino acids—are a class of food additives. The commonly enriched foods are salt, milk, margarine, cereals, and cereal products. Additionally, a variety of other foods may be enriched or fortified with vitamins and minerals to maintain or improve the nutritional value. There are reasons for enriching foods, and principles of enrichment to follow when considering the value of enrichment. Moreover, once it has been determined to enrich food, there are guidelines, standards, and labeling practices to follow for enrichment practices. 

In the food industry, it is the addition of one or more nutrients—vitamins, minerals, amino acids, and/or protein concentrates—to a food thus raising its nutritive value. Enriched bread, and milk fortified with vitamin D, are probably the best well-known examples. Originally, the FDA differentiated between enrichment and fortification, but now the two terms are used interchangeably. 

Mixtures of legumes and cereals have a protein quality which comes close to that of meat, milk, and other animal proteins. The highest protein quality is usually achieved in mixtures comprised of 50% legume protein and 50% cereal protein because the amino acid patterns of the two types of foods complement each other. Some examples of food combinations utilizing this principle are corn tortillas and refried beans, baked beans and brown bread, peanut butter sandwiches, and macaroni products fortified with soy protein. 

Imitation foods or analogs—High prices for such staple foods as fruit juices, milk, ice cream, butter, meats, and poultry, along with the concern over the cholesterol and fat content of certain of these foods, have stimulated the development of imitation products or analogs. These products are made from lower-cost materials, like soybean derivatives, and they are usually fortified with minerals, vitamins, and amino acids so eis to be nutritionally equivalent to the items which they are designed to replace in the diet... 

Nutrified cakes, cookies, and food bars—The new term nutrification, which is derived from the words nutrient and fortification, was coined by food scientists to denote the providing of nutrients through fabricated, fortified foods such as snack cakes, cookies, food bars, and chips laced with minerals, vitamins, and amino acids. However, some of these products are too high in fats and/or sugars to be used by sedentary adults, who might easily eat too much of these concentrated sources of calories. 

Another important property of the protein amino acids is that they are all L-isomers, with the exception of glycine (glycine only has one configuration). The body cannot use the D-isomers of these amino acids, and, in fact, some o-isomers may be toxic. An exception is D-methionine, which the body can convert into L-methionine through transamination. Naturally produced amino acids are L-isomer however, manufactured amino acids can be a racemic mixture with half of the molecules being D-isomers. These can then be separated and only the L-isomer used to fortify foods. The amino acid analysis methods normally employed in the nutritional laboratory will not differentiate the d- and L-isomers. There are, however, chiral chromatography and enzymatic methods that can be used if the product is suspected of containing D-isomers. 

---