Protein caloric value

Foods that yield in the range of 5-10 calories/g protein should be excellent dietary sources of protein. However, those that yield 50-100 or more calories/g protein should probably be used more where calories for energy are needed and supplemented with other protein sources. In many countries man has supplemented his diet with protein by the consumption of animal products and meat in order to eliminate this problem and balance the protein-caloric values. 

Amino acids are the building blocks of body proteins. There is no excess storage form of protein in the body, so amino acids are an essential component of the PN admixture. Amino acids are provided to preserve or replete lean body mass and visceral proteins and to promote protein anabolism and wound healing. Amino acids are a source of calories with a caloric value of 4 kcal/g. 

Table VIII. Protein and Caloric Value of Different Types of Vegetables (Per 100 g Fresh wt)a...

It is recommended that about half of the energy intake should be in the form of carbohydrates, a third at most in the form of fat, and the rest as protein. The fact that alcoholic beverages can make a major contribution to daily energy intake is often overlooked. Ethanol has a caloric value of about 30 kj g (see p. 320). 

Sea animals are rich in soluble dietary fibers, proteins, minerals, vitamins, antioxidants, phytochemicals, and polyunsaturated fatty acids, with low caloric value. Polysaccharides from marine animals have been reported to possess biological activities with potential medicinal values in addition to their current status as a source of dietary fibers and prebiotics. Moreover, they have a lot of dietary fiber, which lowers blood cholesterol, and iodine, which improves metabolism, vascular and cardiac action, body temperature, and perspiration regulation, and are effective in... 

The resulting reduction in caloric value of browned or caramelized foods is of little significance for well-fed Americans. Loss of biologically available amino acids is of concern only for those consuming diets of marginal protein quality. 

Caloric values of foods (physiological fuel values) are enthalpies of combustion but with an opposite sign, (-AH ), and corrected for energy lost in urine (e.g., as urea) and feces. While enthalpies of combustion of foods are all negative, the caloric values are given as positive numbers. Caloric values for proteins are... 

Aspartame. This synthetic sweetener is included with the nutritive sweeteners because it does have some caloric value (when metabolized as a protein, it releases 4 keal/g). The relationship between sweetness of aspartame and sucrose is almost linear when plotted on a log-log scale. Aspartame is 182 times sweeter than a 2% sucrose solution, but only 43 times sweeter than a 30% solution. The clean, full sweetness of aspartame is similar to that of sucrose and complements other flavors. 

Aspartame is non-cariogenic and, like all amino acids and protein products, has a caloric value of 4 kcal/g. However, as the level at which it is used is so low, its contribution to the caloric value of soft drinks is negligible. 

Foods differ in their energy value, which is usually expressed in kilocalories or kilojoules, with proteins and carbohydrates having less caloric value than fats (lipids). Fats... 

Food is "burned" in the body to yield H20, C02, and energy, just as natural gas or coal is burned in a furnace to yield the same products. In fact, the "caloric value" of a food is just the heat of reaction, AH0, for complete combustion of the food (minus a small correction factor). The value is the same whether the food is burned in the body or in a laboratory calorimeter. One gram of protein releases 17 kj (4 kcal), 1 g of carbohydrate releases 17 kj, and 1 g of fat releases 38 kj. As shown in Table 8.4, which gives the caloric value of some common foods, data are usually given in Calories (note the capital C), where 1 Cal = 1000 cal = 1 kcal = 4.184 kj. 

Fats and carbohydrates are the principal sources of energy in foods. Pure fat has a caloric value (heat of combustion) of 4080 kcal per pound, and pure carbohydrate (sugar) a caloric value of about 1860 kcal per pound. The caloric values of foods are obtained by use of a bomb calorimeter, just as was described above for fuels. The third main constituent of food, protein, is needed primarily for growth and for the repair of tissues. About 50 g of protein is the daily requirement for an adult of average size. Usually about twice this amount of protein is ingested. Tliis amount, 100 g, has a caloric value of only about 400 kcal, the heat of combustion of protein being about 2000 kcal per pound. Accordingly fat and carbohydrate must provide about 2600 kcal of the 3000 kcal required daily. 

Edible fats and oils (lipids) are derived from plant, animal, and marine sources. Fats and oils differ in that fats are solids at normal room temperature whereas oils are liquids under similar conditions. Lipids are recognized as essential nutrients in both human and animal diets. They provide the most concentrated source of energy of any foods. The caloric value of lipids (9 kcal/g) exceeds twice that of proteins and carbohydrates (4 kcal/g). Lipids not only contribute to flavor, color, odor, and texture of foods, but also confer a feeling of satiety after eating. Lipids also act as carriers of fat-soluble vitamins, supply essential fatty acids, and increase the palatability of foods. Dietary fats are often categorized as visible or invisible ... 

Lipids comprise one of the three broad classifications into which nourishing substances can be broken. Lipids, proteins, and carbohydrates are the three very general classifications. Fiber may be filling but is not called nourishment. Lipids are rich in energy, supplying twice the caloric value per unit weight than carbohy-... 

The emulsifiers have essentially the same caloric value as fats. Thus, there is no advantage to use them as fat replacers. Lipid-based replacers (also referred to as synthetic fat substitutes) are non-caloric, but the majority of them are not approved for food use at this time (Tab. 5.5). Carbohydrate-based fat replacers include starches and their derivatives (Tab. 5.6) as well as non-starch hydrocolloids (Tab. 5.7). A selection of protein based and mixed-blend replacers is given in Tab. 5.8 and 5.9, respectively. 

The energy content of foodstuffs varies. The approximate caloric content of generic carbohydrates, fats, and proteins are listed in Table 23-1. These values are based on a varied diet, i.e., all components are present. Recall that humans cannot synthesize glucose from fat. In the absence of carbohydrates, therefore, fat metabolism becomes inefficient, and the caloric value of fat decreases. 

Proteins are not required for their caloric value, but for their content of amino acids. This presents two nutritional problems (1) Does a food protein contain the correct numbers of types of amino acids (2) How accessible are the amino acids, i.e., how digestible is the food These qualities of a dietary protein are expressed as its biological value. 

Hazelnut contains all major macronutrients fat, carbohydrate, and protein. Table 12.1 shows the proximate composition and caloric value of various hazelnut varieties grown in different countries [6,10,11,13,14]. Based on the date given in Table 12.1, fat is the predominant component (58.40-64.10g/100g), followed by carbohydrate (15.50-17.61 g/lOOg), protein (10.86-16.30g/100g), moisture (3.90-5.40g/lOOg), and ash (2.20-2.69g/lOOg). These values are comparable with those published in the literature [6,9,15-18]. Several factors have been reported to affect the proximate composition of hazelnut [3,6,9,13,16,17,19,20]. 

Aspartame (NutraSweet), which has replaced saccharin as the principal artificial sweetener, is used in more than 3000 products and accounts for 75% of the one-hiUion-dollar worldwide artificial sweetener market. It is a dipeptide derivative made from aspartic acid and the methyl ester of phenylalanine. Aspartame can he digested, and its caloric value is approximately equal to that of proteins. However, since much smaller amounts of aspartame than of table sugar are needed for sweetness, many fewer calories are consumed in the sweetened food. Aspartame is not stable at cooking temperatures, which limits its use as a sugar substitute to cold foods and soft drinks. 

For example, if a steak is 49% water, 15% protein, 0% carbohydrate, 36% fat, and 0.7% minerals, then 3.5 ounces of steak (about 100 g) would provide about 384 kcal, or 384 food Gal. Note that a food Calorie (Cal) is indicated with a capital G and is actually equivalent to 1000 calories (cal) or 1 kilocalorie (kcal). The caloric values of most foods are found as illustrated in the margin, and these are the values that are hsted in diet books and on food labels. (Some representative values are given in Table 16.2.)... 

The calorific (caloric) value of beer is due to ethanol, residual carbohydrate, and protein and can be calculated from the equation ... 

The tamarind fruit that is grown in upper Egypt is brewed into a popular soft drink. The oil yield and fatty acid composition were very different from the Indian tamarind. The seeds contain 16.25% oil with a composition that is high in linoleic, oleic and lauric acids (Table 5.11). Lesser amounts of stearic and linolenic were present. The tamarind seed meal was also low in protein (2.66%) compared to other oil seeds (cottonseed, peanut) but does contain a substantial amount of sugar (25.28%) which would give the meal a high caloric value if used as an animal feed (Morad et al., 1978). 

Vitamin K This vitamin is necessary for the synthesis of four proteins involved in blood clotting, vitamins Those organic compounds essential in the diet in small amounts but with tittle or no caloric value, volatile Tending to vaporize easily, volume The volume of an object is a measure of the amormt of space it occupies. Voliune has units such as m or cm. ... 

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