Calculated Protein Efficiency Ratio Research Articles

Chemical Composition and Nutritional Quality of Camel Milk

ABSTRACTThe chemical composition and nutritional quality of camel milk was studied. Results showed 11.7% total solids, 3.0% protein, 3.6% fat, 0.8% ash, 4.4% lactose, 0.13% acidity and a pH of 6.5. The levels of Na, K, Zn, Fe, Cu, Mn, niacin and vitamin C were higher and thiamin, riboflavin, folacin, vitamin Bt12, pantothenic acid, vitamin A, lysine and tryptophan were relatively lower than those of cow milk. Gas liquid chromatography analysis of milk fat showed a molar percent of 26.7 for palmitic, 25.5 oleic, 11.4 myristic, and 11.0 palmitoleic. In vitro protein digestibility and calculated protein efficiency ratio values were 81.4% and 2.69, respectively, based on 90.0% and 2.50 for ANRC‐Casein.

Chemical Composition and Nutritional Quality of Date Seeds

ABSTRACTABSTRACT The seeds of Ruzeiz and Sifri date cultivars, on the average, contained 6.5% protein, 10.4% fat, 22.0% fiber, 1.1% ash, and 60.0% carbohydrates on a dry weight basis. Mineral analysis showed higher concentration of K followed by P, Mg, Ca and Na. Among the microelements, Fe was in higher concentration (7.4 mg/100g dry weight) followed by Mn, Zn and Cu. Oleic (44.25%), lauric (17.35%), myristic (11.45%), palmitic (10.30%) and linoleic (8.45%) were the major fatty acids in date seed oil. Tryptophan (chemical score = 77) was the first limiting amino acid in date seed proteins (FAO/WHO, 1973). The average in vitro protein digestibility and calculated protein efficiency ratio values were 63.5% and 1.65, respectively, compared to 90% and 2.50 for ANRC‐Casein.

Chemical composition and nutritional quality of sorghum flour and bread

Two Saudi Arabian sorghum cultivars, white and reddish white, were investigated for their chemical and nutritional quality. The two cultivars were similar in proximate composition (white 15.3% protein, reddish-white 15.9% protein), mineral profile, fatty acid composition, vitamin content (except vitamin-B12 was higher in reddish-white), in vitro protein digestibility (IVPD) and calculated protein efficiency ratio (C-PER). White sorghum had lower tannins (0.09% catechin equivalent) compared to the reddish-white (0.27% catechin equivalent). Lysine was the first limiting amino acid in both with chemical scores of 45 and 47 for the proteins of white and reddish-white cultivars, respectively. Baking had no effect on proximate, fatty acid and amino acid composition. However, it increased the Na and Ca contents but decreased the K, P, and pantothenic acid contents. Tannins were not detected in the breads. Breads fermented for 18 h had higher vitamin-B12 and pantothenic acid levels but lower P content than unfermented breads. A slight increase in tyrosine, lysine, methionine contents as well as C-PER was also observed in fermented bread.

Nutritional quality of pearl millet flour and bread

Market samples of pearl millet flour and bread from Saudi Arabia were analysed for chemical composition and nutritional quality. Pearl millet flour contained, on a dry weight basis, 17.4% protein, 6.3% fat, 2.8% fiber and 2.2% ash. Lysine was the most limiting essential amino acid with a chemical score of 53 (FAO/WHO, 1973). Linoleic acid (44.8%), oleic acid (23.2%) and palmitic acid (22.3%) were the dominant fatty acids in millet oil followed by stearic acid (4.0%) and linolenic acid (2.9%). The invitro protein digestibility (IVPD) of millet flour was 75.6% and the calculated protein efficiency ratio (C-PER) was 1.38 in comparison to ANRC casein values of 90% and 2.50, respectively. Baking at 300°C for 15 min had only little effect on the proximate and fatty acid composition of the bread but decreased the arginine, cystine and lysine contents by 31.3%, 15.8% and 13.8%, respectively. The IVPD was not affected but the C-PER decreased by 18% on baking.

Date Bars Fortified with Soy Protein Isolate and Dry Skim Milk

ABSTRACTFortification of plain and chocolate coated date bars with soy protein isolate (SPI) and dry skim milk (DSM) in different proportions (1.5% SPI + 10.5% DSM; 3.0% SPI + 7.0% DSM and 4.5% SPI + 3.5% DSM) resulted in an increase of protein, fat, fiber, ash, Na, K, Ca, Mg, P, Zn, and all the essential amino acids. The chemical score increased from 48 to a range of 83–95. The in vitro protein digestibility (IVPD) values (77.8–81.8%) and calculated protein efficiency ratios (C‐PERs) of the fortified bars (2.40–2.47) were close to the IVPD (90.0%) and C‐PER (2.50) of ANRC‐casein. In general, sensory evaluation indicated no difference in the control and fortified date bars, which were stored up to six months. 1.5% SPI + 10.5% DSM was the optimum level of supplementation in terms of nutritive benefit.

Nutritive value of prickly pear seeds,Opuntia ficus-indica

Results are reported on the nutritional quality of prickly pear seeds,Opuntia ficus-indica. The seeds contained 16.6% protein, 17.2% fat, 49.6% fiber and 3.0% ash. The meal showed a high amount of iron (9.45 mg %). The contents of Mg, P, K, Zn and Cu were nutritionally significant contributing approximately 10–20% of the Recommended Dietary Allowances (RDA) of these elements per 100 g of dry weight. The amount of Ca represented less than 10% of the RDA for that element. Aspartic acid, glutamic acid, arginine and glycine were the most abundant amino acids making nearly half of the total amino acids content. The seeds were rich in sulfur amino acids (methionine + cystine). Lysine was the first limiting amino acid resulting in a chemical score of 62 for the protein. The in-vitro protein digestibility and the calculated protein efficiency ratio were 77% and 1.82 compared to 90% and 2.50, respectively, for ANRC casein.

In Vitro Assay for Predicting Protein Efficiency Ratio as Measured by Rat Bioassay: Collaborative Study

Seven laboratories collaborated in testing the calculated protein efficiency ratio (C-PER and DC-PER). The collaborative study required each laboratory to analyze 6 foods and a control protein (ANRC casein) for in vitro apparent protein digestibility, amino acid composition, and PER via rat bioassay. The 6 foods or food ingredients tested were nonfat dry milk, cooked chicken muscle, protein-fortified dry breakfast cereal, textured soy protein, oat-based dry breakfast cereal, and durum wheat flour. Data obtained from the study were analyzed statistically for the intralaboratory variation for each method of analysis (i.e., amino acid analysis, PER, etc.). The ability of the C-PER to rapidly predict rat PER was also measured. The C-PER and DC-PER methods were adopted official first action.