Nutrient Level in Saudi Arabia Wheat Flour

The chemical composition and protein quality of four varieties of wheat flour grown in Saudi Arabia (Rice Mexi-Pak, Red Mexi-Pak, Lugemi, and Moaeah), and one type of home bread (Korsan) made from Moaeah were evaluated. Analysis performed included proximate analysis, thiamine, riboflavin, iron, amino acid composition and protein efficiency ratio (PER). Protein and iron were higher in Moaeah and Lugemi. The protein quality assessed by PER was higkest for Rice Mexi-Pak and lowest for Korsan, the cooked product. Chemical scores based on the essential amino acid content of the proteins were calculated; lysine and/or methionine was the limiting amino acid in the varieties of wheat studied.

, while in some developing countries cereals contribute up to 753 of the cal6ries and 90% of the protein (Pomeranz, 1971).
Some of these nutrients are consumed directly; those in animal feed derived from wheat are consumed indirectly.
The quantity of wheat-based nutrients available for direct Approximately 60% of the wheat consumed is now from local production (Alyamamah, 1982).
Several experiments have been conducted in past years to evaluate the nutritional value of wheat flour.  determined the amino acid composition and protein quality of wheat flour. They concluded that lysine was the first limiting amino acid in all cases. Sikkaat al. (1975) analyzed the mill fractions of whole wheat flour, bran, white flour and resultant atta. The protein quality index based on protein efficiency ratio and net protein retention at the 10% protein level was found tq be highest in resultant atta, followed by bran, whole wheat flour, and white flour. The chemical score based on the essential amino acid content of egg protein and on the FAO provisional pattern indicated the limiting amino acids in different fractions. In resultant atta and bran, methionine and isoleucine were limiting, whereas in whole wheat and white flour, lysine, threonine and methionine were limited.  showed that toasting affected the amino acid composition and protein of wheat flour and with increasing toasting temperature, destruction of some essential amino acid increased, and protein utilization decreased.  reported the nutrient levels of internationally milled wheat flour. They concluded that the nutritional quality of large proportions of flour produced throughout the world is lower than that of wheat as a result of milling process.   The ash content was determined by ignition of the sample in a muffle furnace at 600°C for two hours.
2:5 Crude fiber: The crude fiber was determined using the Association of Official Analytical Chemists method (AOAC, 1979 fed rat chow, on the fifth day assay groups were assembled in lots of 10 rats in random manner, so that the weight differential was less than 5 g. Throughout the 28-day test period, feed and water were available ad libitum.
Individual food consumption records and weight gain were · determined two times per week. Upon conclusion of 28 day feeding ~tudies, PER values were calculated for each group as follows: protein efficiency ratio (PER) = body weight gain (g) protein consumed (g) 6:1 Amino acid: Amino acid content was determined by Hebert V.
6:2 Tryptophan: The method described by   6:3 Chemical score: Calculation of chemical score was based on the essential amino acid pattern of egg as reference protein.
The method of  was adopted to calculate chemical scores. The ratio of the quantity of each essential amino acid in wheat protein compared to the quantity of the respective amino acid in whole egg protein was computed and stated as a percentage. The lowest of these percentages is the chemical score. In the U.S.,  reported a range of 1.72-2.43 ash in wheat; Keagy et al. (1980) reported 1.843 for hard and 1.873 for soft wheats; Kent (1975) reported 1.8% ash in wheat; and  reported 1.17-2.96% ash in wheat. Thus, the overall means of Arabian wheat was similar to those reported by , and Keagy et al. (1980).

Crude Fiber:
Crude fiber values had an overall mean of 2.3 except for Moaeah which was 2.62%.  Riboflavin: The mean riboflavin content of all four varieties was .127 mg/100 g. The range was from .12 mg/100 g (Rice Mexi-Pak, Korsan) to .14 mg/100 g (Red Mexi-Pak).  have reported a riboflavin content in ranges of .1 mg/100 g to .17 mg/100 g, and  has reported a mean .14 mg/100 g.

Mienrals:
Iron: -------Ta~le 2 shows the iron content of the wheat flour; Moaeah contained higher iron than other varieties. A variation in iron content of different varieties of wheat has been reported by .
Amino acids: The results of analysis for amino acids are given in  Sikka et al. (1975) and Simmonds (1968).
Threonine and tryptophan did tend to be lower in  and a Casein as control. Figure II shows the average weekly gain.    were within the average for wheat given by FAQ (1.17-1. 77).
The PER for Korsan was lower than Moaeah, but the difference was not statistically different. The lysine content of Korsan was lower than that of Maoeah, however that difference did not make a significant difference in the utilization of the protein by growing rats.
From the overall evidence presented, it appears obvious that the nutrient value of the old varieties In view of the wide acceptance of modern milling technology even in the developing countries, these losses are not inconsequential.
Protein and protein quality: Cereals are regarded primarily as energy food; however, they are also important sources of protein. Protein is one of the most difficult nutrients to obtain because foods high in protein are usually the most expensive food stuffs. It has been recognized that the human body requires protein in sufficient amount and of specific amino acid composition. Although the quantity of protein in wheat can vary from 7 to 22%, the average value is higher than for other cereal grains. However, other protein sources such as meat are higher in protein content.
The quality of wheat protein is poor relative to other protein sources such as meat, fish, and soybeans.
Protein quality and quantity are affected by several factors including milling procedures, cooking, the variety of wheat, the location and growing conditions. Miladi, et al (1972)     shoed that toasting affected the amino acid composition and utilization of protein from unsupplemented wheat flour, and with increasing toast-ing temperature, destruction of some essential amino acid increased. Rat feeding tests showed the protein utilization decreased with increasing toasting temperature.
Protein and amino acid profiles of normal and yellowberry bread wheat have been examined (Waines et al., 1978).
The investigators concluded that values for nitrogen concentration in yellow-berry kernels of bread wheat varied from 91.6 to 72.93 of those for normal kernels. Also, values for total amino acid concentration in whole wheat flour of,yellow-berry kernels were less than those of whole wheat flour of normal kernels. Lysine and threonine were higher in yellow-berry kernels than in normal kernels. Glutamic acid was lower in yellow-berry kernels than in normal kernels. Abrol et al. (1971), reported that the enhanced protein content of wheat observed following increased fertilizer application is mainly accounted for by an increase in gluten content. Levels of glutamic acid, phenyalanine, proline, and leucine increased at high fertilizer levels, while the reverse was true for lysine, valine, threonine, isoleucine and tryosine. Haber et al. (1976) had studied the amino acid composition of hard red winter wheat and tritical. They found that the amino acid composition of tritical flour showed higher lysine levels than hard red winter wheat flour.

Vitamins and Mienrals:
Wheat contains a significant amount of vitamins, but processing changes and reduces their content. Wheat also contains a variety of minerals, usually in small quantity.