Raw Wheat Germ Research Articles

Detection of an Anti-Proteolytic Substance in Raw Wheat Germ

RECENT work from this station has demonstrated that raw wheat germ is detrimental to growth of young chicks, and markedly interferes with the absorption of fat (Creek et al., 1961a, b). These effects are reversed by autoclaving. The behavior of the raw wheat germ is very similar to that of raw soybeans which contain an antitrypsin factor (Brambila et al., 1961). In view of this similarity it was decided to test wheat germ for the presence of factors which inhibit proteolytic enzymes.EXPERIMENTAL AND RESULTSThe two samples of wheat germ used in this work were obtained from different commercial companies, and intended for feed grade use. The extraction and assay procedures used were identical to those of Bowman (1944) except for digestion time.Preliminary work indicated that the water extract of wheat germ contained a factor which inhibited the enzymatic digestion of casein and the water soluble protein in …

Evidence for the Presence of a Thermolabile Growth Inhibitor in Raw Wheat Germ

ALTHOUGH wheat and its by-products have been used in poultry feeds for many years, results have not always measured up to expectance. Recently Leong et al. (1960) found that the feeding value of certain wheat samples and their by-products could be increased by water treatment, and in some cases by enzyme additions. Willingham et al. (1961) concluded that autoclaving and mild acid hydrolysis improved the growth response observed on enzyme treatment. Adams and Naber (1961) ascertained that the growth promoting effect from water treatment could be duplicated by soaking in dilute acid. These workers concluded that the improved growth was due to alterations in the flour portion of the grain.In a report from this station (Creek et al., 1961) it was noted that raw wheat germ (WGM) was extremely deleterious to the growth of young chicks and that the growth depressant effects were minimized by autoclaving. The presence of …

The Improvement of the Nutritive Value of Raw Wheat Germ Meal by Autoclaving

The germ of wheat (WGM) constitutes approximately 2% of the total grain. It is an excellent source of water soluble vitamins, and is also extremely high in content of the tocopherols. Samples vary from 18.3 to 35.3% protein, the amount present depending upon the type of wheat, and upon the amount of middlings, flour, and bran acting as diluents (Ewing, 1951). Early work indicated that the germ protein was of relatively high biological value (Boas-Fixsen and Jackson, 1932; Chick et al., 1935; and Greve and Le Clerc, 1943). Unfortunately, the results of these studies cannot be considered valid when viewed in the light of today’s knowledge of nutrition.In an attempt to test the availability of manganese in wheat germ meal it was noted that substitutions of 15 and 30% of the product for yellow corn resulted in highly significant growth depression (Creek, 1955). The depressions could not be accounted…

The quality of the protein in germ and milk breads as shown by the growth of weanling rats: The significance of the lysine content

AbstractBy calculation from data obtained previously, on the growth rate of weanling rats on diets containing white bread as the source of protein supplemented with different amounts of L‐lysine, it is now shown that the mean rate of growth is directly proportional to the mean intake of lysine. This applies when the protein content of the diet is 12–13% and the amounts of lysine added are within the range 0–0.25% of the diet. Under these conditions the rate of growth y (g./rat/day) is related to the intake of lysine x (mg./rat/day) by the empirical equation y = 0.06154x + 0.03. Growth rates on bread containing (a) wheat germ, (b) skim milk powder, and on bread crust have been measured, and the applicability of the equation to these data has been examined. On bread crust the rate of growth was significantly less than on bread crumb. When the observed growth rates were substituted in the empirical equation the calculated lysine content of the crust indicated a loss of available lysine compared with the crumb of about 20%. The observed rates of growth were comparable with the growth rates calculated from the lysine contents of bread containing added raw wheat germ. Heat processing of the raw wheat germ gave slightly lower rates of growth and food consumption, suggesting a small reduction in available lysine due to the processing. Similar results were obtained with bread prepared with dried milk powders (6% of flour weight).

An Experiment in Feeding Wheat-Germ Oil Prepared by Ether Extraction

Experimental production of sarcomas in white rats by the feeding of oil prepared by ether extraction of raw wheat germ was first reported by Rowntree (1) and associates. Malignant intra-abdominal tumors appeared as early as fifteen days and as late as two hundred days in animals continuously receiving wheat-germ oil in amounts varying from 1 to 4 c.c. per rat per day. Practically all the rats thus fed developed malignant tumors which were histologically sarcomas. An attempt to reproduce this experiment was undertaken by the author. The services of a research chemist and the facilities of a large commercial experimental chemical laboratory were obtained to aid in the preparation of wheat-germ oil. The first batches were prepared after Rowntree's method, which consisted of extraction of wheat germ with ether and washing the extract with sodium hydroxide solution to remove fatty acids. Later the sodium hydroxide washing was abandoned. The oil was subsequently obtained by percolation as suggested by Rowntree et al (3). Part of the animals used were young commercial white rats and others were Wistar strain rats. Control rats were fed a refined wheat-germ oil, “Vio-Bin wheat-germ oil,” and other controls received dry raw wheat germ. All animals were kept on a standard balanced diet. The oil was mixed with the food for those receiving oil. The results are presented in the accompanying table.

Note on the variation in the vitamin B1 activity of raw wheat germ.

Arising out of the routine selection of wheat germs for the production of a composite high-value and reasonably uniform mixture, it has been found that the variation in the vitamin B activity of unselected wheat germ is greater than has been generally suspected.