Screening spring wheat for midge resistance in relation to ferulic acid content.

The concentration of ferulic acid (FA), the major phenolic acid in the wheat kernel, was found to differ significantly in the mature grain of six wheat cultivars known to have a range of tolerance to the orange wheat blossom midge (Sitodiplosis mosellana). Differences in FA content were correlated with floret infestation level of the cultivars. The wheat cultivars ranked similarly in FA content at the four locations where they were tested, despite a significant effect of environment. Ferulic acid was synthesized mainly during the early stages of grain filling but at different rates among cultivars. Ferulic acid was concentrated primarily in the shorts and bran fractions in an insoluble-bound form. A high correlation was obtained between FA contents as determined by GLC, fluorometry, UV, and colorimetry. The colorimetric procedure was modified as a qualitative, simple, and rapid test for identifying midge-resistant wheat and evaluated in several field trials. The method should provide a rapid tool in the preliminary screening of experimental lines in the development of midge-resistant wheat cultivars.

Preprocessed barley, rye, and triticale as a feedstock for an integrated fuel ethanol-feedlot plant.

Rye, triticale, and barley were evaluated as starch feedstock to replace wheat for ethanol production. Preprocessing of grain by abrasion on a Satake mill reduced fiber and increased starch concentrations in feedstock for fermentations. Higher concentrations of starch in flours from preprocessed cereal grains would increase plant throughput by 8-23% since more starch is processed in the same weight of feedstock. Increased concentrations of starch for fermentation resulted in higher concentrations of ethanol in beer. Energy requirements to produce one L of ethanol from preprocessed grains were reduced, the natural gas by 3.5-11.4%, whereas power consumption was reduced by 5.2-15.6%.

Selected nutritional, physical and sensory characteristics of pan and flat breads prepared from composite flours containing fababean.

Composite flour blends containing wheat (W), fababean (F), cottonseed and sesame flours were formulated to provide the FAO/WHO/UNU protein requirements for the 2-5 year old child, and evaluated in pan and flat bread applications. Water absorption of composite flour doughs was up to 35% greater than the control but gluten strength and slurry viscosities were markedly reduced. Loaf volume and specific volume of pan breads prepared from composite flours were 25-60% less than that of the control bread but flat breads tolerated the protein supplements extremely well. The W/F flat bread, containing 27% of fababean flour, received acceptable taste, texture and colour scores and was only slightly inferior to the control in puffing and layer separation. Additions of cottonseed or sesame flours to the W/F blend failed to improve sensory properties of the flat breads.

Composition, structure, functionality, and chemical modification of legume starches: a review.

The major carbohydrate of the legume seed is starch, which represents up to 45% of the total seed weight. In recent years, substantial progress has been made in understanding the relationship between starch structure and functionality. However, these studies have been mainly on cereal and tuber starches. The present status of knowledge on the composition, structure, functionality, digestibility, and chemical modification of legume starches is reviewed. In addition present concepts of granule structure, gelatinization, retrogradation, and rheology are also reviewed. Future research needs in the area of legume starch chemistry are discussed.

Trypsin inhibitors and nutritive value in cereals.

Chemical assays demonstrated that rye and barley cultivars contained relatively high levels of trypsin inhibitor activity as compared to oat and wheat cultivars, and there was a low degree of stability to prolonged wet treatment. In feeding trials with broiler chicks, incorporation of 67% raw barley or 50% raw rye in the rations enhanced feed intake and weight gains, and the marginal increases in pancreas weight were not reversed by feeding autoclaved cereals. Raw rye cultivars fed at the 75% level in mouse diets reduced weight gains, feed efficiency, protein digestibility, protein efficiency ratio and biological value. Autoclaving to inactivate trypsin inhibitors, or ether extraction to remove the resorcinols, failed to improve the nutritive value of rye diets for mice. It appeared that the protease inhibitors in the four cereals were relatively weak inhibitors of trypsin in the digestive system despite stability to dry heat and acid pH.

Phenolic acids in oilseed flours.

Noticeable quantitative differences were found in the content of free and bound phenolic acids in flours obtained from soybeans, cottonseed, peanuts, rapeseed, white mustard, flax and sesame seeds. Independently of the type of seeds used to produce flour, the highest amounts of acids were liberated from ester bonds. These acids were especially abundant in flour made from rape and white mustard seeds. Phenolic compounds identified in these flours were predominated by sinapic and p-hydroxybenzoic acids and in the other flours by other phenolic acids.

Assessment of rat growth methods for estimating protein quality: interlaboratory study.

An interlaboratory study involving protein efficiency ratio (PER), net protein ratio (NPR), relative NPR (RNPR) and relative nitrogen utilization (RNU) was carried out. Six collaborators assayed 6 samples, including casein plus methionine which was used as a reference protein. Collaborators prepared their own diets and analyzed the diets for nitrogen. Test proteins were added at the 8% level (N X 6.25). PER values varied more than NPR values which varied more than either RNPR or RNU. RNU and RNPR produced almost identical values, but RNPR remains the official method of choice, because it is a well established method.

Protein nutrition of Tenebrio molitor L. XX. Growth response of larvae to graded levels of amino acids.

Larvae of Tenebrio molitor L;, Gembloux strain, race F, having an average initial weight of 10 mg were reared for 4 weeks at 27 +/- 0.25 degrees C and 65 +/- 5% relative humidity on diets containing an amino-acid mixture resembling the composition of larval tissues; Each of 14 amino acids was tested individually at levels of 0, 10, 20, 50, 100 and 200% of the amount found in larval tissues, while the concentration of other amino acids remained constant. Diets were maintained isonitrogenous at 1.6% nitrogen with supplementary glutamic acid, glycine, serine and tyrosine; Maximum fresh weight gains and dry weights were achieved by larvae fed reference levels of all essential amino acids except phenylalanine, threonine and tryptophan. Maximum growth was achieved by larvae fed 50% of the phenylalanine level found in larval tissues, Threonine and tryptophan were the limiting amino acids in this study and are probably required in the diet in excess of twice the concentration occuring in larval tissues, Probable ranges for quantitative amino-acid requirements of T. molitor were determined and suggestions were made for improving the nutritional adequacy of the amino-acid mixture.

Nutritional evaluation of oilseeds and legumes as protein supplements to cereals.

Several oilseed and legume protein products were fed to rats as the sole source of dietary protein, and in blends with cereals for the determination of protein efficiency ratio (PER) and biological availability of amino acids. In addition oilseed protein isolates were fed to mice for the determination of PER. Results of the mouse study revealed that the adjusted PER (casein = 100)for Target rapeseed isolate (108) was higher than those of sunflower (74), safflower (77), soybean (86) or flax (92) isolates. Results of the rat trials revealed that the adjusted PER for Twoer rapeseed meal (88) was higher than those of fababean (21), field pea (59) and soybean meal (72). Supplementation with methionine (0.2%) resulted in improved PER for fababean (84), field pea (101) and soybean meal (97). Mustard flour and rapeseed flour gave PER of 109 and 106, respectively, while the value of sunflower flour was low (56). Protein isolates of Tower rapeseed and soybean gave PER of 92 and 80, respectively. Blending of legumes and oilseeds with wheat flour (PER = 28) gave high PER values (60--85), as also occurred in rice blends (71--88). Supplementation of wheat-legume blends with lysine (0.4%), methionine (0.2%) and threonine (0.1%) brought all PER values above 100. It appeared that differences in PER of the diets paralleled the levels of the first limiting amino acid for rat growth. Results of balance trials indicated that the availability of the limiting amino acid(s) was lower than other essential amino acids for each protein source.

Determination of useful barley selections in an improvement program for increased lysine content by larvae of Tenebrio molitor L.

Larvae of the yellow mealworm, Tenebrio molitor L., Gembloux strain, race F, were reared for 4 weeks at 27 +/- 0.25 degrees C and 65 +/- 5% relative humidity. They were fed on each of 22 cultivars of barley, at the protein level occurring in harvested seed and at a protein level of 10% of dietary protein. Growth and body composition of the larvae were correlated positively and significantly with the concentrations of basic amino acids in the barleys and negatively and significantly with the concentrations of leucine. The percentage of crude protein in larval tissues can be used as a measure of available lysine in barley cultivars, and gains in fresh weight of larvae as indices of arginine concentrations. Differences were evident between the biological and chemical estimations of these amino acids. Several of the Saskatoon barley selections, derived from crosses with Hiproly, were equal to Hiproly or Risø varieties in the amounts of lysine available to the larvae.

Nutritional evaluation of wheat and barley cultivars by growth rate and body composition of larvae of Tenebrio molitor.

Larvae of the yellow mealworm, Tenebrio molitor L., Gembloux strain, race F, were reared on diets of 17 cultivars of wheat and 29 cultivars of barley, prepared for determination of digestible energy with mice, for 4 weeks at 27 +/- 0.25 degrees C and 65 +/- 5% relative humidity. Values for percentage crude protein of tissues of larvae fed wheat cultivars were significantly and positively correlated with values for digestible energy as determined with mice. These values were not correlated for larvae fed barley cultivars; however, values for per cent dry matter content of larvae were significantly and positively correlated with values for digestible energy determined with mice. This apparent discrepancy is explained on the basis of the chemical constitution of barley and the availability of amino acids of barley to the larvae. Use of larvae of Tenebrio molitor to indicate the digestible energy of cereal grains is feasible, provided that the proper parameter is chosen. Nevertheless, use of this biological method seems more suitable for evaluation of protein quality and of amino acid availability than for a measure of digestible energy of feeds.