3-Monochloro-1,2-propandiol (3-MCPD) in soy sauce from the Bulgarian market.

The 3-monochloro-1,2-propandiol (3-MCPD) levels in soy sauces which contained hydrolysed vegetable protein were evaluated for the Bulgarian market. For analysis of 3-MCPD, a gas chromatography-mass spectrometry (GC-MS) method was applied with a linear range of 0.03-2.00 µg mL⁻¹ and a limit of detection (LOD) of 2.3 µg kg⁻¹ and a limit of quantification (LOQ) of 3.4 µg kg⁻¹. At these levels, the standard deviation was 5.1%, with recoveries between 81% and 102%. The method was applied to the analysis of 21 samples of soy sauce from the Bulgarian market. Results ranged from 3.7 to 185.6 µg kg⁻¹. Soy sauces produced from hydrolysed soy protein contained higher levels of 3-MCPD than naturally fermented sauces. In 38.4% of samples of Bulgarian origin, the 3-MCPD content was above the EU limit of 20 µg kg⁻¹. In all analysed samples, 33.3% had a 3-MCPD content above the EU limit.

Enzyme-linked immunosorbent assay kit for the determination of soybean protein in processed foods: interlaboratory evaluation.

The labeling of foods containing ingredients derived from soybean is recommended in Japan because of an increasing number of patients who are allergic to soybeans. To ensure proper labeling, a novel sandwich ELISA kit for the determination of soybean protein in processed foods (FASTKIT Ver. II, "Soybean", Nippon Meat Packers, Inc.; "soy kit") has been developed. Five types of incurred samples (model processed foods: rice gruel, sausage, sweet adzuki bean soup, sweet potato cake, and tomato sauce) containing 10 microg soybean soluble protein/g food were prepared for use in interlaboratory evaluations of the soy kit. The soy kit displayed a sufficient RSD(R) value (interlaboratory precision: 9.3-13.4% RSD(R)) and a high level of recovery (97-114%) for all the incurred samples. The RSD(R) value for the incurred samples was mostly < 4.8%. The results of this interlaboratory evaluation suggest that the soy kit can be used as a precise and reliable tool for the determination of soybean proteins in processed foods.

Statistical and kinetic studies of the changes in soybean quality during storage as related to soymilk and tofu making.

The objective of this study was to develop statistical equations and kinetic models to describe the changes of soybean quality during storage. Significant correlations (P < 0.0001) were found among most of quality attributes including color parameters (Hunter L, a, b, and DeltaE), solid extractability (as expressed by soymilk solids content), soymilk pH and protein content, tofu yield, hardness, and protein content. Regressed linear equations were developed between color indices (L/L(0), DeltaE) and soymilk/tofu making properties. Empirical equations were developed to relate soybean color indices (L/L(0), DeltaE) and storage conditions including variables of initial moisture content (MC), relative humidity (RH), temperature (T), and duration (t). Kinetics of the changes in soybean color and extractability during storage at 70% RH and 22 to 40 degrees C were investigated. The kinetics was well described by zero-order kinetics. The Arrhenius equation adequately described the temperature dependence of the reaction rate constants for all parameters, from which the activation energies and rate constant were obtained. The equations developed in this study provided simple methods to monitor soybean quality and predict quality changes of soybeans during storage at various conditions.

Vegetable proteins: are they nutritionally equivalent to animal protein.

On the basis of the rate of animal growth, proteins have been traditionally classed as high quality, such as egg and milk protein, or low quality such as gluten. In general, vegetable proteins are of low quality but soy protein is an exception. The paper by Capristo et al. in this issue of the journal has shown that enteral formulations consisting of soy protein are as effective nutritionally as enteral formulations containing milk protein.

[Medical and biological evaluation of safety of protein concentrate from genetically-modified soybeans. Biochemical studies]. / Mediko-biologicheskaia otsenka bezopasnosti belkovogo kontsentrata, poluchennogo iz geneticheski modifitsirovannoi soi. Biokhimicheskie issledovaniia.

The rats were fed with albuminous concentrate from the genetically modified soybean 40-3-2 ("Monsanto Co", USA) 1.25 g/rat/day for 5 months. Their blood, urea and liver were investigated to measure total protein and glucose levels, aminotransferase and alkaline phosphatase activities, pH, relative density and creatinine level in the urea, as well as hepatic enzyme activity of the I and II phases of xenobiotic metabolism, and the whole and non-sedimentated lysosomal enzyme activities. The lasting albuminous concentrate supplementation from the genetically modified soybean to the rat's diet has been shown to modify hepatocyte membrane function and enzymatic activity within physiological standards. It was not harmful to the adaptation systems.

The effect of using different levels of shrimp meal in broiler diets.

The objective of this study was to measure the effect of substituting different levels of shrimp meal (SM) for soybean meal (SBM) in broiler diets. In Experiment 1, 0, 10, 20, 30, and 40% of the crude protein contributed by the SBM in broiler diets was substituted by crude protein from SM. In Experiment 2, 0, 60, 80, and 100% of the crude protein contributed by SBM in broiler diets was replaced by crude protein from SM. Body weight, cumulative feed consumption, and feed conversion (feed:gain) were determined on a weekly basis for 49 d in Experiment 1 and 42 d in Experiment 2. Mortality was reported daily. Carcass weight and percentage yield were determined on a prechilled basis. In Experiment 1, no significant differences were found for body weight, feed consumption, feed conversion, mortality, carcass weight, or yield. In the second experiment, body weight was found to be significantly higher (P < 0.01) at 21, 28, 35, and 42 d of age in treatments in which SM was introduced at a 100% substitution for SBM. Growth responses to SM were also seen at lower levels of substitution at 21, 28, and 35 d. No significant differences were observed for feed consumption, feed conversion, mortality, or carcass yield for any of the treatments. Carcass weight increased significantly by 12.1% when SM was substituted 100% for SBM. Results of the present study show that the particular SM used in this study could partially or totally replace SBM in broiler diets without negatively affecting performance or carcass quality.

Protein requirements of growing steers limit-fed corn-based diets.

In Exp. 1, six steers (254 kg) were used in a 6 x 4 incomplete Latin square to determine the effects of solvent-extracted soybean meal alone or in combination with rumen-protected methionine and lysine on N balance in steers limit-fed a high-corn diet to gain 1.1 kg/d. The basal diet contained (DM basis) 80% rolled corn, 15% alfalfa, and .9% urea (13.9% CP), and 2 or 4% soybean meal replaced corn to give CP concentrations of 14.8 and 15.6%, respectively. Each diet was fed with and without 5 g/d of Smartamine-ML (.75 and 2.0 g of rumen-protected methionine and lysine, respectively). Nitrogen retention increased linearly (P = .09) with level of soybean meal. Rumen-protected methionine and lysine had no effect on N balance. In Exp. 2, seven steers (233 kg) were used in a 7 x 4 incomplete Latin square experiment to investigate optimal levels and sources of CP for steers limit-fed to gain 1 kg/d. Treatments included a negative-control diet (urea; 11.7% CP) and six diets containing either 13.5, 15.4, or 17.2% CP with either solvent-extracted or expeller-processed soybean meal. Diets provided 75, 87.5, 100, or 112.5% of estimated CP requirement for a gain of 1 kg/d. The basal diet contained 83% rolled corn, 15% alfalfa, and .2% urea. Nitrogen retention increased linearly (P = .006) with soybean meal addition, and no differences were observed between CP sources. The CP system underpredicted the protein requirements of limit-fed steers under our conditions.