Soy flour and grits for use in food products

Processing alternatives enable the soybean processor to manufacture soy flour products which vary in fat content, granulation and degree of heat treatment. By controlling these variables, the processor is able to regulate the nutritional value and functional properties of these products. The application of soy flour products is dependent upon their functional properties, nutritional value and low cost. Currently, the major markets for soy flour and grits are in pet foods and animal feeds, cereal based foods and ingredients, meat based foods, and as a substrate for refined protein products such as the textured vegetable proteins, soy protein concentrates, isolates and hydrolysates. These soy protein products are generally marketed as functional and nutritional substitutes for meat, milk and egg protein. For example, soy flour is a functional replacement for milk in many cereal-based foods, e.g., bread, and also enhances the nutritional value of the cereal protein by supplying lysine to the formulation. The United States government has pioneered the development and marketing of protein-enriched, cereal-based foods designed to combat worldwide starvation. The government has directly supported the research and development of corn and wheat-based food substrates supplemented with soy flour, and has purchased over one billion pounds of these products since 1966 for worldwide distribution. One of 21 papers presented at the Symposium, “Oilseed Processors Challenged by World Protein Need,” ISF-AOCS World Congress, Chicago, September 1970.     

Soy flour dispersibility and performance as wood adhesive

Soy flour adhesives using polyamidoamine-epichlorohydrin (PAE) resin as the curing agent are being used commercially to make bonded wood products. The original studies on the soy-PAE adhesives used purified soy protein isolate, but the much lower cost soy flour is now used commercially. We examined the performance of commercially available soy flours that have their proteins either mainly in their native (90 protein dispersibility index (PDI)) or denatured (70 and 20 PDI) states. We expected that the more native state soy proteins with their better dispersibility would provide better adhesion to wood surfaces and enhanced reaction with PAE resin. Small-scale wood bonding tests showed that neither of these effects was observed without and with a low level of PAE. In these tests, the solids content of the soy formulations had a large influence on adhesive viscosity but little influence on bond strength. Additionally, little difference was observed in any of the adhesive or viscosity properties between the soy flours having either a 0.152 or 0.075?mm (100 or 200 mesh) particle size.     

Soy grits,flour, concentrates,and isolates in meat products

Because of changing attitudes of consumers, processors, and regulatory agencies, soy protein products are being used at an increasing rate in various processed meat systems. The use of basic soy protein products in several meat systems is examined and guidelines are presented to optimize their use. Soy products as a supplemental ingredient in various meat systems can contribute nutrition, flavor, and valuable functional properties. As the price of meats continues to rise, and consumer interest in nutrition continues to increase, their demands will prompt governmental agencies to reconsider present meat regulations.     

Surfactants as replacements for natural lipids in bread baked from defatted wheat flour

Petroleum ether (PE) extracted 1.00% total free lipids (0.70% nonpolar and 0.30% polar) and 2-propanol (PrOH) extracted 1.36% total free and bound lipids (0.73% nonpolar and 0.63% polar) from wheat flour; the lipid fractions were characterized by thin layer chromatography. PE- or PrOH-defatted flours were baked after reconstitution with total, nonpolar, or polar wheat flour lipids; or with equivalent amounts of nonionic sucrose monopalmitate (SMP), ethoxylated monoglycerides (EMG) — each with a hydrophile-lipophile balance (HLB) of 14.0 or anionic sodium stearoyl-2-lactylate (SSL) — with an HLB value of 9.0. Defatted flours supplemented with surfactants alone or in combination with wheat flour lipids were used in bread with no-shortening and with 3%-shortening. The importance of the polar flour lipids in breadmaking was verified. The lipids in wheat flour were essential for maximizing the beneficial effects of shortening on breadmaking quality. Nonionic SMP or EMG completely replaced both PE-extractable wheat flour free total lipids ( or their non-polar or polar fractions) and 3% shortening; nonionic surfactants with high HLB were better than the anionic SSL for replacing free flour lipids. No surfactant completely replaced unfractionated PrOH-extracted lipids (free + bound) and shortening or total polar flour lipids (free + bound). All surfactants, especially anionic SSL, added with PrOH-extracted polar lipids improved the overall bread-making properties of the PrOH-defatted flour both in the absence and in the presence of shortening. Presented at the AOCS Meeting, New York, May 1977     

Fortification of bread with bean flour (Phaseolus vulgaris, L.). I. Flour and bread aspects

This paper deals with the incorporation of bean flour (Phaseolus vulgaris, var. Tórtola) (BF) made at laboratory scale in bread enrichment, by substituting 2, 4, 6, 8 and 10% wheat flour by bean flour. First, wheat and bean flours blends were prepared to study the farinological properties of these combinations. Then, breads containing bean flour in the above-mentioned proportions were made. At the 6, 8 and 10% levels, a deterioration in farinological properties of the blends, such as water absorption, developing time, weakening and W value were evident. Baking tests showed that no significant changes occurred with respect to water absorption, mixing time, weight and volume of breads, and color and texture of crumb in BF levels of 2, 4 and 6%. However, overall qualities of the breads were significantly impaired at the 8 and 10% levels.     

Extruded rice flour as a gluten substitute in the poduction of rice bread

Research regarding the production of gluten-free bread (GFB) is very important nutritionally, technically and economically speaking, both to celiac patients and to developing countries who import wheat. The main technological problem in the production of GFB is obtaining a gluten substitute that is both inexpensive and capable of retaining gas during bread fermentation and baking. The use of gelatinized starch as an alternative for gluten seems promising. In this project, rice bread was made using pregelatinized extruded rice flour as a gluten substitute. Pre-gelatinized rice flours (PRF) were manufactured in a single screw Brabender extruder, varying extrusion temperature (108-192 degrees C) and the moisture of the raw material (19.2 - 24.8%), and were used in a proportion of 10 g for every 100 g of raw rice flour, in the production of gluten-free bread. Results showed that rice flour extruded at a high temperature (180 degrees) and low moisture content (20%), rendered bread with the best technological characteristics, presenting crust and crumb color similar to those of conventional wheat bread, although with volume and texture not as satisfactory in the same comparison.     

Fortification of bread with bean flour (Phaseolus vulgaris). II. Nutritive value of the fortified bread

The protein value of breads containing bean flour (BF) (Phaseolus vulgaris, cv Tórtola) was tested in rats. BF replaced wheat flour by 2, 4, 6, 8 and 10 per cent. Protein content was 9.3 (N x 5.7) per cent and 24.4 (N x 6.25) per cent for wheat flour and bean flour, respectively. The protein content in the control bread was 11.6%, and increased to 12.6% at the 10% level of substitution. Parameters measured were protein efficiency ratio (PER), net protein ratio (NPR), and apparent and true digestibility of the protein. PER, in the control bread, was 1.44; a slight, non-significant increase occurred up to the 10% level of substitution. The control bread showed a NPR value of 2.78, figure which also remained practically unchanged at the higher levels of replacement. Nevertheless, both apparent and true protein digestibility decreased significantly with increasing levels of substitution of WF by BF (p less than 0.05). In conclusion, substitution of WF by BF in bread did not produce the expected increase in protein quality under our experimental conditions.     

Soy and corn flour precooked with microwaves and its use in the preparation of arepas]

Unhusked corn and soy grits were used as raw material, with a particle size ranging between 10 and 20 mesh (ASTM). The results obtained in this study reveal that microwave heating is effective in destroying the antinutritional factors present in soybeans. The trypsin inhibitor activity, in effect, was reduced to a 76% inactivation. The hemagglutinating titer was labile to the heating process, showing values of +8 to +3 for the full-fat soy flour and precooked soy flour, respectively. The quality of soy protein was measured by the protein efficiency ratio (PER) showing values of 2.63 for the precooked soy flour, and 2.46 to 2.21 for the precooked corn:soy blends (70:30 and 50:50). These uncooked blends present values of 1.17 and 1.04. The enriched corn:soy flour had a PER value of 1.60, in comparison to casein (PER = 2.90). The microwave heating improved the digestibility of the soy flour and blends. There were no significant differences (P less than or equal to 0.05) in relation to the functionality of the precooked flour and mixtures. The results obtained revealed that the applied process markedly improve the functional properties and nutritional value of the enriched flour, and of the "arepas" prepared from them.     

Supplementation of wheat flour with chickpea (Cicer arietinum) flour. I. Preparation of flours and their properties for bread making

The feasibility of adding chick-pea flour substituting part of wheat flour in yeast-leavened bread-making in order to increase the protein value, was studied. A 70% extraction chick-pea flour of commercial granulometry (150 mu) was prepared. Wheat flours of 74% and 78% extraction were then blended with 5%, 10% and 15% of chick-pea flour. Every flour and blend were subsequently analyzed to determine protein, ash, fiber, fat and maltose content, as well as sedimentation, farinogram and bread-making. Addition of chick-pea flour increased protein, fiber, ash and fat content in the blends, not causing a severe effect on quality, even at the 15% level of substitution. Blends showed an increase in maltose content, W value and bread specific volume. Furthermore, breads prepared were of good quality even without the use of maturing agents.     

Use of flour of pejibaye fruit (Bactris gasipaes H.B.K.) in bread making

Trial were conducted in Costa Rica in 1984 and 1985, to determine the possibility of substituting pejibaye (Bactris gasipaes H.B.K.) meal for wheat flour in bread. Utilization in three distinct mixtures was examined: 90:10, 85:15 and 80:20 percentage of wheat flour to percentage of pejibaye meal, respectively. The breads were made, and dough analyses were conducted at "Molinos de Costa Rica, S.A.", the country's principal flour mill. Chemical analyses were carried out at the University of Costa Rica. Results indicate a marked inverse relationship between both initial dough development time and dough strength maintenance, and the content of pejibaye meal present in the flour mixture. Consequent problems with sufficient dough expansion preclude utilization of this fruit meal for bread-making in proportions significantly greater than 10% of the total composite flour. The above-mentioned findings reflect the high nutritional value of the pejibaye fruit. Although the protein content is inversely correlated with the amount of pejibaye meal in the mixture, vitamin A and fat contents are positively correlated. This fact demonstrates that the utilization of pejibaye meal in bread-making may well be in some ways considered as a form of nutritional enrichment. As a final conclusion drawn from the results of analyses of the trials and sensory observations, the 90% wheat flour with 10% pejibaye meal mixture apparently was the optimum substitution level of the breads examined. The potential macroeconomic ramifications on the Costa Rican economy of producing and utilizing pejibaye meal in bread-making, are highly favorable.     

Sensory evaluation and acceptability study, at the consumer level, of bread supplemented with sweet lupine flour

The purpose of this study was to determine the effect of incorporating sweet lupine flour (SLF) to bread, upon the organoleptic characteristics and acceptability of the product. The substitution levels were 3, 6, 9 and 12%. The sensory evaluation test was done by 25 trained judges using the hedonic scaling method (9 to 1 scoring). Internal and external characteristics of appearance, color, aroma, texture, bitterness and flavor, as well as general acceptability, were measured. Sensory evaluation results of the external characteristics were significant at the 9 and 12% SLF levels for color (p less than 0.05) while the other parameters did not show significant differences. In regard to the internal characteristics, a significant difference for color was found at the 3% level of SLF (p less than 0.05); and at 6, 9 and 12% SLF levels, for appearance (p less than 0.05). The general acceptability was good at all the levels tested, with no significant differences among them. An acceptability study at the consumer level for 9% lupine flour bread was carried out in a group of 90 girls, aged 10-12 years, during a 10-day period. The results showed a very good acceptability of the product (p less than 0.01). The results of this study indicate that the incorporation of 6% SLF to the bread, did not affect adversely its sensory properties. Moreover, the acceptability of bread containing up to 12% SLF was excellent.     

大豆中硼形态研究及豆制品中硼形态调查

文章以大豆为研究对象,建立微波辅助分步连续提取方法并应用于大豆及大豆制品中硼形态及分布的分析研究。按照该方法可将大豆中硼大致分为有机态硼和无机态硼,而无机态硼又可分为水溶性硼、络合态硼、沉淀态硼。其含量分布为:大豆总硼含量为36.15 mg/kg,无机态硼含量为30.66 mg/kg,占总硼含量的84.8%,有机态硼含量为5.49 mg/kg,占总硼含量的15.2%;无机态硼中水溶性硼占57.7%,络合态硼占29.4%,沉淀态无机硼占12.8%。对10种常见大豆制品中硼形态研究发现:豆豉的有机态硼含量高达82.7%,而其他非发酵性豆制品中无机态硼为主要的硼形态,占总硼比例的64.2%~98.6%,表明豆制品中硼形态与加工工艺有关。本研究可以为内源性硼及外源性硼鉴别提供一定的借鉴。     

Soy products in bakery goods

Applications of soy proteins in baking are reviewed and original data on taste and texture tests are presented. New foods employing soy for nutritional improvement are described. A plea is made for production of soy proteins with higher baking functionality and improved taste.     

Soy protein gelation

Heat-induced protein gels are of importance for the structure and properties of many food products. Gel formation is a complex process which often involves several reactions such as denaturation, dissociation-association, and aggregation. The kinetics of the reactions involved will determine the type of structure formed. Protein gels can be divided into two types: gels formed by random aggregation and gels formed by association of molecules into strands in a more ordered way. The two soy proteins glycinin and conglycinin both have the ability to form ordered structures consisting of strands 10–15 nm thick. The glycinin gel strands formed in distilled water are regular, and cross sections of strands showed a hollow cylindrical structure. In the presence of sodium chloride, glycinin forms an aggregated gel structure at 85 C, but at 95 C a regular structure similar to that found in distilled water was formed. The aggregated structure was interpreted as a transient state similar to the soluble aggregate formed on heating dilute solutions prior to dissociation into subunits. Conglycinin gels are more irregular and more cross-linked than gels of glycinin. Also, the strands of conglycinin showed a complex mode of aggregation possibly in the form of double spirals. The addition of salt does not affect the microstructure of conglycinin gels as dramatically as in the case of glycinin gels. Commercially produced soy protein isolates may behave quite differently from native soy proteins, due to processing conditions causing denaturation and various states of aggregation.     

Protein complementation of defatted hazelnut flour with pea flour

A great deal of research has been carried out to increase the availability of naturally-occurring proteins, or obtained from secondary products derived through industrial processes. As a result of the industrial exploitation of the native hazelnut (Gevuina avellana) in Chile, a defatted residue is obtained which eventually could be utilized as a human food. To determine the complementary potential capacity of the defatted hazelnut flour and pea flour, a study was carried out in weaning rats of the Wistar strain, as follows. The biological evaluation considered diet formulation with defatted hazelnut flour and pea flour in the 30:70, 50:50, 60:40 and 70:30 proportions, respectively. The NPR values obtained in this evaluation of the assay diets were: 3.4, 3.5, 3.9, 4.1 and 4.1, in comparison with 3.7 for casein. In percentage terms, the 4.1 NPR value was 11% higher than that obtained for casein. The maximum protein quality was observed when the two protein sources were mixed in the 60:40 and 70:30 (w/w) ratios. In regard to true digestibility, there were no significant differences among the experimental diets, but were lower than casein. The results of this study demonstrate that the defatted hazelnut flour constitutes an attractive nutritional alternative for the amino acid supplementation of cereal and legumes, the latter being of habitual consumption by the Chilean population.