A beverage consisting of water, whole soybeans (including hulls), sugar and flavor has been developed. Preparation includes soaking and then blanching the whole soybeans in 0.5% sodium bicarbonate, grinding with water in a hammermih, heating the slurry to 200"F, homogenizing, neutralizing, dilution, addition of sugar and flavor, pasteurizing and rohomogenizing. Enzyme inactivation by blanching prior to grinding of soaked beans was found to completely prevent formation of painty (oxidized) flavor and result in a bland flavored product. Trypsin inhibitors were also inactivated by blanching. A sufficient degree of tenderization of soybean tissue during the soak and blanch treatments was necessary to obtain good mouth feel and colloidal stability. Homogenizing conditions such as temperature and pressure were also important; when the soybeans had been blanched to a LEE-Kramer Tenderometer reading of 300 lb or below and homogenization was done at 200°F and 3500 psi, the resulting beverage showed zero separation after 2 months refrigerated storage. Dilution to below 1% protein had no effect on colloidal stability. Coulter Counter measurements of the beverage indicated that 81% of the particles fell between 3.4-7.3 microns which is larger than the defined colloidal particle range. Recoveries of protein and total solids based on the raw soybean were 99% and 90%, respeo tively.

Cereal Chem. 74(1):83-90Interest in biodegradable materials for packaging and agricultural uses has grown in recent years. Plant proteins have been proposed as inexpensive, renewable, and abundant feedstock. Corn zein was investigated based on value-added considerations and on the unique thermoplastic and hydrophobic properties of zein. Films prepared from zein are known to be tough and resistant, but also hard and brittle, thus requiring the addition of plasticizers to improve flexibility. The objectives of this research were to study the tensile properties, water absorption, and microstructure of zein sheets plasticized with palmitic and stearic acids. Both palmitic and stearic acids showed similar effects as plasticizers of zein. Tensile strength of zein sheets increased with the addition of low levels of plasti-cizers. However, beyond a critical point, tensile strength decreased with further addition of fatty acids. Water absorption decreased continuously with increasing fatty acid content. Kinetic parameters indicated fatty acids decreased water absorption by decreasing the saturation level of zein sheets. Coating zein with flax oil decreased the rate of water absorption by sealing off surface pores. Scanning electron micrographs of zein sheets showed the development of layered structures as fatty acid content increased. Zein-fatty acid layers were believed to be responsible for the increased tensile strength of plasticized zein sheets and to have contributed to increased resistance to water absorption.

A new concept is described for mechanical extraction of oil from soybeans, using dry extrusion as a pretreatment. It was found that coarsely ground whole soybeans at 10 to 14% moisture could be extrusion cooked so that the extrudate emerges from the die in a semi‐fluid state. The dwell time within the extruder was less than 30 seconds, and the temperature was raised to about 135 C. The semi‐fluid extrudate was immediately pressed in a continuous screw press to obtain high quality oil and press cake. Extrusion prior to expelling greatly increased the throughput of the expeller over the rated capacity. An oil recovery of 70% was obtained in single pass expelling using pilot model expellers. Higher recovery rates can be expected with commercial scale expellers. The high temperature‐short time extrusion cooking process eliminates the prolonged heating and holding of raw material in conventional expelling. Under the experimental conditions, press cake with 50% protein, 6% residual oil and 90% inactivation of trypsin inhibitors was obtained. The low fat cake was easily ground in a hammer mill without the usual problems associated with milling of whole beans. The expelled oil was remarkably stable with an AOM stability of 15 hr, which is comparable to refined deodorized oil according to NSPA specifications. The new procedure offers potential for producing natural soybean oil and food grade low fat soy flour by a relatively low cost operation. It may be adopted as an improvement to existing conventional expelling operations in less developed countries or as a commercial or on‐farm operation for producing value added products from soybeans within the U.S.

The objective of this work was to determine the processing conditions responsible for suspension stability of Illinois soybean beverage and to elucidate the role of lipid in this stability. Stability was determined by visual and objective means after 5 days quiescent storage at 1°C. Pressure and temperature of first and second homogenization, formulation, lipid component and accelerated settling were studied. Homogenization pressure must be such that the sum of the two pressures must be at least 5000 psi and the minimum temperature of one of the two homogenizations must be 82°C. Free and, especially, bound lipid are necessary for stability. The hypothesis that stability is promoted by formation of a lipid-protein complex was further demonstrated by centrifugation and film formation studies. Formulation plays a minor role in stability.

Chalkiness is a defect used to describe a food which coats the mouth and throat with fine, grainy particles. This study evaluates the processing and formulation variables which affect chalkiness of Illinois process soymilk produced from dehulled soybeans. Alkalinity of the blanch solution, homogenization conditions, soymilk pH, and solids concentration had the most pronounced effects on chalkiness. Increasing blanch alkalinity decreased chalkiness; beverages adjusted to higher final pH were less chalky. Homogenization at higher temperatures or pressures also significantly reduced chalkiness. Chalkiness increased with soy solids concentration. Beverages produced using conditions to effect optimal quality were compared to low quality products. Centrifugal desludging reduced chalkiness to an imperceptible level. Particles retained by 150 mesh were primarily responsible for chalkiness. The process conditions leading to minimum chalkiness were: direct blanch of cotyledons in 0.25% NaHCO, ; homogenization at 180°F and 3500 psi; formulation with 6% soy solids; beverage pH of 7.5.

A detailed TEM investigation on the microstructure of TiN/Si3N4 nanocomposite coatings, which is believed to be responsible for the coatings' remarkable mechanical properties, was carried out. Parallel simulation utilizing two-dimensional TiN/Si3N4 nanomultilayered coatings was further performed to study whether the variation of Si3N4 interlayer thickness has an influence on the coatings' microstructure and mechanical properties. The results revealed that, in nanocomposite coatings with high hardness, Si3N4 tissue has a thickness of about 0.5–0.7 nm and exists in the crystalline state. Low-energy coherent interfaces are formed between Si3N4 and neighbouring elongated TiN grains. For TiN/Si3N4 nanomultilayered coatings, Si3N4 modulation layers with thicknesses less than 0.7 nm were also found to crystallize and form coherent interfaces with the neighbouring TiN layers; at the same time, the hardness of the coatings is remarkably enhanced. When its thickness exceeds 1.0 nm, Si3N4 transformed its growth mode into amorphous and the coherent interfaces were damaged; as a consequence, hardness enhancements in the coatings vanished. The similarity of the microstructure and the mechanical properties response between nanocomposites and nanomultilayered coatings indicates that the crystallization of Si3N4 as well as the formation of coherent interfaces between TiN and Si3N4 is the main reason for the hardening of the nanocomposites.

This study was done to characterize the changes that occur during refrigerated storage of six salad vegetables individually and in a mixture.Salad-cut and intact lettuce, carrot, celery, radish, green onion and endive, and a salad mixture were stored at 4.4"C in packages made from a film having low gas permeability. Respiration of individual vegetables during storage showed two patterns: carrot and celery respired throughout the storage time while respirations by the others was halted after a few days. Respiration of cut vegetables exceeded that of intact. Total plate counts (TPC) for intact vegetables in storage increased slower than for cut vegetables; lettuce and endive showed higher TPC than the others. The cut vegetables were invariably poorer in organoleptic quality. Mixed vegetable salads were sealed with either air or an atmosphere containing 10.5% CO,, 2.25% 0,. After 2-wk storage, organoleptic evaluation indicated that the chemical treatments were generally of no value and in some cases were even detrimental but the modified initial headspace was beneficial.

Intermediate moisture soy-sugar concentrates were formulated with dehulled, blanched, ground and desludged soybeans. The influence of specific sugar, sugar content and soy solids content on the activity, and NMR mobility of the water and the rheological properties of the model systems were determined. Both activity and mobility of water were strongly influenced by the moisture content but not by the soy solids content. Interactions between added sugar and soy solids contents limited the lowest water activity achievable. All samples showed non-Newtonian behavior. The consistency coefficient was influenced by the soy content, moisture content, specific sweetener, polymer-tosolute ratio and temperature. Flow behavior index was strongly influenced by soy solids contents but not by specific sweetner and temperature.