SENSORY ANALYSIS OF SOY YOGURT AND FROZEN SOY YOGURT PRODUCED FROM RAPID HYDRATION HYDROTHERMAL COOKED SOY MILK

Sensory studies have been conducted on flavored soy yogurt (FLAVSYO) and frozen flavored soy yogurt (FROZSYO) made from rapid hydration hydrothermal cooked soy milk. Trained panel testing was conducted with a panel of 5. Consumer acceptance tests were carried out with 195 consumers using standard nine-point hedonic scales. The frequencies of the consumers who liked FROZSYO were high at like slightly to like extremely, the FLAVSYO and FROZSYO had less beany flavor than the soy milk. The data from the trained panel indicate that processing, fermentation, and flavoring significantly changed the major attributes. Relative to unflavored soy yogurt, the beany flavors, chalkiness, aftertaste, sweetness, uniformity, and mouth coating scores of the FLAVSYO and FROZSYO were closer to the corresponding sensory scores for the commercial yogurt.     

EFFECT of PROCESSING TEMPERATURES ON MICROBIOLOGICAL and CHEMICAL QUALITY of SOY MILK PRODUCED BY RAPID HYDRATION HYDROTHERMAL COOKING

Soy milk samples produced from 11% soybean slurry cooked by the rapid hydration hydrothermal cooking (RHHTC) process at temperatures from 105-157C for 24-90 s were studied for their sterility, microbiological quality, flatulent sugar reduction, and physical characteristics. Soy milk produced at the temperature of 132C, or higher, for 29 s or longer was sterile. All of the bacteria ( Pseudomonas aeruginosa, Serratia lequefaciens, S. rubidaea, and Enterobacter cloacae including the bacilli cells and spores) were destroyed completely. At lower temperatures, 105-127C, the Gram negative bacteria were destroyed; however, the spores of Bacillus licheniformis and B. cereus , Gram positive bacteria survived the heat. Temperatures of 143-157C with a retention time of soy slurry solids in the holding tube of 30 s or longer are recommended to sterilize the product . the mean residence time of soy solids processed by the RHHTC unit was 30 s.     

Zymogen Activation in Pancreatic Endoproteolytic Preparations and Influence on Some Whey Protein Hydrolysate Characteristics

A proteolytic preparation from porcine pancreas was isolated. Trypsin, chymotrypsin and elastase were characterized and their time-dependent stability at 37°C was studied. The supematant of a 30% (w/v) saturated ammonium sulfate precipitation of a pancreatic extract (30S) was developed to pilot-scale level. The influence of zymogen activation time on molecular characteristics of whey protein hydrolysates produced by 30S and the commercial pancreatic preparation Corolase PP were compared. Amino acid analysis and gel permeation chromatography were used to characterize lactalbumin hydrolysates produced. Physicochemical characteristics of whey protein hydrolysates could be altered by manipulation of zymogen activation conditions in pancreatic proteinase preparations to be used during subsequent protein hydrolysis.     

Use of near infrared spectroscopy to evaluate the intensity of extrusion-cooking processing of pea flour

Twenty-five different pea extrudates were produced using a Clextral BC45 twinscrew extruder. Near infrared reflectance (NIR) spectra of the extrudates were recorded between 1100 and 2500 nm. the application of principal component analysis (PCA) on these spectral data permitted discrimination between the extrudates produced under moderate, intermediate or severe conditions of extrusion-cooking. the study of protein quality through solubility experiments, polyacrylamide gel electrophoresis, determination of available basic amino acids and brown colour measurement showed that, under moderate conditions of extrusion-cooking, protein was only slightly affected. All protein subunits could be restored after solubilization in phosphate buffer containing a detergent and a reducer of disulphide bonds. However, under severe conditions of extrusion-cooking, the extrudates exhibited a relatively intense brown colour and all protein fractions were implicated in non-disulphide covalent bonds and underwent some macromolecular degradation. Therefore, the spectral discrimination between pea extrudates which was related to the processing parameters, could also be related to the degree of transformation of these extrudates. Thus, the method may be used to classify an extrudate produced under unknown conditions by projecting its spectrum on the similarity maps obtained by PCA on a known collection of extrudates.     

Microcomputer-based expert systems: where we are, where we are headed

Abstract: While the idea of developing 'true' expert systems in the current microcomputer environment continues to be a subject of derision among serious AI researchers, undaunted developers and designers of microcomputer-based systems continue to make progress on the personal computer front. This article presents an overview of the current state of expert systems in a microcomputer environment and then offers some prognostications about the near-term future of expert systems on desktop and personal computers. It is suggested that the history of software developments on the small computers indicates that a pattern of growth exists. If this same pattern is applied to expert systems, the author contends, the near-term future of micro-based knowledge-based systems is at least forecastable if not predictable.     

Analysis of Fracture Probabilities in Nonuniformly Stressed Brittle Materials

The results of theoretical studies on the effect of nonuniform stress fields encountered in prismatic beams under bending on the fracture of brittle materials are described. Derivations were carried out to determine the risk of rupture of bending specimens subjected to a symmetrical four-point load of arbitrary spacing, the symmetric three-point loading and pure bending forming limiting cases of this more general loading. The analysis was based on materials obeying the Weibull distribution function with assumptions for either volumetric or surface flaw dispersion conditions. The predicted strengths of bending and tensile specimens are compared. An analytical method for the determination of the three Weibull parameters from a pure bending test is proposed. This method, based on the best fit of a theoretical curve to the experimental data, was applied successfully to experimental results on Columbia Resin, a brittle amorphous polymer.     

Electrical Conductivity of Iron-Doped NiO Single Crystal at Equilibrium and During Internal Oxidation

The dc electrical conductivity of (Ni_{1- x} Fe _x )O single crystals (0.01 < x < 0.09) has been measured at controlled oxygen partial pressure, at temperatures ranging from 1170 to 1490 K. The behavior of single-phase (Ni,Fe)O is characterized as a function of temperature, oxygen partial pressure, and iron content, and interpreted in terms of diffusive transport of the electronic charge carriers. From in situ electrical conductivity measurements performed during the internal oxidation of (Ni,Fe)O to a two-phase mixture of "NiO"+ NiFe₂O₄, kinetics data for the internal oxidation are inferred.