Gelation Properties of Ovalbumin as Affected by Fatty Acid Salts

The physicochemical properties of heat-induced ovalbumin (OVA) gels containing fatty acid salts (FAS) were investigated. Water-holding ability and transparency markedly increased in the presence of sodium caprate or sodium laurate. At 9% of the protein concentration transparent and hard gels formed; at 7%, transparent and soft gels formed. Scanning electron microscopy showed that the transparent gels had a more homogeneous structure than turbid gels without FAS. Differential scanning calorimetry indicated that denaturation temperature of OVA was decreased and the peaks became broader after addition of FAS.     

A new theory of evidence for non-exclusive elementary propositions

Though probability theory has been used widely, it cannot treat quantities of ignorance well. To solve the problem, the Dempster-Shafer theory has been developed as a reasonable tool to represent situations in which various kinds of ignorance exist in our knowledge or information. However, the Dempster-Shafer theory assumes that elementary propositions are mutually exclusive. Therefore, we cannot treat non-exclusive elementary propositions in the Dempster-Shafer theory directly. In the paper a new theory is proposed to deal with non-exclusive elementary propositions, and is illustrated by a simple example.     

Stable identification scheme for linear discrete-time systems

This paper is concerned with the problem of identifying parameters in stochastic systems described by single-input single-output linear discrete-time equations. A stable estimation error system is developed by using the extended Kalman filter technique and the concept of strictly positive real transfer function. The identifier corresponding to the estimation error system is constructed, and the convergence of parameter estimates to the exact values is proved under some bounded conditions. It is shown that the recursive maximum likelihood identifier and the recursive extended least squares identifier are obtained by neglecting the correction terms in the proposed identifier. Numerical examples for a fourth-order system are presented to illustrate the effectiveness of the proposed method.     

THE COMPOSITION AND VITAMIN A VALUE OF THE CAROTENOIDS OF PUMPKINS OF DIFFERENT COLORS

The carotenoid pigments of the yellow and orange flesh varieties of the pumpkins Cucurbita moschata and C.maxima were identified and quantified, α-Carotene, β-carotene, ζ-carotene, β-carotene 5,6-epoxide, β-cryptoxanthin, lutein, taraxanthin, zeaxanthin, luteoxanthin and auroxanthin were detected in the pumpkins. The difference was that the yellow variety of C. moschata had no zeaxanthin. The quantitative patterns of the two varieties were similar. Although some quantitative variation was observed, lutein, β-carotene and luteoxanthin predominated. The difference in the color between the two varieties resulted from these quantitative differences in carotenoid composition. The vitamin A activity of the C. moschata variety with yellow flesh was higher than that of the C. maxima, which had many oxygenated carotenoids.     

A method of predicting failure or life for stochastic systems by using autoregressive models

This paper discusses on-line detection and prediction problems of the failure or life of stochastic systems by using autoregression (AR) models. We regard the change of the equipment from an ordinary state to failure as a variation of the characteristics of a time aeries signal. An AR model is fitted to the time aeries signal and the change is detected by variations of the model. Using four types of performance index of the variations, we detect the failure of a cutting tool of a lathe and predict the width of flank wear.     

The optimal smoothing estimators based on the Wiener-Hopf theory

It is well known that the Wiener-Hopf theory plays a fundamental role in estimation problems. In this paper, we derive the basic equations for the optimal smoothing estimators by using the Wiener-Hopf theory. The interrelation between the Wiener-Hopf theory and the innovation theory is also considered. Finally based on the basic equations three kinds of the smoothing estimators, that is, the fixed-point, fixed-interval, and fixed-lag smoothing estimators are derived.     

On the stability of control systems with randomly time-varying characteristics†

The purpose of this paper is to study the stability conditions of randomly time-varying control systems.

First we define the stability, in the stoehastic sense, of the control system with randomly time-varying characteristics and secondly we obtain the conditions for global stability in the mean for a control system which is governed in each time interval by two different differential equations with probability p and 1-q respectively.

Finally we examine the stability condition for the concrete control systems by experiments of the Monte Carlo method.     

Sodium Caseinate and Skim Milk Gels Formed by Incubation with Microbial Transglutaminase

Several suspensions and emulsions containing commercial sodium caseinate or skim milk were gelatinized by Ca²⁺-independent microbial transglutaminase treatment. The characteristics of the gels were largely affected by the enzyme concentrations employed. For caseinate gels generally the higher enzyme concentration gave steep decreases in breaking strength, strain and cohesiveness of the gels. The creep tests on emulsified gels prepared to two different enzyme concentrations showed that the gel made with a higher enzyme concentration was the more viscoelastic. For skim milk gels, the enzyme treatment in higher concentration caused substantial increase of the breaking and hardness while the strain and cohesiveness had little or no changes.     

Production of Restructured Meat using Microbial Transglutaminase without Salt or Cooking

To produce restructured meat, microbial transglutaminase (MTGase) was evaluated for its ability to introduce covalent crosslinks between protein molecules. Pork muscle cubes were mixed with MTGase and held at 5°C for 2 hr for the enzyme reaction. Restructured products were analyzed for binding strength without cooking. MTGase treatment resulted in effective binding of meat pieces provided there was addition of salt (NaCl). To ensure proper binding without NaCl, some food proteins with MTGase were also investigated. Meat cubes in combination with MTGase and sodium caseinate showed acceptable bind, and sodium caseinate appeared to be a superior substrate for the crosslinking to meat proteins than soy protein, whey protein, or gelatin. These results suggest a useful method for producing restructured meat which can be distributed in the raw, chilled state.