KINETICS AND HYDROLYSIS PARAMETERS OF TOTAL FRUCTOOLIGOSACCHARIDES OF ONION BULBS: EFFECTS OF TEMPERATURE REGIMES AND CULTIVARS

This work studied the percentage of hydrolysis, observed hydrolysis rate constant (k_obs), half‐life time (t_1/2) and kinetics of degradation of the total fructooligosaccharides (FOS) of three different onion bulb cultivars (Yellow Spanish, Red Amposta and Tenshin) kept during 6 months under three temperature regimes, 10, 15 and 20C. The percentage of hydrolysis of FOS was higher at 20C than at 10C and ranged from 47 to 58% at 10C, from 63 to 68% at 15C and from 74 to 83% at 20C. The k_obs ranged from 27 × 10^?3 to 36 × 10^?3/week at 10C and from 41 × 10^?3/week to 47 × 10^?3/week at 15C, while at 20C, it was high and was about k_obs 56 × 10^?3/week.. The t_1/2 decreased when temperature increased, and varied from 19.5 to 26.0 weeks at 10C, from 14.6 to 16.8 weeks at 15C and from 9.4 to 12.3 weeks at 20C, indicating that high degree of polymerization (DP) FOS have shorter lives than low DP FOS. Linear regression and kinetics of hydrolysis have shown that FOS hydrolysis is higher at 20C, with a coefficient of regression ranging between 0.87 and 0.99. Apparently, FOS hydrolysis is temperature independent, and storage time had more effect on the higher DP FOS than on the lower DP FOS.     

Carboxymethyl Kefiran: Preparation and Viscometric Properties

Carboxymethyl (CM-) kefiran was prepared with monochloroacetic acid in isopropyl alcohol at 30, 40 and 50°C for 4 and 24 hr. Resulting CM-kefiran varied in degree of substitution (0.73-0.89), molecular weight (5.0-7.0 × 10⁵) and viscosity (4.5-14.5 cP in 0.5% aqueous solution) depending on the conditions. Carboxymethylation resulted in a maximum fourteenfold increase in viscosity. ¹³C-NMR spectra of CM-kefiran indicated C-6 of native kefiran was preferentially substituted with CM-groups.     

Isolation and Characterization of Major Apoproteins from Hen's Egg Yolk Granule

Different patterns were obtained from granular and plasma fractions of egg yolk by SDS-polyacrylamide gel electrophoresis. Three major components of granular apoprotein which constitute 19.4, 14.5, and 43.4% of the protein moiety with estimated molecular weights of 28,000, 74,000, and 109,000 daltons, respectively, were isolated by preparative SDS-gel electrophoresis. They were found to be glycoproteins containing mannose, galactose, and hexosamine. Sialic acid was found only in the 74,000 and 109,000 dalton components. Phosphorus content of the 28,000, 74,000, and 109,000 dalton components were 2.0, 1.2, and 0.4%, respectively.     

Effects of pH and ATP Concentrations on the Heat Contracture of Glycerinated Single Fibers of Rabbit Psoas Muscle

The occurrence of heat contracture of glycerinated single fiber of rabbit psoas muscle was investigated in relaxing solutions with varying pH values and ATP concentrations. The threshold temperature for inducing heat contracture of single muscle fibers in relaxing solutions decreases with increasing pH values and decreasing ATP concentrations. There seems to be a relationship between heat contracture of muscle fibers and the tremor of skeletal muscle of porcine stress syndrome. Also, there seems to be a relationship between the heat contracture and alkaline rigor development.     

HPLC Analyses of Amino Acids in Plant Materials as DNP-Derivatives by Use of Methyl Benzoate as the Internal Standard

A liquid chromatographic procedure has been developed for the separation and quantification of amino acids in some vegetables by using methyl benzoate as the internal standard. The DNP-amino acid derivatives are separated on a reverse phase column (LiChrosorb RP-18, 5 μm), eluted with a linear gradient of 20–75% v/v acetonitrile in 1% v/v glacial acetic acid in water. The column effluent is monitored at 254 run. A total analysis of DNP-amino acids was completed in less than 55 min. For 14 amino acids and asparagine plus glutamine, separation and quantification were satisfactory. This technique has been used effectively to analyze amino acids in biological samples by the internal standard method.     

The analysis of change in occupational qualities by ageing

The ageing process was studied by means of the changes in the aptitude measured by the general vocational aptitude test constructed by the Japan Labour Ministry. The aptitudes were classified in terms of three activities, viz. analytical, synthetic and motion. Four groups of subjects participated in the study: 271 male manual workers aged 20-59; 111 male non-manual workers aged 20-59; 196 male and female university students aged 18-19; and 123 male and female junior high school students aged 13-15. Changes with age were observed in the scores, in the activity balance diagram and in the time required for the basic motion (therblig).     

A method for estimating spatial resolution of real image in the Fourier domain

Spatial resolution is a fundamental parameter in structural sciences. In crystallography, the resolution is determined from the detection limit of high‐angle diffraction in reciprocal space. In electron microscopy, correlation in the Fourier domain is used for estimating the resolution. In this paper, we report a method for estimating the spatial resolution of real images from a logarithmic intensity plot in the Fourier domain. The logarithmic intensity plots of test images indicated that the full width at half maximum of a Gaussian point spread function can be estimated from the images. The spatial resolution of imaging X‐ray microtomography using Fresnel zone‐plate optics was also estimated with this method. A cross section of a test object visualized with the imaging microtomography indicated that square‐wave patterns up to 120‐nm pitch were resolved. The logarithmic intensity plot was calculated from a tomographic cross section of brain tissue. The full width at half maximum of the point spread function estimated from the plot coincided with the resolution determined from the test object. These results indicated that the logarithmic intensity plot in the Fourier domain provides an alternative measure of the spatial resolution without explicitly defining a noise criterion.     

Performance evaluation of marked graphs by linear programming

Performance evaluation is an important issue for discrete event dynamic systems, which in many cases can be described in terms of the language of Petri nets. In particular, for marked graphs, a subclass of Petri nets, a formula for performance evaluation is widely known. That is, the ratio of the total execution time to the number of tokens in a cycle gives a lower bound for the cycle time of the system, and the maximum of these ratios over all cycles determines the overall system performance. However, we need to enumerate all directed cycles in a graph to apply this formula of performance evaluation. Carrying out this enumeration for an actual system is often impractical, since the number of cycles in a graph usually grows exponentially with the size of a system. We give a linear algebraic characterization for directed cycles, and based on this result, transform the problem of performance evaluation into a simple linear programming problem. A few explanatory examples are also given.     

Agmatine as a Potential Index for Freshness of Common Squid (Todarodes pacificus)

Changes in amines (tyramine, putrescine, cadaverine, agmatine, and tryptamine) were examined in the muscle of common squid during storage at 0°C, 3.5°C, and 15°C. Agmatine appeared to be most useful as a potential index for freshness of common squid. Agmatine was detected in small amounts even in the fresh muscle and the concentration increased with storage time, exceeding 30 mg/100g at the stage of initial decomposition and reached the level of 40 mg/100g at the stage of advanced decomposition. Putrescine was detected in small amounts (less than 1 mg/100g) at the stage of initial decomposition and increased rapidly at the stage of advanced decomposition. This amine might be involved in the putrid smell. The pH values became higher at the stage of initial decomposition.