Abalone (Hariltis discus): Seasonal Variations in Chemical Composition and Textural Properties

Seasonal changes in adenosine 5′-triphosphate, total free amino acids, and total oligopeptides in abalone meat were analyzed. Levels were higher in summer and lower in winter. In both seasons, the most abundant free amino acid was taurine followed by arginine, glycine, glutamine, and glutamic acid. The largest peptide-bond amino acid was glutamic acid + glutamine. The collagen content decreased in summer and increased in winter. The breaking stress values of the meat were low in summer and high in winter, indicating that summer abalone would be more tender. Scanning electron microscopy revealed the collagen network was more compact in winter.     

Reverse-Phase HPLC Analysis of Cheese Samples Aged by a Fast-Ripening Process

Cheese ripening accelerated by adding enzyme extracts derived from lactic bacteria promoted proteolysis and produced an acceptable novel cheese based on sensory tests. However, HPLC profiles for watersoluble compounds were considerably different from those for control Cheddar cheese without the added enzyme extracts, probably indicating a different mechanism of proteolysis. The samples did not follow the usual aging pathway on a similarlity scattergram, when HPLC data were processed by principal component similarity (PCS) analysis. Such analysis was useful for evaluating effects of accelerated cheese ripening.     

Grade Classification of Canned Pink Salmon with Static Headspace Volatile Patterns

Pacific pink salmon (Oncorhynchus gorbuscha) were subjected to refrigerated decomposition prior to canning. Data on 44 volatile compounds obtained by static headspace gas chromatography were analyzed using multivariate statistical methods. Principal component analysis and common factor analysis showed two dimensions were particularly important to delineate variation between quality grades A, B, and reject. Three types of discriminant analysis (DA) were carried out on PCA scores as well as three selected volatiles (ethanol, 3-methyl-1-butanol, and 2-methyl-l-propanal). Although all DA procduced misclassification rates below 7%, the nonparametric Epanechnikov kemal DA was more reliable followed by quadratic and linear DA. Use of 3-methyl-1-butanol and 2-methyl-1-propanal in addition to ethanol improved the detection of initial decomposition stages.     

Extraction of Milk Clotting Enzyme from Sodom Apple (Calotropis procera)

A milk clotting enzyme with low proteolytic activity was extracted with ammonium sulfate, at 0.40-0.65 saturation, from sodom apple leaves. The enzyme with apparently a basic isoelectric point was activated by cysteine and was more active at 65°C than at 35°C. Milk clotting activity increased with pH at 65°C, with the enzyme being almost twice as active at pH 6.4 as at pH 5.4-5.7. Storage at 4°C for 15 days resulted in a 30-50% loss in enzyme activity.     

Immunoglobulin Separation from Egg Yolk: A Serial Filtration System

A serial filtration system was developed for separating immunoglobulin from egg yolk (IgY). Egg yolk was diluted 10 times with water, adjusted to pH 5.0, frozen, then thawed. The diluted yolk was diafiltered through a hard filter paper at 4-6°C to produce a clear water-soluble fraction (WSF). The WSF was then delipidated by filtering through a hydrophobic membrane filter. Ultrafiltration of delipidated WSF at pH 9.0, at 4-6°C, in the presence of 1.5M NaCl resulted in electrophoretically pure (>90%) IgY with a recovery of about 92%. Advantages of this method are the use of only a few mild chemicals and the potential of developing a continuous process.     

Anti-E. coli lmmunoglobulin Y Isolated from Egg Yolk of Immunized Chickens as a Potential Food Ingredient

Active immunoglobulin (IgY) was isolated from egg yolk of chickens immunized with formalin-treated E. coli. The antibody activity was measured by enzyme-linked immunosorbent assay using E. coli lipopolysaccharide as an antigen. The anti-E. coli IgY aggregated the bacterial cells and inhibited their growth in vitro. IgY was relatively heat-stable without loss in antibody activity by pasteurization. IgY was stable at pH above 4, but was more susceptible to pepsin than bovine IgG, while appreciable activity was retained by IgY after trypsin- and chymotrypsin-digestion. It appears possible, therefore, to use IgY for the fortification of food products, especially infant formulae.     

Simultaneous Isolation of Avidin and Lysozyme from Egg Albumen

A single column cation exchange method was developed which allowed simultaneous recovery of lysozyme and avidin from undiluted egg white. A unique application-elution sequence was developed, involving accumulation of avidin on the column through several cycles of egg white application and lysozyme elution. Lysozyme was recovered with higher yields than reported for the isoelectric precipitation methods often used in the industry (86% vs 60–80%). Lysozyme peaks appeared homogeneous on SDS-PAGE. Avidin recovery was also as good or better than that of previously reported ion exchange methods (74%–80%). The purity of the avidin fraction (up to 40.9%) was superior to that of other reported primary avidin fractions.     

Surface-acoustic-wave frequency-to-voltage converter

A frequency-to-voltage conversion technique is described by using a surface-acoustic-wave delay line with three interdigital transducers, one for input and two for output. Two output signals have a phase difference corresponding to different delay lengths, which are detected as a frequency-to-voltage converted signal via a differential amplifier. The operational principle as a discriminator is reported together with successful experimental results. This type of frequency-to-voltage converter is valid in a number of applications where high frequency is an important consideration.     

High-intensity laser-driven particle and electromagnetic wave sources for science, industry, and medicine

We simultaneously observed both the fast proton generation and terahertz (THz) radiation in the laser pulse interaction with a thin-foil target.The maximum proton energy of ～2.3 MeV and an intense THz radiation were observed at the pulse duration of ～30fs.We also measured the proton beam and UV harmonics from a thin-foil target by changing the laser pulse duration.In the case of the ～500 fs, peaks of UV harmonics up to fourth order appeared.This unique combination of the multiple beams will provide useful applications such as pump-probe experiments.     

Immunoglobulins from Egg Yolk: Isolation and Purification

Simple water dilution was employed for the separation of water-soluble plasma proteins from egg yolk granules. An optimum recovery of immunoglobulin Y (IgY, 93–96%) in water-soluble fraction was obtained by sixfold water dilution at pH between 5.0–5.2 with incubation time of 6 hr at 4°C. Among the factors studied, pH was found to be the most important factor affecting IgY recovery. Active IgY of high purity with good recovery was obtained by a combination of several techniques including salt precipitation, alcohol precipitation, ultrafiltration, gel filtration and ion exchange chromatography. Salt precipitation, ultrafiltration, and get filtration is the recommended sequence. Over 100 mg of electrophoretically pure IgY was routinely obtained from one egg.