Model System Studies on N-Nitrosamine Formation in Cured Meats: The Effect of Curing Solution Ingredients

Solutes commonly employed in curing solutions were evaluated for their effect on nitrosamine formation utilizing a ground pork model system. Sodium erythorbate and sodium ascorbate were found to be equally effective in reducing nitrosopyrrolidine levels. The incorporation of sodium tripolyphosphate or sucrose had no detectable effect on nitrosamine formation. However, sodium chloride, the solute present at the highest concentration in bacon curing solutions, exhibited a concentration dependent inhibition of nitrosopyrrolidine formation. Nitrosopyrrolidine levels in samples containing no added sodium chloride were found to be 50% higher than samples processed with 1.5% added salt.     

ISOLATION OF INTACT TYPE V COLLAGEN FROM FISH INTRAMUSCULAR CONNECTIVE TISSUE

A purification method for intact type V collagen from fish intramuscular connective tissue was developed. Collagens were extracted with 0.5 M acetic acid from fish intramuscular connective tissue. Intact type V collagen could not be isolated by conventional salt fractionation which has been used for isolation of pepsinized collagens. Isolation was achieved by ion-exchange chromatography in the presence of 5 M urea. This is the first report on isolation of intact type V collagen from muscle tissue.     

SOLVENT EXTRACTION OF SOME TERVALENT LANTHANOIDS WITH 4-ACYL-3-PHENYL-5-ISOXAZOLONES

ABSTRACT

The solvent extraction of some tervalent lanthanoid ions (Ln³⁺) with five 4-acyl-3-phenyl-5-isoxazolones (AcyPI or HL),i.e. 4-acetyl-, 4-benzoyl-, 4- (4-toluoyl)-, 4- (4-fluorobenzoyl) - and 4-(4-nitrobenzoyl)-3-phenyl-5-isoxazolones (API,BPI, TPI, FBPI and NBPI respectively) into benzene was studied in the presence of tri-n-butylphosphate (TBP). The extracted species were (Ln³⁺) (L^-)₃ (TBP)₂ for AcyPI.     

Single crystals of RAlO3 (R: Dy, Ho and Er) for use in magnetic refrigeration between 4.2 and 20 K

Single crystals of RAlO3 (R: Dy, Ho and Er) were grown using the Czochralski technique. The magnetization of the single crystals along the a-, b- and c-axes was measured in the paramagnetic region using a superconducting quantum interference device (SQUID) magnetometer. Using these values of the magnetization, the magnetic entropy change, which depends on the crystal axis direction, was calculated. Single crystals of DyAlO3 oriented along the b-axis and c-axis oriented ErAlO3 single crystals are promising materials for use in magnetic refrigeration systems using the Carnot cycle in the temperature range between 4.2 and 20 K. This revised version was published online in November 2006 with corrections to the Cover Date.     

Biochemical Characterization of Collagen in Myocommata and Endomysium Fractions of Carp and Spotted Mackerel Muscle

Myocommata and endomysium fractions were prepared from the different parts of body muscle of carp and spotted mackerel. Both type I and V collagens were detected in the myocommata and endomysium fractions of both fish. The relative concentration of type V collagen to type I collagen was higher in the endomysium fraction than in the myocommata fraction. Both type I and V collagens were less soluble in the endomysium fraction than in the myocommata fraction. These results indicated that the biochemical property of the collagen in the pericellular connective tissue was different from that of the collagen in the interstitial connective tissue of fish.     

Fundamental Aspects of Viscosity Monitoring by the Hot Wire Technique

Fundamental aspects of the monitoring of viscosity by the hot wire technique in stagnant test fluid was investigated. The behavior of the hot wire viscosity sensor was well described, theoretically, by the stagnant layer analysis combined with the Ostrach solution for natural convection heat-transfer from a vertical plate. To improve the sensitivity of the sensor to the change in viscosity of a test fluid, lower curvature for the sensor structure and higher heat flux for the operating condition were recommended theoretically and proved experimentally. As a practical example, the change in apparent viscosity during the coagulation of soy protein was monitored using the hot wire sensor.     

EFFECT OF SLAUGHTER METHOD ON DEGRADATION OF INTRAMUSCULAR TYPE V COLLAGEN DURING SHORT-TERM CHILLED STORAGE OF CHUB MACKEREL SCOMBER JAPONICUS

The present paper demonstrates that a nonstntggling slaughter method can delay degradation of type V collagen in meat of chub mackerel Scomber japonicus and softening of the meat during postharvest chilled storage. The fish were slaughtered by piercing a knife into nape (nonstruggling method) or by leaving on ground (struggling method) and then stored in an ice box. Sensory study revealed that the postharvest softening of the meat was moderated at 4 and 8 h by the non‐struggling slaughter method in comparison with the struggling method. On the basis of the specific solubilization of type V collagen and reduced tyrosine content in it, a cleavage of the nonhelical regions (telopeptides) of the type V collagen occurred during the chilled storage in the fish slaughtered by the struggling method. The degradation of type V collagen was also slower in the meat of the fish slaughtered by the nonstruggling method, which can be directly linked to the moderation of the postharvest softening.     

Hexagonal β-SiC Particles

Among small β-SiC particles (0.2 ∼ 0.4 μm in size) produced by chemical vapor reaction, hexagonal particles having diameters around 0.2 μm are sometimes found. When observed by TEM, they have image contrasts reminiscent of "multiply twinned particles". Analysis of diffraction patterns and image contrasts observed indicates that these particles consist of multiple twins with twin planes parallel to the basal plane. The characteristics of growth processes of such particles are discussed.