No abstract

The qualities of beef cuts were compared with near-infrared (NIR) spectroscopy readings using reflectance, transmittance and a fiber optic probe. Multiple linear regression analyses were used to select the optimum wavelengths for estimating beef properties. High multiple correlation coefficients (R) were obtained for Warner-Bratzler shear value (R=0.798-0.826), protein (R=0.822-0.904), moisture (R = 0.895-0.941), fat (R = 0.890-0.965) and energy content (R=0.899-0.961) with each reflectance, transmittance and using the fiber optic probe. Total pigment content also highly correlated with optical densities using transmittance (R=0.946) and the fiber optic probe (R=0.893). NIR with a fiber optic probe is a useful tool for determining physical and chemical characteristics of beef.The objective of our work was to evaluate NIR spectroscopy using reflectance, transmittance and fiber optic modes as a means of determining physical and chemical characteristics of beef important to consumers. MATERIALS & METHODS MaterialsMuscles from eleven Japanese black steers were used in this study. The range of age at slaughter was 22.5-32.4 mo and the range of body weights was 505-681 kg. The following 6 muscles were dissected from the left side of carcasses 48 hr postmortem: semitendinosus, semimembranosus, psoas major, latissimus dorsi, the anterior portion of the longissimus dorsi, supraspinatus. The sample was cut from the center or thickest portion of each muscle and stored for 24 hr at 1°C for subsequent analyses.

No abstract

Transparent TiO/PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO nanoparticles in the bulk hybrids was investigated. The surfaces of TiO nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO content and could be increased up to 1.566 for 6.3 vol % TiO content (1.492 for pristine PMMA).

No abstract