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Near-infrared spectroscopy (NIR) scanning from 1100 to 2500 nm was applied to measure the unfreezable water bound to egg white lysozyme and soluble starch. Two characteristic absorption bands corresponding to water molecules were changed into the second derivative difference spectra. In the changed spectra, the peaks at each lower and higher wavelength might be attributed to the freezable and unfreezable water, respectively. When the correlation coefficients between absorbances at wavelengths with maxima in the peaks attributable to the unfreezable water and the results of differential scanning calorimetry used as a reference analysis method of unfreezable water were calculated, the correlation coefficients at 1908, 1952 and 1992 nm assigned to the combination of the stretching and bending vibrations of OH were above 0.91 in both lysozyme and starch. Therefore, it can be concluded that the NIR second derivative difference spectra, in the region assigned to the combination of the stretching and bending vibrations of OH in water molecules, have potential for the measurements of the unfreezable water bound to egg white lysozyme and soluble starch used as model samples of food materials.

Near-infrared (NIR) spectroscopy scanning from 1100 to 2500 nm was applied for the determinations of heme and nonheme iron in raw muscle meats. Ground meat samples were divided into two sets of 30 and 15 samples as a calibration and a prediction set, respectively. The multiple regression equations (MREs) established for the calibration set between the chemical analysis reference data and the second derivative data of the NIR spectra gave the multiple correlation coefficients of 0.966 and 0.923 for heme and nonheme iron contents, respectively. The best MREs were obtained with the NIR data recorded at wavelengths where NH groups in protein molecules and C–C and CH in the porphyrin ring of heme give absorption. The correlation coefficients between the data calculated from these MREs and the reference data for the prediction set were 0.991 and 0.906 for heme and nonheme iron contents, respectively. The results indicate that the NIR diffuse reflectance procedure is a technique which serves the need for rapid and simple heme and nonheme iron determinations, thereby allowing an in vitro estimation of bioavailability of iron in muscle meats.

Activation by different anions of γ-glutamyltransferase obtained in a. particulate form from fruiting bodies of Lentinus edodes has been studied using either L -γ-glutamyl- p -nitroanlide or lentinic acid as substrate. The mushroom transferase was activated by SCN − , NO 3 − , Cl − , Br − , ClO 3 − , Bro 3 − , N 3 − , I − and F − , but not those alkali and earth cations previously believed to activate the animal transferase, nor by citrate, claimed to be effective for the kidney bean transferase. Among anions proved hardly to activate the transferase were ClO 4 − , NO 2 −, HCO 3 − , H 2 PO 4 − , SO 3 2− and SO 4 2− . A high concentration of these anions more or less impeded the halide activation. Kinetic studies revealed that halides function as activators of increasing V max while keeping K m constant. These observations appeared least compatible with the possibility that the anion activation might involve a non-specific effect of high solute concentration, viz . dissociation of the enzyme from the supporting structure in the particulates. The activating effect of halides described here probably extends also to the animal enzymes.

Sixty-nine brown rice ( Oryza sativa L. japonica ) samples, composed of 18 different cultivars, were collected from 37 sites in Japan, and their selenium contents were determined by a fluorometric method. The total mean ± standard deviation value for the 69 samples was 43 ± 27 ng Se/g. The selenium levels were found to vary by the site at which the rice was grown but not by cultivar. The average selenium intake by Japanese was calculated as 127,ug/day/capita based on the data obtained in this study and the food consumption pattern revealed in the annual nutrition survey conducted by the Ministry of Health and Welfare, Japan. Selenium intake from rice was estimated to account for only 5–10 μg/day/capita; rice is not a significant selenium source in the Japanese diet.

A major component of β-glucosidase multi-enzymes was highly purified from rice bran, and by its use, PIN-β-G was synthesized from p-nitrophenyl-β-glucoside and pyridoxine. The synthetic product contained both 4′- and 5′-isomers, which were successfully separated by high-voltage paper electrophoresis. The 4′-isomer was used as a convenient subsrate for intestinal absorption of PIN-β-G, because it gave a positive reaction with 2,6-dibromoquinone chlorimide irrespective of the presence or absence of borate. The absorption experiments with in situ isolated rat jejunal loops revealed that the PIN-β-G level remaining in the loop did not significantly change within an hour and that δ-gluconolactone, a potent inhibitor of β-glucosidase, did neither affect the luminal disappearance of PIN-β-G. It thus can be assumed that PIN-β-G is absorbed across the intestinal wall by a mechanism of simple diffusion, but not of “hydrolase-mediated transport”.