Watercored (WC) apples, characterized by flesh that has a translucent, water-soaked appearance, have gained wide popularity with Japanese consumers. To understand this preference for WC apples, we performed a combination of sensory analysis and metabolic profiling on apple flavors using ‘Fuji’ and ‘Kotoku’, cultivars susceptible to watercore. The sensory characteristics of WC ‘Fuji’ were enhanced in aroma intensity, floral, sweet and fruity attributes compared to non-WC apples. Rating of preference was also high in WC apples. In regards to the flavor components of ‘Fuji’ and ‘Kotoku’, solubles of sorbitol, sucrose, L-alanine, pyro-glutamate and putrescine, volatiles of methyl and ethyl esters, such as methyl 2-methylbutanoate, ethyl 2-methylbutanoate and ethyl hexanoate, were significantly greater in WC apples. While the degree of sweetness with sugar composition slightly increased in a trial calculation, sweet and floral aroma presenting volatiles were remarkably elevated in the WC apples. Thus, we propose that ethyl and methyl esters, which are anaerobically-biosynthesized in the watercored area, contributed to the high preference for WC apples among Japanese consumers.

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Taste-active components in dried horse mackerel prepared by cold air drying at 20°C(CAD) were compared to those by hot air drying at 50°C(HAD). The content of inosine monophosphate in dried horse mackerel by HAD was significantly smaller than that by CAD. On the other hand, the contents of bitter-taste components including hypoxanthine, valine, and leucine in dried horse mackerel by HAD were greater than those by CAD. Next, the two kinds of dried horse mackerel prepared by CAD or HAD for 2 hours were grilled and the changes in taste-active components were investigated. As a result, free amino acids, lysine, and histidine in dried horse mackerel by HAD were decreased to a greater extent by grilling than those by CAD. Conversely, the content of hypoxanthine in grilled-dried horse mackerel by HAD was greater than that by CAD. Sensory evaluation rated grilled-dried horse mackerel by CAD as sweeter and more acceptable than that by HAD. These results indicated that the differences in taste-active components of dried horse mackerel prepared by CAD and HAD were closely related to the sensory evaluation results and that the dried product by CAD was preferred to that by HAD.

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In this study, we investigated the potential utility of electron spin resonance (ESR) spectroscopy combined with multivariate analysis for the easy and rapid estimation of ash content in wheat flour. Japanese “Kitahonami” wheat was assessed using this method. Partial least squares (PLS) regression analysis was performed using the ESR spectra and wheat quality parameters (protein content, volume weight, falling number and moisture content) as independent variables, and ash content values obtained by combustion as dependent variables. The correlation coefficient between measured and predicted ash content from the PLS regression analysis was 0.683.

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Effect of inhomogeneous distribution of radioactivity within a food sample on the measurement of total cesium with a germanium semiconductor detector was investigated. Each of the brown rice, buckwheat seed, and soybean sample polluted with radioactive cesium was packed in a 2 L Marinelli container with unpolluted foamed polystyrene beads. When all of the beads were at the bottom region of the container, the measured value tended to be lower than that of the sample without beads, even after density correction. On the other hand, the measured radioactivity of the sample with beads at the top region tended to be higher. This trend was the same for brown rice, buckwheat seed, and soybean samples regardless of the level of radioactivity.

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