Evaluation of changes in the taste of cooked meat products during curing using an artificial taste sensor

The purpose of this study was to assess an evaluation method using an artificial taste sensor, in comparison with chemical analysis and sensory evaluation of the taste of meat during curing. Samples of Canadian pork were treated with salt, nitrite and phosphate. Curing time ranged from 0 to 168 h. In the sensory evaluation, there were no significant differences in the all characteristic items at 72‐h cured sample compared to the 0‐h sample. Some of the characteristic items for the 168‐h sample (umami, overall taste, richness and overall palatability) showed significant difference (P < 0.05) compared to the 0‐h sample. Taste sensor analysis indicated that the sensor outputs of bitterness and saltiness were significantly correlated with curing time (R = 0.98 and 0.97, respectively), and total free amino acids (R = 0.91 and 0.96, respectively). The sensor output of bitterness was significantly correlated (R = 0.96) with the sum of amino acids corresponding to bitter taste. The increase in the chemical components contributing to bitterness and/or saltiness was indicated as the cause of the characteristic taste. Taste sensor analysis may be applicable as a qualitative method for evaluating taste characteristics generated during the curing of manufactured cooked meat products.     

Collection of expressed genes from the transition zone of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> in the dormant season

Heartwood affects the utility of wood because it differs in some properties compared to sapwood. To regulate heartwood formation, its mechanism must be elucidated. However, the molecular basis underlying heartwood formation remains largely unknown. To obtain clues to understand the mechanism at a molecular level, we collected expressed sequence tags (ESTs) from the transition zone (TZ) of Cryptomeria japonica D. Don in November, in which heartwood formation is considered to proceed. A total of 1029 ESTs were assembled into 744 unique sequences (103 clusters and 641 singletons). Putative functions were assigned to 291 nuclear-encoded sequences, and they were grouped into 21 categories according to the eukaryotic orthologous groups functional classification. We selected 20 genes for enzymes or proteins, then examined their expression patterns among different organs. The expression levels of nine genes were higher in November than in June in the TZ. The genes encode two enzymes in glycolysis, invertase, methionine adenosyltransferase, glutathione transferase, the lipid transfer protein, Bet v 1 allergen, the dehydrin and the function-unknown protein. This study has provided the first large-scale EST information from the TZ of conifers, which will be useful for understanding the physiological processes in the TZ at a molecular level.     

Suppression of conidial germination and appressorial formation by silicate treatment in powdery mildew of strawberry

The mode of action of soluble silicon against strawberry powdery mildew (Sphaerotheca aphanis var. aphanis) was investigated in four experiments. First, silicon-treated leaves from plants grown with silicate (Si+) and control leaves were excised, inoculated with conidia, and subsequent germination and formation of appressoria in a petri dish was assessed after 24 h. The germination rate was 49.7% on Si+ leaves, and was 67.2% on control leaves (t-test, P < 0.01). Second, we soaked cellulose membranes in various solvents and then placed the membranes on 4% water agar, dusted the membranes with conidia, and examined after 12 h. No difference was apparent between any treatment and the control (distilled water). Third, strawberries growing hydroponically with additional silicon in the medium were inoculated with conidia, and leaves were observed with a scanning electron microscope 1–2 days after inoculation. Germ tubes and secondary hyphae were shorter and had fewer branches on Si+ leaves than on the control. Moreover, penetration appeared to be inhibited. Fourth, the cuticle was separated from leaves from plants grown as in the third experiment, placed on water agar, and dusted with conidia. Germination of conidia, observed with a light microscope, on Si+ leaves was suppressed markedly to 40%–60% of that of the control. These results suggested that soluble silicon induced physiological changes in the cuticle layer after absorption by the plant. In addition, soluble silicate reduced germination of conidia, formation of appressoria, and possibly the penetration of powdery mildew.     

Food habits of introduced brown trout and native masu salmon are influenced by seasonal and locational prey availability

A knowledge of food habits is important for evaluating interspecific competition and predation between sympatric species. Data on food availability should be combined with data on food habits in this type of survey. Although food availability differs between habitats or seasons, these differences had never been considered in previous studies. We conducted year-round field surveys throughout a stream to compare the food habits of an introduced salmonid, brown trout Salmo trutta, and a native salmonid, masu salmon Oncorhynchus masou. Masu salmon did not constitute a large proportion of the diet of brown trout and vice versa. Thus, predation will likely not affect the population level of either species. The dietary overlap between brown trout and masu salmon varied depending on the presence of Gammaridae and terrestrial invertebrates; i.e., the intensity of interspecific competition for food resources may differ according to food conditions.     

Extensive Screening for Plant Foodstuffs in Okinawa,Japan with Anti-Obese Activity on Adipocytes <Emphasis Type="Italic">In Vitro</Emphasis>

To search for plant foodstuffs with potent anti-obese activity, we conducted a large scale screening based on the inhibitory activity on adipogenesis and the facilitating activity on adipolysis in vitro. That is, inhibition of intracellular lipid accumulation and facilitation of lipid degradation in 3T3-L1 adipocytes were extensively screened from ethanol and hexane extracts of approximately 100 kinds of plant foodstuffs marketed in Okinawa prefecture, which has been famous for the highest prevalence of exceptionally long-lived individuals in the world. Among them thirty one foodstuffs showed potent inhibitory activity on intracellular lipid accumulation in 3T3-L1 adipocytes, whereas only four foodstuffs showed clear facilitating effect on lipid degradation in 3T3-L1 adipocytes. Although further study to examine the in vivo effects on adipogenesis and adipolysis is required, this is the first study to investigate anti-obese characteristics of wide range of traditional Okinawa foodstuffs so that the results give useful information to take another look at Okinawa food culture.     

Development of acid soil conditioning agent from lignin by ozone treatment I

A purified softwood kraft lignin was modified by ozone treatment and its activity as an acid soil conditioning agent, mainly focusing on elimination of aluminum toxicity, was assayed by planting experiments. The growth of radish root was examined in nutrient solution containing CaCl₂ and AlCl₃ at pH 4.8 with and without modified kraft lignins. The modified kraft lignins that absorbed 1.8 and 3.9 moles of ozone per C6-C3 unit (M _w 180) showed two effects: the elimination of aluminum toxicity and the acceleration of root growth. The effect on the elimination of aluminum toxicity was observed even with modified kraft lignin that absorbed 1.0 mole of ozone per C6-C3 unit. The high molecular weight part of the modified kraft lignin that absorbed 3.9 moles of ozone per C6-C3 unit also proved to be effective not only in elimination of aluminum toxicity but also in acceleration of root growth. The acceleration effect of ozone-treated lignins on root growth was also observed under the absence of aluminum in planting experiments. This report was presented in part at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006     

Identification of a novel gene (Apq1) from the indica rice cultivar ‘Habataki’ that improves the quality of grains produced under high temperature stress

The appearance of brown rice grown under high temperature conditions is an important characteristic for improvement in Japanese rice breeding programs. We performed a QTL analysis of the appearance quality of brown rice using chromosome segment substitution lines of the indica cultivar ‘Habataki’ in the ‘Koshihikari’ genetic background. A line carrying a ‘Habataki’ segment on chromosome 7 showed a high percentage of perfect grains produced under high temperature conditions during the ripening period. To verify the role of this segment, and to narrow down the region containing the useful allele, substitution mapping was performed using multiple paired lines. As a result, the chromosomal location of a gene that we named Appearance quality of brown rice 1 (Apq1) was delimited to a 48-kb region. In addition, we developed an Apq1-near isogenic line (NIL) to evaluate the effect of Apq1 on various agronomic traits. Under high temperature conditions during the ripening period, the Apq1-NIL produced significantly higher percentages of perfect grains than ‘Koshihikari’. Other agronomic traits, including yield and palatability, were similar between the Apq1-NIL and ‘Koshihikari’. Therefore, the ‘Habataki’ allele of Apq1 will be useful in breeding programs aimed at improving the quality of grains ripened under high temperature conditions.     

Mineralogy and petrology of comet 81P/Wild 2 nucleus samples

The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk.