The quality of Shiikuwasha (Citrus depressa Hayata) juice was improved by combining base anion exchange resin treatment and insoluble pulp addition in order to maintain the levels of polymethoxylated flavones (PMF) such as nobiletin, tangeretin, sinensetin and synephrine. Among 16 resins tested, the base anion exchange resin WA30 was selected as the best resin to decrease acidity in the juice. A treatment of 3% WA30 resin (v/v) for 30min showed a 46% decrease in acidity of the juice, thus improving sourness for sensory evaluation of healthy beverages. °Brix/acid ratio of the juice was within the range of 6.0-10.0 used for healthy beverages in the sensory evaluation. To maintain the level of PMF, 1g of insoluble pulp prepared using a centrifugal juice extractor during processing was added to 100ml WA30 resin-treated juice with decreased acidity and the mixture was homogenized. The resulting juice was fortified with 8.5% nobiletin, 16.6% tangeretin, and 15.3% sinensetin, demonstrating that the combined method of decreasing the acidity by resin treatment and adding insoluble pulp can improve sourness and maintain PMF levels.

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Inhibitors of Salmonella Enteritidis adhesion to microplates were screened among 39 additives including natural and food additives known to be highly safe. S. Enteritidis adhered strongly to microplates after incubation in 0.1% Bacto-soytone for 24h. Adhesion was inhibited in the presence of pigments (Annatto pigment, Gardenia yellow, and Monascus pigment), food coloring products (Annatto AN, San-brown AC, San-yellow No. 2AU, San-red YM, San-red RCFU, and San-beet L), food additives (protamine, Chili extract, sucrose fatty acid esters, and monoglycerine fatty acid esters), and a flavonoid (Kaempferol). Among them, Annatto AN, Gardenia yellow, Monascus pigment, and sugar fatty acid esters inhibited adhesion at concentrations below antibacterial activity. In the case of sugar fatty acid esters of C8 to C18, the longer the fatty acid chain the stronger the inhibitory effects. Monascus pigment and sucrose monostearate were the strongest inhibitors of S. Enteritidis adhesion, even at 0.01% without antibacterial activity.

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We investigated the effect of the Japanese quail trypsin inhibitor ovomucoid (OM) on lipid metabolism. Wistar male rats were divided into 4 groups and each group was given one of the following diets for 4 weeks : OM-free control diet, and OM diets containing 0.2%, 0.4% and 0.8% OM. After the feeding trial, body fat protein content of each rat was determined by X-ray computed tomography (CT). The rats were then dissected for measurement of their liver and plasma lipids and enzyme activities in liver and pancreas. No significant differences were seen in liver fats, while plasma triglyceride levels showed an OM-dose-dependent decrease. Pancreas weights, and protein and enzyme activities were increased in the OM-diet groups, especially in the 0.8% OM-diet group, which showed a significant difference compared with the control group. In the OM-diet groups, a dose-dependent decrease was present in liver glucose-6-phosphate dehydrogenase, malic enzyme and fatty acid synthesis activities. Moreover, X-ray CT analysis showed decreased percentages of rat body fat in the OM-diet groups. These results suggest that OM feeding induced a trophic effect on the pancreas, most likely leading to an increase in energy expenditure followed by a decrease in adiposity.

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We investigated the effects of apple varieties and their fruit components on mycotoxin production by Penicillium expansum inoculation. Among five major apple varieties in Japan, Jonagold showed substantially higher patulin production by P. expansum (ATCC 36200) than Fuji 12 and 16 days after inoculation. Although patulin production in Tsugaru, Sansa, and Orin varieties tended to be lower than that in Jonagold and higher than that in Fuji, no significant difference in production was detected among these apple varieties. Moreover, inoculation of Jonagold, Orin, and Fuji with three strains of P. expansum (Pa447, Pa452, and Pa553) isolated from naturally infected fruits resulted in higher patulin production in Jonagold than in Fuji and Orin. Citrinin production levels were not significantly different in either the five varieties inoculated with ATCC 36200 or the three varieties inoculated with Pa447, Pa452, and Pa553. In addition, no significant difference in expansolides A/B production by Pa447, Pa452, and Pa553 was observed among Jonagold, Fuji, and Orin. The total polyphenol and malic acid contents were positively correlated with patulin production, while the total free amino acid content was negatively correlated. These results suggest that the apple cultivar and the components in the fruit affect patulin production by P. expansum.

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It has been reported that dried bonito (katsuobushi) shows antioxidant activity. In our previous study, we found that both absorbed (ABF) and non-absorbed (NAF) fractions of the hot-water extract (dried bonito stock or katsuodashi) from katsuobushi fractionated by a Porapak^TM Q (a porous polymer) column were determined to be equally antioxygenic by the diphenylpicrylhydrazyl (DPPH) method ; the phenol compounds were determined to be the main participants in the antioxidant activity in the ABF. Here, we investigated the compounds responsible for the antioxidant activity in the NAF. The NAF was separated by gel filtration, resulting in three fractions with radical scavenging activity. The fraction with the most prominent activity was purified by reversed-phase high performance liquid chromatography ; ¹H-NMR, ¹³C-NMR and mass spectrometry analyses identified the active compound as creatinine. IC₅₀ of creatinine for quenching the DPPH radical was 18mg/100ml.

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The non-destructive determination of soluble solid content (SSC), as well as the glucose, fructose, and sucrose concentrations, in strawberry cultivars, including ‘Akihime’, ‘Benihoppe’, and ‘Sachinoka’, using near-infrared (NIR) spectroscopy was examined. Soluble sugars in the cultivars at different maturing stages were analyzed enzymatically and then calibrated against the NIR spectra. The optimal wavelength range for all components was 700-925nm. The spectral pretreatment such as second derivative and multiplicative scatter correction showed no improvement on the calibration accuracy. The calibration results of the three cultivars analyzed as one group determined R² and standard error of prediction for SSC (0.86 ; 0.9%), glucose (0.74 ; 5.6mg·g⁻¹ fresh weight (FW)), fructose (0.50 ; 6.3mg· g⁻¹ FW) and sucrose (0.51 ; 12.5mg·g⁻¹ FW) concentrations to be as good as those determined for each cultivar. Therefore, the NIR non-destructive measurement technique using a wavelength range of 700-925nm is applicable for the prediction of not only SSC but also the concentrations of each sugar component in strawberries, irrespective of cultivar.

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Fat crystallization in oil-in-water (O/W) emulsion is one of the major factors of destabilization phenomena of O/W emulsion through partial coalescence. Partial coalescence causes serious deterioration of O/W emulsion that is used in many food products, such as whipped cream. In this study, we found that stability of the O/W emulsion containing palm-mid-fraction (PMF) was improved by using hydrophobic and hydrophilic sucrose fatty acid esters with high-melting point fatty acid moieties as additives. Emulsion without additives showed gelation occurring at chilled temperatures from 60°C to 0°C by partial coalescence of oil droplets through the crystallization of PMF. Furthermore, the oil and water phases were separated after heating the chilled emulsion to 60°C (oil-water separation). However, when hydrophobic and hydrophilic sucrose fatty acid esters were added in the oil and aqueous phase, respectively, gelation at 0°C was remarkably retarded and the oil-water separation after re-heating did not occur. The differential scanning calorimetry (DSC), polarized optical microscopy and X-ray diffraction analyses indicated that the inhibition of destabilization was caused by promotion of the crystal nucleus formation by a template effect of the hydrophobic additive, limitation of a crystal growth direction, reinforcement of the emulsification membrane by the hydrophilic additive, and retardation of the transformation of an α to β′ form of the PMF crystals in the oil droplets.

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Trp-P1 is a known carcinogen in rats and humans and is produced during cooking fish or meat. To investigate the effect of burdock and cabbage powder administration on the excretion of Trp-P1 and its metabolite, n-OH Trp-P1, rats were fed a diet containing 10% burdock or cabbage powder, followed by peroral administration of Trp-P1 (750μg) for 4 days. HPLC and the bacterial mutagenicity assay analyses of the feces and urine of Trp-P1-fed rats found mutagenic zones corresponding to Trp-P1 and its metabolite at Rf 0.1 and 0.3, respectively, on the thin layer chromatography C18 gel (Trp-P1, UV absorbance ; n-OH Trp-P1, electrochemical detector absorbance). Moreover, the metabolite was detected in the feces, but not the urine. Following administration of burdock and cabbage powder, urinary Trp-P1 excretion significantly decreased from 31.9±9.1μg to 25.2±4.7 and 14.3±2.6μg, respectively (p<0.05), while fecal metabolite excretion showed no significant difference.

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The number of food allergy sufferers has been increasing and foods containing allergenic proteins have caused concern for many of the people especially in developed countries. Although rice, a staple food for Japanese people, rarely induces severe allergic symptoms such as anaphylactic shock, it has long been known to be a potential cause of atopic dermatitis. We investigated the effects of high-pressure carbon dioxide treatment, an alternative to methyl bromide fumigation for insect pest control, as well as both methyl bromide and phosphine fumigation, on rice allergenic proteins. In addition, brown rice samples were treated with the larvae of the stored-product insect Plodia interpunctella to determine the effects of insect damage on these proteins. We found that neither these insect control treatments nor damage caused by stored-product insect have any effect on allergenic proteins.

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