The structure-activity relationship of allergy enhancing and suppressing factors in foodstuffs was summarized in this text. Polyunsaturated fatty acids (PUFA) enhance allergic response by enhancing IgE production and by suppressing production of other antibodies in rat lymphocytes. Because the expression of IgE production enhancing activity was inhibited by lipophilic antioxidants, lipid oxidation reaction seems to have participated in the activity. Xanthene dyes, a group of synthetic dyes, also exert IgE production enhancing effect, and the activity is dependent on the degree of halogenation. On the other hand, PUFA exert anti-allergic effect by suppressing the release of chemical mediators from rat peritoneal exudate cells, and the activity becomes stronger with the increase in the number of double bonds. In addition, antioxidants such as tea polyphenols (TP) and flavonoids exert anti-allergic effect mainly due to the suppression of chemical mediator release. Histamine release suppressing activity is observed in triphenol derivatives, but not in diphenols. On the contrary, LTB4 release suppressing activity is observed in mono and diphenolic derivatives with antioxidative activity. These results suggest that various food components have immunoregulatory activity and that optimization of their intake is desirable.
A variety of glutaraldehyde (GA) activated-aminopropyl controlled pore glass supports were prepared in lower protogenic solvents (methanol, ethanol, and n-propanol). When trypsin was used as the ligand, the amount of trypsin immobilized on them decreased in the order of water, methanol, ethanol, and n-propanol; the maximal reduction of 22% was observed in n-propanol versus that in water. The Michaelis constants of the trypsins immobilized on the support activated with GA in alcohols, especially ethanol and propanol, were smaller than that in water, and the minimum K m value of 1.84×10-1 mM was obtained in propanol (4.29×10-1 mM in water). During the reaction of GA with 2-aminoethanol, the amount of the aldehyde group from GA being capable of reacting with 2-aminoethanol significantly decreased when the reaction was done in n-propanol (0.18 mmol/assay volume, cf. in water; 0.35 mmol/assay volume). The gel permeation chromatography (GPC) measurement of the GA complex, glycine-GA-phenetylamine, also revealed the suppression of the GA self-polymerization in the lower protogenic alcohol as a support activating solvent.
Bananas were coated with 2% sucrose palmitic acid ester after treatment with 100 ppm ethylene for 12 h and stored at 20°C. The use of 2% sucrose palmitic acid ester coating significantly reduced weight loss, and retarded degreening and delayed ripening of banana. The rate of ethylene production was significantly reduced and the rate of respiration reduced up to 4 days in storage by the coating. In vivo and in vitro 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase activities were studied in the peel and pulp tissues of the ripening banana during storage. The in vitro ACC oxidase activity was higher than that of in vivo. The changes in both in vivo and in vitro ACC oxidase activities showed that the coating reduced this activity in the peel tissue of banana but had almost no effect on the ACC oxidase activity in the pulp tissue. These results suggested that the coating treatment reduced the ethylene biosynthesis of the banana fruit through reduction of the activity of ACC oxidase of the banana peel tissue.
A chloride ion-selective solvent polymeric membrane electrode (Cl-ISE) using quaternary ammonium salts for determination of the ethanol concentration during sake fermentation is described. The ethanol response by a Cl-ISE is based on the change in the transfer activity coefficient of Cl- from water to ethanol. The logarithm value of the transfer activity coefficient increases linearly with increasing ethanol concentration. The Cl-ISE using a mixture of o-nitro-phenyloctyl ether and n-tetradecylalcohol as plasticizers and tetradodecylammonium salts as sensing materials showed good linearities for ethanol (−2.39 mV/%) and for Cl- (−53.6 mV/decade). Furthermore, the interference from co-existent components in sake mash with the response of the Cl-ISE was improved in comparison with that using other plasticizers and sensing materials. The Cl-ISE was found to show good accuracy in the measurement of ethanol in sake mash.
A transparent testing cell was constructed to assess flow of fish tissue during a compression-back extrusion mechanical assay. The net action of the plunger over the fiber-interfibrillar collagen matrix appears to involve flow of intact fibers due to yield of the matrix as well as compression resisted by fibers. The force at yield point F (N) coincided with initiation of flow and followed a power relationship with sample weight W (g) of the type F=2.76W1.21. Mechanical assays after incubation at 30°C showed that light/dark tissue had higher yield point values than light tissue, with a strong effect of time of incubation, temperature and pH. The proposed method was effective in assessing softening of the collagen matrix in fish tissue without destruction of the fibers.
Autoxidative processes of mono- and trilinolein and mono- and trilinolenin were observed at different temperatures. Rate expression of the autocatalytic type was applicable to the entire autoxidative process of mono- and trilinolein at any temperature. The rate expression could also be applied to the first-halves of autoxidation of mono- and trilinolenin, although the latter halves did not obey the expression but first-order kinetics. The rate constants for each substrate were evaluated at different temperatures, and the apparent activation energy and the frequency factor were estimated. From these two parameters obtained here and reported previously, it was demonstrated that the enthalpy-entropy compensation held in autoxidation of fatty acids, their ethyl esters and acylglycerols.
Progressive freeze-concentration was applied to concentrate tomato juice. Effective partition constants of the solute between the solid and liquid phases were experimentally determined for total solid and potassium chloride (KCl)-equivalent salts. The partition constants were strongly dependent on the stirring rate at the ice front and the advance rate of that front. Increasing stirring rate and reducing advance rate of the ice front lowered the effective partition constant and improved freeze concentration performance. The partition constant was different between total solid and salts suggesting a different mechanism in the partition phenomena between the two components. Tomato juice of 4.3 wt% in solid content was concentrated up to 18.8 wt%. After the reconstitution of freeze concentrated tomato juice based on Brix, no substantial differences, except for salt content, were observed in acidity, vitamin C content, or color quality compared with before the concentration.
Effects of light on the chlorophyll (Chl) degradation in stored broccoli (Brassica oleracea L. var. italica Plen.) florets after blanching were studied. Chl contents decreased greatly during storage at 10°C in the light (30 μmole · m-2 · s-1), whereas original levels of Chl were maintained in the dark. Small amounts of 132-hydroxychlorophylls a and b (Chls a-1 and b-1), an oxidized form of Chls a and b, were formed during storage in the light with Chl degradation. Chls a′ and b′, isomers of Chls, and pheophytins a and b were formed after blanching and the proportions of these derivatives increased during storage in both light and dark. L-Ascorbic acid and α-tocopherol contents decreased greatly during storage in the light, whereas thiobarbituric acid values increased. Activity levels of lipoxygenase, chlorophyllase and Chl degrading peroxidase became very low after blanching and showed almost no change during storage in the light and the dark. This suggests that active oxygens formed nonenzymatically on the Chl pigment might act effectively on Chl degradation due to decline in the protection of antioxidants.
This study was conducted to investigate the relationship between several blanching conditions and remaining enzyme activities, especially pectinesterase (PE) and polygalacturonase (PG), on the formation of coagulum. Eight commercial enzyme preparations were added to carrot juice, and PE or PG caused coagulum formation while the other six enzymes had no effect. Since the endogenous activities of PE and PG were also observed in carrots, these activities were believed to be a major cause of coagulum formation. Coagulum formation was prevented under blanching conditions above 70°C, at this temperature, PE activity was inactivated, and PG activity was reduced about 60% in relation to the non-blanching juice. Since blanching in a 0.02 M citric acid solution (pH 2.4) at 60°C prevented the formation of coagulum, blanching under low pH conditions was more effective. Although PE activity was not reduced in relation to blanching in water at 60°C, the reduction of PG activity was 14%. These results lead to the conclusion that coagulum formation in carrot juice depended on the remaining activities of both PE and PG and that to prevent coagulum these enzyme activities must be suppressed.
The effect of zinc-containing marine algae on bone components in the femoral tissues of rats in vitro and in vivo was investigated. Marine alga (fucus, Phaeophyceae) contained a comparatively higher concentration of zinc (3.16%). Water-extracted marine alga solution was prepared at concentrations of 10-7 to 10-5 M zinc. The femoral-diaphyseal and -metaphyseal tissues obtained from weanling rats were cultured for 24 h in Dulbecco’s modified Eagle’s medium containing either vehicle or zinc-containing marine alga water extract (10-7 to 10-5 M zinc) in vitro. The presence of zinc-containing marine alga extract caused a significant increase of calcium content, alkaline phosphatase activity, and deoxyribonucleic acid (DNA) content in the femoral-diaphyseal and metaphyseal tissues. This anabolic effect was completely blocked by the presence of a chelator of zinc ion or an inhibitor of protein synthesis. Moreover, when weanling or elderly rats received daily an oral administration of zinc-containing marine alga suspension (5.0 mg zinc/100 g body weight) for 8 or 10 days, respectively, the femoral-diaphyseal and -metaphyseal components were significantly elevated. This administration produced a significant increase in the serum and femoral zinc concentrations of elderly rats (50 weeks old). The present study demonstrates that zinc-containing marine alga materials have an anabolic effect on bone metabolism in vitro and in vivo, suggesting a useful role for zinc-containing food on the prevention of bone loss with increasing age.
The rates of carbon dioxide and ethylene production and the levels of 1-aminocyclopropane-1-carboxylic acid (ACC) and polyamines, putrescine and spermidine, in chilling-sensitive water convolvulus and resistant chingensai were measured during storage at constant 5°C and 20°C or with temperature rise from 5°C to 20°C. Water convolvulus stored at constant 5°C or transferred from 5°C to 20°C on day 3 developed chilling injury on day 4, while chingensai showed no chilling injury at any temperature storage. Following temperature rise to 20°C with two periods of storage at 5°C, water convolvulus showed differences between the two in the rates of carbon dioxide and ethylene production and the levels of polyamines, putrescine and spermidine; however, chingensai remained essentially the same. These results suggest that chilling stress affected the ethylene biosynthetic pathway and polyamine metabolism in chilling-sensitive water convolvulus but not in resistant chingensai.
The preventative effects of (—)-epigallocatechin gallate (EGCg), (—)-epicatechin gallate (ECg), and (—)-epicatechin (EC) against paraquat-induced oxidative stress were compared in rats in order to discover whether the gallic acid moiety in the EGCg and ECg molecules was necessary to their stronger preventive activity; in addition, the relation between the difference in the chemical structures of their B-ring and their preventive effects was studied. EGCg and ECg strongly suppressed decreases in food intake, body weight gain, and serum and liver triacylglycerol concentrations as well as increases in serum and liver TBARS which were caused by use of the paraquat diet. However, these suppressive effects were almost not observed in EC. The preventive effects of EGCg and ECg against the paraquat-induced oxidative stress were not significantly different. These results indicate that the presence of the gallic acid moiety of EGCg and ECg molecule is important in regard to their stronger preventive effects compared to those of the EC and also that those effects against oxidative stress in the rats were not significantly affected by the differences between the pyrogallol and catechol structures in the B-ring in EGCg and ECg.
Free and bound phenolics in 21 japonica cultivars (Oryza sativa) of rice bran and polished rice were analyzed using 3D-HPLC. Although we observed high content variations among cultivars, the major free phenolics were ferulic acid (1) and p-coumaric acid (2). Rice bran and polished rice contained 0.25-2.9 (mean, 0.56) mg/100 g and 0-277 (mean, 65) μg/100 g of 1 and 0.1-1.1 (mean, 0.43) mg/100 g and 0-159 (mean, 24) μg/100 g of 2, respectively. Contents of bound phenolics were much more than those of free phenolics and variations in contents of bound phenolics among cultivars were less than those of free phenolics. The major bound phenolics were 1, 2 and 5, 5'-diferulic acid ((E, E)-4, 4'-dihydroxy-5, 5'-dimethoxy-3'-bicinnamic acid, 3). Rice bran and polished rice contained 22-225 (mean, 155) mg/100 g and 1.7-13 (mean, 7.1) mg/100 g of bound 1, 51-243 (mean, 116) mg/100 g and 0.5-4.9 (mean, 1.8) mg/100 g of bound 2 and 3-22 (mean, 9.8) mg/100 g and 0.04-0.5 (mean, 0.26 mg/100 g) of bound 3, respectively. 5, 8'-Diferulic acid benzofuran form (trans-5-[(E)-2-carboxyvinyl]-2-(4-hydroxy-3-methoxyphenyl)-7-methoxy-2, 3-dihydrobenzofuran-3-carboxylic acid, 4) was first detected in cell wall of rice bran and the content of 4 was seven times higher than 3, showing that 4 is the major diferulic acid in this location.
Physical properties which influence the quality of seasoned umeboshi were examined and microscopic observations and sensory evaluations were undertaken on 13 commercially prepared products and 4 laboratory-prepared samples pickled with calcium hydroxide. The physical properties of alcohol insoluble solid (AIS) content, pectin composition, calcium content bound to AIS and adhesiveness varied in the commercially prepared samples, and the differences were believed to be due to the condition of the materials and methods used. A high correlation was observed between adhesiveness-AIS and adhesiveness-water soluble pectin. Among the commercially prepared products, some were assumed to have had calcium compounds added during the process because of the high values of calcium in AIS, and microscopic observations revealed that cell walls had been strengthened by calcium just beneath the skin of these products. Laboratory-prepared samples pickled with 0, 0.05, 0.10 and 0.15% calcium hydroxide showed that the addition of calcium had the effect of reducing damage to the skin and flesh of umeboshi during the rest of the process, and there were no differences in the physical properties except for the calcium content bound to AIS even with differences in the calcium concentrations. The areas just beneath the skin which were affected by the added calcium deepened progressively depending on the calcium concentration, and the sample pickled with a concentration of 0.1% had a skin strong enough to prevent damage and yet thin enough to be sensory-evaluated appropriately.
Nineteen main volatile esters were detected from the headspace of strawberry fruit cv. Toyonoka, twelve of which were aliphatic esters which included abundant amounts of methyl butanoate and methyl hexanoate. Likewise, small amounts of thioesters, methylthiol acetate and methylthiol butanoate were also identified in strawberry fruit. A large amount of methylthiol acetate and ethylthiol acetate was produced when methanethiol and ethanethiol were added onto slices of strawberry, respectively. Thioester production was competitively inhibited by aliphatic alcohol, indicating that strawberry alcohol acetyltransferase (AAT) reacted with not only aliphatic alcohol but also thioalcohol which was converted to thioester. Strawberry-AAT had a weaker affinity with thioalcohols than corresponding aliphatic alcohols with the same carbon-chain structures. The thioalcohol specificity of strawberry-AAT had a similar pattern to the aliphatic alcohols, showing that the 1-hexanethiol and 1-pentanethiol were preferable substrates for strawberry-AAT than methanethiol and ethanethiol.
The yield and the physical, chemical and rheological properties of agars extracted from six commercial Gracilaria from different localities around the world, and one species of Gracilariopsis lemaneiformis, collected from a Japanese locality, were investigated after an extended storage at different treatment conditions. Agar was extracted by pretreatment with 5% NaOH incubated for 2 h at 80°C. Changes in the agar quality occurred at variable rates and were dependent on species and its origin. The Japanese Gracilariopsis species and Chilean Gracilaria chilensis were more resistant to degradation than the other agarophytes during the storage period. The agar extracts of Chilean G. chilensis showed an increase in its gel strength with tendence to be harder and less flexible, while those of Japanese Gracilariopsis were not affected even neither by storage nor by the different temperature conditions. The agar characteristics of the commercial agarophytes examined were not significantly affected by the different temperature conditions, except for Argentinean and Turkish G. gracilis.
Two phytase isozymes (PHY1 and PHY2) were purified homogeneously from bran of Triticum aestivum L. cv. Nourin #61 by (NH4)2SO4 fractionation, methanol fractionation, Sephacryl S-200 HR gel filtration chromatography, DEAE-TOYOPEARL chromatography, CM-TOYOPEARL chromatography and second Sephacryl S-200 HR gel filtration chromatography. Molecular weights of the two enzymes were 71,000 and 66,000 by gel filtration, and 68,000 and 66,000 by SDS-PAGE, respectively. Optimum pH and temperatures were 6.0 and 45°C for PHY1, and 5.5 and 50°C for PHY2. The activity of both phytases was stable at pHs between pH 4.0-7.0 and below 40°C. The Km values for myo-inositol hexakisphosphate (IHP) were 0.48 μM for PHY1 and 0.77 μM for PHY2. The Ki values for Pi were 2.69 mM for PHY1 and 6.59 mM for PHY2. Both phytases showed relatively high specificity for IHP.
Effect of curdlan with or without trehalose on retort stability of a minced-pork gel system was investigated. The addition of curdlan suppressed the deterioration of physical properties as well as the water-holding capacity of the gel system upon retorting. Effect of the addition of curdlan at the same concentration on the suppression of deterioration was larger by its addition in pre-suspended form via a brine solution than by dry addition; in the case of pre-suspended addition, 1% curdlan was sufficient to suppress deterioration of the above properties significantly, while in the case of dry addition, 2% curdlan was required. The addition of 0.5% curdlan and 10% trehalose also had a significant effect on the suppression of deterioration of these properties. The addition of trehalose did not cause browning of the gel surface through Maillard’s reaction.
Chemical components and quality of Welsh onion (Allium fistulosum L.) wrapped roughly or completely heat-sealed with orientated polypropylene (OPP) film were investigated during storage at 5 and 20°C. Concentrations of oxygen (O2) and carbon dioxide (CO2) in the roughly heat-sealed packages were the same as in air, whereas O2 concentration in the completely heat-sealed packages decreased to 2-3% at 20°C and to 4-5% at 5°C. Contents of reduced ascorbic acid (RAA) and chlorophyll in onion which was roughly sealed and stored at 20°C decreased, and withering of leaf tip occurred. This meant that the quality deteriorated severely. However, the contents of RAA and chlorophyll in Welsh onions which were sealed completely and stored at 20°C, and which were sealed roughly or completely and stored at 5°C, did not change or only slightly decreased. In Welsh onion sealed completely and stored at 20°C, off-odor was detected after 2 days and severely after 7 days and leaf tips began to wither after 7 days, suggesting that quality could be kept only for 4 days storage. In Welsh onion sealed completely and stored at 5°C, off-odors and withering of leaf tip was not observed for 9 days, indicating that quality marketability could be kept for that period.
The effects of the maturation and the sodium chloride concentration on the composition of pickled sun-dried ume products ‘umeboshi’ were investigated using ume fruit harvested on May 31 (immature stage, salted in 15.0% sodium chloride), June 7 (stage from immature to just before mature, salted in 15.0% sodium chloride) and June 14 (a stage from mature to slightly ripe, salted in 12.5%, 15.0% and 17.5% sodium chloride). There were no differences in moisture or sodium chloride concentration among the different harvesting dates of fruit which was salted with the same sodium chloride concentration, and the titratable acidity was highest in June 7 fruit and then dropped as the harvesting date advanced due to the original content in the fresh ume. The moisture content increased and acids eluted less when a lower quantity of sodium chloride was used during salting, however, no differences were observed in the final sodium chloride concentration. Therefore, it is concluded that there was no effect on reducing the final sodium chloride concentration even after lower concentration had initially been added. In the NaCl-reduced condition, the concentration of sodium chloride after salting was less, however, a larger volume of moisture evaporated. Sucrose, glucose, fructose and sorbitol increased with the advance of harvesting date, and sucrose dissolved completely, consequently glucose and fructose increased in all samples during salting. Free amino acid content was not influenced by the harvesting date or initially added sodium chloride concentration. Asn, Gln and Glu decreased during salting, and Ala and γ-ABA increased in all samples during the process.
The accumulation of vitamin K in the plasma of healthy persons ingesting 2-100 g of natto was dose dependent. Ingesting natto bacilli (B. subtilis natto) also resulted in a rise of vitamin K concentration in the plasma. It was better for vitamin K retention in the plasma than the ingestion of standard natto product. This means that the natto bacilli influences vitamin K production in the digestive system. In both cases, there was no difference observed in the blood coagulation or fibrinolytic systems tested by TEG pattern and PT, APTT.
The effect of wasabi leafstalk (Wasabia japonica MATSUM.) extract on bone metabolism in vivo was investigated. The extract was obtained from a homogenate with 20% ethanol and was orally administered 7 times at 24-h intervals (1.0, 10, and 40 mg/100 g body weight) to young rats. Administration of wasabi extract (1.0 and 10 mg/100 g) caused a significant increase in alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the femoral-metaphyseal tissues; the DNA content was significantly elevated by the dose of 40 mg/100 g. In the femoral-diaphyseal tissues, alkaline phosphatase activity and calcium content were significantly increased by the administration of 1.0 and 10 mg/100 g, while the DNA content was not appreciably altered. The present study demonstrates that wasabi leafstalk extract has an anabolic effect on bone metabolism in rats in vivo.
The contents of d-limonene, a major essential oil component in citrus species, were determined in Citrus unshiu, C. sinensis and C. limon during fruit development. d-Limonene was separated from l-limonene by a capillary chiral column attached to GC. The ratio of d-form in the total limonene remained higher than 95% throughout all stages of development. In these fruits, d-limonene content reached maximum just before the pericarps turned from deep green to yellowish green. d-Limonene synthesis was confirmed to take place in the early stage of development within the month from August to September.
We investigated the absorption and metabolism of quercetin, a typical flavonoid, in Caco-2 cells, which are obtained from a human colon adenocarcinoma cell line and have been used as a good model for the small intestinal epithelial cells. After incubation of Caco-2 cells with quercetin, cell homogenates were treated with sulfatase type H-5, which releases quercetin from its glucuronides and sulfates. HPLC analysis of the homogenates with an electrochemical detector revealed absorption of quercetin by the cells. The amount of quercetin in the cell homogenates treated with sulfatase type H-5 was much higher than that in the cell homogenates before treatment with the enzyme. These results indicate that quercetin was conjugated easily in Caco-2 cells and suggest that similar conjugation of flavonoids probably occurs in the intestinal epithelial cells.
Kurozu is a brewed rice vinegar prepared by a traditional method in Kagoshima prefecture, Japan, and is regarded as a healthful food. The effects of the non-volatile components obtained from Kurozu (the residue of Kurozu) on the primary monolayer culture of rat hepatocytes were examined. In serum-free L-15 medium supplemented with the residue of Kurozu, about 60% of the hepatocytes inoculated to a dish survived for 6 days of culture. In contrast, without the residue, the number of hepatocytes decreased to less than one-third of the inoculated cells during the culture. The amount of albumin secreted in the medium was monitored as an expression of liver-specific function. In the medium with the residue of Kurozu, the rat hepatocytes secreted a considerable amount of albumin in 4-day culture (2.5 μg/ml medium/24 h), and even at 6 days (1.3 μg/ml medium/24 h), while albumin secretion by the hepatocytes cultured without the residue decreased rapidly with time. These results suggest that some components in Kurozu residue are effective to maintain the primary culture of rat hepatocytes and thus for albumin production by the hepatocytes.