The effect of viscosity µ of thickener solutions on their velocity through the human pharynx measured using the ultrasonic pulse Doppler method was investigated to develop an index for thickener solutions used as foods for dysphagic patients. The B-type viscometer determined an approximated value of viscosity at a selected shear rate γ. The maximum velocity V_max of water, which is often aspirated into trachea of patients with dysphagia, was about 3 times higher than that of yogurt, which is rarely aspirated. Moreover, the velocity spectra for water and thickener solutions of low concentration tended to be distributed over a wider range than those of yogurt and thickener solutions of high concentration. The maximum velocity V_max of the thickener solutions approached that of yogurt as concentration increased. The maximum velocity V_max correlated well with µ; the correlation coefficient at the shear rate of 10 s^-1 was somewhat larger than those at the shear rate of 1 s^-1 and 100 s^-1.

View full abstract

Alicyclobacillus acidoterrestris spores inoculated in orange juice were inactivated by applying a high electric field alternating current (HEF-AC) to food for a short duration. This new method is effective for inactivating all microorganisms in liquid foods. HEF-AC was compared with a conventional heating method using two oil baths and a tubular heat exchanger for the inactivation of A. acidoterrestris spores in orange juice. Using an HEF-AC pilot plant system at a flow rate of 100L/h, A. acidoterrestris spores in orange juice were exposed to an electric field of 2.5 - 2.7 kV/cm at 20 kHz for 13.8 ms in an electrode unit, as the temperature of orange juice was increased from 35°C to above 110°C upon leaving the electrode. Holding times between the electrode and cooling unit varied from 0.3 - 0.9 s. Increasing the holding time of HEF-AC enhanced microbial inactivation, while changing the holding time after the electrode unit was replaced with a tubular heat exchanger had no effect. Comparative studies revealed that the HEF-AC inactivated A. acidoterrestris spores 30 times faster than conventional heating using two oil baths during the holding time.

View full abstract

To understand the puffing phenomenon of wheat flour dough, the effect of baking powder (BP) on thermal-physical properties during heating was investigated. The effect of BP on the thermo-physical properties including thermal conductivity, heat capacity, and thermal diffusivity, was evaluated at 30 min after preparing dough samples with or without BP at 20°C, 40°C, 60°C and 80°C. The increasing velocity of the temperature in the samples with BP during heating was higher than that in the samples without BP. Thermal conductivity in each sample correlated with the retardation phenomenon irrespective of the presence of BP, while the increasing velocity of the temperature along the x-axis of the samples with BP was higher than that of the samples without BP. Thermal conductivity of the samples irrespective of the presence of BP tended to increase, as the temperature and moisture increased. Thermal diffusivity based on the values of thermal conductivity, heat capacity and density greatly increased with increasing temperature and moisture content of the samples with BP, which is essential for the puffing phenomenon in the baking of bread.

View full abstract

To define the influence of osmotic pressure, solute adsorption, and gel layer formation on permeate flux during the ultrafiltration of an ovalbumin solution, the characteristics of the gel-like layer formed on the membrane surface were investigated and the adsorption rate of ovalbumin to membranes was measured under different conditions. Gel-like layer observed on the membrane surface was found to be a deposit layer formed by an aggregate of denatured ovalbumin which could be precipitated by centrifugation. This layer had a rejection ability for ovalbumin itself and little resistance for permeate flow. In both cases where there is a layer and where is not, the flux values during the ultrafiltration could be precisely predicted by the osmotic pressure and adsorption resistance model which took into account the influence of osmotic pressure and solute adsorption. The forced flow of solution into membrane pores shortened the time to reach adsorption equilibrium, suggesting a notable influence of solute adsorption into membrane pores.

View full abstract

Abstract: A quick (headspace: 1 min and retronasal aroma simulator (RAS): 2 min) sampling method for capturing volatiles released from coffee drinks by solid-phase microextraction (SPME) (fiber type; divinylbenzene (DVB)/carboxen/polydimethylsiloxane (PDMS)) has been applied to freshly brewed espresso and café latte (espresso and milk). Headspace volatiles and volatiles in the RAS effluent were collected from espresso and café latte, and examined by gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O, CharmAnalysis™). When milk was added to espresso in 60% by weight, aroma release (odor activities) was generally suppressed, both in headspace and RAS aromas. The relative charm value of sweet-caramel odor increased in the headspace aroma, while the phenolic odor increased markedly and the smoke-roast odor decreased in the RAS aroma. These results suggested that milk addition had different effects on the headspace and RAS aromas.

View full abstract

Attempts were made to remove the oxidation products from fish oil with membrane process as an improved refining method. A study was conducted with hexane-diluted fish oils of Engraulis japonicus and Maurolicus japonicus in a batch membrane cell using hydrophobic nonporous denser membrane. Peroxide, anisidine and TOTOX values were reduced by 58-72%, 45-75% and 53-73%, respectively. During the membrane process, fatty acids compositions of both fish oils were not changed. The membrane process has an effect in the removal of oxidation products such as toxicity, off-flavor, and color compounds maintaining the beneficial function arising from polyunsaturated fatty acids of fish oils. In the fish oilhexane systems, when the oil contents of feeds were 25-33%, the oil fluxes were obtained in the range of 1.0-2.0 kg/(m² h). In addition, preferential permeations of hexane over fish oils through the membrane were observed.

View full abstract

To study the protective effects and mechanisms of cartilage-selenium polysaccharide on liver injury caused by diethylnitrosamine DEN in mice. During the entire experimental period, to analyze liver injury indexes, the liver was greatly injured by DEN induced and completely prevented by low and high cartilage-selenium polysaccharide. GSH-Px and SOD activities and quantity of mRNA of GSH-Px and SOD were significantly higher to decrease MDA content and ·OH and O₂^-· scavenging. Cartilage-selenium polysaccharide was evidently reduced quantity of collagen type I and mRNA of α-SMA and HSP47 compared to model group by RT-PCT detecting. Cartilage-selenium polysaccharide had protective effect on liver injury induced by DEN in mice, and its mechanisms were related to free radical scavenging, increasing SOD and GSH-px activities, enhancing quantity of mRNA of GSH-Px and SOD, decreasing quantity of collagen type I and mRNA of α-SMA and HSP47 and inhibiting the production of proinflammatory mediators.

View full abstract

To determine preferred texture of cooked rice, sensory analysis and measurements were conducted using 116 elderly and 81 young individuals. Six types of cooked rice with a significant difference in texture were prepared by cooking rice with a weight of water 1.1 - 2.6 times the weight of rice. Seven factors of oral condition, including the number of remaining teeth, occlusal supporting area and occlusal force in dental prescale, were examined. Significant differences in oral condition were observed between the elderly and young individuals. Furthermore, the elderly individuals preferred the texture of rice cooked with 1.9 times the weight of water, while the young preferred the texture of rice cooked with 1.5 times the weight of water. Using these data, the panelists were divided into five groups using a neural network method. The measurements within these stratified groups revealed that oral condition was not necessarily correlated with the preference for cooked rice, which is likely the result of the particular preference among Japanese people for the texture of flavorful cooked rice.

View full abstract

The relationship between the coagulant concentration and soybean protein composition for the finer structure of tofu was investigated using its textural and microstructure data. The textural property of tofu with different ratios of 11S/7S globulin was measured at various concentrations of coagulant, and the tofu structure was observed by scanning electron microscopy. The tofu microstructure had the finest network near its change point of breaking stress (CaSO₄) or breaking strain (glucono-δ-lactone). Thus, the coagulant concentration for obtaining a finer tofu network is important for tofu preparation. At concentrations below and above the optimal coagulant concentration, the tofu network consisted of large cell-like units, while at the optimal concentration it consisted of small, uniform units. The structural change point of tofu rich in 11S globulin was at lower coagulant concentrations (0.15~0.2%) and that rich in 7S was at higher coagulant concentrations (0.3~0.4%)

View full abstract

We have studied the neutrophil-increasing effects of fruits and vegetables and their priming effects on cytokine induction. Among fruits, bananas exhibited the most marked priming effects. Therefore, we evaluated possible differences in the biological response modifier (BRM)-like activities of bananas (such as the effects on neutrophil accumulation and macrophage morphology, and the priming effects on cytokine induction), according to their strain and maturity, using a conventional strain and a strain for highland cultivation. As a result, the total intraperitoneal leukocyte count and % neutrophils increased in parallel with the concentration and maturity of banana extracts. These effects were more marked in the highland strain. After the addition of banana extracts, marked macrophage spreading was observed, and morphological changes differed according to the strain and maturity of bananas. The priming effects on TNF-α or IL-12 induction also differed according to the maturity and strain of bananas, and could also be confirmed after oral administration. These results suggest that banana intake is associated with various BRM-like activities, and these effects differ according to the maturity level of the bananas.

View full abstract

This study focused on the effects of a humidity-stabilizing sheet (HSS) containing different levels of glycerol (humectant) and a drip-absorbing sheet (DAS) on quality parameters of frozen/thawed bigeye tuna meat stored in sealed containers at 4°C for 3 days. As the glycerol concentration increased, the humidity around samples and increases in volatile basic nitrogen (VBN) were suppressed, while the weight loss percentage and total ATP-related compounds (t-ARCs) were increased. Tuna portions wrapped with HSS and DAS and then unwrapped showed no difference in Hunter color values L*, a*, and b* or K values. Wrapping tuna samples with any kind of sheet seemed to effectively maintain the initial values of thiobarbituric acid reactive substances (TBARS) and metmyoglobin percentage (Met-Mb%). Based on the analysis of these parameters, we conclude that HSS is a good packaging material that can be employed in the preservation of frozen/thawed, chilled tuna meat.

View full abstract

Natto, a fermented soybean food made in Japan, is spoiled occasionally by Bacillus subtilis (natto) bacteriophages. Twenty phages, primarily isolated from abnormally fermented natto, were classified into two groups based on host ranges and comparative whole-genome hybridization. JNDMP (group I) had a hexagonal head (diameter, 60 nm), a flexible tail (length, 200 nm) and required a magnesium ion for amplification. ONPA (group II) had a hexagonal head (diameter, 89 nm) and a sheathed tail (length, 200 nm). Genome sizes of JNDMP and ONPA were estimated to be 42 kb and 91 kb, respectively. Previously reported phages from three serologically different groups of B. subtilis (natto) were also classified into group I or group II based on the results of Southern hybridization using JNDMP and ONPA genomic DNA as probes. These results suggest that there are at least two groups of B. subtilis (natto) phages in Japan.

View full abstract

The difference in stickiness between cooked Nipponbare (Japonica rice) and Khao Dawk Mali (Indica rice) that have similar apparent amylose content was investigated, and the fine structure of starch in both cooked rice and extract from the surface of cooked rice was analyzed. Non-sticky high-amylose rice (Indica rice) was also studied for comparison. The solid content and amount of amylopectin in the extract from the surface of cooked Nipponbare were the highest, followed by cooked Khao Dawk Mali, and cooked high-amylose rice. This difference in solid content and the amount of amylopectin contributed to the stickiness of cooked Nipponbare. This suggests that the stickiness of cooked rice is less when less amylopectin is dissolved into cooking water, even when the amylose content and fine structure of the starch in the rice grains is similar. Thus, cooked Khao Dawk Mali is less sticky than cooked Nipponbare, despite having similar amylose content.

View full abstract

Okara, a soybean by-product of tofu production, was treated with microwave irradiation in water for solubilization of its components. The solubilization rate increased with increasing temperature and reached higher than 70% around 200°C with a heating time of 7 min. The main solubilized components were neutral carbohydrates consisting of arabinose and galactose, while the residues were mainly composed of cellulose. LV-SEM images confirmed solubilization of cell wall components. Production of new polyphenolic compounds that have antioxidant activity was observed above 180°C. The heating temperature and heating time were optimized for neutral carbohydrate solubilization using the response surface methodology. The optimized condition was heating at 196°C for 2 min, indicating that a short heating time is effective for solubilization of carbohydrates to prevent secondary decomposition.

View full abstract

As part of the search for new sources of mental health supplements, alcohol extracts of 11 Bangladeshi medicinal fruits and plants were investigated for neuropharmacological effects in mice and on ionotropic γ-aminobutyric acid receptors (GABA_A receptors). The extracts of S. caseolaris, T. bellirica, S. cumini, and T. arjuna significantly potentiated the GABA-induced response of GABA_A receptors expressed in Xenopus oocytes, though the extracts alone induced no response. In mice, administration of these extracts prolonged pentobarbital-induced sleeping time. Potentiation of GABA_A receptor response reportedly generates anxiolytic, sedative, sleep-inducing and anesthetic activities in the human brain. Thus, these extracts may have potential regarding the development of a supplement with tranquilizing and sleepinducing effects that is beneficial for mental health.

View full abstract

The aim of the present study was to investigate the changes in protein and nitrogen compounds in a novel fermented product generated from soybean protein-calcium-gel (SP-Cal-Gel) and Monascus fungus during fermentation. Slab SDS-polyacrylamide gel electrophoresis and measurement of nitrogen contents clearly revealed the occurrence of protein digestion in the form of degradation of α'-, α-, and β-subunits in β-conglycinin and of acidic polypeptide in glycinin; however, the band of basic polypeptide in glycinin still remained. The ratios of water-soluble nitrogen and TCA-soluble nitrogen to total nitrogen reached 52.4 or 46.6% after 60-days ripening, respectively. Moreover, involvement of a large amount of free amino acids, especially aspartic and glutamic acids, were shown in this novel fermented SP-Cal-Gel food product.

View full abstract

The aqueous ethanolic extract of Eucalyptus globulus leaves has been used as an antioxidant in food additives. From the extract, five ellagitannins and four gallotannins were isolated as the major antioxidative components. Heterophylliin A, 1,3-di-O-galloyl-4,6-hexahydroxydiphenoyl-β-D-glucose, 1,2,4-tri-Ogalloyl-β-D-glucose, 1,2,3,6-tetra-O-galloyl-β-D-glucose and 1,2,4,6-tetra-O-galloyl-β-D-glucose are the first to be isolated from this plant. These hydrolyzable tannins exhibited more potent antioxidant activity (superoxide dismutase-like activity) than ascorbic acid, as well as inhibitory activities against tyrosinase and hyaluronidase. Thus, the eucalyptus leaf extract may be useful in food and cosmetics for not only an tioxidation, but also anti-melanogenesis, anti-allergy and anti-inflammation.

View full abstract

2-[3-(2-Thioxopyrrolidin-3-ylidene)methyl]-tryptophan (TPMT) is the main yellow pigment in salted radish roots (takuan-zuke). In the present study, we investigated the content of 1-(2-thioxopyrrolidin-3yl)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (TPCC) as a precursor of the yellow pigment and TPMT in commercial takuan-zuke. The total content of stereoisomers was 0.2-36.4 mg/100 g (2-364 ppm) for TPCC, and 0-6.6 mg/100 g (0-66 ppm) for TPMT. TPCC and TPMT showed radical scavenging activity against ABTS radical cation than the classical antioxidant (ascorbic acid and Trolox). The antioxidative activity showed no differences for TPCC stereoisomers, but showed differences for E/Z ratiocontrolled TPMT solutions.

View full abstract

Allium vegetables have been shown to have beneficial effects against several diseases, including hyperlipidemia and cancer. This study was carried out with enzymatic method to investigate the inhibition on fatty acid synthase by nine Allium vegetables to explore their health protective mechanisms. It was found the fatty acid synthase inhibitors in most Allium vegetables extracts were concentrated in the lower polar solvents and the inhibition could be reversed by dithiothreitol. Ethyl acetate extract of red onion (Allium cepa L., IC₅₀ = 0.45 μg/mL) was the most active of the samples tested. In garlic, diallyl trisulfide was suggested to be an effective component which may react with the essential sulphydryl groups in the enzyme. Additionally, the Chinese chive (Allium tuberosum L.) exhibited the most total inhibitory capacity, and its inhibitory components showed more polar than that of other Allium vegetables. It is suggested that different inhibitors of FAS exist in these vegetables.

View full abstract