An average recovery of 57.7% is obtained when cultured yellowtail are processed into fillets, while the remaining 42.3% forms wastes, primarily composed of heads, backbones, and viscera. The head, accounting for 13.8%, contained high levels of lipid, making it a suitable source for recovering EPA and DHA for food application. The lipid was tested to supplement to jyakotenpura, a special kamaboko of Ehime, and was added to chicken feed to enrich DHA in an egg yolk. Cultured yellowtail backbone (8.7% of the round fish) contained relatively high levels of lipid. When the bones were retorted, they turned to edible products due to fragility induced by gelatinization of bone matrix collagen. The retorted bones were easily crushed into fine paste-like homogenates, which were utilized as functional additives to various types of kamaboko, seasoning, and soup stock to enrich EPA, DHA, and minerals. The retorted bone was superior as a source of calcium to chemicals, such as CaPO3, because of a low interference of iron absorptivity.
By the use of MRI, we clearly showed that starchy food has a complicated water content profile during cooking, a profile which is hard to be described by Fickian diffusion equation. In the search for the missing factor which governs the behavior of water absorption characteristic of starch, we come to the conclusion as follows: (1) There exists some confusion in the discussions of the published papers in terms of the usage of the word“gelatinization”. (2) The gelatinization reaction of starch should be understood in terms of“terminal extent of gelatinization”. (3) The information on the terminal extent of gelatinization as a function of temperature and water content at heat-treatment is of most importance. (4) The factor which governs the water migration in starchy food is“ceiling water content”which is the potential maximum of water holding capacity that a starchy food has. Fickian diffusion equation is applicable on a system that is homogeneous in terms of ceiling water content. We proposed Water Demand Model which has a potential to be applicable on a system that is inhomogeneous in terms of ceiling water content.
Freezing-thawing dehydration, as a method with the less energy consumption for the reduction of food waste, was applied to about forty food-related samples chosen from vegetables and fruits, their waste, meat and fish, gel materials, and cooked food. Samples were frozen, thawed, and dehydrated either by centrifugation or compression. Freezing-thawing-dehydration treatment was very effective for vegetables and fruits, their waste, and gel materials to reduce their weight by 40 to 60% although it was not so effective for meat and fish. The average water content of samples decreased from 86.0% to 76.9% after the treatment. From these results and statistical data, 37% reduction in weight was expected for the total kitchen refuse. Freezing-thawing-dehydration is expected to be effective for transportation, incineration, and composting of food waste.
The water diffusivity of white potatoes measured using pulsed-field-gradient nuclear magnetic resonance (PFG-NMR) before and after heating reveals behavior contradictory to its simple starch-water counterpart. When heat-treated, water diffusivity increases in potato tubers, while it decreases in starch-water mixtures. Parallel investigation with polarized light microscopy and scanning electron micrographs seems to show that water migrates from the outer cell during the heating process. Results for unheated and heated edamame and adzuki were consistent with potatoes.
In the tofu production process, quality evaluation of soybean is most important to control the tofu quality at a constant because the quality of soybean directly affects the quality of the product. In this study, the germination percentage of soybean was selected as an indicator of the quality evaluation of soybean for tofu production. Effects of storage temperature and relative humidity on the germination percentage of stored soybean, the protein contents of soybean, soymilk and tofu refuse, soymilk Brix and hardness of tofu were examined. The protein contents of soybean and soymilk were not suitable as indicators for the quality evaluation of soybean because the protein contents were'unchanged. It may be important to measure the quality of the protein because the quality of soybean may change during soybean storage. The germination percentage was suitable as an indicator for the quality evaluation of soybean because the hardness of tofu could be predicted from the germination percentage of the soybean. The quality evaluation of the soybean using the germination percentage and the soymilk Brix (protein content of soymilk) was possible.
A model for predicting changes in O2and CO2partial pressures in modified atmosphere packages of tomatoes stored at 10°C was developed by using a respiration model based on enzyme kinetics and a simple mathematical model. The respiration models of tomatoes were determined using a Michaelis-Menten-type equation without inhibition by CO2by means of a closed system experiment. Mathematical model equations were solved simultaneously by the fourth-order Runge-Kutta method using Microsoft Excel software to predict changes in O2and CO2partial pressures inside the package. The validity of the model was verified by results of simulation and an experiment using two types of model package, one containing about 0.24 kg of tomatoes with a film surface area of 0.01 m2and the other containing about 0.55 kg of tomatoes with a film surface area of 0.02 m2. The predicted values of gas composition inside the package agreed well with the experimental data. This model enables prediction of changes in O2and CO2partial pressures inside a package of tomatoes by using input variables that are used in the design of modified atmosphere packaging to prevent fruit damage caused by anaerobic respiration.
Multilayer film elements are used for clinical diagnosis. They contain all chemicals for colorimetric reaction sequence. To assay the concentration of TG (Triglycerides) in blood is important in relation to adiposis and heart diseases. We have developed a multilayer film element for determining the concentration of TG based on enzymatic analysis. There are two major assay methods of TG. TG is hydrolyzed to glycerine and fatty acids by LPL (Lipoprotein lipase) . Then, glycerine is phospholylated by GK (Glycerol kinase) . These two steps are same, but the third step is different between two methods. Glycerophosphate is oxidized by GPO (Glycerophosphate oxidase) and H2O2 is formed. H2O2, POD (Peroxidase) and leuco precursor form dye. On the other hand, NADH is produced by glycerophosphate and GPDH (Glycerophosphate dehydrogenase) . NADH, DI (Diaphorase) and NTB (Nitrotetrazolium blue) form another dye. Our method is the latter, however, this method has some defects. Because GPDH is expensive, we have changed the assay method of TG. We report some advantages of the method using GPO. It needs four minutes to determine the concentration of TG, while the method using GPDH needs five minutes per one specimen. By using this multilayer film element, we can obtain the concentration of TG easily without any other experiments except for setting the multilayer film element and specimen to an analyzer.
We examined sterile filtration of apple juice by ceramic microfiltration (MF) membrane to develop apple juice production technique in which long term storage was possible without heat sterilization. Under the operating condition at 3.5 m/s crossflow velocity and at a mean transmembrane pressure of 0.20 MPa, it was possible to get 95% permeated juice, and the average flux was about 35 l⋅m-1⋅h-1. The MF membrane after the juice treatment was cleanable by using a mixed solution of sodium hydroxide and sodium hypochlorite at 70°C for 30 min; 100% recovery of pure water flux was attained. It was confirmed that the high value on the logarithmic reduction value (LRV) ≥13.0 in challenge test using Brevundimonas diminuta and Streptococcus faecalis. The color and sensory tests after long storage periods showed that the quality of MF permeated juice was better than that of juice sterilized at 65°C for 10 min. It was concluded that the sterile filtration by ceramic MF membrane was useful to produce the high quality unheated sterilized apple juice which retained the fresh flavor and color, and it was demonstrated that this method could be used in the commercial production.
Chinquapin powder was treated with hot-compressed-water (HCW) at the temperature ranges of 170-210°C using a batch type reactor. A part of the components in Chinquapin was converted to water-solubles. The water-solubles formed by hydrolysis with the HCW mainly consisted of xylose and xylooligosaccharides derived from hemicellulose (xylan), and the water-insoluble residues mainly consisted of cellulose and insoluble-lignin (a part of lignin was converted to water-solubles) . The maximum xylose yield was about 40 wt% (dry hemicellulose base) and xylobiose yield was 11 wt% (hemicellulose base) under all reaction temperature conditions. The obtained water-soluble saccharides can be used as various chemicals, functional foods, sweeteners and so on.
Growing activity of bacteria in dried wheat noodles was estimated with colony forming curve. A straight line was obtained when the logarithm of Nx-N was plotted against incubation time, indicating that the colony was formed following a first-order reaction. The rate constants of colony appearance (λ, h-1) from the tested noodles were calculated from the straight lines; Himi udon about 0.025, Inaniwa udon 0.026-0.038. A λ of bacteria in Inaniwa udon was decreased form 0.038 to 0.026 during 8 to 15 month storage at room temperature.
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