Near infrared spectroscopy (NIRS) is being practically used for measuring sugar and acid contents in intact fruits because NIRS has advantages of easy handling, and quick and nondestructive measurement. However, NIRS involves many problems which should be considered. Regarding samples for calibration and validation, there are many factors affecting the measurement accuracy such as variety, producing place, harvesting season and year, maturity level, sample temperature, and the distribution of constituents interested. To make a robust calibration equation, proper selection of samples for calibration and validation, and suitable wavelength selection should be needed. As for sample selection, calibration samples should be representative of samples which will be measured in the future. As for wavelength selection, the main wavelength of the calibration equation should be absorption band of constituents interested. It is also important to clarify the measurement accuracy needed for practical use.
CDs are homogeneous cyclic oligosaccharides which can include various guest molecules in their hydrophobic cavities. The molecular inclusion of flavor compounds into CDs is one of these techniques, and is accepted as the most efficient way for protecting flavor. The minimum number of water molecules required was measured to encapsulate d-limonene into α-, β-, and γ-CD by means of a micro-aqueous method. Effect of ethanol on the encapsulation of flavor compounds was also investigated. Ethanol plays the autocatalytic function as water on the formation of the inclusion complex. The formation of the inclusion complex between CD and d-limonene was examined with kneading method in low water condition and under a high shear stress of kneading. Menthol retention in CD solution during one-droplet drying was calculated with selective diffusion theory considering the inclusion equilibrium between CD and menthol. The rate constants of flavor release rate, which were obtained by Avrami equation, were correlated with water vapor pressure.
Microchannel (MC) arrays with various shapes and sizes were micro-fabricated using a single-crystal silicon substrate. An emulsion is prepared by simply forcing dispersed phase fluid into continuous phase fluid through the MC. Real-time optical observations of the emulsification process can be realized with a microscope video system. The grooved type MC and module were used to characterize MC emulsification, and straight-through MC and module were developed for higher productivity. O/W-emulsions can be obtained due to its hydrophilic surface property after MC oxidation. Hydrophobic MC modified by silanization can be also applicable to W/O-emulsions. Monodisperse emulsions with average droplets sizes ranging 3-90 μm and coefficients of variations lower than 10% have been successfully obtained. Emulsification was significantly affected by MC sizes and structures. Analysis by high-speed camera revealed that the structure of terrace is so important for instability at the outlet, and spontaneous droplet formation caused by interfacial tension. An oblong straight-through MC was highly applicable to emulsification. MC emulsification was also applied to productions of solid-lipid and polymeric microsheres, and microcapsules, showing high availability. The MC emulsification technology has great potential for food, pharmaceutical and chemical industries.
Gel forming abilities of unwashed or washed meat from 19 fish species, which were caught in Tosa Bay and usually used for a fried product of fish meat paste, were investigated to make clear the properties as raw materials for Kamaboko. The fish species could be classified into the following 4 groups. Type I: Neither unwashed nor washed meat gels were disintegrated at 30-90°C. Type II: Unwashed meat gels were disintegrated at about 60°C, but washed ones were improved. Type III: Both unwashed and washed meat gels were disintegrated at about 60°C. Type IV: Unwashed meat gels were disintegrated at about 60°C, but washed ones were newly disintegrated at about 40°C. Type V fish is a novel group at the point that modori (phenomenon of elasticity deterioration) was newly induced around 40°C by washing the meat, accompanying with the degradation of myosin heavy chain. The two-step (2S) heating was carried out by heating at 40°C for various times at first step and subsequently at 80°C for 20 min. 2S heating was not effective for the washed meat gels from Type IV, whose washed meat indicates modori-phenomenon at 40°C. In order to utilize the washed meat from Type IV fish, this meat was mixed with the unwashed meat and the washed meat from the fish Type I and II which have excellent gel-forming ability. The meat pastes mixed with the unwashed meats of these two types did not exhibit the modori at 40°C, while those with the washed meats exhibited it. However, the modori at 60°C occurred in the mixture with the unwashed meat of Type II. Therefore, it is necessary to take attention to the heating temperature when the washed meat of Type IV is mixed with meats except for the unwashed meat of Type I, although the gel-forming ability of it at 80°C was improved.
Flexible packages, which consist of thin films and make shapes with contents, attract more attention than rigid packages (which have rigid shapes itself) as minimal environmental impact packaging materials that are suited for recycling-oriented society. The greatest feature of flexible packages is the point that their function can be improved by laminating various plastic films and aluminum foil. I explain plastic films and the laminating technology used for flexible packages. Since most flexible packages are meant for use in direct contact with foods, their safety and sanitary conditions are very important and are subject to control by laws and regulations such as Food Sanitation Law and self-imposed standards of allied hygiene associations. Transparent metallizing high-barrier package materials and automatic opening microwavable retortable pouches are taken up as the latest technology of flexible packages and explained.
This paper reports the effect of sodium chloride on freeze concentration of food components. Freezing and thawing was conducted on various combinations of food component, i.e. glucose-sodium chloride, dextrin-sodium chloride, egg albumin-sodium chloride and milk protein-sodium chloride. Sodium chloride and glucose had greater freezing point depression than dextrin and protein. The freeze concentration effect in glucose solution dropped as the sodium chloride concentration in the aqueous solution increased. Freezing and thawing could concentrate both dextrin and protein solutions in their first fractions with addition of sodium chloride. The presence of sodium chloride caused freezing point depression in both dextrin and protein solutions and affected the freeze concentration of the food components by freezing and thawing.
An iron kettle has widely used for the tea preparation for the long time in Japan. However, low quality and low price iron kettles have spread on the market in Japan recently. We investigated the water quality change during heating with iron kettle to elucidlate the quality scientifically. Tap water was heated by LPG gas heating using Nanbu-made (Mikasa and Marunanbu type) or foreign-made iron kettle, and then, the water quality change was analyzed. In heating of Nanbu-made iron kettles, water quality change were small. On the other hand, in the case of a foreign-made iron kettle, it had the significantly changed, that is, pH rose from 7.00 to 9.40, and total hardness changed from 19.00 to 53.00 mg/L during 30 minutes heating. Furthermore, green tea was prepared using the hot water from both kinds of iron kettle, and then, components were analyzed. Amino acids and tannic acid elution into the tea were more rapid by using Nanbu-made iron kettles compare with foreign-made kettles.
The small intestine plays a very important role in digestive absorption of food. Whether certain diets are good for physical conditions can be judged by bowel sounds. However, there are problems with using bowel sounds to judge food quality. In this paper we discuss methods for improving the judgment of food quality on the basis of bowel sounds. A high sensitivity acceleration sensor was placed on the surface of the abdomen in four places to detect bowel sounds. A multi-signal processing system consisting of A/D converter, DAT, HD and a personal computer was used for the data analysis. Independent component analysis (ICA) for pretreatment of data signals and application of six ICA algorithms improved the accuracy of bowel sound detection. The results of this analysis clearly showed an original power spectrum pattern exists in the bowel sounds. Moreover, an unknown bowel sound was detected using the standard bowel sound power spectrum as a template. The system we developed clearly detects all bowel sounds perceivable to the human ear.
Washing and sterilizing a clean room is indispensable for aseptic production, which means that the clean room usually has a wet environment. Optical particle counter (OPC) may be used to maintain and control the aseptic environment. However, an ordinary OPC can only work under low environment humidity, and therefore the environment is monitored in an intermittent manner or the environment monitoring does not start until the concentration of liquid particles in the measurement environment decreases after completion of the washing cycle. Because of these limitations, net production time is shortened, affecting the productivity. In an effort to resolve these issues, we developed a new type OPC system. Using the inertia impact of minute particles, we attempted to design, make and test a measuring system that selectively separated and removed liquid particles that would hamper the ability of the OPC. The resulting OPC system proved to be suitable for particle continuous monitoring even in a wet environment. It has also become clear that particles with 1.0 μm or larger diameters can be precluded from the object of OPC monitoring. Furthermore, it was confirmed that not only micron-size particles, but also sub-micron particles were generated in large quantities during washing and sterilizing processes.