This study demonstrated the vasorelaxation effect of small peptides and their underlying mechanisms as a novel function of blood pressure-lowering peptides. In particular, the small peptide Trp-His elicits not only a vasorelaxation effect in isolated aorta but also an anti-atherosclerotic effect in vivo. Viewing the composition of food products as a mixture of many components, the synergistic effect on vasorelaxation by the combination of multi-food compounds was also investigated. In this review article, we summarize the aforementioned beneficial effects of food compounds on vascular functions as well as the intestinal absorption and bioavailability of these bioactive peptides, clarified by using LC-MS and/or MALDI-MS imaging analyses.

The odorants contributing to the characteristic aroma of Darjeeling black tea infusion were investigated using aroma extract dilution analysis (AEDA) of the volatile fractions of eight black tea infusions, prepared by a combination of the adsorptive column method and the solvent-assisted flavor evaporation (SAFE) techniques. Principal component analysis (PCA) of the flavor dilution (FD) factors of all the detected odorants in the AEDA revealed that 3,7-dimethyl-1,5,7-octatrien-3-ol (floral: FD factor 4³), 2,3-diethyl-5-methylpyrazine (roasty: FD factor 4⁵) and an unknown compound (green, meaty: FD factor 4⁶) were characteristic odorants of the Darjeeling infusions. In order to identify the unknown compound, the simultaneous distillation extraction (SDE) extract of Darjeeling tea leaves was highly purified by a combination of silica-gel column chromatography and off-line two-dimensional gas chromatography-mass spectrometry (GC-MS). Comparison of the GC retention indices, mass spectrum and odor quality to the authentic compound indicated that the unknown odorant was 4-mercapto-4-methyl-2-pentanone (MMP), which is known as a potent odorant of muscat grapes. Furthermore, comparison of the potent odorants of the Darjeeling tea to those of muscat grapes suggested that the muscatel flavor of Darjeeling tea is formed by the combination of linalool, geraniol, β-damascenone and MMP. In addition, the relationship between the contents of the characteristic odorants in Darjeeling tea and its unusual growing environment or manufacturing process was discussed.

Although the high stability and low-density lipoprotein (LDL) cholesterol-lowering effect of high oleic sunflower oil (HOSO) have often been reported, its sensory characteristics have not received similar attention. Therefore, in this study, we investigated the sensory characteristics of HOSO using sensory analysis as well as aroma extract dilution analysis (AEDA). A comparison between the volatiles of HOSO and four other oils, including soybean oil (SBO), rapeseed oil (RSO), palm olein (PO) and corn oil formed at 180°C revealed that HOSO had the lowest intensity of oily flavor. When fried foods, such as deep-fried tempura batter, shrimp tempura, and croquette, were prepared using HOSO and PO, the flavor intensities were obviously low. In addition, we evaluated the flavor duration of the fried foods. The result of the flavor duration test was similar to that of flavor intensity. Moreover, the overall flavor quality of fried foods prepared with HOSO was significantly higher than that of fried foods prepared with RSO. These results suggest that HOSO has a less oily flavor and is suitable for deep-fat frying. On the other hand, AEDA revealed that the volatiles from HOSO, SBO, and RSO are closely involved in the fatty acid compositions of these oils, and that not only SBO and RSO but also HOSO generate volatile components that contribute greatly to the aroma. In conclusion, it is suggested that the fatty acid composition of HOSO strongly affects its sensory characteristics, and the flavor of fried foods prepared with HOSO is not easily perceived.

The standard method prescribed in the Analytical Manual of the Standard Tables of Food Composition in Japan for measuring total iodine is not always applicable to fish, particularly when they contain large amounts of lipophilic iodine compounds. In this study, we developed a new analytical method with alkaline-ashing followed by ICP-MS (AA-ICP-MS) to cover this shortcoming in the standard method. The fish samples were ashed with potassium hydroxide and iodine was subsequently extracted with water from the ash; iodine content was then determined by ICP-MS. A single-laboratory validation of the AA-ICP-MS method showed recoveries ranging from 85±9% to 96±7%, and the difference between certified and determined values was not significant. Furthermore, both of the repeatability and intermediate precision in the RSD are 7.7%, with a quantification limit of 0.20mg/kg. Based on these results, we suggest that this AA-ICP-MS method represents a superior supplementary method for the Analytical Manual to determine 0.20mg/kg and more of total iodine specifically in fish.

Microencapsulation of flavor is an important technology whereby liquid flavor is enclosed in a carrier matrix by spray drying. In this review, the flavor release from spray-dried powder is discussed. Flavor release from the spray-dried powder could be correlated using the Avrami (Weibull) equation. In the analysis of flavor release from the powder, the unknown parameters were: the diffusion coefficient of flavor in the matrix, D_out, diffusion coefficient of flavor in the flavor droplet, D_in, and mass transfer coefficient from the powder, κ_L, which were estimated to fit d-limonene release behavior by using the partial differential equation model. First, the parameters were determined by fitting with the experimental database, assuming that the release in the matrix was the rate limiting step (D_in»D_out). The diffusion model could explain well the release characteristics of encapsulated d-limonene. For the release of encapsulated d-limonene from the spray-dried powder at 51% RH and 50°C, diffusion of flavor inside the matrix was the rate-limiting step. The encapsulated flavor powder with vacuoles showed greater release than powder without vacuole formation.

Bioencapsulation of food additives or functional ingredients aims to protect sensitive core materials during storage and consumption, transport them to designated positions in the gastrointestinal tract, and release them at appropriate rates to maximize bioavailability. Bioencapsulation systems need to be designed with GRAS (generally recognized as safe) materials, and the physicochemical processes involved in matrix formation are crucial for realizing expected functionality. From an engineering perspective, it is important to develop a processing method for obtaining products with desirable features. The author has previously reported that a freezing step represents an interesting processing tool for controlling the properties of an encapsulation system. During freezing, the growth of ice crystals in an aqueous solution results in a cryoconcentrated (freeze-concentrated) phase that is controlled by phase equilibrium. The author’s idea is to control matrix formation in the cryoconcentrated phase for optimizing encapsulation systems. This review summarizes this concept and future scope.