Functional food compounds with physiological activity are unstable against light, heat, oxygen and so on. Microencapsulation with wall materials and emulsifier is an important technique to form functional food and flavor powders in the food industry to prolong the shelf life of functional oils and flavors. Encapsulation techniques are classified into three methods: physical methods (spray drying, freeze-drying, extrusion, and crystal transformation), chemical methods (molecular inclusion, and coacervation) and bacterial cell methods (yeast and other cells). Among the various encapsulation techniques, spray drying is cost-effective since the product can be obtained continuously in a one-step operation. One of the key steps in the spray drying technique is emulsion preparation, which has a marked influence on the surface-oil content in the powder. Molecular inclusion with cyclodextrins (CDs) is also useful method to encapsulate hydrophobic functional food compounds such as polyunsaturated acids in CD cavity. In this paper, the encapsulation of functional lipids was discussed in the effect of oil-droplet diameter and particle diameter on the stability of functional lipids. Molecular inclusion was reviewed about the formation of flavor and a gas such as 1-methylcyclopropene.

Typical delicatessen foods have shorter shelf life, which may cause food loss. Heat treatment has been used to extend shelf life, but heat treatment will cause loss of freshness and browning of ingredients. To solve these unfavorable issues, we focused on high-pressure processing, or HPP, as non-thermal processing and started researching. Compared to heat treatment, our knowledge of HPP still remained limited. Therefore, many examinations were necessary for product design, safety, and quality control operations. As a result of these examinations, the “Producing method for maintaining freshness by high-pressure cold pasteurization” was established for the first time in Japan to utilize HPP for commercial delicatessen foods. This technology is expected to contribute to reducing food loss and solving environmental issues. We are currently utilizing this technology for delicatessen foods, and aiming to make it one of our main food processes in the future.

This study aimed to apply the multiband optical sensing information to comprehensive quality evaluation of foods and agricultural products and to operations in food processing by focusing on the characteristics that could grasp the multifaced nature of molecules. The topics of the applications to the fundamental aspects relating to the measurements of food and biological information, comprehensive quality evaluation of foods and agricultural products, and the novel food process operations using the electromagnetic radiation were described. A multiband optical sensing method for associating micro-bioinformation such as gene expression and changes in metabolites with macro-bioinformation such as appearance formed through metabolism could be developed based on the experimental and analytical results. Additionally, it was considered that the developed sensing methods could be extremely effective for advanced food processing methods using the scientific and objective information. Furthermore, it was presented the important and quantitative information for the design of the use of electromagnetic waves in drying and pasteurization operations. Consequently, this study could contribute the development of advanced food system based on the optical sensing information.

This study demonstrates correlations between water activity (a_w) and albumin denaturation temperature (ADT), and the density of intermolecular hydrogen bonding of free water (D_oh(w-s)) in hydrogenated starch hydrolysate (HSH) solutions. We first measured the osmotic concentration (c) of sugar solutions of known molecular weight (MW) and found a significant linear relationship between 1/c and MW (r²＝0.998, P＜0.0001). Next, D_oh(w-s) was calculated using the MW estimated from this relationship and the glass transition temperature, and the relationships between D_oh(w-s) and a_w, and between D_oh(w-s) and ADT were clarified. Linear regression analysis revealed a significant and positive linear relationship between D_oh(w-s) and a_w (r²＞0.900, P＜0.0001), and a significant and negative linear relationship between D_oh(w-s) and ADT (r²＞0.900, P＜0.0001). The findings also showed that the ADT of the HSH solutions could be estimated using a_w, which is easy to measure, and that the Spearman correlation between the measured and estimated ADT is significant (r²＝0.930, P＝0.00280). The results suggest that the ADT of HSH solutions can be estimated at any HSH concentration and any sugar composition by measuring the a_w values of the solutions.

In this study, white rice bran, which is a by-product in sake industry, was applied to rice flour blended bread, taking its high degree of damaged starch into account. We prepared a standard formulation of rice flour blended bread by replacing 20% of wheat flour with rice flour and, further, prepared two kinds of testing formulations of bran blended bread by half or all of the rice flour with the white rice bran. Degree of the damaged starch of the bran use in this study was 52.8%. Development of dough volume and specific loaf volume of the bran blended breads were decreased with increase of the bran content but the measured values satisfied the requirements of bread making. The crumbs of the bran blended breads accumulated maltose, which would be generated from damaged starch by wheat flour endogenous β-amylase. The bran blended bread decreased the water loss from the crumb and kept softness during 72 h storage, which indicates the addition of the bran would retard aging of the bread. Furthermore, various sensory evaluations were almost corresponding to the measurements and revealed that the crumb with the bran was sweeter than the crumb without the bran. These results suggested that the generated maltose in the bran blended bread prevented starch retrogradation by steric hindrance of starch molecules crystallization and kept moist with its high capacity for water holding. Although further research should be required, white rice bran could be an interesting and promising material of rice blended bread.

Krill oil extracted from Euphausia pacifica, known as Isada on the Sanriku coast, is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as well as other polyunsaturated fatty acids (PUFAs). We previously reported that the oxidation of EPA and DHA in microencapsulated krill oil with a low surface-oil ratio was interdependent and the contribution of other n-3 PUFAs on the oxidation was not considered (J. Oleo Sci., 70, 633 (2021)). This study demonstrated that EPA and DHA were also interdependently oxidized in microencapsulated krill oil with both low and high surface-oil ratios even though the contribution of oxidized PUFAs on the oxidation of EPA and DHA was taken into consideration.