This article reviews different studies on the gelation mechanisms and network structural characteristics in polysaccharide gels at the different length scales of observation: macroscopic, microscopic, and molecular. Rheological and micro-DSC (Differential Scanning Calorimetry) measurements represent the macroscopic viewpoints on the gelation of pure kappa-carrageenan (KC), iota-carrageenan (IC) and KC/IC mixtures. Microscopic rheological properties observed using particle tracking experiments have been used to elucidate the formation of heterogeneous networks of KC-rich and IC-rich domains in mixed KC/IC gels, and facilitate observations of their aging process. Nuclear magnetic resonance (NMR) relaxation time measurements provide information on the tumbling motion and local mobility; these molecular-level experiments are presented for agar, agarose, native gellan and deacylated gellan chains. NMR diffusion measurements of gelling and probe polymers give insights into the conformational changes, aggregation and network formation, and aging mechanisms, and are presented for all studied polysaccharides.

A flavor lexicon of milk coffee was developed based on the perceptions of Japanese consumers. To collect an exhaustive set of sensory terms for milk coffee, sixty types of samples were prepared. The samples were presented to 203 untrained panelists, and 456 sensory terms were collected. Following qualitative and quantitative screening, 53 terms were selected. The validity of the 53 terms was confirmed by check-all-that-apply (CATA) questions for six samples. The results indicated that the frequency of use of 42 terms was significantly different for the samples, and all terms were used at least once. In addition, the configuration of the six samples in the correspondence analysis of the CATA results was similar to that for a quantitative descriptive analysis conducted on the same samples. The developed flavor lexicon and its application to CATA will provide a new means for evaluating milk coffee from the perspective of Japanese consumers.

In Japan, the empirical method for preventing root vegetable collapse is to place them in room temperature water and then heating them. This study aims to determine the effects of water temperature increase rate on the softening and optimum boiling duration of the Japanese radish and potato. We found that the lower the rate of increase in water temperature, the lower the softening rate constants (k) of both the radish and potato. With decreasing rates of water temperature increase, the optimum boiling duration of radish increased. However, because the potato softened easily before boiling, the difference in optimum boiling duration among all rates of water temperature increase was very small. The k and degree of methylation (DM) of pectin showed a linear relationship, which suggested that the decrease in DM is the main reason for the reduction in k at low rates of water temperature increase.

We tested a continuous inline food-drying system that consists of a conveyor belt passing through three chambers containing Aqua-gas^® (AQG), superheated steam (SHS) in the near-anaerobic state, and cooling nitrogen or carbon dioxide gas. Common viable and coliform bacteria were sterilized by the AQG, SHS, AQG→SHS, and steaming treatments. The SHS, AQG→SHS, hot air (HA) drying, and steaming→HA drying treatments each produced dried perilla leaves with a final wet weight-based water content of <10 %. Most of the treatments preserved the α-linolenic acid content. The rosmarinic acid content was greatly increased by SHS and AQG→SHS treatment but greatly decreased by HA drying treatment. The AQG treatment produced significantly higher antioxidant activity, which was greatly increased by the SHS and AQG→SHS treatments due to the increase in the total soluble polyphenol content by the blanching effect, but the activity was greatly decreased by HA drying treatment. Radical-scavenging activity was well correlated with the total soluble polyphenol content. This prototype continuous inline AQG drying system both retains functional components and enables more efficient processing.

In a batch reactor, 0.01 mol/L arginine, lysine, or histidine, which are natural basic amino acids, was used as an environmentally friendly, “green”, catalyst to isomerize 0.2 mol/L ribose to the corresponding ketose, ribulose, at 110 °C. The changes over time in the conversion of ribose, the yield of ribulose, pH, and the absorbance of the reaction mixture at 280 and 420 nm were measured. The yield of ribulose was highest (ca. 8.5 %) when arginine was used as a catalyst, followed by lysine. Ribulose was also produced with histidine, but the yield was very low (ca. 1.5 %). On the other hand, the coloration, which was evaluated by the absorbance of the reaction mixture at 280 and 420 nm, was highest when lysine was used, followed by arginine. Therefore, arginine was the most suitable green catalyst for isomerizing ribose to ribulose among the three basic amino acids tested.

A This study aimed to employ three reducing sugar (fructose, galactose and glucose)-lysine mode reaction systems (FLMRS, GaLMRS and GLMRS) in examining the influences of reaction conditions, such as initial pH value, reaction temperature, and time on the N^ε-(1-Carboxymethyl)-L-lysine (CML) formation. Results indicated that the initial pH value were positively correlated with the CML content in the system. However, the influence of reaction temperature and time on the CML content in the system displayed an initial increasing trend followed by a decline. A temperature of 100.58/125.24/123.24 ° C and a heating time of 30.00/24.66/25.38 min maximized the formation of CML on FLMRS/GaLMRS/GLMRS and resulted in a CML production of 2.11/1.39/1.34 mmol/mol lysine of response surface methodology. The results of this study would provide particular theoretical support for studying the formation mechanism and control methods of CML in food processing.

Espuma was examined for its suitability in meals for older adults with masticatory disturbance or dysphagia. Espuma is foam-style food prepared from pureed ingredients mixed with emulsifying agents and combined with nitrous oxide gas. Three whipping creams were used to prepare espuma: milk fat, vegetable fat, and soy milk cream. Boiled salmon was mixed with each cream to create the espuma foods and the resultant mixtures were examined. The soy milk cream espuma sample did not show syneresis, indicating that it was extremely suitable as a coagulating agent for espuma food. The texture of the boiled salmon in soy milk cream satisfied the Consumer Affairs Agency standard for people with dysphagia. Endoscopic examination of swallowing revealed little to no laryngeal residue. The results showed that boiled salmon in soy milk cream prepared as espuma food is suitable for use in meals for older adults with masticatory disturbance or dysphagia.

In the present study, the effectiveness of sterilization of peracetic acid (PA) solution and sodium hypochlorite (SH) solution for several fungi (Penicillium sp., Cladosporium sp., and Fusarium sp.) attached on the cut surface of sweet potato (Ipomoea batatas) was evaluated. The mixture of each strain isolated from rotten sweet potatoes was inoculated on the cut surface of presterilized sweet potato blocks. Further, each inoculated cut potato was washed with water, 200 mg/L SH, a mixture of SH, and 100 mM acetic acid (SH+AA), or 20–80 mg/L PA for 5 min at room temperature. Comparing with the untreated ones (4.2–5.1 log CFU/mL), the 80 mg/L PA washing could reduce 2.2, 2.2, and 2.0 log CFU/mL of Penicillium, Fusarium, and Cladosporium species, respectively. The increasing concentration of PA resulted in an increase the fungicidal efficiency. The use of 80 mg/L PA solution was suggested to be more highly effective than the one of (pH controlled) SH solution to control the spoilage fungi on cut sweet potato.

Combined medium-high hydrostatic pressure (MHHP) and medium-high temperature (MHT) treatment is an effective process for liquid impregnation and food pasteurization. Although several fruit processing additives are known to inhibit polyphenol oxidase (PPO), the effect of additives on PPO activity after MHHP+MHT treatment has not been studied. This study describes the effect of citric acid and calcium chloride on PPO activity after MHHP+MHT treatment. The lyophilized powder of Fuji apples was subjected to MHHP+MHT treatment in a solution containing sucrose, citric acid, and calcium chloride, and residual PPO activity was measured. Combined citric acid and calcium chloride additive use reduced PPO activity more effectively than their individual use. Using this additive combination to decrease PPO residual activity in conjunction with MHHP+MHT proved to decrease apple compote browning homogeneously, which we believe will prove a useful method in preservation processes.