Study on Shrinkage Deformation of Food in Microwave-Vacuum Drying

Selected Papers from the 19th International Drying Symposium (IDS 2014), Part 2Drying shrinkage is an important problem in the food industry. Focusing on microwave vacuum drying, we study the mechanism of deformation due to shrinkage of the food structure. A relationship between the strain and the water content is introduced for a finite element analysis. The temperature and water distributions are obtained by a finite difference method with the use of a variable permeability and diffusion coefficient depending on the water content. Comparisons with experimental data on radishes, carrots, and tofu indicate that the present model can express the deformation as well as the water content inside the materials

Possibility of cryopreservation of medaka eggs using liquid meniscus

The First Pacific Rim Thermal Engineering Conference (PRTEC2016), Marchi 13-17, 2016, Waikoloa Beach Marriott Resort & Spa Hawaii's Big Island, USAThe cryopreservation of fish eggs is an important subject in the field of fishery and preservation of biological species. Thus far, there has been no success in the preservation of fish eggs because of the large size of the eggs and the thick external shell. This paper discusses the effectiveness of using the liquid meniscus formed around the egg for protecting its morphology. Freezing and thawing experiments of medaka eggs were performed under different freezing conditions, and the hatching rate of the egg was examined. Before freezing, the eggs were dehydrated at room temperature in order to reduce the effect of volume expansion caused by freezing. It was confirmed that 100% of the eggs dehydrated by 15% or less were successfully hatched. In the freezing process, a medaka egg was placed on a hydrophobic cooling plate and a thin liquid meniscus was formed around the hydrophilic egg surface. An aqueous solution of trehalose was used as the liquid meniscus as well as a cryoprotectant to prevent damage caused by freezing. Cryopreservation of the egg was not successfully performed for all processes, including intracellular freezing; however, 80% of the eggs were alive even after freezing of the external meniscus. Therefore, it is confirmed that the liquid meniscus is effective for the cryopreservation of the external shell. The liquid meniscus can reduce the physical stress due to extracellular ice growth. Moreover, since the liquid meniscus system has a low heat capacity, the thermal process is easy to control compared to the conventional method. We concluded that the present method can be used for the cryopreservation of fish eggs

Ambient temperature drying of therapeutic protein solution with use of microwave

[EN] High quality drying of therapeutic protein-solution is important in medical and pharmaceutical processing. Freeze-drying is mostly used, but it takes a long drying-time and causes damages of protein structures. In order to improve the drying quality, we propose a microwave vacuum drying performed at ambient temperatures under low-pressure conditions. We are focusing on the Parma-Zyme method for the evaporative drying of protein solutions such as egg white or lysozyme with vitrification. Circular dichroism (CD) spectroscopy is used to detect protein conformation changes due to the drying, and it is found that the ambient temperature drying can preserve the protein conformation.CD analysis and chemical works were supported by Prof. Shigeori Takenaka, Department of Applied Chemistry, Kyushu Institute of Technology. This study was financially supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research, Project No. 17K18843.Tsuruta, T.; Ogawa, T.; Abe, R.; Tanigawa, H. (2018). Ambient temperature drying of therapeutic protein solution with use of microwave. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 651-658. https://doi.org/10.4995/IDS2018.2018.7537OCS65165

Improvements in the Subjective Sleep of Japanese Middle-aged Managers from the Consumption of an Edible Film Containing Crocetin

It has been reported that Japanese people sleep for an average of 7 hours and 22 minutes per night, with those in their 40s and 50s sleeping the least. This is much less than in other developed countries. Aging has also been reported to decrease the total sleep time and sleep latency as well as increase wake after sleep onset (WASO). Crocetin is a carotenoid with antioxidant activity. It has been reported that 14 consecutive days of crocetin intake increases delta power during sleep and decreases WASO. However, the benefits of short-term ingestion have not been clarified. In this double-blind, randomized crossover study, we examined the effects of crocetin-containing edible films consumed for seven consecutive days on the sleep quality of healthy Japanese subjects working in management positions who were aged 45 years or older.The study participants comprised 20 subjects (12 males and 8 females; mean age 50.4 ± 4.8 years; body mass index (BMI) 22.5 ± 2.7). An electroencephalography (EEG) measuring device (InSomnograf®) was used to measure sleep objectively and a questionnaire, OSA Sleep Questionnaire MA version (OSA-MA) was used to assess sleep subjectively upon waking. The crocetin group demonstrated significantly higher values of OSA-MA Factor 3 (frequent dreaming) than the placebo group (placebo: 46.8 ± 6.9; crocetin: 49.5 ± 7.4). No differences were observed for the other four factors. No differences were observed in the sleep parameters determined with InSomnograf®.Our findings suggest a new effect of crocetin on sleep quality of frequent dreaming

固体高分子形燃料電池内の水分挙動に及ぼすガス流路形状の影響 : 第2報,実験と格子ガス法三次元数値解析による検討(熱工学,内燃機関,動力など)

Water management is the most important subject in the development of the Polymer Electrolyte Fuel Cells (PEFC) with high performance and high reliability. Experimental and three-dimensional numerical study has been done for the serpentine channel. Two kinds of the channel width, 2mm and 8mm, were selected. It is found that the rib of each separator plays as the coverage to reduce the escaping of the water content from the GDL to the channel

固体高分子形燃料電池内の水分挙動に及ぼすガス流路形状の影響 : 第1報,格子ガス法を用いた二次元数値解析による検討(熱工学,内燃機関,動力など)

Effect of water production on the performance of the fuel cell has been studied numerically. We have done two-dimensional simulations by using the Lattice Gas Automaton (LGA) method in order to analyze the gas flow and water distributions in the different type of flow passages. Three kinds of flow passage, that is, serpentine-type, straight-type and column-type were selected and their performances were compared. The results show that the serpentine-type flow is effective for the drainage and the electric generation performance and the electrode of hydrophilic surface is effective for reducing the plugging phenomenon. It is found that the LGA method is a promising tool for the analysis of the fuel cell performance

The possible interplanetary transfer of microbes: assessing the viability of Deinococcus spp. under the ISS environmental conditions for performing exposure experiments of microbes in the Tanpopo mission

To investigate the possible interplanetary transfer of life, numerous exposure experiments have been carried out on various microbes in space since the 1960s. In the Tanpopo mission, we have proposed to carry out experiments on capture and space exposure of microbes at the Exposure Facility of the Japanese Experimental Module of the International Space Station (ISS). Microbial candidates for the exposure experiments in space include Deinococcus spp.: Deinococcus radiodurans, D. aerius and D. aetherius. In this paper, we have examined the survivability of Deinococcus spp. under the environmental conditions in ISS in orbit (i.e., long exposure to heavy-ion beams, temperature cycles, vacuum and UV irradiation). A One-year dose of heavy-ion beam irradiation did not affect the viability of Deinococcus spp. within the detection limit. Vacuum (10−1 Pa) also had little effect on the cell viability. Experiments to test the effects of changes in temperature from 80 °C to −80 °C in 90 min (±80 °C/90 min cycle) or from 60 °C to −60 °C in 90 min (±60 °C/90 min cycle) on cell viability revealed that the survival rate decreased severely by the ±80 °C/90 min temperature cycle. Exposure of various thicknesses of deinococcal cell aggregates to UV radiation (172 nm and 254 nm, respectively) revealed that a few hundred micrometer thick aggregate of deinococcal cells would be able to withstand the solar UV radiation on ISS for 1 year. We concluded that aggregated deinococcal cells will survive the yearlong exposure experiments. We propose that microbial cells can aggregate as an ark for the interplanetary transfer of microbes, and we named it ‘massapanspermia’