Development of a Time–Intensity Evaluation System for Consumers: Measuring Bitterness and Retronasal Aroma of Coffee Beverages in 106 Untrained Panelists

In order to develop products that are acceptable to consumers, it is necessary to incorporate consumers’ intentions into products’ characteristics. Therefore, investigation of consumers’ perceptions of the taste or smell of common beverages provides information that should be useful in predicting market responses. In this study, we sought to develop a time–intensity evaluation system for consumer panels. Using our system, we performed time–intensity evaluation of flavor attributes (bitterness and retronasal aroma) that consumers perceived after swallowing a coffee beverage. Additionally, we developed quantitative evaluation methods for determining whether consumer panelists can properly perform time–intensity evaluation. In every trial, we fitted an exponential function to measured intensity data for bitterness and retronasal aroma. The correlation coefficients between measured time–intensity data and the fitted exponential curves were greater than 0.8 in about 90% of trials, indicating that we had successfully developed a time–intensity system for use with consumer panelists, even after just a single training trial using a nontrained consumer. We classified participants into two groups based on their consumption of canned coffee beverages. Significant difference was observed in only AUC of sensory modality (bitterness compared with retronasal aroma) among conventional TI parameters using two‐way ANOVA. However, three‐way ANOVA including a time course revealed significant difference between bitterness and retronasal aroma in the high‐consumption group. Moreover, the high‐consumption group more easily discriminated between bitterness and retronasal aroma than the low‐consumption group. This finding implied that manufacturers should select consumer panelists who are suitable for their concepts of new products.     

Heat deterioration of phospholipids. VI. Clarification of mechanism for the new pseudo Maillard rearrangement reaction by using 2-aminoethyl dihydrogenphosphate

2,3-Dihydro-1H-imidazo[1,2-a]pyridine-4-ylium derivatives with UV absorption at 350 nm were formed by reaction of one molar of any sugar except 2-deoxysugars with two molar of phosphatidylethanolamines involving a new pseudo Maillard rearrangement reaction. To elucidate the reaction mechanism, 2-aminoethyl dihydrogenphosphate, which had a partially similar structural moiety to PE, was reacted with D-galactose. Though the UV absorption at 365 nm was not observed and the four pyridinium derivatives were also not formed in the reactant solution, the UV absorption at 286 nm and browning of the reactant solution were observed. From this reactant solution, two compounds with lambdamax at 283 nm and 297 nm were isolated and former was determined as 5-(hydroxymethyl)furfural (HMF) and later did as phosphoric acid mono{2-[2-formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]ethyl}ester (PMPEE), which is a new compound, respectively. Because reaction of PMPEE with PE leads to form the pyridinium derivatives, we concluded that a compound like PMPEE was one of intermediates in this new reaction.     

Tribological Characteristics of Imidazolium-based Room Temperature Ionic Liquids Under High Vacuum

Tribological characteristics of two imidazolium-based room temperature ionic liquids (RTILs), 1-hexyl-3-methylimidazolium tetrafluoroborate, and 1-hexyl-3-methylimidazolium hexafluorophosphate were investigated under high vacuum conditions. Viscosity–temperature characteristics and thermogravimetric characteristics of these compounds were also investigated. Imidazolium-based RTILs have relatively good viscosity–temperature characteristics that are comparable to those of multiply-alkylated cyclopentane (MAC). Thermogravimetric results showed that ionic liquids have high thermal stability and low vapor pressure. Ionic liquids showed low friction and low wear rate under high vacuum conditions, and high load-carrying capacity was observed.     

Top‐emission AMOLED display driven by organic TFTs with semiconductor layer patterned by inkjet process

We have developed an inkjet process for laying down an organic semiconductor layer in organic thin‐film transistors (OTFTs). The organic semiconductor crystallinity was improved by adjusting the contact angles of the bank, the gate insulator, and the source/drain electrodes. The threshold voltage of the OTFT was controlled by means of several surface treatments of the silicon dioxide gate insulator. The OTFTs showed a high mobility of 2.5 cm²/Vs and uniform threshold voltages of ?0.4 ± 0.7 V. We also fabricated a 4‐in., 80‐ppi active‐matrix organic light‐emitting diode on a glass substrate that showed good luminance uniformity and high moving picture quality.     

Influence of forecast accuracy of photovoltaic power output on capacity optimization of microgrid composition under 30‐minute power balancing control

A microgrid (MG) is one of the measures for enhancing the high penetration of renewable energy (RE)‐based distributed generators (DGs). If a number of MGs are controlled to maintain the predetermined electricity demand including RE‐based DGs as negative demand, they would contribute to supply–demand balancing of the whole electric power system. For constructing an MG economically, capacity optimization of controllable DGs against RE‐based DGs is essential. Using a numerical simulation model developed on the basis of a demonstrative study on an MG using PAFC and NaS battery as controllable DGs and photovoltaic power generation system (PVS) as an RE‐based DG, this study discusses the influence of the forecast accuracy of PVS output on capacity optimization. Three forecast cases with different accuracy are compared. The main results are as follows. Even with no forecast error during every 30‐minute period, the ideal forecast method, the required capacity of NaS batteries reaches about 40% of the PVS capacity for mitigating the instantaneous forecast error within 30 minutes. The required capacity to compensate for forecast error is doubled under the actual forecast method. The influence of forecast error can be reduced by adjusting the scheduled power output of controllable DGs according to weather forecasts. Besides, the required capacity can be reduced significantly if the error of balancing control in an MG is acceptable for a few percent of periods, because the total periods of large forecast error are not frequent. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(2): 20–29, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22328     

Basic study of loss reduction effect by Stator‐Tooth slits in turbine generators. comparison between calculated results of generators and basic experiments

In this study, we investigate the loss reduction effect by stator‐teeth slits in turbine generators on the basis of electromagnetic field analysis and basic experiments. First, the loss reduction effect in the generator is estimated by the 3D finite element method and the theoretical solution of eddy current loss. Next, an experiment using a simple model that simulates the stator‐core ends of the turbine generator is carried out. It is clarified that the loss reduction effect by the slits depends on the frequency, flux density, and permeability of the stator teeth because the loss reduction effect weakens with the skin effect. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(3): 17–25, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22345     

Capillary rise properties of porous geopolymers prepared by an extrusion method using polylactic acid (PLA) fibers as the pore formers

The geopolymers were prepared from sodium silicate, metakaolinite, NaOH and H₂O at SiO₂:Al₂O₃:Na₂O:H₂O of 3.66:1:1:x, where x = 8–17, and curing temperatures of 70–110 °C. Since the bending strength of the geopolymers was highest (36 MPa) where H₂O/Al₂O₃ = 9 and the curing temperature = 90 °C, these conditions were adopted. The porous geopolymers were prepared by kneading PLA fibers of 12, 20 and 29 μm diameter into the geopolymer paste, at fiber volumes of 13–28 vol%. The resulting paste was extruded using a domestic extruder, cured at 90 °C for 2 days then dried at the same temperature. The PLA fibers in the composites were removed by alkali treatment and/or heating. The highest capillary rise was achieved in the porous geopolymers containing 28 vol% of 29 μm fibers. The capillary rise of this sample, estimated by the equation of Fries and Dryer¹ was 1125 mm.     

High docosahexaenoic acid levels in both neutral and polar lipids of a highly migratory fish: <Emphasis Type="Italic">Thunnus tonggol</Emphasis> (Bleeker)

The lipid and FA compositions of various organs (light muscle, dark muscle, liver, pyloric cecum, and the orbital region) and of the stomach contents of a highly migratory fish species Thunnus tonggol (Bleeker) were analyzed. TAG and phospholipids (PE and PC) were the major lipid classes in the total lipids of T. tonggol. DHA was characteristically the major FA of all the major classes of all its organs except for only one case of liver TAG. The mean DHA contents of the various organs accounted for more than 20% of the total FA (TFA), even though it is a neutral depot lipid. However, DHA in the stomach contents, originating from their prey, fluctuated and was generally low. DHA levels were generally higher in a year (2000) when water temperatures were colder than in one when it was warmer (1998). Furthermore, DHA levels in muscle TAG were consistently high in spite of the fluctuation of those in the visceral TAG, which might be directly influenced by the prey lipids. This phenomenon suggests the physiological selective accumulation of DHA in the muscle, after the migration of the digested FA in the vascular system and absorption of the prey lipids in the intestine. In contrast, the FA composition of other species is generally variable and their DHA contents of TAG are usually less than 20% of TFA.