Miki Yoshimura

In this study, the effects of wheat noodles alone(C) and mixed with crystalline cellulose (SA) on the physical and sensory properties and structure of noodles and gels after boiling, freezing, and thawing were investigated. The initial elastic modulus and firmness at strain 0.3 were substantially higher for frozen and thawed noodle gels (CG-F, SAG-F) than for noodle gels (CG, SAG). The breaking stress at strain 0.42-0.63 was significantly lower for CG-F and SAG-F than for CG, SAG. The rupture stress of SAG-F was significantly higher than that of CG-F, suggesting that the crystalline cellulose mixture suppressed the softening caused by freezing and thawing operations. For the sensory evaluation, the mixed noodles after freezing and thawing(SA-F)were significantly evaluated to be firmer, stiffer, and less watery than the wheat noodles after freezing and thawing (C-F), suggesting that crystalline cellulose maintains the water distribution state. Synchrotron radiation X-ray micro-CT observations revealed that there was a gap structure and starch aggregation inside the dried noodles. In the gap structure of the crystalline cellulose mixed noodles (SA), a lot of starch aggregation was observed, suggesting that they retained their firmness after freezing and thawing.

Resistant starch (RS) displays similar physiological properties as dietary fiber. In this study, bread making properties and sensory acceptability of bread replaced with RS type 4 (RS-4, chemically modified starch) were evaluated. Distarch phosphate potato, rice and tapioca starch, phosphated distarch phosphate sweet potato and wheat starch were used as RS-4 source. RS-4 replaced 20% (w/w) of wheat flour, and each of the breads were thereby considered RS-4 breads. Bread without RS-4 was called Control bread. RS-4 breads were shown to have less specific volume than Control bread. Hardness of RS-4 breads was higher than that of Control bread. It was observed by SEM that RS-4 were not gelatinized in bread. However, RS-4 breads obtained overall acceptability similar to Control bread in sensory evaluation.

The objective of this study was to evaluate the appearance, texture, palatability, and nutritional content of apple chips fried either under vacuum or at normal pressure. Furthermore, we also evaluated the effects of heating temperature (75°C, 85°C, 95°C) on the properties of apple chips fried under vacuum. Vacuum-fried apple chips (VFACs) were brighter than normal-pressure-fried apple chips (NFACs). A palatability evaluation revealed that the VFACs were lighter in color, smelled better, less greasy, had a more suitable texture, and tasted better compared to NFACs. VFACs had a significantly higher vitamin C content and lower amounts of lipid peroxidation products compared to NFACs, indicating that oxidation was suppressed during the processing of VFACs. A palatability evaluation revealed that VFACs that were heated at 75°C were lighter in color, less greasy, and tasted better compared to VFACs that were heated at 95°C. VFACs that were heated at 75°C had a significantly higher vitamin C content compared to VFACs that were heated at 95°C, indicating that the aminocarbonyl reaction was inhibited and oxidation was suppressed during the processing of VFACs at 75°C.

The aim of this study was to determine the physical properties and structural characteristics of wheat noodles after various storage periods. The samples were evaluated after 0, 6, 12, and 24 months of storage. X-ray computed tomography images of sections from dried noodle samples that had been stored for 12 and 24 months showed surfaces with large interstitial structures and high absorption coefficients. Differential scanning calorimetry indicated that as the storage period increased, the enthalpy per 1 mg of dried noodle sample tended to increase, and the first and second endothermic peaks shifted toward lower and higher temperatures, respectively. Such changes would be expected to retard starch gelatinization and protein denaturation.

シカ肉は蛋白質・鉄分を多く含み、脂質含量が低い。また、脂質代謝に関与するアミノ酸誘導体であるカルニチンを多く含み、栄養性・機能性を有している。シカ肉加工品では、プロテアーゼ活性を含む麹を利用することで、総遊離アミノ酸量が増加し、軟らかく嗜好性が向上する。シカ肉調理では焼く・煮る・揚げる・スチーム加熱・マイクロ波加熱の調理法により、放出肉汁量と硬さ、カルニチン量に違いがみられる。シカ皮由来のコラーゲンペプチドの物性と熱的挙動は、その分子量および分子量分布、濃度に大きく影響すると推察された。

Resistant starch (RS) is a form of starch that is not digested and absorbed in the stomach and small intestine, but passes to the large intestine. RS displays similar physiological properties to dietary fiber. In this study, bread making properties and sensory acceptability of bread replaced with RS type 4 (RS-4, chemically modified starch) were evaluated. Hydroxypropylated tapioca starch (HPTS) and cross-linked phosphate tapioca starch (CLTS) were used as RS-4 sources. RS-4 (20％) was used to replace (w/w) wheat flour, and the resulting breads were called RS-4 breads. Bread without RS-4 was called WF-bread. RS-4 breads showed lower fermentation volumes on fermentation tests and specific volume of bread than WF-bread. Hardness of RS-4 breads was higher than that of WF bread. The color of RS-4 breads was different from WF bread. However, RS-4 breads obtained overall acceptability similar to WF bread in sensory evaluation.

The objective of this study was to evaluate the appearance, texture, palatability, and nutritional content of vegetable chips fried in either vacuum or at normal pressure. Scanning electron microscopy revealed that vacuum fried chips (VFCs) displayed dehydrated cell walls, whereas normal-pressure fried chips (NFCs) appeared to be coated with a film of oil. VFCs were brighter and more vivid than NFCs. A palatability evaluation revealed that VFCs smelled better and were less oily, possessed a more suitable texture, and had an improved taste compared to NFCs. Using rupture measurements, a certain trend in VFCs and NFCs was not observed. VFCs possessed a significantly higher vitamin C content and significantly lower lipid oxide content compared to NFCs, indicating that oxidation was suppressed during the processing of VFCs. Furthermore, the antioxidant capacity of VFCs was lower than that of NFCs, indicating that the aminocarbonyl reaction during cooking was inhibited under vacuum.

［Aim］ We investigated the physical properties, palatability, and chewiness of fish meat after treatment with a texturizer and/or different heating conditions (normal pan or pressure cooker). ［Methods］ Fish meat samples were immersed in distilled water or 3％ texturizer solution and then heated in either a normal pan or pressure cooker. We measured the compressive stress, hardness, cohesiveness, and adhesiveness of the samples, and employed young and elderly testers for sensory evaluation. The young testers also underwent electromyography (EMG) . ［Results］ Samples treated with texturizer had smaller weight reduction rates and lower values of compressive stress and hardness than did samples that were not. The samples treated with texturizer were evaluated favorably in sensory evaluations by both the young and elderly testers, who described the fish meat as soft, cohesive, easy to chew, easy to swallow, palatable, and tasty. For the fish meat treated with texturizer, EMG showed a reduced number of chews from the start of the oral preparatory phase until the oral transit phase of swallowing. Treatment with texturizer shortened the active mastication period and oral preparatory time, and also decreased mastication effort. No difference in softening was observed between the different heating methods. ［Conclusion］ We confirmed that the use of a texturizer improved softening due to enzymatic protein degradation and moisture retention by sodium bicarbonate.

The effects of soy protein isolate (SPI) on the gelatinization of rice flour (RF) were studied as a function of mixing ratio by compression measurements, differential scanning calorimetry (DSC), and confocal scanning laser microscopy. The total concentration was 16.7%w/w, and the SPI/RF ratios ranged from 0:10 to 10:0. Gels with SPI/RF ratios of 0:10 to 4:6 showed a decrease in Young's modulus, compression stress, and compression energy with increasing SPI concentration. On the other hand, gels with SPI/RF ratios of 7:3 to 10:0 showed an increase in the above-mentioned values as the SPI concentration increased. The concentration- dependent graph of Young's modulus appeared to follow a convex downward curve. The DSC endothermic peak appearing upon the gelatinization of RF shifted slightly to higher temperatures while the enthalpies of the SPI/RF mixtures decreased with increasing SPI concentration. The results of the compression test and DSC changes suggested that SPI inhibited RF gelatinization. The results of confocal laser scanning microscopy confirmed the phase separation of SPI and RF mixture.

Wistar系の3週齢雄性ラットを用いて、コントロール群(C群)、制限食群(PF群)、ビオチン欠乏群(BD群)の3群に分類した。BD群にはAIN-93G組成ビオチン欠乏試料を与え、C群、PF群にはビオチン欠乏飼料にビオチンを2mg/kg添加したコントロール飼料を与えた。味覚試験は飼育3週目と7週目に行い、8週間飼育後、イソフルラン麻酔下で開腹し、採取した血液から血漿を分離し、ビオチン量測定に用いた。その結果、BD群の血漿および肝臓中のビオチン量がC群、PF群と比べて有意に低下した。飼育4週目以降、BD群は脱毛や摂取量と体重低下が認められた。また、塩味嗜好試験では、塩味の忌避濃度においてBD群の嗜好率がC群とPF群と比べて高値を示した。2回の味覚試験を比較すると、7週目の塩味試験におけるBD群の嗜好率が低下した。苦味嗜好試験においては、BD群の嗜好率がC群、PFより高値であった。以上の所見より、ビオチン欠乏が味覚に影響している可能性が示唆された。

This study examined the influences of commercial gelling agents on the texture of jelly foods. We assessed the physical properties and sensory characteristics of jelly foods prepared using three commercial gelling agent preparations: Agent A, Agent B, and double-concentration Agent B (hereafter called "C") Commercial gelling agents were dissolved in taro paste, spinach paste, and salmon paste, temperature was adjusted to either 20°C or 65°C, and physical properties and sensory characteristics were measured. Hardness and adhesiveness were decreased and cohesiveness was increased in the jelly foods at 65°C. Results revealed that there was little influence of temperature and ingredients on foods gelled with Agent A and that Agent A was suitable for jelly foods at 65°C. Evaluations of texture and sensory characteristics revealed that foods gelled with Agent A were moderately softer, less adhesive, less sticky, remained in the mouth to a lesser degree, and had higher palatability than foods gelled with Agents B or C. The results suggest that when providing jelly foods, physical properties and sensory evaluation differ depending on the main components, temperature, and concentration of the gelling agents as well as the components of the food to be gelled.

In the present study, we examined the effects of heating and treatment with commercial enzymes on soybean texture. Soybeans were prepared by boiling for 60 min with (NB) or without (NA) enzyme treatment, or in a pressure cooker for 3 min with (PB) or without enzyme treatment (PA). Soybean weight, physical properties, and protein content were analyzed. Mastication was evaluated by electromyography and palatability was assessed using a sensory test. Our experiments revealed that weight and cohesiveness increased markedly in PA and PB soybeans compared to that in NA and NB soybeans. In addition, PA and PB soybeans had low penetration stress, short chewing time, and high palatability. Furthermore, NB and PB soybeans required fewer chewing cycles and shorter chewing time and were found to be softer and easier to chew during a sensory test. These results demonstrate that it takes less time for samples to become softer, easily aggregate, and become palatable, when they are treated with enzyme and heated in a pressure cooker.

We examined the effects of the concentration and molecular weight of collagen peptide (CP) added to rice flour cake on its taste and physical properties based on the density of cake batter, properties such as specific volume, weight variation, and texture as well as the appearance and sensory evaluation of the cake. Three types of CPs isolated from porcine skin, namely, CP1000, CP5000, and CP10000, with molecular weights 1.1, 5.4, and 10 kDa, respectively, were investigated. We found that the addition of 2% (w/w) CP5000 resulted in a cake batter of least density and improved the color, sweetness, softness, and moistness of the cake. Further, these cakes were easier to swallow and showed a higher overall palatability than cakes without CP5000. Based on these findings, we concluded that the use of CP of medium molecular weight, consisting of both low and high molecular weight fractions, and at 2% (w/w) concentration was needed to make puffed and delicious rice flour cake.