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.

Copyright © 2018 Japanese Society for Food Science and Technology. Soybeans exhibit excellent functionality as a food and are often a dietary component for the elderly. In the present study, we examined the effects of heating and enzyme treatment on soybean texture. Cooked soybeans were prepared either by boiling or in a pressure cooker, with or without enzyme treatment, and soybean weight and physical properties were determined. Palatability was assessed by sensory evaluation and mastication was evaluated by electromyography. The results demonstrated that soybeans treated with enzyme and prepared in a pressure cooker require less time to soften, easily aggregate, and become palatable. Here we discuss the relationship between the physical properties, palatability and mastication of cooked soybeans.

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.

【目的】本研究では、食肉の形状を変えることなく軟化させる方法について、加熱方法と食品品質改良剤の浸漬による軟化処理により、物性・嗜好性・咀嚼性の点から検討した。【方法】試料には豚ヒレ肉を半解凍で幅2cm、高さ1cmの直方体に形成後、蒸留水および3%食品品質改良剤溶液(スベラカーゼミート((株)フードケア))に15時間浸漬し、普通鍋は10分間、圧力鍋は8分間加熱を行なった。試料の浸漬前後の重量、加熱調理後の重量より、重量増加率および重量減少率を算出した。レオメーターを用い、貫入応力、貫入エネルギーおよび硬さ、凝集性、付着性を求めた。また、5段階採点法で、8項目について、若年者と高齢者を対象として官能評価を行なった。筋電図は若年者を対象とし、舌骨上筋群(開口筋)と咬筋(閉口筋)を測定し、咀嚼開始から第一嚥下までと第一嚥下以降についての解析を行った。【結果】軟化処理試料は軟化未処理試料と比較して、重量減少率が低く、貫入応力および貫入エネルギーが小さいことがわかった。また、テクスチャー特性の硬さは軟らかくなった。官能評価では、若年者および高齢者とも、軟化処理試料は軟らかく、まとまりやすく、噛みやすく、飲み込みやすく、おいしい、という回答を得た。筋電図測定では、咀嚼開始から第一嚥下までは、咀嚼回数が減少し、活動時間および咀嚼活動時間が短縮し、咀嚼活動量も低下した。また、第一嚥下以降は、食肉のまとまりがよいほど咀嚼時間が短縮した。加熱方法の比較では、圧力鍋加熱試料は普通鍋加試料より、重量減少率は高く、貫入応力、貫入エネルギーおよびテクスチャー特性の硬さが小さくなることがわかった。さらに、圧力鍋加熱・軟化未処理試料では、凝集性の著しい低下が認められた。【結論】食肉に市販食品品質改良剤を用いることにより、酵素および保水性の向上による軟化が起こり、咀嚼障害のある高齢者に有効であり、食べやすさに繋がることを明らかにした。また、圧力鍋加熱は、普通鍋加熱より貫入応力・エネルギー、硬さが低くなる傾向を示した。(著者抄録)

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.

It is necessary to control the rheological properties of bolus to prevent aspiration. To know the risk of aspiration for each person with difficulty in mastication and swallowing, it will be effective to use a test fluid which enables doctors to judge the safe range of the viscosity based on videofluorography. Since the knowledge of dominant factors which govern rheology is required, effects of shear rate, cooling rate, concentration of polysaccharides, coexisting seasonings on viscosity and viscoelasticity are overviewed. Since chemical senses are also known to affect the swallowing behavior, the relation between texture and flavor release is described briefly. Mixture of polysaccharides, proteins and fluid gels are overviewed as texture modifiers. Acoustic analysis of swallowing, extrusion method, a falling needle viscometer, tribological study on frictional coefficient of bolus are also described as each method is expected to be a useful tool to understand the complicated aspect of the disorder in mastication and deglutition. Mastication and swallowing of minced foods and model food gels are also described. Finally, the importance of the communication and collaboration between different disciplines is emphasized. PRACTICAL APPLICATIONS Polysaccharides have been used to modify the texture of foods. It is necessary to know how these polysaccharides influence the swallowing behavior to design foods for elderly. Since the texture of foods is influenced by taste, aroma and conversely these are influenced by texture, the knowledge on the relation between texture and flavor release is crucial to manipulate the foods to reduce the risk of aspiration. Some examples which are expected to be helpful to design foods for elderly are shown.

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.

Food hydrogel was produced from an oil in water emulsion of soy milk and rice powder mixture. We investigated the rheological properties during soy milk gelation with rice powder on addition of an acetic acid coagulant. The pH value of soy milk decreased on addition of rice powder and an acetic acid coagulant. Soy milk with rice powder formed a weaker gel with increasing concentration of soy milk and decreasing concentration of acetic acid coagulant. The frequency dependence of dynamic viscoelasticity suggested that soy milk formed hydrogel on addition of an acetic acid coagulant and rice powder. The time dependent changes in dynamic viscoelasticity suggested that palm oil retarded soy milk gelation early and then promoted it a little later. It was suggested that the oil droplet which was acting as an inactive filler acted as an active filler after that the first stage.

Food hydrogel was produced from an oil in water emulsion of soy milk and rice powder mixture, and a processing technique with freezing was investigated in terms of the rheological properties of the resultant products. The emulsion specimens were stored at 4℃, −5℃, −10℃ and −20℃ for 1 day. The time dependent changes in dynamic viscoelasticity suggested that the gel formation above freezing point, that was 4℃, allowed to form a gel network covering its bulk specimen. Whereas, when the specimens were aged in frozen state, gel formations could occur at localized positions due to the geometrical limitation by ice. The characteristics of viscous liquid could be confirmed in these specimens by the linerly increased loss tangent values, and this trend was obvious in the order of −5℃, −10℃ and −20℃. Gel specimens were cooked with an oven at 180℃ in order to observe their melting behavior. It was found that the degree of melting correlated to the rheological properties, and this correlation was obvious when gels were aged at −10℃. The results of this study suggested that freezing could be a useful processing tool for tuning rheological properties of food hydrogels, that may allow to process food functionalities.

Elasticity of potassium type gellan gels prepared at different thermal histories was examined using dynamic viscoelastic measurements. The storage Young's modulus E' decreased with increasing cooling rate during gelation. Once gel formation occurred, thermal history at lower temperature did not influence the elastic modulus and thermal stability of the gellan gels. On the other hand, thermal history around gelation temperature influenced strongly the elastic modulus and thermal stability of resulting gels. When the gellan solution was kept for a certain time before cooling at a temperature near the gelation temperature, it was found that gels with higher elastic modulus and thermal stability were formed. (C) 2014 Published by Elsevier Ltd

The objective of this study was to evaluate the effects of esterified tapioca starch on the physical and thermal properties of Japanese white salted noodles prepared by residual heat to reduce the use of heat sources for energy saving. Dried noodles prepared with wheat flour and with wheat flour partly mixed with esterified tapioca starch were used. Reducing the boiling time of noodles and using residual heat to continue cooking standing noodles reduced electrical energy consumption by 32%. The physical properties and gelatinization characteristics of the food were then assessed. The koshi of standing noodles differed from that of boiling noodles because water temperature decreased in standing noodles. However, noodles that had been boiled for 3 min followed by standing for 6 min were as soft as those boiled for 10 min. The addition of esterified tapioca starch partly caused gelatinization and softening of the noodles, even while standing, because the amylopectin content of dried noodles mixed with esterified tapioca starch increased, and the structure was sparse. Noodles boiled for 3 min and kept standing for 6 min were more elastic (or springier) than those boiled for 10 min, but had the same hardness. The addition of esterified tapioca starch was partly responsible for maintaining or raising the physical and thermal properties of noodles prepared by residual heat compared with boiling, and the physical properties of the noodles could be changed by adjusting the standing time. Therefore, the addition of esterified tapioca starch is partly effective for optimizing energy savings. (C) 2013 Elsevier Ltd. All rights reserved.

© 2014, Japan Society for Food Engineering. All rights reserved. Food hydrogel was produced from an oil in water emulsion of soy milk and rice powder mixture, and a processing technique with freezing was investigated in terms of the rheological properties of the resultant products. The emulsion specimens were stored at 4°C, −5°C, −10°C and −20°C for 1 day. The time dependent changes in dynamic viscoelasticity suggested that the gel formation above freezing point, that was 4°C, allowed to form a gel network covering its bulk specimen. Whereas, when the specimens were aged in frozen state, gel formations could occur at localized positions due to the geometrical limitation by ice. The characteristics of viscous liquid could be confirmed in these specimens by the linerly increased loss tangent values, and this trend was obvious in the order of −5°C, −10°C and −20°C . Gel specimens were cooked with an oven at 180°C in order to observe their melting behavior. It was found that the degree of melting correlated to the rheological properties, and this correlation was obvious when gels were aged at −10°C. The results of this study suggested that freezing could be a useful processing tool for tuning rheological properties of food hydrogels, that may allow to process food functionalities.