High-frequency pulse continuous heating (HFP) is a newly developed electric heating technique that can increase the temperature of slurry foods to over 100 °C in less than 1 s. In this study, we investigated the effect of heating soybean slurry by HFP on lipoxygenase (LOX) activity, the extraction ratio of soy protein, and aroma components of soymilk. Despite the short heating time, HFP inactivated 99 % and 100 % of LOX at 80 °C and 90 °C, respectively. However, conventional heating at 80 °C took 5 min to inactivate LOX. Furthermore, HFP increased the extraction ratio of protein, and decreased the unpleasant beany flavor. These results show that HFP can significantly reduce heating time, thereby enhancing the quality of soymilk.

In this study, it became possible to make barley flour-blended bread having the same breadmaking quality as wheat bread, even when the barley flour content was increased from 20 % to 30 %. If the proportion of barley flour is increased in barley flour-blended bread, the expansion properties and palatability of the resulting bread decrease. The expansion properties of barley flour-blended bread are affected by the hard and thick endosperm cell walls, which are formed by dietary fiber. Since the fragments and particles of the endosperm cell walls generated by milling (crushing) were thought to inhibit the extension of the continuous phase of gluten in the dough, a dietary fiber-degrading enzyme was added for the purpose of further crushing and refining them. However, the addition of the enzyme was expected to decrease dietary fiber, especially β-glucan. A new enzyme addition method was examined that aims both to improve the expansion properties of barley flour-blended bread and to suppress the decrease in dietary fiber, and the optimal conditions for achieving these aims were evaluated. After adding the enzyme, the expansion rate of the barley flour-blended bread improved by 10% on average, and the decrease in total dietary fiber content was limited to approximately 20 %.

The objective of this study was to elucidate the texture characteristics of machine-made somen noodles based on their microstructure. The findings of sensory tests revealed that the firmness (elasticity) of somen noodles increased in the following order: machine-made somen (Kanzaki Somen, MS1), hand-pulled somen (Ibonoito, TS), and machine-made somen (Number One, MS2). On the other hand, when firmness was determined by measuring breaking strength, somen was stronger in the order of MS1 < MS2 < TS. Synchrotron radiation computed tomography (CT) scan measurements showed that the TS somen (dry noodle) had a large band of voids at their center, and that some of these bands of voids remained after boiling. This difference in the structure of the outer and inner portions is thought to be the reason for the higher firmness. On the other hand, the small voids that were evenly distributed inside the machine-made somen noodles were identified as the cause of the low breaking strength. However, the sensory tests showed that MS2 had higher firmness than TS, suggesting that the rate of water absorption during boiling also affected somen texture.

The aim of this study is to understand the key textural attribute of “richness” of ice creams. Twelve commercially-available vanilla or milk ice creams with different contents of milk components and 13 prepared samples with different stabilizers were used in this study. The textural “richness” of each sample was scored on a line scale after consumption. Then, temporal texture profiles during consumption were evaluated using Temporal Dominance of Sensations (TDS) with 8 terms (hard, soft, sticky, easily cracked, smooth, icy, light, and heavy). Both the line scale analysis and TDS were performed by the same trained panel consisting of 12 panelists. Stepwise multiple regression analysis was used to model the relationship between the perceived “richness” and the 16 variables based on area under the curves (AUCs) calculated from the TDS curves. As a result, the textural characteristics during consumption of each sample were well expressed by the TDS variables, and 3 of the 16 variables including sticky, easily cracked, smooth, icy, light, and heavy contributed to the model, indicating that perceived “richness” is related to stickiness, mouthfeel, and after feel. Results also suggest that dynamic texture profiling could be a useful tool in developing production methods for ice cream, including ice cream formulas and stabilizers. Additionally, ice cream stabilizers could modify the in-mouth texture and overall perception such as “richness”.

We established a method for visualizing the three-dimensional oil distribution in rice crackers, and analyzed the correlation with sensory evaluations of texture to clarify the effect of oil permeation on the texture. The internal structure of the model rice crackers permeated by oil was investigated at 5 levels (oil content ranging from 10 % to 50 %), and the permeation distribution was recorded by X-ray micro-computed tomography (CT). To clarify the relationship between the degree of permeation and the texture, texture evaluation terms related to oil were classified into 8 groups, e.g., crispness (as "kari-kari" in Japanese), tenderness ("shittori"), and hardness ("zaku-zaku"), by cluster analysis, and the model rice crackers were evaluated using these terms. The oil content tended to be higher near the surface than in the deep interior proportion to the total amount of permeated oil. The crispness increased up to 30 % oil content but dropped sharply at 40, 50 %, showing that the oil content and texture were not well correlated. On the other hand, the oil distribution analysis showed that permeation into the deep interior influenced the crispness and tenderness, and permeation into the middle layer enhanced the hardness. The model enabled quantification of the optimum oil distribution to create the desired texture.

1, 5-Anhydro-D-fructose (1, 5-AF), which is produced from starch by the action of alpha-1, 4-glucan lyase, competitively inhibited Agaricus tyrosinase (L-tyrosine, L-dopa: oxygen oxidoreductase, EC 1.14.18.1) with a Ki value of ~20 mM. In silico modelling of the catalytic subunit of the enzyme docked with a 1, 5-AF molecule showed that only the keto form of the 1, 5-AF molecule could bind to the bottom of the active site of tyrosinase. The binding mode seemed to be very similar to that of tropolone, a strong, competitive inhibitor. 1, 5-AF also inhibited an enzyme partially purified from wheat flour and retarded the browning of commercial avocado paste. Thus, its colour protection activity, in conjunction with its bacteriostatic effect, appears applicable to food processing.

Using hydrocolloids as gelling agents, 15 kinds of hydrogels and 8 kinds of emulsion gels with different textures were prepared. To assess changes in pressure distribution, the gels were placed on a film-type multipoint pressure sensor and then crushed with the aluminum plunger. The gels were subjected to sensory evaluation of 4 kinds of texture attributes, “smoothness”, “elasticity”, “stickiness” and “granularity”, by 8 subjects. Then, the relationship between the values obtained by sensory evaluation and the pressure distribution data was numerically modeled by applying image texture analysis, and a suitable texture estimation modeling formula was derived. Using this modeling formula, 5 kinds of jellies and 3 kinds of puddings commercially available and of unknown texture were estimated. The modeling formula using the 15 hydrogels could estimate the texture of the 5 jellies with high accuracy (r > 0.8), whereas all 23 gels, including the 8 emulsion gels, were needed to estimate the texture of the 3 kinds of pudding with equivalent high accuracy.

The Liquor Tax Law in Japan was revised in 2018, and the revision has significantly deregulated both the variety and the quantity of the auxiliary ingredients permitted for use in beer. Consequently, we prepared worts containing three citrus fruits (Kara, Miekinan4gou, and Summer fresh), passion fruit, and atemoya that were local fruits in Mie Prefecture, and brewed beers by fermenting the worts with top-fermenting yeast or bottom-fermenting yeast. By the fourth day from the beginning of fermentation, various sugars included in the worts, such as glucose, fructose, maltose, and maltotriose, were substantially decreased, and had been utilized for ethanol fermentation. The flavors of the fruits, especially organic acid and the volatile terpenes, remained in the beers. Microorganisms were detected in the juices of the passion fruit and atemoya, but were not detected in the beers in which these fruit juices were employed as auxiliary ingredients. The antibacterial action of the alcohol and hop likely had a sterilization effect. The results of sensory evaluations indicated that, although the fruit flavors remained in the beer, the conditions of fruit addition need to be optimized.

In order to clarify the risk management ability of the elderly in the daily life, a study was carried out, in which, 150 elderly and 105 young control panelists have been asked to detect and identify three smells which are serving as indices of food degradation, namely acetic acid, trimethylamine, and methyl mercaptan in order to determine the olfactory thresholds. The results revealed that the thresholds were all higher in the elderly, and that their sense of smell had deteriorated compared with the young. The threshold distribution in the elderly was more widespread for acetic acid, and the difference between the detection and the recognition thresholds was smaller compared with the young. Regarding trimethylamine, some old panelists could not detect the prepared sample with the largest density, so its spread could not be determined using only a simple sample average. In order to determine the spread, a data fitting method was introduced. Regarding methyl mercaptan the spread of the threshold distribution was more widespread compared with other smells, even in the young, and this tendency was clearer with the recognition threshold. It was also found that 76 % of the elderly did not notice any deterioration in their olfactory ability.

The effects of water jet treatment on dispersion and gelation of deacylated potassium gellan gum in the presence of calcium were investigated. In the presence of calcium, gellan gum was finely dispersed in water, “Fine dispersion with Ca^2＋”, by the water jet treatment at 245 MPa (the temperature of the solution reached 90 °C), or just dispersed without the water jet treatment, “Just dispersion with Ca^2＋”, and then heated to 90 °C. Thereafter, both gellan gum dispersions were cooled to 10 °C. “Fine dispersion with Ca^2＋” formed gel by cooling, but “Just dispersion with Ca^2＋” did not form gel only by heating and cooling. Conventionally, gellan gum is just dispersed in water and heated to 90°Cin the absence of calcium, and then calcium is added followed by cooling to obtain gel formed using “Just dispersion before Ca^2＋ addition”. The gelation behavior of gel formed using “Just dispersion before Ca^2＋ addition” was compared with that of gel formed using “Fine dispersion with Ca^2＋”. Circular dichroism spectroscopy and dynamic mechanical analysis revealed that the coil-helix transition temperature and sol-gel transition temperature were not significantly different between gels formed using the two methods. The storage modulus value at 10°Cof “Fine dispersion with Ca^2＋” gel was lower than that of “Just dispersion before Ca^2＋ addition” gel. In agreement with this result, compression testing revealed the low breaking stress of gel formed using “Fine dispersion with Ca^2＋”. Furthermore, scanning electron microscopy demonstrated that the microstructure of gel formed using “Fine dispersion with Ca^2＋” was coarse compared to that of gel formed using “Just dispersion before Ca^2＋ addition”.

The Standard Tables of Food Composition in Japan (FCTJ) is the only official database on food ingredients and is used for various purposes in Japan. However, the method used in the FCTJ, the FCTJ manual, is sometimes unsuitable for accurately measuring some components. In this report, we focused on dietary fiber analysis mainly by reviewing resistant starch and low molecular weight water-soluble dietary fiber (LMWSDF) data. The data from three methods other than the FCTJ manual were compared as follows: AOAC 2011.25, the improved 2011.25 reported by McCleary, and a modified method of the FCTJ manual in which the LMWSDF by HPLC was added. Although the results showed that all three methods are suitable for the FCTJ, AOAC 2011.25 as a CAC Type 1 method is considered to be best suited to the FCTJ.

Japanese traditional fermented foods are characterized by their diversity. We constructed a fermented food database. The distinguishing features of the database are as follows: First, the database can store several types of data with the principal four data types: fermented foods, microorganisms, materials, and cultures; and supporting data such as documents and references. Second, the user interface enables users to operate the database while the data is being presented. Users often come up with new ideas in this environment. Third, statistical data can be easily retrieved from the database. For example, the total number of food cultures related to “miso” stored in the database was 204: which included 25 places, 1 occasion, 79 persons, 17 events, and 43 expressions, among other entries. To use this database as a portal site for fermented foods, we will continue to collect source data for storing in the database.

The kuchidoke of rice crackers refers to their “melt-in-the-mouth” sensation, which includes the “absorption of saliva” and the feeling of a “bolus residue in the mouth”. The saliva absorption rate of the bolus and the mass fraction of bolus particles (≤53µm) were positively correlated with the kuchidoke score. The viscosities of an artificial bolus were reduced by the addition of α-amylase, and the time required for reducing the initial viscosity by half was negatively correlated with the kuchidoke score. Additionally, the thickness of the rice cracker’s cellular structure was negatively correlated with the kuchidoke score, while the size of the cellular structure was positively correlated with the kuchidoke score. Therefore, rice crackers with a high kuchidoke score tend to be thinner with a larger cellular structure. This leads to a higher saliva absorption rate and a finer bolus residue, resulting in more rapid enzymatic digestion during mastication.

We used spectrophotometric and image analyses of squashed cooked rice grains to evaluate staling of cooked rice during storage. After storage at 4°C for 0-48 h, individual grains of cooked rice were squashed to 0.1 mm thickness between the cover and slide glass. Brightness (L^*) of the squashed cooked rice grains was measured by reflectance spectroscopy, and image analysis of the squashed cooked rice grains photographed using transmitted light microscopy was performed. Furthermore, measurement of physical properties and sensory evaluation of cooked rice were performed. L^* of squashed cooked rice grains was high at a high amylose content, which increased with storage time. The shape of luminance histograms of gray-scale images photographed using a microscope differed among the rice varieties, and the proportion of low luminance increased with time. It was suggested that changes in the shape of histograms were related to the degree of staling. Ratio of White Area_α130, which was calculated from the ratio of the area of gray value 130 or less in a gray-scale image, and L^* were highly correlated with the physical properties of cooked rice and the staling score determined by sensory evaluation. Therefore, L^* of squashed cooked rice grains and Ratio of White Area_α130 by image analysis suggested that this novel method is useful to evaluate staling of cooked rice.

Recently, raw soy sauce without heat sterilization was developed and has become popular among consumers. Its sensory properties, however, have not been well studied. In this study, we aimed to reveal sensory differences between raw- and heated-soy sauces by conducting detailed sensory analysis. Quantitative descriptive analysis (QDA) was performed for 12 (6 raw/6 heated) commercially available soy sauces from six manufactures by 13 trained panelists. As a result, a total of 48 sensory attributes were identified. Statistical analysis revealed that raw soy sauce had stronger sweetness, umami and soy flavor, whereas heated soy sauce had stronger bitterness, astringency, metallic taste and bitter aftertaste. The differences in sweetness and bitterness of samples were supported by the results of chemical analyses. Further, we incorporated the 48 attributes into the 74 previously reported Japanese soy sauce attributes, for a total of 91 attributes. These 91 attributes were organized into a flavor wheel applicable to today’s Japanese soy sauce market. We also confirmed that the flavor wheel contained essential attributes commonly found in commercially available Japanese soy sauces and could effectively characterize these soy sauces. This is the first study to present sensory characteristics that can describe commercially available raw soy sauces. Furthermore, the schematization of soy sauce attributes will facilitate communication among stakeholders and contribute to the standardization, simplification and rapidity of Japanese soy sauce evaluation steps.

In recent years, studies of the antioxidant capacity of foods has been actively pursued, with the antioxidant activity of various food components being reported. Many methods have been developed to evaluate antioxidant activity, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, superoxide dismutase (SOD) activity, and oxygen radical absorbance activity (ORAC). The DPPH radical-scavenging method measures radical removal, producing a characteristic change to colorlessness in the assay upon conversion to the DPPH radical, which is a stable organic radical. SOD is an enzyme that was discovered by McCord and Fridovich, and is a superoxide radical (O₂^·-) scavenger that is component of the endogenous antioxidant system. SOD catalyzes the conversion of superoxide to either hydrogen peroxide (H₂O₂) or oxygen (O₂), and is used to measure antioxidant ingredients exhibiting SOD-like activity. Implementation is simple and easy, and these methods are widely used for the evaluation of antioxidant activity. The ORAC method was developed in 1992 by Cao et al. at the U.S. National Institute of Aging. The assay uses fluorescein as a fluorescent probe to measure antioxidant activity in the presence of underlying reactive oxygen generation. The fluorescent intensity of fluorescein degrades over time in the presence of reactive oxygen, which is used to measure antioxidant activity as an index. Because the ORAC assay relies on generated peroxy radicals, the classification of fixed quantities of hydrophilic and lipophilic antioxidant materials is possible and is correlated with in vivo effects. Additional merits of the ORAC assay include the ability to assess antioxidant activity using a chemical reaction that is relatively simple, easily operated, and does not require specialized apparatus. However, the presence of compounds with antioxidant activity greatly influences the ORAC assay, and a potential drawback of the assay is that its results may not reflect antioxidant activity in vivo. In this study, chemical analyses (DPPH radical removal activity, SOD assay copper ion reduction) and the cellular antioxidant stress response, measured using a luciferase reporter assay of antioxidant response element induction through the Keap-1/Nrf2 pathway, was used to more accurately reflect in vivo conditions in evaluating antioxidant activity. The possibility that food components exhibit various antioxidant activities was evaluated using multiple assay systems.