Fumiyo Hayakawa

The Japanese pepper (Zanthoxylum piperitum DC.) is an attractive plant that is highly palatable and benefits human health. There are several lineages of pepper plants in Japan. However, the classification of each lineage by analyzing its volatile compounds and studies on the effects of differences in volatile compounds on human flavor perception have not been performed in detail. Herein, we conducted gas chromatography (GC) and GC/mass spectrometry (GC/MS) analysis of volatile compounds and sensory evaluation of flavor by an analytical panel using 10 commercially available dry powdered Japanese pepper products from different regions. GC and GC/MS analysis detected limonene, β-phellandrene, citronellal, and geranyl acetate as the major volatile compounds of Japanese peppers. The composition of volatile compounds showed different characteristics depending on the growing regions, and cluster analysis of composition classified the products into five groups. The sensory evaluation classified the products into four groups, and the results of both classifications were in good agreement. Our results provide an important basis for proposing cooking and utilization methods that take advantage of the unique characteristics of each lineage based on scientific evidence.

Japanese pepper, Zanthoxylum piperitum , is native to Japan and has four well-known lineages (Asakura, Takahara, Budou, and Arima), which are named after their production area or morphology. Restriction-site associated DNA sequencing (RAD-Seq) was used to analyse 93 accessions from various areas, including these four lineages. Single nucleotide variant analysis was used to classify the plants into eight groups: the Asakura and Arima lineages each had two groups, the Takahara and Budou lineages each had one group, and two additional groups were present. In one Asakura group and two Arima groups, the plants were present in agricultural fields and mountains, thus representing the early stage of domestication of the Japanese pepper. The second Asakura lineage group was closely related to plants present in various areas, and this represents the second stage of domestication of this plant because, after early domestication, genetically related lineages with desirable traits spread to the periphery. These results demonstrate that domestication of Japanese pepper is ongoing. In addition, this study shows that spineless plants are polyphyletic, despite the spineless lineage being considered a subspecies of Japanese pepper.

To enable the taste evaluation of many food samples at a time as well as the comparison of taste evaluation data acquired at different times, a standardization method for taste intensities was developed by a combination of a taste sensor system and a standard solution prepared with taste substances. In the case of tomato juices, citric acid, sucrose, and monosodium glutamate were used as standard taste substances for sourness, sweetness, and umami taste, respectively. Each standard point of the taste intensities was determined using only one standard solution including these standard substances. The taste intensity was described as a value on a scale based on discrimination thresholds of human gustation, where intensities of sourness, sweetness, and umami taste of the tomato juices were classified into multiple levels. Organoleptic evaluation supported these results. Validation for the present standardization method revealed that this approach has enough precision for practical tomato taste evaluation.

Watercore is a so-called physiological disorder of apple (Malus domestica L.) that commonly occurs in several well-known cultivars. It is associated with a rapid softening of the flesh that causes a marked changed in flavor and texture. In Asia, apples with watercore are preferred and considered a delicacy because of their enhanced sweet flavor. The ‘Fuji’ cultivar, the first cultivar with rich watercore that is free from texture deterioration, has played a key role in the development of the market for desirable watercored apples. This review aimed to summarize and highlight recent studies related to the physiology of watercore in apples with special focus on ‘Fuji’ and related cultivars.

総合学術電子ジャーナルサイト「J-STAGE」－国内で発行された学術論文全文を読むことのできる、日本最大級の総合電子ジャーナルプラットフォームです。

Pasta is a common and popular food all over the world. However, neither a detailed sensory profile nor sensory lexicon of pasta quality has been reported. In this study, a lexicon for describing the sensory attributes of cooked, dried long pasta was developed using a large sample set of pasta. One hundred twelve pasta samples were prepared and then classified into four groups according to similarities in their sensory characteristics. Among them, 50 samples were selected as representative samples. A highly experienced and trained panel generated expressions following a sensory evaluation of the 50 pasta samples. The final lexicon consisted of 35 terms (5 for appearance, 11 for aroma/flavor, and 19 for texture). Definitions and references were determined for each term. Each descriptor was ranked according to its frequency of use by the sensory evaluation and discussion. Eight samples that were selected from each group as representative samples made in Italy were evaluated using the lexicon in a trial evaluation. The results show that the descriptors were appropriate for differentiating the sensory qualities among the samples.Practical applications: A lack of clarity of words and insufficiency of common terms in the sensory evaluation of cooked pasta result in communication gaps. Precise and objective evaluations based on the lexicon described herein will enable clear descriptions of subtle differences in the qualities of various long pastas. Improving the evaluation system will lead to enhanced quality control of existing products and the development of new, high‐quality products. This will also be beneficial for buyers and consumers when choosing products. As the definitions and references for the terms are provided in the lexicon, it will facilitate a common understanding of the evaluation descriptors between sections within companies, between companies, and between countries.

Several studies have reported that experts outperform novices in specific domains. However, the superiority of experts in accuracy, taking both trueness and precision into consideration, has not yet been explored. Here, we examined differences between expert and novice performances by evaluating the accuracy of their estimations of physical concentrations of sodium chloride in solutions while employing a visual analog scale. In Experiment 1, 14 experts and 13 novices tasted 6 concentrations of the solutions until they had learned their intensities. Subsequently, they repeatedly rated the concentration of 3 other solutions in random order. Although we did not find a difference between the performances of the 2 groups in trueness (difference between rating and correct concentration), the precision (consistency of ratings for each participant) of experts was higher than that of novices. In Experiment 2, 13 experts who had participated in Experiment 1 and 10 experts and 12 novices who had not participated in Experiment 1 rated the salt concentration in sodium chloride/sucrose mixtures in the same way as in Experiment 1. Both trueness and precision of performance were higher in both expert groups than in the novice group. By introducing precision and trueness parameters, we succeeded in quantifying the estimations of experts and novices in rating the concentration of solutions, revealing experts’ superiority even for a task they had not been trained for.

A total of 445 Japanese texture terms were classified. First, terms with almost the same meaning represented by different Chinese characters, and onomatopoeic words derived from the same sound were classified into same‐term groups for a total of 271 term groups. Next, eight experts in texture studies categorized the 271 term groups into the three texture attributes proposed by the International Standard Organization (ISO 11036): mechanical attributes, geometrical attributes and other attributes. Term groups were compared within each of the three attributes, and their similarities were assessed by 96 texture scientists/technologists. The data were analyzed by multidimensional scaling and cluster analysis. The classification in this study showed some similarities with the classification of texture terms in other languages. However, the results also revealed some characteristics that were unique to Japanese texture vocabulary, such as a wide variety of terms concerned with stickiness and elasticity.Practical Applications: Developing a comprehensive list of texture terms in every language is necessary for comparing terms between languages, as well as for sensory evaluation within each language. The data obtained in this study can be applied to preliminary lexicons of descriptive sensory evaluation of texture. Classification of texture terms helps sensory evaluation researchers to define descriptors and to train panelists. The data also provide useful clues for worldwide understanding of Japanese texture terms.