We can find that Japanese companies have much knowledge for product development and quality control techniques, because the Japanese products are trusted and extremely popular by the majority of consumers in the world. Sensory evaluation is using as one of product management techniques for profiling to make clear the product characteristics and/or finding improvement for preserving the quality. With the changing times, Sensory test came to be called sensory evaluation, and it seems that the technique or usage have also changed to develop different needs.
The characteristics of black tea consist of three components; aroma, taste and liquor color. However, since perception and expression of these characteristics, particularly aroma and taste, varies according to the individual, describing them in a way that is comprehensible to a majority of people can be problematic. Thus a glossary of specific terms is required which can be used to accurately assess these characteristics in the development and quality control of tea products, and to clearly convey the complex and subtle qualities of black tea to consumers in Japan. Our character wheel for black tea was created as a means of bringing more people to a common understanding of the widely varied black tea characteristics of aroma, taste and color. On the basis of sensory evaluations using the character wheel we compiled pictorial charts visually depicting the characteristics of various types of black teas.
The most important points when we deal with customers’ complaints about off-flavors in foods are carrying out the sensory analysis of odors in-site, sharing the result, then analyzing the odors by the sensory analysis and the instrumental analysis in the laboratory. As each analysis is not perfect, or each has its own limit, a comprehensive determination based on all information and analytical result can lead us to the resolution of the case precisely and quickly, including the cause of the off-flavor case. During these procedures it is necessary to keep the very off-flavor in the food properly.
There are 3 merits in introducing the sensory analysis of odors into the dealing process of customers’ complaints about off-flavors. We can determine the urgency of the case at the first step, detect the odors quickly, estimate the candidate compounds properly. To maintain the sensory analysis of odors, we have to make rules, educate the panel leader and panels and carry out periodic training. These efforts lead us to obtain confidence in our results and reliance from our customers.
When it comes to the instrumental analysis, we have to choose the most appropriate method for the condition or the requirement of the case, rapidity, easiness or accuracy. There are useful instruments for these purposes, such as SPME, GC/MS and GC-olfactometer. But, so far, these instruments are often fail to reach the lower limit of the sensory analysis. It is necessary to make the most of the results obtained from the sensory analysis and the instrumental analysis altogether. First we estimate the cause or the compounds of the off-flavor by he sensory analysis, then we confirm the estimation by the instrumental analysis, finally we can make a comprehensive determination.
When there is indication of a nasty smell, after identifying a nasty smell causative agent and clarifying the cause of generating, it is required to carry out recurrence prevention, but a nasty smell is not visible, and since the method of touch changes with people, it is required to judge a smell clearly in each stage.
The method from identification of a nasty smell causative agent to recurrence prevention and training of a sensory evaluation panel required for it are explained.