Sensory testing methods

ANONYMUS 1982. On target values for odour control by sensory test method. Japan environment summary. Vol. 10, no 9. 

Chambers, E.C. and Wolf, M.B. (eds.) 1996. Sensory Testing Methods. American Society for Testing and Materials, Manual Series MNL 26. West Conshohocken, Penn. 

Manual on Sensory Testing Methods". ASTM Tech. Publ. 434, 1968. 

ASTM.In Manual on Sensory Testing Methods. Spec. Tech. Pub. 

Method validation is often based on the combined use of validation procedures. The validation used can be direct or comparative. The selection of the validation procedures should also be justified on a cost-benefit basis as long as the fitness-for-purpose is maintained. Focusing the effort on the most critical factors affecting the test method will lead to a different solution for the validation of exact physical and chemical test methods as compared to that for product or subjective testing. For example, in the validation of ergonomics and sensory test methods not all possibilities are applicable. 

As the factors of the sensory test methods show, flavour is the most important aspect of ice-cream. Added flavourings improve many details which contribute to an overall positive perception. 

SQC is carried out by sensory assessors (panelists). In this case, the characteristics (mostly of the vhole product) are measured vith sensory test methods in order to provide a solution to a given problem. 

American Society for Testing and Materials Special Publication No. 434. "Manual on Sensory Testing Methods", Published by the ASTM 1916 Race Street, Philadelphia, Pa. 19103 (1968). 

Exposure to a flavor over time always results in a decrease in the perceived intensity. This dynamic effect of flavorants, called adaptation, is a central part of the process by which people experience flavors in foods as well as in sensory tests. Measuring the dynamics of flavor perception is an emerging technology made possible by inexpensive computing. Called time-intensity analysis, these methods are finding wide appHcations in taste analysis. 

In non-metric MDS the analysis takes into account the measurement level of the raw data (nominal, ordinal, interval or ratio scale see Section 2.1.2). This is most relevant for sensory testing where often the scale of scores is not well-defined and the differences derived may not represent Euclidean distances. For this reason one may rank-order the distances and analyze the rank numbers with, for example, the popular method and algorithm for non-metric MDS that is due to Kruskal [7]. Here one defines a non-linear loss function, called STRESS, which is to be minimized ... 

In a study comparing organic and conventional apples (variety Golden Delicious) from a range of commercial orchards it was found that reproducible differences between apples from organic and conventional systems can be detected (Fig. 16.6). Additionally, the vitality index produced based on the picture forming method was found to be correlated with the technical standard index based on chemical quality tests and the sensory test results (Fig. 16.7, left) (Weibel et al., 2004a). 

The physicochemical nature of the oil phase components in a cosmetic emulsion, the emollients, determines the skin-care effects, such as smoothing, spreading, sensorial appearance. Test methods have been developed to characterize and classify the numerous emollients available on the market, such as silicones, paraffins, and oleochemical-based products. The latter include glycerides, esters, alcohols, ethers, and carbonates with tailor-made structures, depending on the performance needed (Table 4.8). However, especially with regard to additional effects, there is still a demand for new products with unique performance properties. 

Over the last few decades scientist have developed sensory testing from the earliest individual examinations into a formalised, structured and codified methodology. Subsequently, sensory tests have become valuable, important and precise tools in quality control, which are equivalent to the physical and chemical methods used. However, sensory testing is not only a tool in quality assurance, but also in grading, product development and marketing, as well as for the correlation between specific chemical/physical properties of a food and the effect on the human sensorial perception. 

The direct transformation from the output pattern to the taste quality was performed here as one trial of expressing the actual human sensation using the output electrical pattern. A similar trial was done for evaluation of the strengths of sourness and saltiness, which will be mentioned later. These two trials depend on the utilization of simple transformation equations by extracting typical properties of output patterns. This method is effective if some data on sensory tests, using humans as a standard, can be obtained to compare with the sensor outputs. However, the expressions for the tastes of beer are obscure because they are not described by the five basic taste qualities. The purpose of the application of the taste sensor is also to express these kinds of obscure terms of human sense in scientific terms. 

Choosing a Sensory Test. The types of sensory methods available for citrus evaluation are numerous. Two excellent refer-... 

Danish Society of Indoor Climate (2003) Standard Test Method for Determination of the Indoor-Relevant Time-Value by Chemical Analysis and Sensory Evaluation, 2nd edn, Taastrup, Denmark. 

As a consequence of this state of the art, the need and justification for establishing a conventional method for reproducible inertness testing of refill-bottle materials was identified in our laboratory a few years ago. In our opinion, a practical, cost-efficient and relatively quick standard test procedure which could also be used by surveillance labs was worth development. Within an European project (Castle 1997, Jetten et al. 1999), an investigation was undertaken to elucidate the feasibility of such a quick test method for refillable PET bottles, with respect to evaluating their inertness concerning the uptake and subsequent release of chemicals and sensory-active compounds. Before starting method development, the following considerations were made and... 

Correlation of Instrumental Methods With Sensory Testing... 

This method is currently being used for routine laboratory analysis of red pepper heat. Results have been consistent and continue to correlate well with HPLC data. A similar procedure has also been used for sensory evaluation of black pepper heat. The American Society for Testing and Materials (ASTM, Committee E-18) has conducted a collaborative study testing the new method in comparison to the Scoville Method. ASTM E-18 is currently preparing to document it as a standardized test method. Also, a modification of the method is being prepared for oleoresin capsicum and for low-heat capsicums. 

Figure 7. Sensory test heat ratings versus calculated Scoville Heat units (in thousands) for 60 red peppers. Scoville Heat units calculated based upon the method of Todd, et.al. (15). Reproduced with permission from Ref. 4, copyright 1984, Institute of Food Technologists.

ASTM (American Society for Testing and Materials) (1991). Standard test method for estimating sensory irritancy of airborne chemicals. In Annual Book of ASTM Standards, Vol. 11.04. ASTM, Philadelphia, PA. 

Houskaet al. (1998) determined the relationships for five sensory methods of oral and non-oral viscosity evaluation between viscosity scores and instrumentally measured dynamic viscosity for Newtonian fluid foods of low and medium viscosities. From those relationships, the effective shear rates for the five the sensory tests were estimated. Highest shear rates were predicted for viscosity perception by compression of samples between tongue and palate, and the lowest for pouring the fluid foods from a teaspoon. Mixing with a teaspoon, slurping and swallowing exhibited nearly... 

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