Descriptive analysis tests

Judges consisted of 16 panelists experienced in descriptive analysis. Tests were performed in groups of five judges each. 

Historically, descriptive analysis tests, like other sensory tests, were fielded in a laboratory environment, but with the advent of the electronic age, one could look at the methodology as a mobile resource, i.e., able to be used in any environment based on the kinds of information needed and the specific type of product e.g., a home care product. This author recalls using the QDA method (in the 1970s) to evaluate golf clubs, with players actually using the clubs on a golf course. In that time period without a mobile device, it was a paper and pencil exercise requiring lots of paper... 

Assessment of taste is achieved by sensory analysis, from very simple experiments such as triangular tests aiming at determining detection thresholds to complex descriptive analysis approaches. A method referred to as time-intensity that consists in recording continuously the intensity of a given sensation over time under standardized conditions has been applied to study flavonoid bitterness and astringency properties. 

Mood (Ref 1). A concise description of test procedure and analysis of results is found in Ref 5... 

To test the potential of PLS to predict odour quality, it was used in a QSAR study of volatile phenols. A group of trained sensory panelists used descriptive analysis (28) to provide odour profiles for 17 phenols. The vocabulary consisted of 44 descriptive terms, and a scale fiom 0 (absent) to S (very strong) was used. The panel average sensory scores for the term sweet were extracted and used as the Y-block of data, to be predicted from physico-chemical data. 

A complete discussion of the large number of tests that are used for the evaluation of coal (and coal products) would fill several volumes (see, e.g., Ode, 1963 Karr, 1978, 1979 Montgomery, 1978 Zimmerman, 1979 Gluskoter et al., 1981 Smith and Smoot, 1990), and such detailed treatment is not the goal of this book. The focus is on a description, with some degree of detail, of the test methods in common use, as well as a critique of various procedures that are not obvious from the official descriptions of test methods and a description of pitfalls that can occur during application of a test method for coal analysis. 

Data reporting (i.e., the statement of the results of the proximate analysis test methods) usually includes (in some countries but not in all countries) descriptions of the color of the ash and of the coke button. As an interesting comparison, the test for determining the carbon residue (Conradson), the coke-forming propensity of petroleum fractions and petroleum products (ASTM D-189 ASTM D-2416), advocates the use of more than one crucible. A porcelain crucible is used to contain the sample, and this is contained within two outer iron crucibles. This corresponds to the thermal decomposition of the sample in a limited supply of air (oxygen) and the measurement of the carbonaceous residue left at the termination of the test. 

Sensory Analysis. Oat oils and isolates from these oils were sensorially evaluated. Oils from the Magne variety, both crude and heated, were analysed by a panel consisting of 12 to 14 persons who were selected from the laboratory staff. Most of them had previous experience with sensory analysis. Four oat oils, one from crude oats, one heated oil from crude oats and two oils from roasted oats see Figure 1, were subjected to the triangle test followed by descriptive analysis (14, 15). 

Sensory Analysis. Oils from the Magne variety were evaluated by a profile panel. Oil from crude oats (a), two oils from roasted oats (one part milled before roasting (b) and one milled after roasting (c), and heated oil from crude oats (d) were subjected to the triangle test and descriptive analysis. No evaluations were performed of oils from the Chihuauhua variety, due to lack of material and also to similarities with the various Magne oils. 

The process of analysis of LSD blotter acid follows the same general principles and sequence as for other controlled substances, namely physical description, presumptive testing, TLC and confirmatory analysis. These processes are discussed below. 

In some cases, identification and confirmation of the dose form can be achieved by using internationally available databases. If this is not possible, then the traditional process of physical description, presumptive testing, TLC and GC-MS should be followed to identify the drug components. However, some benzodiazepines are thermally labile and in such cases HPLC, possibly with diode-array detection, is often the chosen method of analysis. The latter technique is, in addition, the preferred method for quantification purposes. 

Acid hydrolysates were added to a low aroma intensity white wine (ie the base wine), and the aroma properties of these samples were assessed by sensory descriptive analysis. In addition, the glycoside isolates from the Australian vineyards were subjected to glycoside hydrolase enzyme treatment, and duo-trio difference tests were performed on these hydrolysates added to a base wine. The volatile composition of each of the hydrolysates was investigated by GC/MS, and relationships between the two sets of data were determined. Finally, the glycoside concentration of each of the juices and skin extracts was determined by the glycosyl-glucose assay. 

Odour can be described using a number of different dimensions, each of which can be measured using different sensory tests threshold, intensity and quality (odour profile or qualitative descriptive analysis). 

W. M. Kays and A. L. London, Heat Transfer and Flow Friction Characteristics of Some Compact Heat Exchanger Surfaces—Part I Test System and Procedure, Trans. ASME, Vol. 72, pp. 1075-1085, 1950 also Description of Test Equipment and Method of Analysis for Basic Heat Transfer and Flow Friction Tests of High Rating Heat Exchanger Surfaces, TR No. 2, Department of Mechanical Engineering, Stanford University, Stanford, 1948. 

Analytical methods can be sub-divided into difference tests and descriptive analysis. Difference tests such as triangle and paired comparison tests are designed to identify differences between samples. In a triangle test, the assessor is given three samples, two of which are the same, and asked to identify which sample is different. In a paired comparison test, the assessor is asked to identify whether there is a difference in a particular sensory characteristic between a pair of samples. Descriptive analysis, in which the sensory characteristics of a sample are described and scored on a scale, is probably the most important analytical method. 

The workflow should be broken down to manageable chunks each of which become a target for a round of hazard analysis and perhaps our what-if questions. It is at this stage that detailed hazards, causes and controls can be established which will form the bulk of the hazard register. The system business processes themselves may be derived from a number of different sources depending on the material available. Some systems may have detailed use cases with primary and exception flows carefully documented. For others the processes may need to be ascertained from training material, product descriptions or test cases. 

Consumer tests Dual standard Multiple standard Triangle (ratio) Quantitative descriptive analysis Other methods... 

As noted previously a descriptive analysis capability attracts attention because of the results it provides for example, the ability to describe specific differences among an array of competitive products. This section provides some details on how a descriptive analysis capability can be developed and a panel made ready to evaluate products in a relatively short time period. Starting with newly recruited subjects, one can have a panel available in 2 weeks - three session days for screening, five for language, and one for a pre-test. Once operational, however, a test can be organized in a day, followed by data collection. The duration of a test depends on the number and type of products and, as always, the objective. So any discussion about rapid methods must first begin with what is meant by rapid in the context of existing methods. 

PSP on continuous scales also enables hypothesis testing. Classical ANOVAs (Analysis of Variances) applied to descriptive analysis can be used to infer significant differences between products, which is very convenient. Ongoing studies are also looking for the apphcation of the Mixed Assessor Model (MAM Brockhoflf et al, 2012) in order to take into account the expected high scaling effect between subjects (especially untrained subjects). 

When the evaluation protocol is not standardized, the duration of an evaluation can vary from one product to another (and/or from one subject to another). In this case, it is useful to compare the evaluation durations between products to know whether some products generally need a longer duration to be evaluated than others. To do so, the 2-way ANOVA model usually used for Descriptive Analysis data (product as fixed effect, subject as random effect, with interaction in case there is replicates) can be simply applied to the evaluation duration variable. A multiple comparison test can also be conducted to identify which products have significantly different evaluation durations from which other products. 

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