Emerging And Coalescing Technologies

A happy set of circumstances has made sensory-instrumental correlations both easier to detect and more useful than was true 45 yr ago. Hereafter the term instrumental will be used in a generic sense to encompass all forms of chemical, mechanical, physical, spectral, or auditory tests where there is some type of physical measurement being obtained to match against sensory evaluation. In other instances, the particular form of physical measurement will be named where that is necessary to provide accuracy. That is so for the first development to be described. The detection and isolation of chemical compounds became easier once gas chromatography was established (1). Prior to that time, analytical chemists often had to spend weeks isolating and identifying even a single substance. Inas much as almost every food contains hundreds of compounds, if not thousands, and most of these have sensory import, there was little prospect of being able to establish good correlations when only a few compounds in a given kind of food could be identified and quantified. Fortunately, sometime before gas chromatography enabled chemistry to go "multicomponent," food and other sensory substances began to be looked at in the same way.

Prior to 1949, sensory judgments were generally quite simple. Expert tea tasters or wine judges rendered a composite judgment that this tea or that wine met their company's buying specifications, perhaps with a few comments as to particularly pertinent qualities. Generally, they kept the basis for their judgments to themselves. In fact, their status as an expert depended on the imperiousness of their judgments. In some industries, sensory panels came into use and worked in parallel with experts. In other industries, the first sensory analyses were those provided by sensory panels. In either case, the panels also rendered simple judgments. At the most they examined the material for odor, taste, texture, or color or for such specific attributes as sweetness, bitterness, saltiness, and sourness. Even the latter attributes are often not as specific as is desirable, because different substances can have different nuances of bitterness. The same is true of the other character notes.

The development that changed things in 1949 was the development of the flavor profile method (FPM) (2). The method required panelists to attempt to pick out from the melange of sensory notes comprising odor or flavor the particular odor or taste character notes that were there. FPM set the feet of sensory scientists on the right path (3), but it was inadequate in some respects. The responses sought were only semiquantitative. Furthermore, one of the objectives of the method was to get the panelists to arrive at a consensus as to which sensory notes were present, the order of their perception, and their intensities. Semiquantitative data and the merging into a consensus differences expressed by the individual panelists made difficult the establishment of sound correlations between the sensory-instrumental measurements. The deficiency of strict quantitative data to match against the quantitative data of instrumental methods changed in 1974 when quantitative descriptive analysis (QDA) was devised (4). QDA requires that the panelists make their judgments independently, and the rather crude scoring system of the FPM was replaced with more carefully defined scoring systems. Other differences between the FPM and QDA procedures as well as the quantitative sensory profiling (QSP) methods that have been developed more recently have been described (3). The FPM and QDA procedures were singular developments for the influence they had on sensory analysis.

Sleeping Sanctuary

Sleeping Sanctuary

Salvation For The Sleep Deprived The Ultimate Guide To Sleeping, Napping, Resting And  Restoring Your Energy. Of the many things that we do just instinctively and do not give much  of a thought to, sleep is probably the most prominent one. Most of us sleep only because we have to. We sleep because we cannot stay awake all 24 hours in the day.

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