Testing organoleptic analysis

Organoleptic Analysis. Laboratory checks must be made to test all blends and fining prior to the actual operation in the plant. Rechecks of the finished tank by organoleptic and chemical analyses after the operation is completed in the cellar are the only good way to ensure that... 

The section Panel test for organoleptic analysis was adapted from a contribution of F. Angerosa. L. Giansante is thanked for help with the literature search. The review of the first draft was made by M.R. Mucciarella and L. Di Giacinto. 

Food deterioration can occur by means other than transport of gases into the food container or water into or out of the container. The loss of food characteristics in plastics packaging may also occur from direct interaction of the food with the polymer. The measurement of these types of transport is often termed organoleptic analysis because they may involve human taste tests. The tainting of food by transport of substances from the polymer into the food is termed migration. The loss of flavor constituents from the food into the polymer is termed scalping (32). Water content can affect these transport characteristics as well. 

Analysis shows that concentrations of polysaccharides and volatile fermentation products in white wines are reduced by tangential microfiltration, as compared to filtration through a kieselguhr precoat. Anthocyanins and tannins are affected in red wines. However, in view of the natural modifications that occur in wines during aging, these differences tend to become less marked over time. The standard tests used in organoleptic analysis did not identify any significant differences (threshold of 5%) after samples had been kept for 1, 6, and 12 months. 

Since the substance to be examined in this test is identified by its smell, great care should be exercised so that the test is not performed on a substance that could give off gases that would be hazardous to inhale. When elaborating new monographs, the inclusion of organoleptic analysis is discouraged. ... 

Such definitions imply that there is a reliable test for rancidity, but this is not the case. The difficulties are centered about the fact that in the final analysis, rancidity must be detected through organoleptic observation, which is subject to all the weaknesses inherent in a test involving personal judgment. As was pointed out in a recent discussion (S), these weaknesses include variabilities in the taste and odor sensitivities of persons in the same or different laboratories, their previous taste experiences, the prevailing condi-... 

Among a wide variety of sea foods with a great variety of tastes, the overall taste pictures of only a few have been studied by detailed chemical analysis of their extractive components accompanied by organoleptic tests. Sea foods provide fascinating materials for food chemists who are interested in flavor. 

In 1966, Le Magnen proposed a designation of the organoleptic qualities of coffee. A choice of tests for the organoleptic valuation of coffee has been presented by Depledt (1968) and a sensory analysis of coffees and instant coffees has also been published by Van Roekel (1976). Vitzthum et al. (1976) were the first to use the sniffing -technique in the analysis of coffee volatiles. 

In addition to organoleptic assessment, several chemical/physical methods have been developed to measure lipid oxidation. These include peroxide value, thiobarbituric acid (TBA) value, ultraviolet absorption (at 233 nm), ferric thiocyanate, Kreis test, chemiluminescence, oxygen uptake and analysis of carbonyls by HPLC (see Rossell, 1986). 

Except for specific applications, the requirements for routine polyphenol analysis can be adequately met by the application of a number of tests that are rapidly carried out without the need for elaborate instrumentation. It is difficult to determine or to express the results in terms of concentration, so therefore various indices are used that represent either total polyphenols or different groups of polyphenolic compounds. The tests briefly described below are useful in following the progress of a vinification, in making comparisons between different wines, and in seeking to quantify certain organoleptic properties of wines (notably bitterness and astringency). 

The area of flavor and aroma barrier is receiving growing attention in the field of plastics packaging. The permeation of flavors is difficult to measure quantitatively because they contain many components. Many times, only a simple component of a flavor is measured if a quantitative value must be determined. Gas chromatography and mass spectrophotometric (GC/MS) techniques have been developed that allow the analysis of complex flavors. However, in most cases, the use of organoleptic testing provides reliable and pertinent data at a greatly reduced cost. 

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