Sensory approaches

Sensory Test - The choicest of the tested materials are now subjected to an actual Utility Test in a food system. These will include both the successes and the failures of the Model Test, with a range of values of significant variance. The foods prepared are then tested by a purely sensory approach. 

Sensory Approach. The main sensory studies applied have been in the determination of odor thresholds of components and the calculation of odor unit values (Uo), the ratio of the concentration of the component in the food to its odor threshold in water. The results of these studies are summarized in Table I. It can be seen that (Z)-3-hexanal shows the most odor units... 

However, although countless examples of fluorescence or electrochemical labels have been demonstrated as signal-generating components of aptamer-based sensors, the specific nucleic acid structure of these novel binders has so far not been used sufficiently to improve the sensitivities, and thus the detection limit, of sensorial approaches. A combination of aptamers and DNA machines might take the field to new heights. 

Barbe, J.C. Pineau, B. Silva, A.C. (2008). Instrumental and sensory approaches for the characterization of compounds responsible for wine aroma. Chemistry and Biodiversity 5,1170-1183. 

Lastly, the nature of the differences to be detected is becoming increasingly precise and subtle. Basic evaluation without a precise design is inadequate. The challenge is therefore to be able to set up new sensory approaches that will be able to detect differences between products. 

This type of tasting must be used correctly in addition to the other sensory approaches, and should never be seen as a substitute for them. This is now well understood. 

D hauteviUe, F., Aurier, P. and Sirieix, L. (1997). A sensory approach to consumers preferences for rice. First results of a European survey (France, Greece, Netherlands, Spain). International Symposium on rice Quality, Nottingham, UK. 

Molares S, Ladio A (2014) Medicinal plants in the cultural landscape of a Mapuche-Tehuelche community in arid Argentine Patagonia an eco-sensorial approach. J Ethnobiol Ethnomed 10 61... 

One of the few situations requiring a QC panel evaluation is the determination of Scoville heat units. While there are analytical methods available for the determination of capsaicins [15], a sensory approach [16,17] is often still used. 

There is no combination of chemical or physical analyses which can, or is ever likely to, replace human sensory evaluation completely. Sensory examination of wines employs two major approaches detecting differences and evaluating quaUty or, more briefly, analytical and hedonic (16,19). The former can be objective and the latter is inevitably somewhat subjective regardless of the expertise of the judges. 

This example demonstrates the most challenging problem of flavor chemistry, ie, each flavor problem may require its own analytical approach however, a sensory analysis is always required. The remaining unknown odorants demand the most sensitive and selective techniques, and methods of concentration and isolation that preserve the sensory properties of complex and often dehcate flavors. Furthermore, some of the subtle odors in one system will be first identified in very different systems, like o-amino acetophenone in weasels and fox grapes. 

Fleterocycles as chemosensors in molecular wire approach to sensory signal amplification 98ACR201. 

There have been a number of different synthetic approaches to substituted PTV derivatives proposed in the last decade. Almost all focus on the aromatic ring as the site for substitution. Some effort has been made to apply the traditional base-catalyzed dehydrohalogenation route to PTV and its substituted analogs. The methodology, however, is not as successful for PTV as it is for PPV and its derivatives because of the great tendency for the poly(u-chloro thiophene) precursor spontaneously to eliminate at room temperature. Swager and co-workers attempted this route to synthesize a PTV derivative substituted with a crown ether with potential applications as a sensory material (Scheme 1-26) [123]. The synthesis employs a Fager condensation [124] in its initial step to yield diol 78. Treatment with a ditosylate yields a crown ether-functionalized thiophene diester 79. This may be elaborated to dichloride 81, but pure material could not be isolated and the dichloride monomer had to be polymerized in situ. The polymer isolated... 

Future medical training, diagnosis and - even surgical - treatment will increasingly be performed remotely. Thus, the combination of sophisticated sensory devices with advanced micro-manipulation equipment will, together with 3D interactive feedback models, provide new tools and approaches for the medical profession. 

Neurotransmitter receptors have evolved as one of the key components in the ability of the central nervous system to coordinate the behaviour of the whole animal, to process and respond to sensory input, and to adapt to change in the environment. These same receptors are therefore ideal targets for drug action because of their central role in the activity of the nervous system. A rational approach to the development of new therapeutic strategies involving the action of drugs at receptors in the nervous system is based on knowledge of receptor structure, distribution and function. 

These are normally based on the use of either electrical stimulation or chemical convulsants. When applied generally, i.e. an electric shock to the whole brain or convulsants injected systemically, the resulting convulsions are indicative of generalised seizures. If they are applied locally to specific brain areas, the same approaches induce activity indicative of partial seizures. Also some animals can be bred in which seizures either occur spontaneously or can be induced easily by appropriate sensory stimulation. 

There are four main types of data that frequently occur in sensory analysis pair-wise differences, attribute profiling, time-intensity recordings and preference data. We will discuss in what situations such data arise and how they can be analyzed. Especially the analysis of profiling data and the comparison of such data with chemical information calls for a multivariate approach. Here, we can apply some of the techniques treated before, particularly those of Chapters 35 and 36. 

A table of correlations between the variables from the instrumental set and variables from the sensory set may reveal some strong one-to-one relations. However, with a battery of sensory attributes on the one hand and a set of instrumental variables on the other hand it is better to adopt a multivariate approach, i.e. to look at many variables at the same time taking their intercorrelations into account. An intermediate approach is to develop separate multiple regression models for each sensory attribute as a linear function of the physical/chemical predictor variables. 

An early effort using this approach in Guinea-pigs reported variable results — attributable to incomplete nerve sectioning (Planel, 1953). Sectioning procedures may also produce some unwanted effects as intracranial nerve section will remove part of the animal s N. terminalis sensory capability (Devitsina and Cherova, 1992). 

The equivalent procedure for the main olfactory epithelial sheet (MOEx) is chemical ablation by treatment with (5%) zinc sulphate solution. The adoption of this approach was determined by practical anatomy, given the inevitably partial, let alone traumatic, results of cutting/scraping epithelia from the intricately folded sensory surfaces (Negus, 1958). 

Among the many sensory reactions Phycomyces displays, the study of the photoreceptor and adaptation deserves maximal attention, since Phycomyces shares these two attributes with a variety of other blue light sensitive organisms. Action-spectroscopy indicates a flavin as the photoreceptor of Phycomyces. /3-carotene was positively ruled out as a possible receptor, since mutants with no trace amounts of )3-carotene are phototropical normal. The photoreceptor has not yet been isolated. As in other systems the difficulty consists in distinguishing the flavin photoreceptor from the bulk flavoproteins in the cell. One therefore needs unambiguous criteria for the identification of the photoreceptor. The most promising approach for an isolation would be a photoreceptor mutant and we described the properties those mutants should have. Until now there is no firm evidence that the photomutants, madA or madB are defective in the photoreceptor. 

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