Sensory quality control

The two research investigations reported here - the sensory quality control specification model and the application of sensory and analytical data for defining differences in tobacco aroma - both demonstrate the usefulness of multivariate analysis techniques for analyzing analytical and sensory data as well as correlating these data. Although these tasks do not compare in complexity to that of the prediction of sensory response to analytical data collected on cigarette smoke, our research to date has revealed no element which indicates that this is an impossible task. In fact, the results of these and similar... 

Sensory Quality Control - Practical Approaches in Food and Drink Production", Proc. Symposium, Symons, H.W, and Wren,... 

Although some efforts have been made (25-26), until now there have been no statistically sufficient, rapid and cost effective sensory quality control (QC) procedures against cork taint for either wineries or cork suppliers. At UC Davis, we have developed a Cork Sensory QC Manual (27) which evaluates the major valid sampling procedures, and exemplifies their use based on a case study at a premium winery in California. In addition, the manual provides instructions for a taste panel evaluation which is essential for wineries in order test their winemakers and cellarmasters as well as the tasting room staffs sensitivities to detect the off-odor. Once individual... 

Suprenant, A. Butzke, C.E. Cork Sensory Quality Control Manual, DANR, University of California, Davis, CA, 1998. 

Sensory Quality Control (SQC) / Sensory Quality Testing (SQT)... 

Using these rhelogical methods laboratories for quality control and research and development have good tools to characterize pectins in gels and solutions. The most important points are the reproducable handling, pretreatment, and measurement of the samples and the knowledge which information can be derived from the measured data regarding the texture, the production parameters, and the sensory evaluation of the product. 

The determination and analysis of sensory properties plays an important role in the development of new consumer products. Particularly in the food industry sensory analysis has become an indispensable tool in research, development, marketing and quality control. The discipline of sensory analysis covers a wide spectrum of subjects physiology of sensory perception, psychology of human behaviour, flavour chemistry, physics of emulsion break-up and flavour release, testing methodology, consumer research, statistical data analysis. Not all of these aspects are of direct interest for the chemometrician. In this chapter we will cover a few topics in the analysis of sensory data. General introductory books are e.g. Refs. [1-3]. 

P. Lea, T. Naes and M. R0dbotton, Analysis of Variance for Sensory Data. Wiley, London, 1997 D. H. Lyon, M. A. Francombe, T. A. Hasdell and K. Lawson, Guidelines for Sensory Analysis in Product Development and Quality Control. Chapman and Hall, London, 1990. 

Cake Donuts. The effects of 0-30% substitution of dry-roasted air-classified navy, pinto or black protein flour for wheat flour on the physical and sensory qualities of cake donuts were investigated. In general, fat absorption decreased as the level of substitution increased with the pinto bean variable having the lowest values. An increase of navy bean and pinto protein levels decreased donut height after the 10% level. The donuts with pinto bean protein exhibited less spread than the other bean type donut variables. Navy bean protein produced a more tender donut than the other bean types. The control donut and those with navy bean protein were the lightest in color, followed by pinto and black bean protein donuts,... 

In frozen vegetables, health quality, nutritional quality, and aspects of sensory quality like color and texture can be objectively assessed and controlled also, in frozen potato products the effects of the thermal treatments included in the process have to be assessed due to their influence on texture, color, and nutritional value. However, in the case of overall assessment of sensory quality, only the consumer can perceive and process the overall blend of sensations that denote quality and cause consumers to prefer, accept, or reject a product. 

Quality control of fragrance and flavor substances as well as the products derived from them, comprises the comparison of sensory, analytical and if necessary, microbiological data with standards and specifications. To a large extent these have been established in official specification collections (Pharmacopoeias, ISO, AFNOR, Essential Oil Association). 

Supported by the overall development in all fields of analysis during the past few decades, a precise analytical methodology has been developed for the different aspects of quality control, comprising physicochemical, biotechnological, sensory and microbiological methods. In order to meet the sense of the quality control system and by that the customers requirements, all methods applied have to be validated by adequate quality assurance tools. 

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. 

Hansen, T., Agerlin-Petersen, M., Byrne, D.V. (2005) Sensory based quality control utilising an electronic nose and GC-MS analyses to predict end-product quality from raw materials. MeatSci. 69 621-634. 

In the food industry it has often been difficult to obtain true viscosity measurements (unithj.j) of complex fluid foods such as coarse fruit suspensions. These are usually non-Newtonian suspensions. Fruit concentrates are dispersions of solid particles (pulp) in aqueous media (serum). Their rheological properties are of interest in practical applications related to processing, storage stability, and sensory properties. Expensive rheometers are often not available in quality control and product development laboratories. However, viscosity is nonetheless an important quality factor of these products. 

The taste sensor will be applicable for quality control in food industry and help automation of the production. The sense of taste is vague and largely depends on subjective factors of human feelings. If we compare the standard index measured by means of the taste sensor with the sensory evaluation, we will be able to assess taste objectively. Moreover, the mechanism of information processing of taste in the brain as well as the reception at taste cells will also be clarified by developing a taste sensor which has output similar to that of the biological gustatory system. 

The quality control of the main enological parameters of commercially available wines, according to EC regulation (EC No. 822,1987), is almost nonexistent in the literature (Nogueira and Nascimento, 1999). The physicochemical and sensorial parameters must also be definitely controlled as a strategy to confirm the authenticity and to prevent or detect possible adulterations (Nogueira and Nascimento, 1999), which contributes to increase consumer confidence. Nogueira and Nascimento (1999) were... 

Sensory analysis The odour of an essential oil can be evaluated by conducting investigations on the evaporation of an essential oil under standardized conditions and comparing this to a standard sample of the oil. This is sometimes referred to as odour purity but is a rather subjective method. It involves putting the essential oil and a standard sample onto separate smelling strips and allowing them to evaporate to a final dry-out under the same environmental conditions and time scale. This, along with a visual inspection of the oil, is the only immediate quality control measure available to the aromatherapist. 

Most of the methods used to characterize the rheological behavior of butter are empirical and attempt to imitate certain sensory perceptions. They typically involve penetrometry, extrusion or sectility tests (Prentice, 1972). In these tests, the structure of the material is destroyed in order to probe its response to an applied stress or deformation. These methods mostly serve a quality control function. Their results provide an index of consistency to adjust milk-blending operations or to regulate a step in the butter-making process. While the results have practical significance, they often have no theoretical basis. Therefore, attempts have also been made to study the intrinsic properties of plastic fats. In many such cases, small deformation tests, in which the structure of the sample remains intact have been used to probe milk fat rheology. 

Stapelfeldt, H., Nielsen, B.R., Skibsted, L.H. 1997b. Towards use of electron spin resonance spectrometry in quality control of milk powder. Correlation between sensory score of instant whole milk powders and concentration of free radicals and 2-thiobarbituric acid reactive substances. Milchwissenschaft. 52, 682-685. 

I believe the future of sensory evaluation will involve an expansion of the use of descriptive analysis in many different situations, such as in plant quality control, as well as product development and research applications. Because of the increased competition in the flavor industry, flavor companies are increasingly expanding their sensory work and sensory capabilities. This is necessary, not only for the flavor company to understand the products they are producing but to be able to satisfactorily service their client companies. 

Fabric hand is defined as the estimated quality of a fabric, evaluated as reaction of the sense of touch, which is integrated in our brain to a total value. Important components of the sensory perception are the smoothness, compressibility and elasticity of the textile sample. As the hand of fabrics is primarily a subjective feeling - similar to the impression of colour - there have been many efforts to find methods for objective evaluation of the fabric hand. While instrumental colour measurement is very common in textile quality control, the automated measurement of fabric hand is still a topic of discussion and subjective manual hand evaluation is still the most important method. Simple methods to measure some aspects of fabric hand were described by Dawes and Owen. Many factors such as the colour of the textile, the hght and the surroundings, influence the manual evaluation of fabric hand. The American Association of Textile Chemists and Colorists has published guidelines for subjective hand evaluation. ... 

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