Sensory Quality Measuring Methods

The sense of pain is also very complex. It can be stimulated in many different ways. In the case of flavourings, sharpness is of particular importance. 

So what could be more obvious than to use man himself as a measuring instrument so that these sensations, which are of such importance for a flavouring, can be measured. Because the ultimate tester of the product, the consumer, is also a human being. Furthermore the human senses are far superior in this respect to normal measuring instruments. As the complex pattern of a product is composed of many sensory pictures from many sensory mosaics , a normal measuring instrument cannot record these. Quite apart from this, psychological influences also pay an important part. We therefore also try to objectify this subjective human characteristic by means of Sensory . 

Technically speaking, as mentioned earlier, quality testing in both ways, sensory or organoleptic, using man more or less as a measuring instrument, has considerable further advantages, such as 

Good assessors can certainly check more samples in a short time than a measuring instrument. 

Sensory or organoleptic quality testing is very effective as high quality information is obtained on the quality of the product. For example, the assessor can immediately describe the sensory difference and appropriate measures can be implemented in the productive process. As the consumer, i.e. the customer for whom the product is manufactured, is in principle an untrained assessor. From the sensory point of view to a great extent he is a layman, therefore sensory control must be relevant to the consumer, as it is carried out by trained assessors. 

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Knowing the relationships between chemical and sensorial variables, objective methods can be obtained to evaluate the food quality. Juries of experts cannot be formed and used so easily as the measurement of chemical quantities can. Besides, the knowledge of these relationships will be able to retain, so to speak, sensorial evaluations and follow the evolution of taste over a long period, so that it may be foreseen as well. 

When consuming whole meat, like steak, roasted beef, and stews, sensory tenderness, toughness, and juiciness are often considered the most important quality attributes. Traditional sensory analysis is both time consuming and sample destructive. Other rheological methods to determine tenderness and toughness are also destructive analysis methods. A noninvasive, nondestructive measurement method is desired by the industry. 

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. 

Dupuy and coworkers have reported a direct gas chromatographic procedure for the examination of volatiles in vegetable oils (11). peanuts and peanut butters (12, 13), and rice and com products (14). When the procedure was appTTed to the analysis of flavor-scored samples, the instrumental data correlated well with sensory data (15, 16, 17), showing that food flavor can be measured by instrvmental means. Our present report provides additional evidence that the direct gas chromatographic method, when coupled with mass spectrometry for the identification of the compounds, can supply valid information about the flavor quality of certain food products. Such information can then be used to understand the mechanisms that affect flavor quality. Experimental Procedures... 

The most obvious method is subjective and here the evaluation is based on the opinion of the tester and the response of the sensory organs. Obviously this technique presents many problems and there is wide variation in the range of results obtained. Objective methods are based on specific analyses and, thereby, exclude tester opinion. Thus, the intrinsic aspects of quality are reduced to chemical, physical, or biological measurements and only the interpretation of the resulting data is related back to the subjective opinion. 

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. 

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. ... 

Most mechanical tests developed for fats are empirical in nature and are usually designed for quality control purposes, and they attempt to simulate consumer sensory perception (3, 4). These large-deformation tests measure hardness-related parameters, which are then compared with textural attributes evaluated by a sensory panel (3, 5). These tests include penetrometry using cone, pin, cylinder and several other geometries (3, 6-12), compression (13), extrusion (13, 14), spreadability (15, 16), texture profile analysis (2), shear tests (13), and sectility measurements (14). These methods are usually simple and rapid, and they require relatively inexpensive equipment (3, 4, 17). The majority of these tests are based on the breakdown of structure and usually yield single-parameter measurements such as hardness, yield stress, and spreadability, among others (4, 17-20). The relationship between these mechanical tests and the structure of a fat has, however, not been established. The ultimate aim of any materials science endeavor is to examine the relationship between structure and macroscopic properties. 

Sensory evaluation is a scientific discipline that uses humans to measure the acceptability and sensory properties of food and other materials. Sensory properties important in food products include attributes of appearance, odor, taste, and texture. The use of humans as measuring devices is necessary because only humans can define what is acceptable, and in many cases, no instmmental or chemical method can adequately measure or replicate the human response. For this reason, sensory evaluation is a vital component in any quality assessment program. In such programs, sensory evaluation can be used to monitor product quality determine effects of alternative processing, ingredients, or formulations evaluate packaging and determine product shelf life. 

Peroxide value, expressed as milliequivalents of peroxide per kilogram of oil, measures the primary oxidation products of oils— the hydroperoxides. The peroxide value has shown a particularly good correlation with sensory flavor scores of soybean oU, and its use during storage is quite common. The peroxide value is an index to the oxidative state of an oU. Soybean oU is considered fresh with a peroxide value <1.0 mEq/kg, to have low oxidation with 1.0-5.0 mEq/kg, to have moderate oxidation at 5.0-10.0 mEq/kg, to have high oxidation at > 10.0 mEq/kg, and to have poor flavor quality at >20 mEq/kg (6). Several methods (300-303) can be used to measure the peroxide value of an oil depending on the specific circumstance. 

STONE M B and young c m (1985), Effects of cultivars, blanching techniques, and cooking methods on quality of frozen green beans as measured by physical and sensory attributes , J Food Qual, 7, 255-265. 

Fried foods quality is defined by their properties, such as moisture and oil contents, porosity, color, taste, and nutritional content (Dogan et al., 2005). Conventional methods of measuring these properties include physical (instrumental), chemical, and sensory methods (Qiao et al., 2007a). Some of these procedures are subjective, cumbersome, and time-consuming, and often require the destruction or modification of a product. During the past decade, a number of novel methods for determining food properties have been proposed, and some of them are presented below. 

Characteristic aroma components in foods and off-flavor substances in processed foods are called character impact compounds. It would be desirable to develop methods for finding such compounds with sensory methods because such information is useful in the food industry. A compilation of odor and taste threshold values was edited by Fazzalari (7). Olfactory-trigeminal response to odorants was measured using rabbits (2). However, aroma quality can be evaluated only by human sense. In spite of this fact, olfactory judgment by humans can not give constant data like... 

Rehabilitation of humans with sensory-motor disability requires effective assistive systems that would allow their fast and maximal reintegration into the normal fife. The cost-benefit functions that humans with disability likely appreciate and optimize comprise elements, such as (1) the quality of life measured by reintegration into the social and work environments (2) reliability of the assistive system (3) energy rate and cost with respect to the one used for accompHshing the same task with alternative methods (4) disruption of normal activities when employing the assistive system (5) cosmetics (6) maintenance and (7) cost. The same elements are considered, but, in a different order by the developers of the rehabilitation technology, practitioners of physical medicine, and rehabilitation and health-care providers. 

The liquor colour is one of the most important quality parameters of tea. During cash valuation, where flavour is not important, the liquor colour is considered to be the qualifying factor for quality, as in those cases the liquor colour alone can represent the other physical attributes of tea. An interesting fact regarding the liquor colour is that in few parts of the world the consumers are biased only to some particular liquor colour of tea and it varies from country to country. Furthermore like other commercial sectors some trade disputes also exist in tea. Measurements on liquor colour help a lot to monitor/rectify such problems also. But uunfortunately there is no standard method other than sensory evaluation available to study the tea liquor colour. 

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