Sensory quality, measurements

Particle size is an important property with respect to the sensory quality of chocolate, and in chocolate manufacture. It can be measured using laser light diffraction spectrophotometry (see Section 22.2.11.2), and by a variety of other means such as micrometry, microscopy, wet sieve fractionation, sedimentation and Coulter counting (Minifie, 1999). 

This is the dilemma—sensory properties should rank very high, but they don t because we lack the tools to measure them effectively. For the most part, these quality measures are subjective rather than objective, and frequently they require direct testing with consumers to determine efficacy of a particular product attribute. So the issue is really a lack of physical measurement tools that directly assess the performance measures important to the consumer of the product. The lack of objective performance measures and unknown mechanistic equations also makes mathematical modeling very difficult for addressing quality problems. 

Enantiomeric purity and enantiomeric excess (ee) are usual terms used in the determination of enantiomers. Enantiomeric purity is defined as the measured ratio (expressed as a percentage) of the detected enantiomers, whereas ee-values describe the relative difference of the separated enantiomers (expressed as a percentage). Usually quantifications are given in ee-values, but one should note, that convincing results can be concluded only for baseline-resolved enantiomers (cRs > 1.50). Exact calculations of partially resolved mirror images, as frequently happened in the current literature, remain unintelligible in view of differences in sensory qualities and odour thresholds of enantiomers Eig. 6.25, [1-9]. 

Aside from deacidification, MLF may also influence the sensory qualities of a wine by the production of many flavor and aroma compounds (Davis et al., 1985, 1988 Henick-Kling, 1993 Kunkee, 1967 Rankine, 1977). However, there is still debate regarding the contribution of MLF to the sensory properties of a wine. Early work by Kunkee et al. (1964) and Rankine (1972) indicated that MLF may not have a measurable effect on the sensory properties of a wine. On the other hand, many other studies have shown that MLF causes significant changes in wine aroma and flavor (Boido et al., 2002 Delaquis-Pascal et al., 2000 De Revel et al., 1999 Gambaro et al., 2001 Henick-Kling, 1995 Laurent et al., 1994 Maicas et al., 1999 McDaniel et al., 1987 Nielsen and Richelieu, 1999). 

MACDOUGALL, D. B. (1983) Instiumental assessment of the appearance of foods. In Sensory Quality in Foods and Beverages its Definition, Measurement and Control, eds A. A. Williams and R. K. Atkin, 121-139, Ellis Horwood, Chichester. 

Wardencki, W., Chmiel, T., Dymerski, T., 2013. Gas chromatography-olfactometry (GC-O), electronic noses (e-noses) and electronic tongues (e-tongues) for in vivo food flavor measurement. In Kilcast, D. (Ed.), Instrumental Assessment of Food Sensory Quality. A Practical Guide. Woodhead Publishing Limited, Cambridge (Chapter 7). 

Four characteristics of odor are subject to measurement by sensory techniques intensity, detectability, character (quality), and hedonic tone (pleasantness-unpleasantness) (16). Odor intensity is the magnitude of the perceived sensation and is classified by a descriptive scale, e.g., faint-moderate-strong, or a 1-10 numerical scale. The detectability of an odor or threshold limit is not an absolute level but depends on how the odorant is present, e.g., alone or in a mixture. Odor character or qualit) is the characteristic which permits its description or classification by comparison to other odors, i.e., sweet or sour, or like that of a skunk. The last characteristic is the hedonic type, which refers to the acceptability of an odorant. For the infrequent visitor, the smell of a large commercial bread bakery may be of high intensity but pleasant. For the nearby resident, the smell may be less acceptable. 

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. 

Slaughter performance (important for butcher) slaughter yield, balanced carcass weight, composition of carcass Meat quality (important for consumer) measurable or sensory meat quality criteria (appearance, colour, tenderness, juiciness, flavour, roast and boil capacity, biochemical values (e.g. pH-value)), and nutritional value... 

Texture is an important and complex quality characteristic. It is determined by variety and by structural and biochemical properties of tuber tissue, with some environmental influence. A considerable amount of research has been undertaken to replace subjective sensory evaluation with objective instrumental measurements (Van Dijk et al., 2002). 

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. 

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