Sensory characteristics

Consumer acceptance of milk is strongly determined by its sensory characteristics. The development of off-flavor in milk as a result of lipolysis can reduce the quality of milk. The enzymatic release, by milk lipase, of free fatty acids (FFA) from triglycerides causes a flavor defect in milk described as rancid . Triglycerides in milk contain both long chain and short chain fatty acids, which are released at random by milk lipase. The short chains FFA, like butyric acid, are responsible for the off-flavor. 

Piagentini, A.M., Guemes, D.R., and Pirovani, M.E., Sensory characteristics of fresh-cut spinach preserved by combined factors methodology, J. Food Sci., 67, 1544, 2002. 

Color is the most obvious characteristic of a food and often predetermines the quality expectations and perceptions of consumers and food handlers who judge food. Color may provide the key to cataloging a food as safe based on good aesthetic and sensory characteristics (Section 7.1.1). A profound understanding of the physical and chem-... 

The experimental designs discussed in Chapters 24-26 for optimization can be used also for finding the product composition or processing condition that is optimal in terms of sensory properties. In particular, central composite designs and mixture designs are much used. The analysis of the sensory response is usually in the form of a fully quadratic function of the experimental factors. The sensory response itself may be the mean score of a panel of trained panellists. One may consider such a trained panel as a sensitive instrument to measure the perceived intensity useful in describing the sensory characteristics of a food product. 

Figure 38.19 shows the contour plots of the foaming behaviour, uniformity of air cells and the sweetness of a whipped topping based on peanut milk with varying com syrup and fat concentrations [16]. Clearly, fat is the most important variable determining foam (Fig. 38.19A), whereas com syrap concentration determines sweetness (Fig. 38.19C). It is rather the mle than the exception that more than one sensory attribute are needed to describe the sensory characteristics of a product. An effective way to make a final choice is to overlay the contour plots associated with the response surfaces for the various plots. If one indicates in each contour plot which regions are preferred, then in the overlay a window region of products with acceptable properties is left (see Fig. 38.19D and Sections 24.5 and 26.4). In the...

Lin, S., Huff, H. E., and Hsieh, F. (2002). Extrusion process parameters, sensory characteristics, and structural properties of a high moisture soy protein meat analog. /. Food Sci. 67 (3), 1066-1072. 

Cloughley, J. B., Storage deterioration in Central African tea Changes in chemcial composition, sensory characteristics and price evaluation. J. Sci. Food Agri., 32 1213, 1981. 

Sensory quality can be defined as texture, flavour (taste), aroma and visual aspect. The sensory properties of milk are highly influenced by its fat content (Phillips et al., 1995a). As a result, research has examined the effects of various food additives on sensory quality when used as a substitute for fat in milk (Philips et al., 1995b). Frpst et al. (2001) showed that a combination of thickener, whitener and cream aroma in 0.1% fat milk was successful in mimicking the sensory quality of 1.3% fat milk. With the interest in the production of milk enriched with cis-9, trans-l 1 CLAs, owing to their relevance to human health (Tricon et al., 2004), recent research has examined the effects of CLA on the sensory quality of dairy products and found that it is possible to produce CLA-enriched dairy products with acceptable sensory characteristics (Jones et al., 2005). 

Horsted K., Henning, J. and Hermansen J.E. (2005). Growth and sensory characteristics of organically reared broilers differeing in strain, sex and age at slaughter, Acta Agriculturae Scandinavica, Section A - Animal Science, 55, 149-157. 

Brewer M S, Zhu L G and McKeith F K (2001), Marbling effects on quality characteristics of pork loin chops consumer purchase intent, visual and sensory characteristics , Meat Sci, 59, 153-163. 

Jonsall A, Johansson L, Lundstrom K, Andersson K H, Nilsen A N and Risvik E (2002), Effects of genotype and rearing system on sensory characteristics and preference for pork , Food Qual and Pref, 13, 73-80. 

Martel J, Minvielle F and Poste L M (1988), Effects of crossbreeding and sex on carcass composition, cooking properties and sensory characteristics of pork , J Anim Sci, 66, 41 16. 

Tacke et al. have also studied the bioisosterism of fragrance materials and reported the synthesis of silamajantol, hydroxymethyldimethyl(3-methylbenzyl)silane 42, which shows drastically different sensory characteristics compared to the parent majantol, 2,2-dimethyl-3-(3-methylphenyl)propanol 43, an important perfume ingredient.203,204... 

Compositional differences in the pea seeds influence the quality of the end products. Pea flours have been used for protein enrichment of a number of cereal-based products however, undesirable sensory characteristics may limit their use, in spite of improved functional effects in food systems. The production of volatile compounds during cooking and baking of foods with pea supplementation affects their acceptability. Enzyme systems active in unheated pea flours may contribute to their functional properties, but adversely affect the sensory quality of the food. 

When the pea flour was heated, the flavor was considerably improved. Cooked yellow pea flour-fortified noodles were comparable to the control with respect to sensory characteristics and yield. 

Raidl and Klein (43) substituted 5, 10, and 15% field pea flour in chemically leavened quick bread. The viscosity of the pea flour batters was significantly lower than either the wheat control or soy containing batters. The starch composition of the pea flour and lower water absorption properties of the protein could have affected the viscosity. Volumes of pea flour loaves were lower than the control and soy loaves. Most of the sensory characteristics of the field pea loaves were similar to those of the control quick breads. However, all flavor scores were significantly lower for pea flour products, since they had a recognizably beany or off-flavor. 

Ca is a comparatively difficult element for the body to absorb and digest. It is essentially only available for consumption associated with various other moieties (e.g., citrate, phosphate, and other anions). Each Ca source has unique physical, structural, and chemical properties such as mass, density, coordination chemistry, and solubility that are largely determined by the anions associated with the Ca +. Aqueous solubility of various Ca salts can vary markedly and comparisons are frequently made under standardized conditions. The water solubility of CCM is moderate when ranked versus other Ca sources frequently used as dietary supplements and food/beverage fortificants. The solubility of CCM (6 2 3 molar ratio) is 1.10-g salt in 100 ml of H2O at 25 °C (Fox et ah, 1993a). Table 6.4 lists the solubility of various Ca sources in water at specific temperatures, and also includes some information on potential sensory characteristics. 

TABLE 6.4 Solubility and sensory characteristics of various Ca sources... 

Polyols too are important in the wine industry, as glycerol is related to the sensory characteristic of smoothness, while inositol is used as a purity parameter for concentrated rectified musts [47], Analysis of sugars is carried out in cider production [48],... 

Castel, C., Morand, A., Pujol, G., Peyron, D., and Naudin, R. (2001). Influence on phenolic composition and sensory characteristics of microoxygenation on grape pomaces and during aging of red wines in Burgundy. Ind. Bevande 30, 771-T76. 

Iwuoha, C. I. and Umunnakwe, K. E. (1997). Chemical, physical and sensory characteristics of soymilk as affected by processing method, temperature and duration of storage. Food Chem. 59,373-379. 

As mentioned before, the sensory properties of the various heterocyclic compounds discussed in this contribution are one of the important factors determining food quality. The data on sensory characteristics of the various numerous compounds formed through the reaction of aldehydes with ammonia or ammonium sulfide, in the presence or in the absence of acetoin, are scattered in the literature (57) and thus are not easy to find. At the same time, information on sensory characteristics of compounds of this type is of primary importance to food chemists. Sultan (29) has compiled much of this information which is presented here in Table IV where also the appropriate references to the original literature are given. 

Table IV, Sensory Characteristics of Selected Heterocyclic Compounds...

This is the major citrus fruit produced worldwide. Since this citrus type has been produced for over 2,000 years, there are a wide range of named cultivars. However, the major cultivars of commercial importance include Valencia, Pera, Navel, Hamlin and Shamouti. The sensory characteristics of juices from a few of these cultivars have been reported [19]. 

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