Texture sensory

Drewnowski, A., Fats and food texture sensory and hedonic evaluation, in Food Texture, Moskowitz, H.R., Ed., Marcel Dekker, New York, 1987, pp. 1-127. 

The presence or activity of water in foods may also enhance the rate at which deteriorative chemical reactions occur. Some products may become rancid through free radical oxidation even at low humidities and thus become unacceptable. Labile nutrients such as vitamins and natural color compounds are oxidized more rapidly when stored at low moisture levels. Enzyme-mediated hydrolytic reactions may reduce the quality of the food product. Other reactions such as the Maillard type of nonenzymatic browning may be enhanced by the presence of higher levels of water. On the other hand, water content is crucial for the textural characteristics and the sensory perception of foods. A food may be found unacceptable by consumers simply because it does not satisfy their textural (sensory) anticipation. 

The aroma of fmit, the taste of candy, and the texture of bread are examples of flavor perception. In each case, physical and chemical stmctures ia these foods stimulate receptors ia the nose and mouth. Impulses from these receptors are then processed iato perceptions of flavor by the brain. Attention, emotion, memory, cognition, and other brain functions combine with these perceptions to cause behavior, eg, a sense of pleasure, a memory, an idea, a fantasy, a purchase. These are psychological processes and as such have all the complexities of the human mind. Flavor characterization attempts to define what causes flavor and to determine if human response to flavor can be predicted. The ways ia which simple flavor active substances, flavorants, produce perceptions are described both ia terms of the physiology, ie, transduction, and psychophysics, ie, dose-response relationships, of flavor (1,2). Progress has been made ia understanding how perceptions of simple flavorants are processed iato hedonic behavior, ie, degree of liking, or concept formation, eg, crispy or umami (savory) (3,4). However, it is unclear how complex mixtures of flavorants are perceived or what behavior they cause. Flavor characterization involves the chemical measurement of iadividual flavorants and the use of sensory tests to determine their impact on behavior. 

Added Water. Frankfurters and bologna are allowed to contain combinations of fat and added water not to exceed 40% with a maximum fat content of 30%. This allows, for example, a 10% fat frankfurter to be produced with 30% added water. Substitution of large amounts of fat with water alone may not give the optimal sensory and textural properties that consumers want (43). To overcome these shortcomings, several binders can be added to improve water and fat-binding properties, cooking yields, texture, and flavor (27). 

Besides all the sensory and texturizing properties, GA has interesting antioxidant properties such as an efficient capacity for deactivation of excited electronic states and moderated radical scavenging capacity. There is increasing experimental evidence that associate the antioxidant function with its protein fraction, mainly by amino acid residues such as histidine, tyrosine and lysine, which are generally considered as antioxidants molecules (Marcuse, 1960,1962 Park et al., 2005). 

For more details about the sensory properties of the pectin preparations additional sizes such as thixotropy and viscosity have to be referred to (see figure 6). Fruit preparations with apple pectin Classic AY 901 have a relatively high yield point after shearing, a small thixotropic area, and a relatively high viscosity. This supports the statement, that their texture is weakly elastic and highly reversible. The apple pectin Classic AY 905 gives products with a sufficiently high yield point at 35 % soluble solids and a pronounced area of thixotropy. 

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. 

Following previous works on physico-chemical characterisation of sunflower low-methoxyl pectins (Alarc o-Silva, 1990, Leitao at al., 1995) and technological utilisation in the manufacture of low calorie gels (Alarc o-Silva et al., 1992), this investigation was carried out to test the suitability of that pectin to the confection of grape juice reduced calorie jellies in comparison with two types of commercial pectin. Aiming at the optimisation of low-calorie jelly formula, based on consumers preferences, the jellies were submitted to a sensory panel test judgement and instrumental texture-analysis. 

The jellies (20 sets) were submitted to a sensory panel (ten panellists from the laboratory staff with some experience in sensory evaluation) requested to give a score (from low to high in a non-structured 10 cm scale) to each of the following characteristics aroma (intensity), taste (sweet, acid and intensity), texture (hardness, spreadability) and overall acceptance. 

The data from sensory evaluation and texture profile analysis of the jellies made with amidated pectin and sunflower pectin were subjected to Principal component analysis (PC) using the statistical software based on Jacobi method (Univac, 1973). The results of PC analysis are shown in figure 7. The plane of two principal components (F1,F2) explain 89,75 % of the variance contained in the original data. The attributes related with textural evaluation are highly correlated with the first principal component (Had.=0.95, Spr.=0.97, Che.=0.98, Gum.=0.95, Coe=0.98, HS=0.82 and SP=-0.93). As it could be expected, spreadability increases along the negative side of the axis unlike other textural parameters. 

The overlapping of textural attributes suggests that characterisation of this kind of jellies could be based on the evaluation of a single parameter. The concept of hardness being the easiest to apprehend and due to its close relation with the same sensory attribute, we believe that when jellies are to be appreciated from a textural point of view, hardness may be measured on its own. 

Beilken et al. [ 12] have applied a number of instrumental measuring methods to assess the mechanical strength of 12 different meat patties. In all, 20 different physical/chemical properties were measured. The products were tasted twice by 12 panellists divided over 4 sessions in which 6 products were evaluated for 9 textural attributes (rubberiness, chewiness, juiciness, etc.). Beilken etal. [12] subjected the two sets of data, viz. the instrumental data and the sensory data, to separate principal component analyses. The relation between the two data sets, mechanical measurements versus sensory attributes, was studied by their intercorrelations. Although useful information can be derived from such bivariate indicators, a truly multivariate regression analysis may give a simpler overall picture of the relation. 

Taylor, B. J. and Walsh, M. K. (2002). Development and sensory analysis of a textured whey protein meatless patty. /. Food Sci. 67,1555-1558. 

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). 

Consumer acceptance of fresh and processed fruits and vegetables is influenced by product appearance, flavor, aroma, and textural properties. Color is a key component that influences a consumer s initial perception of fruit and vegetable quality. Lycopene is the principal carotene in tomato fruit that imparts color. Analytical and sensory... 

Roudaut, G., Dacremont, C., and Le Meste, M. 1998. Influence of water on the crispness of cereal foods Acoustic, mechanical, and sensory studies. J. Texture Stud. 29, 199-213. 

Sensory attributes of akara made from the 1 mm screen flour hydrated to a 60% moisture content before cooking were acceptable when compared to traditional akara (H). A major difference in akara prepared from hydrated meal and that prepared from traditional paste is in the fat content of the cooked product. On a dry weight basis, traditional akara contains about 38% fat whereas akara made from meal hydrated to a 60% moisture content contains 29% fat. A frequent comment made by sensory panelists is that akara made from meal has a drier texture and mouthfeel than traditional akara. 

In the study by Thompson, et al. (11), the ml of gel released per 100 g emulsion for the reference emuTsion without soy, with soy isolate (SIF), soy concentrate (SCF) or soy flour (SF) was 6.07, 5.83, 5.49 and 3.08, respectively, when the hydration ratios were 1 4 (flourrwater) for SIF, 1 3 for SCF and 1 2 for SF. The ml gel released per 100 g emulsion containing 10, 15, 20, and 25% soy protein was 6.70, 5.01, 3.94 and 3.57, respectively. When soy protein concentrate was incorporated into an emulsion at the 3.5% level, the processing yields, textural profile and sensory textural attributes of frankfurters were not different among the products with and without added soy concentrate (13). An objective measure of compression and shear modulus indicated that soy protein concentrate incorporated into frankfurters at the 3.5% level had no effect on batter strength or texture ( M). The addition of a cottonseed protein to frankfurters to replace 5, 10 or 15% of the meat resulted in higher pH, less cured color, less firmness of skin, softer texture and reduced desirability as judged by a sensory panel (J5J. 

When you bite into an apple, what you get is flavor. Flavor depends on odor and taste but also on texture, appearance, and mouth feel. Multiple sensory inputs are integrated in our brains to develop the sensation of flavor. We have developed several aspects of the molecular biology of odor and taste, perhaps the major determinants of flavor. 

Proteins are important food components mainly due to their nutritional and functional value. Dietary proteins provide amino acids and nitrogen necessary for organisms. They also play a major role in determining the sensory and textural characteristics of food products. The functional properties are related to their ability to form viscoelastic networks, bind water, entrap flavors, emulsify fat and oil, and form stable foams [105]. 

Kumar, K. and Mishra, H. N. (2004). Mango soy fortified set yoghurt Effect of stabilizer addition on physicochemical, sensory and textural properties. Food Chem. 87, 501-507. 

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. 

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