Textural attributes

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. 

Overall acceptance is an attribute that seems to be influenced either by textural attributes or the flavour ones. However it is possible to establish correlations between overall acceptance and hardness (Figures 5, 6, 7, 8). 

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. 

Smell, taste, texture, and aftertaste, therefore, are important factors in the development of pediatric dosage forms. In a study of six brands of OTC chewable vitamins, flavor type and intensity, soft texture, and short aftertaste were critical factors in product preference. The flavor and texture attributes of the bestselling product were significantly different from the other brands [97]. 

WATER ACTIVITY, MOISTURE CONTENT, RELATIVE STABILITY LEVEL, EXAMPLE PROCESSING, PRESERVATION AND PACKAGING TECHNOLOGIES, TEXTURAL ATTRIBUTES, AND EXAMPLE FOOD PRODUCTS CORRESPONDING TO EACH OF REGIONS I, II, AND III IN FIGURE 15... 

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. 

A good (70%) prediction of sensory texture attributes of cooked potatoes has been obtained with nuclear magnetic resonance imaging, however, not all sensory attributes of texture are... 

Although studies on potato structure had been carried out previously using conventional SEM, van Marie et al [70] used cryo-SEM to advantage in this high moisture material. The fracture planes of cooked and uncooked samples were used to help characterize cell wall adhesion in the four potato cultivars. In particular, differences in cell wall contact area and surface detail were used to explain the mealy versus firm textural attributes in the cultivars. By determining the parameters which contributed to the texture of potatoes, processing conditions and selection of suitable raw materials could be facilitated. Such information would be difficult to obtain with conventional, chemically fixed material due to the high moisture content and the inability of standard chemical fixation to retain carbohydrate-based structures. 

In contrast to the mechanical and rheological properties of materials, which have defined physical meanings, no such definitions exist for the psychophysical assessment of equivalent textural properties of foods. To identify material properties, or combinations of these, which are able to model sensory assessments requires a mixture of theory and experimentation. Scientific studies of food texture began during the twentieth century by the analysis of the rheological properties of liquid or semi-solid foods. In particular Kokini14 combined theoretical and experimental approaches in order to identify appropriate rheological parameters from which to derive mathematical models for textural attributes of liquid and semi-solid foods, namely, thickness, smoothness and creaminess. 

Many of the desirable flavour and textural attributes of dairy products are due to their lipid components consequently, milk lipids have, traditionally, been highly valued, in fact to the exclusion of other milk components in many cases. Today, milk is a major source of dietary lipids in western diets and although consumption of milk fat in the form of butter has declined in some countries, this has been offset in many cases by increasing consumption of cheese and fermented liquid dairy products. 

Established knowledge is also that the protein content is an important factor. In regular yoghurt manufacture, the dry matter or protein content is normally increased by l%-3% to obtain the required textural attributes, the processing means presented above being options to lower the required protein addition to the minimum. 

Fats provide fundamental structural and textural attributes to a wide range of consumer products, including lipstick, chocolate, and everyday products such as butter and margarine (1, 2). Within these fat-based products, certain textural properties are required to meet desirable sensory attributes to gain consumer acceptance (3). This has led to an increase in research efforts on the physical properties of fats, particularly their rheology. 

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. 

These rheological parameters have been successfully correlated to textural attributes of hardness and spreadabUity and provide information pertaining to the fat crystal network (69). The value of G is useful in assessing the solid-like stmcture of the fat crystal network. Increases in the value of G typically correspond to a stronger network and a harder fat (66). Alternatively, G" represents the fluid-like behavior of the fat system. This value can be related to the spreadability of a fat system, because increases in G" indicate more fluid-like behavior under an applied shear stress. The tan 8 is the ratio of these two values. As the value of 5 approaches 0° (stress wave in phase with stress wave), the G" value approaches zero, and therefore, the sample behaves like an ideal solid and is referred to as perfectly elastic (68). As 8 approaches 90° (stress is completely out of phase relative to the strain). 

The compression of uniform samples to the point where the force exceeds the structural capacity causes it to permanently deform and essentially break (4). A typical load-deformation curve can be used to derive values for yield stress, yield strain, and compressive yield work, and depending on the linearity of the onset of compression, a compressive modulus may be obtained (4). These measurements can be used to provide an index of hardness for fats, which have been successfully correlated to the textural attributes of hardness and spreadability obtained through sensory evaluation (4). Unfortunately, these tests are destructive in nature and yield minimal information about the native microstructure of the system. 

Water molecules are constantly in motion, even in ice. In fact, the translational and rotational mobility of water directly determines its availability. Water mobility can be measured by a number of physical methods, including NMR, dielectric relaxation, ESR, and thermal analysis (Chinachoti, 1993). The mobility of water molecules in biological systems may play an important role in a biochemical reaction s equilibrium and kinetics, formation and preservation of chemical gradients and osmotic pressure, and macromolecular conformation. In food systems, the mobility of water may influence the engineering processes — such as freezing, drying, and concentrating chemical and microbial activities, and textural attributes (Ruan and Chen, 1998). 

From the results of the present work, it can be concluded that the storage at the usual commercial temperatures (T = — 18°C slightly above T g) affects the quality of aqueous starch sucrose pastes without gums caused by amylose and amylopectin retrogradation. However, when hydrocolloids are included in the formulations, the usual storage conditions allows main-tainence of acceptable textural attributes. 

In addition to containing a combination of individual proteins, protein ingredients generally include lipid, carbohydrate, and minerals to varying degrees, which can modify the performance of the product in food applications. Composition may vary as a function of the breed/variety, the season of the year, and the process used to obtain the protein ingredient. Commercial suppliers of proteins provide a range of protein products that have been prepared for different applications. The proprietary product Simplesse represents a process-modified protein where microparticulation is claimed to provide textural attributes useful in fat simulation. However, frequently, the differences are related to variations in chemical composition. 

Thus, the extent of pH displacement is a critical factor controlling the textural attributes of PCPs (Swiatek, 1964 Rayan et al., 1980 Gupta et al., 1984). 

Chong, C. H. and C. L. Law (2011). Application of intermittent drying of cyclic temperature and step-up temperature in enhancing textural attributes of dehydrated Manilkara zapota. Drying Technology 29(2) 245-252. 

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