Quality attributes texture

Typical attributes for evaluating food quality are safety, shelf life, color, taste, flavor, texture, health, and convenience. The level of a quality attribute is determined by levels of physical, microbial, physiological, chemical, and biochemical food processes, product composition, and applied technological conditions. For example, a combination of enzyme-degrading colorants, compositions and concentrations of pigments, and food structure properties contribute to a certain color level perceived by consumers. Depending on the match of expectation and experience, certain attributes will or will not be perceived as quality. ... 

Looking back also over the historical development of quality requirements for processed foods, freezing when properly carried out is undoubtedly the most satisfactory method for the longterm preservation of vegetable produce. The low temperatures commonly prescribed for frozen foods (—18°C) can maintain initial quality and nutritional value practically unchanged, so that frozen and fresh vegetable products differ only in texture (Canet, 1989), which is however a particularly important quality attribute in potato products. 

Thybo, A. K., Szczypihski, P. M., Karlsson, A. H., Donstrup, A., Stodkilde-Jorgensen, H. S., Andersen, H. J. (2004). Prediction of sensory texture quality attributes of cooked potatoes by NMR-imaging (MRI) of raw potatoes in combination with different image analysis methods. Journal of Eood Engineering, 61, 91-100. 

Texture has been recognized as one of the most important quality attributes in dried potatoes which contribute to the consumer acceptance. Texture of potatoes is affected by drying processes and it is strongly associated with composition and stmcture of cells walls (Ramos et al., 2003). As previously stated, water loss is accompanied by loss of internal pressure cellular tissue shrinks and becomes soft. This pressure is known as turgor pressure and plays an important role in the rheological and textural properties of the potato tissue. 

Of course, texture cannot be taken into consideration using this procedure and, therefore, a possible significant part of the overall flavor may be compromised. If sections or segments are to be evaluated, it is a good idea to present the entire contents of a can, if practical, for each judge to make an overall evaluation. Seeds, if present, should be removed as their presence would only serve to confuse the panelist, especially if quality attributes are being evaluated such as firmness, sweetness, etc. Failure to remove seeds in this case could lead to a type of stimulus error, the seeds being an irrelevant characteristic. 

The main quality attributes of fruits are appearance (colour, size, shape, lack of defects), texture and flavour (ripeness). Consumer satisfaction, however, relates... 

Hemicellulose has a greater impact on food texture than do polysaccharides (Kim and Kim, 1988), because it is this group of natural compounds that differentiates crispiness in vegetables (Klockeman et al., 1991). The many physical changes it undergoes with time directly affect the texture of cooked plant tissues whose quality attributes remain resident more in the low DP than in the high DP component (Kim and Kim, 1988). 

The use of low-calorie fat replacers in foods facilitates reductions in the energy density of the diet. However, since fat confers a number of important quality attributes, it is critical that such foods be highly palatable. When all or part of the fat is replaced, the foods must have comparable rheological and sensory-quality attributes to the original high-fat food. Textural properties are particularly important since fat has a pronounced impact on texture, mouthfeel, and hence eating quality. Therefore, in addition to lowering the calorie density, an acceptable fat substitute must have the appropriate functional properties, such as heat stability, emulsification, aeration, lubricity, spreadability, texture, and mouthfeel (Lukacova and Karovicova, 2003 Silva, 1996). 

Because texture is such an important property in foods, a brief diseussion of its meaning, quantification and implications is presented. The term texture refers to an elusive but important quality attribute of foods that is difficult to measure or analyze. Nevertheless, it is clear that whether testing is performed in our mouth or by an engineering device, what is being measured is the manifestation of the structural... 

It Is generally recognised that In fruit and vegetable production more attention should be given to the hidden sensory quality parameters, such as flavor and texture. These quality attributes are the result of a number of pre- and post-harvest factors and are closely related with fruit ripening. Palllard distinguishes external and Internal factors Influencing aroma formation In fruits (U. The... 

In a previous work, Di Scala and Crapiste (2005) studied the effect of temperature on some of the most important quality characteristics of individual pieces of red sweet pepper Capsicum annuum. L) during drying. Color and antioxidant content are among the main quality attributes of these vegetables besides textural and flavor attributes. Both carotenoids (provitamin A) pigments and ascorbic acid contents are related to pepper variety (Roura et al., 2001) and technological factors. 

Taste. Taste Is the human perception of chemicals In the mouth due to their Interaction with receptors on the tongue. Taste consists of four dimensions sweet, salty, sour and bitter. Taste Is affected by odor and texture, which makes it a complicated, subjective quality attribute, difficult to measure objectively (22). In fruits and vegetables, taste Is mostly determined by the types and amounts of carbohydrates, organic acids, amino acids, lipids and phenolics (5.71). CA combinations, to the degree that they modify changes in these constituents, can affect the taste of stored fruits and vegetables. Usually, extremely low O2 or high CO2 will result In off-flavors and reduced quality due to anaerobic respiration. The specific effect of CA on flavor depends on the crop Involved (2). 

Future activities include the improvement of techniques for selecting quality attributes already identified, and to add other attributes. A faster laboratory method for screening the "Iso-coumarlns", volatile terpenoids, sugar types, and carotenoids will be valuable. Other flavor attributes of both fresh and processed carrots need consideration. The potential for genetic improvement of carrot fiber, which is a high quality nutrient (13) that may Influence texture, also warrants investigation. 

The control of water activity in foods is an important tool for extending shelf life. It is responsible for the quality of foods affected by microbiological, chemical, and physical changes. The physical properties, quantity, and quality of water within the food have a strong impact on food effectiveness, quality attributes, shelf life, textural properties, and processing. 

Determining the main chemical constituents, namely, fat, moisture, and protein, in meat and fish muscle is often the most important point of analysis in a production process. Knowing the chemical composition of the raw materials to be used in a process makes it possible to optimize the composition of the final product. However, quality characteristics other than chemical composition may also be important for some products, such as sensory attributes, texture, added NaCl, and added starch. 

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