Food texture sensory measurement

Food texture is measured by sensory analysis or by an instrumental method. Using a human inspector for a textural evaluation is subject to some errors because of variations in perception, even when trained panelists are used and a well-defined standard is referenced. However, Katz and Labuza (1981) compared sensory results and cohesiveness values from force-deformation curves for potato chips, popcorn, puffed corn curls as well as saltines, and obtained a good agreement between the two sets of data. A similar comparison was made by van Loon et al. (2007) for the crispness of French fries comparable results were also noted. 

Peleg, M. 1987. The basics of solid food rheology. In Food Texture Instrumental and Sensory Measurement (H.R. Moskowitz, ed.) pp. 3-33. Marcel Dekker, New York. 

Food Texture Instrumental and Sensory Measurement, edited by Howard R. Moskowitz... 

There would be considerable advantage for both sensory scientists and the food industry in knowing what consumers are measuring in order to assess particular textural properties. Despite many real advances in the instrumental measurement of food texture, we are not significantly closer to understanding the sensory cues used in consumer assessment of texture. The mastication process is adjusted to the consistency of the food bolus in real time. From studies of this process is emerging a novel approach to characterisation of food texture. 

Valles Pamies, B., Roudaut, G., Dacremont, C., Le Meste, M., and Mitchell, J.R. Understanding the texture of low moisture cereal products mechanical and sensory measurements of crispness, /. Sci. Food Agric., 80, 1679, 2000. 

Feeding and texture of food (meeting), Vincent J.F.V, Cambridge UP, 1991, 60 Food texture measurement and perception, Rosenthal A.J, Aspen PubL, 1999, 142 Food texture Instrumental and sensory measurement (meeting), Moskowitz H.R,... 

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. 

Chapter H2 describes the measurement of textural properties of solid-like foods. The first unit in that chapter, unit H2.i, describes a general procedure commonly used to evaluate the texture of solid foods. This method involves the compression of the food material between two parallel plates. There are a number of empirical textural parameters which can be evaluated with this technique. Simple compressive measurements do not provide a complete textural picture of some foods untthi.i presents variations to the parallel plate compression method with the use of special fixtures. For example the use of a puncture probe or a wire cutting device provide data that may relate more directly to the consumer s evaluation of texture for products like apples and cheese, unit m.3 describes a general protocol for the evaluation of a number of sensory texture parameters. This protocol is... 

A considerable problem for both the food industry and sensory scientists is the degree of individual variation in texture perceptions. The differences in breakdown pathways in the mouth for standard samples may underlie some of the variability. Indeed Brown et al31 have demonstrated an influence of chewing behaviour on texture perceptions in a model food system. Even if all individuals shared a common system for assessing a particular textural characteristic, the differences in the way they masticate a sample may cause them to come to different conclusions regarding its texture. However, there is also the real possibility that subjects may use different measuring systems for assessment of a textural characteristic they... 

Since sensory and mechanical properties of a food depend on its microstructure, the knowledge of microstructure must precede any operation aimed to the attainment of a specific texture (Ding and Gunasekaran, 1998). The instrumental measurements of mechanical and rheological properties represent the food responses to the forces acting on the food structure and, for this reason, are affected by the way in which these analyses are performed. Furthermore, mechanical and rheological tests are always destructive and make impossible the execution of other analyses. 

Because most foods are complex disperse systems, there are great difficulties in establishing objective criteria for texture measurement. It is also difficult in many cases to relate results obtained by instrumental techniques of measurement to the type of response obtained by sensory panel tests. 

Notwithstanding all the limitations involved, the continuous improvement in precision and reproducibility of physical measurement equipment that relate to parameters perceived by human subjects make their use straightforward and they can provide consistent results. It is important to keep in mind that although instruments allow precise and objective measurements if applied to whole foods, they only can account for the initial structural properties contributing to texture perception. A correlative approach using sensory and instrumental techniques is often necessary. Indeed, there is no reason to determine accurately a mechanical property if it is not relevant to human sensory perception. Sensory methods become essential when calibrating instrumental equipment and are fundamental in product development, especially at early stages. 

Sensory evaluation is a scientific discipline that uses humans to measure the acceptability and sensory properties of food and other materials. Sensory properties important in food products include attributes of appearance, odor, taste, and texture. The use of humans as measuring devices is necessary because only humans can define what is acceptable, and in many cases, no instmmental or chemical method can adequately measure or replicate the human response. For this reason, sensory evaluation is a vital component in any quality assessment program. In such programs, sensory evaluation can be used to monitor product quality determine effects of alternative processing, ingredients, or formulations evaluate packaging and determine product shelf life. 

The sensory properties are the characteristics of foods perceived by the senses of sight, smell, taste, touch and hearing, such as flavour, texture and appearance. The human sensory organs are a remarkably sensitive means of measuring sensory properties. 

Moore JN, Janick J (1983) Methods in fruit breeding. Purdue University Press, West Lafayette, IN Rettke M (1993) Prediction the storage life of dried apricots. ADFA News, Australia Roberston GL, Koopmanschap EA, Scrivens CA (1984) Comparison of instruments and sensory panel methods for measuring kiwifruit firmness. J Texture Stud 15 275-283 Sould J (1985) Glossary for horticultural crops. John Wiley, New York, pp 570-582 Southgate DAT (1991) Determination of food carbohydrates. Elsevier Applied Science, London, pp 144-148... 

An experimental response (often called dependent variable) is a measurable manifestation that is observed when the studied factors are made to vary. A phenomc-ntm may be described by means of several experimental responses. All sorts of responses can be considered, such as a yield or purity in chemistry, a weight increase in biolpgy. a gustatory quality in wine science, mechanical properties, or still the texture of a food product determined by sensory testing in food science. However, this last type of response, which can take only discrete values, is a source of problems when it comes to the interpretation of the results. It i.s also possible to study a function of a measured response. e.g.. the logaridim of the equilibrium coastant. The term e.Kperitnenral response is taken in a broad sense, as an experimental response can be the experimemal result of an experiment but also the result of a numerical simulation. Hie studied response i.s r xesented by T( and the studied response known with an experimental error by y. 

In-line/on-line feedback control of color of food during processing can improve not only color quality but also color related quality such as texture and appearance. To do this, there are three major aspects development of an in-line/on-line color sensor understanding of color change kinetics and establish correlations between instrumental measured and sensory panel perceived colors of foods. In this research, we have chosen color machine vision technology for the measurement of colors of food due to its superior spatial resolution over conventional instruments such as colorimeter or spectrophotometer. Relationships between measured colors and corresponding principal chemical markers were established for the model food systems. We have also found excellent correlations between the color machine vision system (CMVS) measured and a sensory panel determined colors of food samples (Ling and Tepper, 1995). We believed that a CMVS can be used for food process control to ensure color quality as perceived by consumers. 

In a commercial restaurant, the measurement tools need to be fast, consistent and simple enough for the fryer operators to be able to handle properly. Obviously, the most logical end point of oil is when the fried food starts showing signs of deterioration in sensory attributes (taste, appearance or texture). The challenge is that sensory attributes are somewhat subjective and not easy to measure in an objective and consistent way by multiple operators. The quality and skill level of the staff and operators can also become a limiting factor in terms of managing the oils to their full potential. 

---