INTRODUCTION
Texture is the sum total of kinaesthetic sensations derived from eating a food. It encompasses the mouthfeel, the masticatory properties, the residual properties, and the sound.

According to Szczesniak (1963), textural characteristics can be classified under three main groups: mechanical, geometric, and others. By concentrating on such factors as hardness, springiness, adhesiveness, and chewiness, a taste panel can analyze food texture and describe a texture profile.

The textural characteristics of fruits and vegetables are often referred to as "crispness," "juiciness," "hardness," "toughness," "mealiness," and "fibrousness." These characteristics must be associated with plant tissue, composition and structure of cell wall constituents and intercellular binding tissue, and the water relationships of the tissues.

Examples of desirable texture are crispness of apples, juiciness of oranges, and moderate softness of bananas. In contrast, examples of undesirable texture are mealiness of apples, excessive softness of strawberries, and fibrousness in melons.

The texture of fruits and vegetables is considered of major importance in bringing about their acceptance or rejection. In a consumer survey of 5,171 households iin the West, food buyers stated that "freshness," "firmness," and "ripeness" were important factors in their selection of fresh fruits and vegetables (Hard and others, 1963). These characteristics are directly related to texture. Certain nutrient deficiences have been found in our population, specifically low levels of vitamins A and C, which could be corrected by increased use of fruits and vegetables. Market offerings of fruits and vegetables having desirable textgural charfacteristics will certainly influence consumer acceptance of these products.

Under a western regional project, "Methods of Measuring Textural Quality of Fruits and Vegetables," the physical and chemical attributes of certain fruits and vegetables were studied with empahsis on instrumental and chemical methods which assess the structural characteristics and hence the texture of the plant tissue. The measurements were correlated with sensory evaluations of tissue texture. Methods used included shear, shear compression, penetration, and determinations of pH, pectin, and specific gravity. Apples, carrots, and cantaloupes were selected for testing the applicability of the methods for texture evaluation.

Although some of the methods used have been referred to in other reports, few details were included. The objectives of this manual are:
1. To present a compilation of selected methods for evaluating texture.
2. To present standardized methods in sufficient detail so that a laboratory technician may carry out the determination.
3. To describe the application of various methods to products differing in textural quality.

Methods were standardized within research laboratories and between research laboratories. Correlations were determined among the methods, and the efficiencies of each method were assessed by reference to coefficients of variation. Data from objective methods were highly correlated with sensory panel evaluations of one or more textural attributes of the plant tissue. These results are published elsewhere. The material presented in this manual represents the recommended procedures based on the results of research of several laboratories in the western region engaged in this project.

Updated: Sunday, August 17, 2008.