Ultrasonic techniques used with agro-foods form an entire field of applications, and provide the user with a wide variety of information about the properties of materials being processed [40]. For fruit and vegetable tissues, changes in these features form part of the natural processes that occur during growth and maturation, and in the course of the harvest period, storage and shelf-life. Various physiological and physiochemical changes occurred during these processes, and each transition is specifically evaluated by one or more factors, characteristic of the pre-harvest, harvest, and postharvest periods. The changes are expressed differently in the course of the various periods, and are mostly reflected in the quality of the final produce. Textural attributes are among the main factors considered in quality assessment [41], and are regularly used for determination of the stage of maturity of various kinds of fruit and vegetables [20]. Firmness is considered as one of the main indices of maturity and its changes during the ripening and softening process start on the tree and continue during harvesting, handling and storage. Chemical contents and concentration in fresh tissues are also important factors in determining maturity of fruit and vegetables, but firmness is the factor most closely related to the stage of maturity [41].