SENSORY, INSTRUMENTAL AND ACOUSTIC CHARACTERISTICS OF EXTRUDED SNACK FOOD PRODUCTS

Abstract

ABSTRACT Corn based extrudates produced at three moisture contents and stored at four water activities were evaluated by sensory evaluation and instrumental tests in order to assess how processing and storage affect the sensory characteristics of the products. Acoustic signatures were collected by recording the sounds produced as the samples were bitten through with the back molars. These signatures were analyzed by fast Fourier transformation and the Kolmogorov dimension of fractal analysis. Products with a low moisture content and water activity were crisper than those at a higher moisture content and water activity. Fourier transformations of the data showed peaks between 1 and 2 kHz and between 6 and 7 kHz. Fractal analysis of the normalized raw time‐amplitude curves showed significant positive correlations between fractal dimensions and the sensory characteristics of crispness, crumbliness and pitch.