Description:
<jats:title>Abstract</jats:title><jats:p>The force required to puncture a food has been described previously as <jats:italic>F</jats:italic>=<jats:italic>K<jats:sub>a</jats:sub>?A</jats:italic>+<jats:italic>K<jats:sub>p</jats:sub>? P</jats:italic>++<jats:italic>C</jats:italic> where <jats:italic>A</jats:italic> and <jats:italic>P</jats:italic> are, respectively, the area and perimeter of the punch, <jats:italic>C</jats:italic> is a constant and <jats:italic>K<jats:sub>a</jats:sub></jats:italic> and <jats:italic>K<jats:sub>p</jats:sub></jats:italic> are two coefficients that are properties of the food. This paper describes how the equation can be rearranged for circular punches in a manner that allows the numerical values of the coefficients to be evaluated by a graphical method. A comparison of the numerical values obtained with the new method and those obtained with the older method using rectangular punches showed good agreement when carrots, two varieties of apples, agar gel, margarine, and polystyrene board were used as test materials. The method of deriving coefficients <jats:italic>K<jats:sub>a</jats:sub></jats:italic> and <jats:italic>K<jats:sub>p</jats:sub></jats:italic> is relatively easy and the coefficients may be more meaningful than the raw puncture data.</jats:p>