Measurement of Sticky Point Temperature of Coffee Powder with a Rheometer

Abstract

<p>Sticky point temperature is a parameter that quantifies stickiness of food and biological powders. It is traditionally measured using glass instruments. In this study, a new methodology was developed to measure sticky point temperature using a rheometer, and it was successfully used to determine sticky point temperature for coffee powder samples. The behavior of coffee sticky point temperature as a function of moisture content (%, dry basis) was observed to be non-linear, but after 16% (dry basis) moisture content, there were no changes in sticky point temperature with further increases in moisture content. An exponential prediction model for sticky point temperature = f (moisture content) was achieved with an R² value greater than 0.93; a power law regression model also fitted well, with an R² value of 0.97. Rheometry was shown to be a viable and convenient means to determine sticky point temperature for various coffee powders.</p>