Literature Review on Linear Regression Equations for Relating water activity to moisture content in floral honeys: development of a weighted average equation

Abstract

A literature review on several existing linear regression equations for correlating water activity (a w) and refractometric moisture content in floral honeys was performed in order to provide a weighted average regression equation. For this purpose, a meta-analysis of the literature linear equations was made which takes into account the number of data points as well as the precision involved in the different literature studies. The weighted average linear regression equation is a general linear relationship to calculate the honey water activity on the basis of the honey moisture content. It was obtained from comparing and combining the results of ten independent studies involving 638 observations and including honeys from Argentina, Colombia, Spain, Germany, Czech Republic, China, México, Cuba, Brazil, El Salvador, India, and Vietnam. It was also found that the proposed equation describes satisfactorily the water activity of concentrated (and supersaturated) glucose/fructose solutions, which would confirm that these sugars are the main determinants of water activity in honey.