Chemical prediction of water activity in processed cheese

Abstract

SummaryBy linear regression analysis, a highly significant negative correlation (r = −0·96) was found between the mean ash concentration values (g/100 g moisture) and water activity (aw) of six types of processed cheeses (low-fat, semi-fat, fat, extra-fat, double fat and special). The regression equation aw = 0·9951 − 0·0032* (ash), applied to 40 cheese samples, yielded aw values which differed by < 0·005 aw units from those measured experimentally in 75% of the samples. The maximum differences between the calculated and experimental aw values (found in only two samples) were ±0·01 aw units.