Water activity of fresh bee pollen and mixtures of bee pollen-honey of different botanical origin

A mixture of bee pollen and honey could represent a complete food supplement for human diet. In this study, for three bee pollen-honey mixtures ratios at two storage times (0 and 90 days) at room temperature, water activity (a(w)) were investigated. For the mixtures were employed Castanea and Eucalyptus pollen species, and acacia, chestnut and "beach" honeys. In the mixtures, Castanea and Eucalyptus pollen showed a different a(w) trend in relation to pollen concentration and to storage time. In Castanea-honeys mixtures and in Eucalyptus-honey mixtures (only at time 0) a(w) values were higher than each component of the corresponding mixtures. In Eucalyptus-honeys mixtures (only at time 90) a(w) values were lower than each component. This investigation highlights that honey, bee-pollen and their mixtures, stored at room temperature, could have a little change in their a(w) content, in time. Results shows that a(w) values of bee pollen mixed with honey were all lower than 0.7, although bee pollen-honey mixtures were stored at room temperature instead at freezing temperature (-15 degrees C) for 90 days. (C) 2017 Elsevier Ltd. All rights reserved.