Contribution to the Quality Evaluation and the Water Activity Prediction of La Palma Island Honey

Abstract

The quality of 13 home-produced samples of honey from La Palma Island (Canary Islands, Spain) was evaluated. The samples exhibited adequate maturity as shown by the moisture mean content (1 7.4%). The mean pH was 3.89. The mean total ash content was 0.17% (0.06-0.46%) and the mean electrical conductivity was 4.88 l@s/cm, ranging from 2.86 104s/cm to 7.32 l@sicm.Both are typical values forjloral honeys. Since the hydroxymethylfurjkral content was Low and the diastase activity value was high, a good freshness grade was evident. All samples displayed a water activity (aw) within a narrow range of values (0.570-0.622). Finally, we have obtained an equation for predicting the water activity, which takes the form A d = 0.35732 + 0.01349 moisture/100 g of honey with a R2 coeficient of 0.6541. This model allows the prediction of the water activity for La Palma Island honey in a reasonable, direct and simple way.

Relationship between Water Activity and Moisture Content in Floral Honey

“…The intercept and slope of the equation for the dataset of flower honey from La Palma Island, Spain, significantly differed from those in other datasets [9]. Outlier data (17.2233, 0.6084) was found by the Cook’s distance test [21].…”

“…If we compare all data from Sanjuan et al [9] with the datasets for Argentinian honey [7], the linear equation was as follows:trueleftAw=left0.26838+left0.017675MC−left11.4662Z+left48.35758Z·MCleft(0.48)left(0.59)left(−3.22)left(8.15) R 2 = 0.960…”

“…The amount of free water could be described as water activity (Aw). The Aw for honey ranges from 0.5~0.65 [5,6,7,8,9,10,11]. The limiting Aw for yeast in honey is about 0.61~0.62 [12] according to Beuchat et al [12] and 0.60 [8,10,13,14] according to Beckh et al [13], Gletier et al [8], Ruegg and Blanc [14], and Zamora and Chirife [10].…”

“…Some experiments have been performed to determine the Aw and MC data of honey, subsequently establishing the relationship between Aw and MC by regression analysis. Several models have been proposed [5,6,7,9,11,13,14,15,16,17,18,19].…”

Groups of Honey - Physicochemical Properties and Heavy Metals

“…Individual groups of honey (blossom, blends and honeydew) vary significantly in colour, aroma and taste. There are also differences in the chemical composition which are reflected in many physicochemical properties, such as in the content of ash, the spectrum of saccharides, the activity of enzymes, electrical conductivity, pH and optical rotation (Bogdanov et al 1987(Bogdanov et al , 1999Golob and Plestenjak 1999;Sanjuan et al 1997). The manipulation of honey and its possible adulteration is reflected in many of these characteristics.…”