Apidologie 25 (1994) 297-302
DOI: 10.1051/apido:19940304

Liquefying crystallized honey with ultrasonic waves

A. Thrasyvoulou^a, J. Manikis^b and D. Tselios<sup>c

a</sup>  Laboratory of Apiculture, Sericulture, School of Agriculture, Aristotelian University of Thessaloniki, Greece
^b  North Beekeeping Union, Thessaloniki, Greece
^c  Agriculture Research Station of Halkidiki, Agios Mammas, 63200 Nea Moudania, Greece

Abstract - Ten samples of crystallized honey were divided into 3 equal parts. The first was liquified by ultrasonic waves at 23 kHz, the second by heating at 60°C for 30 mins and the third remained untreated. The time that was needed for the liquefaction of honey varied from 18 to 25 min, the energy from 0.1056 to 0.1466 kWh, and the temperature from 76 to 82°C. The quality of honey was affected by increasing hydroxymethylfurfural (HMF) levels from 6.5 ± 0.8 ppm to 11.4 ± 1.4 ppm and decreasing diastase activity from 20.8 ± 1.8 DN to 17.4 ± 1.5 DN. Significant differences (p < 0.010) were found among the HMF averages of samples liquefied by sonication and samples liquefied by heating. No differences were found among diastase activity, moisture, electrical conductivity, pH and time of recrystallization among ultrasonic and heat treatment.

Key words: crystallisation / honey / ultrasound / HMF / diastase