Effect of processing conditions on characteristics of dehydrated bee-pollen and correlation between quality parameters

The aim of the present study was to compare the physical, chemical and biological parameters and the microbiological quality of bee-pollen samples treated with different dehydration processes and to correlate the results. The samples came mainly from Eucalyptus (Myrtaceae) and Eupatorium (Asteraceae) plants. The dehydration conditions of the samples influenced the L*a*b* colour parameters and the biological value. Unlike the protein and lipid content, the glucose and fructose content were unaffected. The vitamin E content (27.2 +/- 0.3 mu g/g 27.5 +/- 0.4 mu g/g) in oven-dehydrated samples with forced air circulation was significantly lower (P < 0.05) compared with lyophilized samples (37.5 +/- 0.2 g/100 g, 53.7 +/- 3.9 g/100 g). Overall, the results were inconclusive for vitamin B complex, minerals and microbiological indicators. There was a positive correlation between the colour parameters L* and b* and the total phenolic content, as well as between phenolic content and the antioxidant and antimicrobial capacity. The data indicate that lyophilization might be a viable alternative to the current process, resulting in dehydrated bee-pollen with higher biological activity. (C) 2015 Elsevier Ltd. All rights reserved.