Enzymic determination of glycerol in honey

Abstract

The glycerol content of 33 honeys of Galicia (northwestern Spain) has been determined using the Boehringer-Mannheim enzymatic method modified for this purpose. As far as we know, it is the first time this method has been applied to honey. Volumes of 0.5 mL of potassium hexacyanoferrate(I1)-trihydrate solution (Carrez I) and zinc acetate-dihydrate solution (Carrez 11) were used and, following clarification, about 4 mL of 0.1 N NaOH. The enzymatic determination was performed "spectrophotometrically" a t 365 nm using pyruvate kinase, lactate dehydrogenase, and glycerokinase in double the quantities recommended by the supplier. The method combines precision (CV% less than 1.1 % ), good recovery (102.2%), sensitivity (30 mg/kg), simplicity, and low cost. The glycerol content of the honeys analyzed ranges between 50.0 and 366.2 mg/kg (mean 137.6 mg/kg), which is in keeping with values obtained by other authors using other methods (HPLC, GC).

Physicochemical characteristics and pollen spectra of organic and non-organic honey samples of Apis mellifera L.

“…The results obtained in this study are similar to the ones observed by Huidobro and Simal (1984), who informed that the formol index in honey represents, predominantly, the amine compounds related directly with the content in peptides, protein and amino acids, and is a good indicative of the presence of nitrogen in the honey.…”

“…Huidobro and Simal (1984) obtained to honey samples of orange tree flowers 75.90%, and of wild flowers 75.70%. The highest levels of Aw found for organic honey samples are directly related to the highest diastase index, which is responsible for the reaction catalyze.…”

Análises físico-químicas de amostras de méis de flores silvestres, de eucalipto e de laranjeira, produzidos por Apis mellifera L., 1758 (Hymenoptera, Apidae) no Estado de São Paulo. 2. Conteúdo de açúcares e de proteína

“…Autores como TEMIZ [21], HUIDOBRO e SIMAL [13], VIT-OLIVER [26], GÓMEZ et al [11] e BALDI-CORONEL, DALL'OGLLIO & LEZCANO [3] encontraram valores para os teores de açúcares redutores que variaram de 11,2 a 85%. MORAES e MANTOVANI [15] obtiveram, para amostras de méis de flores de laranjeira 75,90% e de flores silvestres 75,7%, valores pouco superiores aos encontrados nas amostras desta pesquisa.…”

Techniques for the Evaluation of Physicochemical Quality and Bioactive Compounds in Honey

“…This is an indicative of the presence of nitrogen in honey and is an important adulteration indicator. When low, it can suggest the presence of artiicial products, while when excessively high it can show that the bees were fed hydrolyzed protein [28]. Thus, formaldehyde content can be used to prove the authenticity of honey [21].…”