María Teresa Sancho

Evolution of fructose and glucose in honey over one year: influence of induced granulation

Abstract Evolution of fructose and glucose over 1 year has been evaluated in 30 honey samples from Burgos (N. Spain). The influence of the induced granulation process in this evolution was also determined. Each sample was divided into two aliquots of 500 g and aseptically bottled. One aliquot was directly stored and the second induced to crystallise by seeding with 10% of finely crystallised honey. Analyses of moisture content, pH, fructose and glucose were carried out over 1 year, once each 4 months. Both, fructose and glucose increased in most samples. Induced-crystallised samples did not show any significant differences in the evolution of the two sugars in comparsion with directly stored samples. Linear correlations were found, for both fructose and glucose, between samples directly stored and honeys in which granulation was induced. These results are clearly different from those reported in previous papers where decrease of monosaccharides below their original values was described. pH of honey might promote reversion of monosaccharides and the formation of disaccharides and trisaccharides. This investigation has demonstrated the possibility of formation of monosaccharides, by the hydrolysis of higher sugars, as a process predominant over the reversion. No statistical relationship was found between pH of honey samples and their fructose and glucose content evolution.

Diastase, invertase and beta-glucosidase activities in fresh honey from north-west Spain

SUMMARYDiastase (α- and β-amylase), invertase (sucrase or α-glucosidase) and β-glucosidase activities in 46 samples of unheated, commercially purchased Galician (north-west Spain) honeys were determined spectrophotometrically. The honeys were from Eucalyptus sp. (25), Rubus sp. (2) and Castanea sativa (1), or multifloral in origin (18). The mean value for diastase (Gothe scale) was 19.3 ± 6.99 (10.6–38.0), for invertase it was 128.3 ± 31.90 (68.7–225.4) μmoles p-nitrophenyl glycoside hydrolysed/kg honey/min, and for β-glucosidase it was 110.8 ± 19.89 (80.3–176.4) μmoles p-nitrophenyl glycoside hydrolysed/kg honey/min. Correlationships were found between invertase and diastase activities (r = 0.878) and between invertase and β-glucosidase activities (r = 0.871). Comparisons between these values and those obtained by other authors are discussed.

Bioactive properties of honey with propolis.

Nowadays, propolis is used as an innovative preservative and as a bioactive food supplement. Due to its bitter and astringent flavour, propolis is hardly accepted by consumers. The aim of this study was to obtain a likeable food product made with honey and propolis, whose antimicrobial, antioxidant and anti-inflammatory properties were enhanced in comparison with those of the base honeys used. 0.1%, 0.3% and 0.5% soft propolis extracts were added to honeys and the products that most appealed to the users were subjected to further research. Total phenolics, flavonoids, ABTS free radical and hydroxyl radicals scavenging and anti-inflammatory activities increased in all mixtures. Antimicrobial activity of the combined products showed synergic effects, resulting in higher results than those of the base honeys and propolis extracts. Therefore, honeys enriched with small amounts of propolis extracts are promising functional foods.

Acaricide residues in honeys from Galicia (N.W. Spain)

Honey samples (101) from Galicia (N.W. Spain) were analyzed by gas chromatography (electron capture and flame ionization) for the presence of acaricides (amitraz, bromopropylate, coumaphos, and fluvalinate). Seventy-three samples were free from detectable residues. Bromopropylate residues were found in 16 samples in levels ranging from 5 to 60 microg/kg. Fluvalinate residues were found in 11 samples in levels ranging from 10 to 40 microg/kg. One sample contained 100 microg of fluvalinate per kg. Neither amitraz nor coumaphos residues were detected.

Acaricide Residues in Honey: Analytical Methods and Levels Found

A bibliographic review on the pollution of honey with acaricides is presented. This paper reviews methods for determining amitraz, bromopropylate, coumaphos, cymiazole, fluvalinate, malathion and phenothiazine residues in honey samples, as well as multiresidue methods. Acaricide residue levels found in European countries are also reviewed.

Expanded parameters to assess the quality of honey from Venezuelan bees (Apis melllifera)

Summary Hive samples from seven Venezuelan states were studied to determine the quality of honeys from the naturalized tropical honey bee Apis mellifera, submitted for a national honey competition. The physicochemical composition varied as follows: antibacterial activity as minimal inhibitory concentration for each of S. aureus and E. coli was 25.0-50.0 g/100 mL, antioxidant activity was 34.90-203.21 µmoles Trolox equivalents/100 g, ash was 0.03-0.13 g/100 g, diastase activity was 3.00-47.81 DN, flavonoids was 2.32-14.41 mg EQ/100 g, free acidity was 24.40-54.55 meq/kg, HMF was 17.70-631.73 mg/kg, moisture content was 17.2-20.2 g/100 g and nitrogen was 28.68-107.29 mg/100 g. Non aromatic organic acids, such as D-gluconic acid, was 13.5-69.3 g/kg, citric acid was 8.0-135.4 mg/kg, and malic acid was 11.2-60.9 mg/kg. Polyphenols were 38.15-182.10 mg EGA/100g, reducing sugars were 62.05-77.57 g/100 g, sucrose was 0.93-13.86 g/100 g, and vitamin C was 12.86-37.05 mg/100 g. Botanical origins of the nine honeys, determined by pollen analysis, indicate that these honeys often were derived from non-forest, non-native and weedy species. The results are a first step to better characterisation of honeys, and some of the parameters were determined for the first time in Venezuelan A. mellifera honey. They can be used for research, educational purposes, and to better understand market values, natural occurrence and chemistry of tropical honey harvested from Apis mellifera.

Nonacaricide pesticide residues in honey : analytical methods and levels found

A bibliographic review on honey pollution with pesticides is presented. This paper reviews the methods set up for determining pesticide residues in honey samples as well as the pesticide residue levels found in European countries.

Composition and properties of Apis mellifera honey: A review

Honey is a natural sweetener with a complex composition. Honey features vary depending on the botanical source and geographical origin, as well as climatic, processing and storage conditions. Honey is mainly composed of carbohydrates and water, parameters that influence its shelf life and some of its properties, including color, flavor, density, viscosity, hygroscopicity, and crystallization. Honey also contains small amounts of other components, such as nitrogen compounds, organic acids, minerals, vitamins, Maillard reaction products, volatile compounds, and several bioactive substances that affect sensory and physical characteristics, as well as biological potential. This review summarizes the literature about the composition and main properties of honey. It also describes the use of honey as a biomonitor for collecting information about the environment, identifying environmental contamination and assessing the level of soil, water, plant and air pollution.

Nonaromatic Organic Acids of Honeys

Pot honeys have delicate, sweet and sour flavors, and are highly appreciated in tropical areas. Their acidity is usually high, and therefore, free acid values could contribute to characterize stingless bee honeys. Organic acids contribute to several honey properties and have been considered potentially useful to determine the origin of honeys. Among other components, organic acids have been studied as possible contributors to honeys’ antioxidant and antibacterial activities. Some honey nonaromatic organic acids have been used as treatments against varroasis and small hive beetles. High acetic acid contents could indicate honey fermentation. The most important procedures to determine honey nonaromatic organic acids are enzymatic assays, chromatographic techniques, and capillary electrophoresis procedures. At the end of this chapter the advantages and disadvantages of each of them are summarized.