Ana Pascual-Maté

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.

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.

Antioxidant activity and physicochemical parameters for the differentiation of honey using a potentiometric electronic tongue

BACKGROUND This work evaluates the capacity of a potentiometric electronic tongue to differentiate between types of honey (orange blossom, rosemary, thyme, sunflower, winter savory and honeydew honey) according to their antioxidant level. The classical procedures used to evaluate the antioxidant potential of honey are inappropriate for in situ monitoring on reception of batches of raw honey in the packaging industry. They are also destructive, time-consuming and very tedious, requiring highly expert analysts and specialised equipment. RESULTS The electronic tongue system made with Ag, Ni, Co, Cu and Au was able to not only differentiate between types of honey but also to predict their total antioxidant capacity. The discrimination ability of the system was proved by means of a fuzzy ARTMAP type ANN, with 100% classification success. A prediction multiple linear regression model showed that the best correlation coefficient was for antioxidant activity (0.9666), then for electrical conductivity (0.8959) and to a lesser extent for aw , moisture and colour. CONCLUSION The proposed measurement system could be a quick, easy option for the honey packaging sector to provide continuous in-line information about a characteristic as important as the antioxidant level.

Methods of analysis of honey

A thorough updated review of both standardized and the most used and novel analytical methods for the analysis of honey is presented. The methodologies applied to honey in the analysis of the physical parameters (electrical conductivity, rheological properties, specific rotation, color and water activity), the analysis of the properties and the most important components of honey (moisture, sugars, enzymes, HMF, types of acidity and pH, formol index, insoluble solids, organic acids, proteins, amino acids, vitamins, minerals, volatile and semi-volatile compounds and polyphenols), and the antioxidant and antimicrobial activities are described. Finally, the most applied methods for multicomponent analysis and/or for honey authenticity verification (both the botanical and/or geographical origin honey classification and the detection of honey adulteration) are provided.

Analysis of Polyphenols in Honey: Extraction, Separation and Quantification Procedures

Polyphenols are secondary plant metabolites playing a major role as potentially functional components. They can also be used for honey authentication. This review gathers the recent literature references about honey extraction procedures, as well as instrumental analysis of phenolic compounds found in honey. Liquid-Liquid extraction is widely used for both extraction and purification purposes, with adequate recovery percentages. However, the use of high solvent volumes is a major disadvantage. More environmentally friendly methods include accelerated solvent extraction, and dispersive and inverse dispersive liquid-liquid microextraction. Solid phase extraction is the most common method for honey polyphenols’ isolation. Polyphenol isolation by a combination of liquid-liquid and solid phase extraction allows good recoveries for a variety of different compounds. High-performance liquid chromatography with ultraviolet or mass spectrometry detectors is by far, the most commonly employed instrumental procedure to separate and quantify polyphenols in honey although capillary electrophoresis has been also successfully used for these purposes. The use of new sorbents, the optimization of current procedures and the development of other simple and rapid analytical techniques are challenges for future analysis of polyphenols found in honey.

Design of a food product composed of honey and propolis

Propolis is a natural bee hive product with potential functional activities. Nowadays, many propolis products are available on the market, including cosmetics and food commodities. However, it is still unknown if edible products with propolis are fully accepted by consumers and are thus commercially viable, due to the bitter and resinous flavor and taste of propolis. This work is focused on the design of a “honey with propolis” foodstuff that can be welcomed by consumers, and, if possible, provide added benefits compared to the honey itself. Propolis tinctures containing three different concentrations of ethanol and times of maceration were prepared, giving the best results with 90% ethanol and two days of maceration. Then, in order to study the maximum amount of propolis in honey that could be accepted by a representative group of consumers, a forced choice paired comparison preference test with 69 people was carried out, giving the best results with a honey product containing 0.3-0.5% propolis extract. Phenolic and flavonoid contents, as well as TEAC antioxidant and antimicrobial activities of propolis, honey, and the product “honey with propolis” were then analyzed. As expected, propolis showed the highest phenolics and flavonoids contents, as well as the highest antioxidant and antimicrobial activities. The product “honey with propolis” showed a significantly higher antimicrobial activity, however, when compared to honey alone. In conclusion, the commercialization of a food product of “honey and up to 0.5% propolis” is promising, interesting and viable, as such a product is greatly appreciated by consumers, as well as being potentially healthy.

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.