Multiclass method for pesticides quantification in honey by means of modified QuEChERS and UHPLC–MS/MS

The physical chemistry characteristics of honey are directly related to floral origin and, as a result, to the production region. There are some available methods that can determine the botanical or geographical origin of honey such as the free amino acids profile analysis. This paper reports data on the free amino acid composition, determined by reversed-phase high-performance liquid chromatography UV detection on 56 honey samples from three different Argentine regions, with characteristic apiarian flora. To evaluate if the quantified amino acid could be used to verify the geographical or botanical origin of honey, statistical analyses were performed. The cluster analysis showed that samples were grouped in clusters related to sampling regions and more strictly to apiarian flora around apiaries. Each cluster appears associated, in accordance with the principal component analysis, to high or low concentrations of different amino acids.

Comparison of free amino acids profile in honey from three Argentinian regions.

Honey mainly consists of sugars at high concentrations from the nectar of flowers and propolis is formed from plant secretions. The chemical composition of honey and propolis can vary according to some factors, which can be directly or indirectly related with bees and the environment. However, this product can experience adulterations and/or problems related to the quality control or addition of ingredients of lower commercial value. In the attempt to detect this problem, the aim of this work is to verify possible alterations or adulterations in eleven commercial samples of honey added with propolis from Sao Paulo State, using some physicochemical analysis: moisture, HMF, reducing sugars, apparent sucrose, proteins, Fiehe, Lugol and Lund reactions. The results indicated that all the samples contain real honey and there is no indication of adulteration with water, starch or commercial sugar.

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Propriedades físico-químicas de amostras comerciais de mel com própolis do estado de São Paulo

In this work, the occurrence of HMF (5-hydroxymethylfurfural) in honey marketed in Porto Alegre – RS was investigated using Micellar Electrokinetic Capillary Chromatography. The HMF, which is the product of the fructose condensation, is an indicator of honey quality and conservation. Eleven types of honey commercialized in Porto Alegre were analyzed, and all of them contained HMF in a range from 0.191 to 6.206 mg.kg –1 . In order to quantify the HMF present in the samples, the technique of standard addition was employed. The recovery was 98% and the detection limit was 0.025 mg.kg –1 . The allowed limit of HMF in honey, according to the Brazilian Legislation, is 60 mg.kg –1

Determinação do 5-hidroximetilfurfural em méis utilizando cromatografia eletrocinética capilar micelar Determination of 5-hydroxymethyl-2-furaldehyde in honey by micellar eletrokinetic capillary electrophoresis

Honey production in Brazil has increased considerably and gaining proeminence on the international market, as a result many demands have become part of the productive honey chain In addition to the analyses provided for the Brazilian legislation, international market demand products that meet the most stringent quality standards Honey has interesting characteristics due to its constitution, but even so there are problems that can change some how your identity and quality The application of gamma radiation is a viable proposal which promotes the reduction of bioburden without changing the constitution and most importantly the physicochemical properties, with smaller nutritional losses when compared to other treatments used in foods This study beyond the physicochemical parameters required by Brazilian regulation also included other relevant analyses, including FT-IR ATR Microbiological analyses were carried out on samples of pure honeys and subsequently inoculated microbial known loads to assess the action of gamma radiation in doses of 5 and 10 kGy The triangular test was used to differentiate the irradiated and not irradiated samples The major changes that have occurred in samples of honeys were mainly in concentrations of HMF (hydroxymethilfurfural) and diastase activity occurring a significant decrease in all analyzed samples There was a reduction microbiological from the application of the 5 kGy, reaching absence with 10 kGy dose except Paenibacillus larvae The sensory analysis conducted on samples of honey and honey irradiated with 5, 10 and 15 kGy doses, pointed out that there is no significant difference (5%) between irradiated and control samples The application of gamma radiation in honeys proved a very useful method in microbiological decontamination, featuring few changes in the product at doses up to 10 kGy

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Efeitos nas características físico-químicas, microbiológicas e sensoriais em amostras de mel de abelhas submetidas à radiação gama

Honey is a known product for its nutritional value. Considering that offer is smaller than the market demand, honey is relatively expensive. This fact contribute to the incentive of its adulteration by commercial sugars derived from sugar cane and corn. As these plants have a distinct stable carbon isotope composition than plants commonly used by bees as sources of nectar, it is possible to use the stable carbon isotope composition of honey to detect addition of commercial sugar cane and corn sugars. In this study we analyzed samples of C3 plants commonly used by bees, subproducts of C4 plants, and 61 samples of honey. The d13C of C3 plants values had on average of -28.9±1.1 (n=8), while the commercial sugars had an average value of -11.1±0.7 (n=3). Approximately 8% (5 samples) of the 61 samples analyzed had d13C values that clearly indicated the addition of commercial sugars (adulteration). The sample number 5 had a d13C valor equal to -12.9, indicating that it was all made of commercial sugars. The samples numbers 13, 14, 33, and 54 had values equal to -21.0, -19.9, -21.9 and -17.6, respectively. These values also indicated the addition of commercial sugars. The methodology used in this study proved to be a valuable and simple complement to the conventional chemical and physical methods normally used to detect honey adulteration.

Nádia F. Rossi

Papers

Análise da adulteração de méis por açúcares comerciais utilizando-se a composição isotópica de carbono