Diferenciación de mieles españolas y extracomunitarias aplicando la espectroscopia infrarroja en combinacion con analisis multivariante

Abstract

[ES] España es un importante productor de miel, sin embargo, las importaciones procedentes de países extracomunitarios han ido en aumento en los últimos años. El problema surge cuando estas mieles se comercializan sin indicar su procedencia de forma adecuada en la etiqueta. Esta situación, además de ser fraudulenta, por el incumplimiento de la normativa comunitaria de etiquetado, ocasiona importantes pérdidas económicas para el sector apícola y desconfianza al consumidor de nuestro país. Por ello, el desarrollo de herramientas analíticas sencillas que permitan garantizar si una miel es de origen español, hoy en día es una prioridad. En este sentido, la espectroscopía infrarroja es una opción cada vez más considerada por ser rápida, sencilla y por no necesitar de personal altamente especializado. El objetivo del presente trabajo es evaluar la efectividad de la espectroscopía infrarroja (ATR-FTIR) en combinación con herramientas estadísticas multivariantes para diferenciar mieles españolas y de origen asiático. Se analizó el espectro infrarrojo de 28 mieles chinas y 70 españolas de diferentes procedencias botánicas (milflores, azahar, romero y tomillo), previamente caracterizadas con atención a diferentes parámetros fisicoquímicos (color, humedad y conductividad). Las variables utilizadas para la construcción de los modelos multivariantes fueron las áreas de las bandas seleccionadas de los espectros infrarrojos obtenidos

[EN] Spain is an important honey producer, however, imports from non-Eu countries have been increasing in recent years. The problem arises when these honeys are marketed without indicating their origin properly on the label. This situation, in addition to being fraudulent due to non-compliance with EU labeling regulations, causes significant economic losses for the beekeeping sector and mistrust among consumers in our country. For this reason, the development of simple analytical tools to guarantee whether a honey is of Spanish origin is nowadays a priority. In this sense, infrared spectroscopy is an increasingly considered option because it is fast, simple and does not require highly specialized personnel. The objective of the present work was to evaluate the effectiveness of infrared spectroscopy (ATR-FTIR) in combination with multivariate statistical tools to differentiate Spanish and Asian honeys. The infrared spectra of 28 Chinese honeys (milfoil and acacia) and 72 Spanish honeys of different botanical origins (milfoil, orange blossom, rosemary and thyme) were analyzed. The previous physicochemical characterization of the honeys showed significant differences between the 6 groups with higher moisture levels for the Asian honeys (acacia and millefiori) without exceeding the legislated limit in any case. Some correlation was shown between color and conductivity, with somewhat high values for some orange blossom and rosemary honeys. The variables used for the construction of the multivariate models were the areas of the selected bands of the infrared spectra obtained from the ATR-FTIR. The model allowed predicting the origin of the samples analyzed, having a good resolution in the geographical origin, differentiating Chinese honeys from Spanish honeys. However, it presented difficulties in predicting the botanical origin, with overlap between Spanish monofloral honeys. The study concluded that the ATR-FTIR technique can provide value for the differentiation of honeys according to their geographical origin and, to a lesser extent, for monoflorality. However, to be conclusive with this statement, it is necessary to increase the number of samples in the monoflorality and provenance categories.