Rheological and Thermal Properties of Selected Brazilian Honeys from Various Floral Origins

Abstract

The rheological and thermal properties of honeys have a practical importance for beekeepers and industries, as their determination allows their proper processing and quality control. However, few studies have been carried out in this area with Brazilian honeys. Therefore, physicochemical, rheological and thermal properties of 40 Brazilian honeys of different floral origins were determined in this study. All the physicochemical properties indicated that the analyzed honey samples met the criteria for honeys established by Codex Alimentarius. The honeys showed non‐Newtonian behavior from 10C to 15C and Newtonian behavior from 20C to 30C with the influence of temperature on viscosity and on the viscous modulus (G″) described by the Arrhenius models. Oscillatory rheological data revealed a liquid‐like behavior (G″> elastic modulus (G′)) of the honeys. The glass transition temperature (Tg) of the honeys varied between −46.7C and −43.7C. By the principal component analysis (PCA), the first component explained 70.0% of the variation of the data, forming two groups described by moisture content, aw, viscosity (10C to 30C), G″ and Tg. This analysis confirms the important influence of the moisture content and of aw in the rheological and thermal properties of honeys and provide useful information for the industrialization of honey and honey‐based products. Practical Application Determining the honey rheological and thermal properties allows its proper processing and quality control, preventing the waste of economic resources. Conclusions for beekeepers and industries are: the honey physicochemical properties are in conformity with the Brazilian legislation and the Codex Alimentarius, which could be used by consumers and the food industry; rheological and thermal properties are inversely correlated with the moisture content and with aw, and could be used to distinguish Brazilian honeys; Brazilian honeys behave as diluted materials, and their viscosity is temperature‐ and floral origin‐dependent. Determining their viscosity helps in the performance, sizing and selection of equipment such as pumps, mixers, filters, centrifuges and heat exchangers; temperature fluctuations induce physical and chemical alterations in the honey, and temperature control during its processing and storage is important for maintaining its quality. All of these parameters provide useful information for the development of new products, optimization of industrial processes and control of quality and authenticity of honeys.

Rheological properties of selected Brazilian honeys as a function of temperature and soluble solid concentration

“…[38] With regards to the steady shear viscosity (Figure 2), results obtained at temperatures ranging from 10°C to 30°C have been reported in a previous study. [14] Between 40°C and 60°C, the honeys presented an excellent fit to the Newton model, with R 2 greater than 0.9995 and RMSE lower than 1.7120, which confirms the results obtained in other studies. [8,9,11] Furthermore, just as η*, η decreases as the temperature increases for all honeys.…”

“…[26] Steady shear rheology of each sample was investigated in the shear rate range of 0.1-100 s -1 in 2 min by three cycles (upward, downward, and upward again) at 10, 15, 20, 25, 30 40, 50, and 60°C. Data referring to the temperatures ranging between 10 and 30°C were published in another study regarding the rheological characterisation of Brazilian honeys from different floral regions [14] , while data for temperatures ranging between 40 and 60°C are exclusive to this study.…”

“…[3,4] As a result, many studies can be found in the literature which evaluated the viscosity of honey from different countries through steady state shear rheological measurements. [1,[5][6][7][8][9][10][11][12][13][14] The small amplitude oscillatory shear (SAOS) test can be used in honey to adequately describe its rheology without considerable changes to its structure. [7] The complex viscosity, measured through SAOS measurements, assesses the total resistance of the sample when subjected to a dynamic shear stress.…”

Técnicas de análisis multivariado, modelamiento factorial múltiple y PLS-PATH para estudio y clasificación de tipos de mieles venezolanas de los estados de Lara y Yaracuy / Multivariate techniques, factorial multiple analysis and PLS-PATH modeling for study and classification of venezuelan honeys from states of Lara and Yaracuy

“…La Organización Mundial para la Alimentación, ha definido a la miel como una sustancia dulce elaborada por la abeja (Apis mellifera L.) y sus diferentes subespecies, a partir del néctar de las flores y de otras secreciones extraflorales, que las abejas liban, transportan, deshidratan, concentran y alma-cenan en los panales [1][2][3]. Debido a que la miel hereda las propiedades de las plantas, su color, aroma, sabor y propiedades fisicoquímicas dependen de las flores utilizadas por las abejas, aunque las condiciones climáticas también influyen en la composición y sus propiedades [4].…”

“…Debido a que la miel hereda las propiedades de las plantas, su color, aroma, sabor y propiedades fisicoquímicas dependen de las flores utilizadas por las abejas, aunque las condiciones climáticas también influyen en la composición y sus propiedades [4]. La demanda de miel entre los consumidores a nivel mundial ha crecido de manera significativa, haciéndose necesaria una verificación de su autenticidad, con el objetivo de satisfacer los requerimientos de los consumidores, que apetecen productos orgánicos, sanos y diferenciados, elaborados bajo rigurosos estándares de calidad y con la certificación de organizaciones y autoridades responsables de la vigilancia y control [5][6][7][8].…”