Polymers with a concentration of 2% melesitose show a non-Newtonian behavior, and in some honey it was reported in a percentage of 11% 23. The presence of compounds with high molecular weight such as proteins or polysaccharides (dextran) in honey composition can cause non-Newtonian behavior 22. Natural honey has a Newtonian behavior, and its rheological properties are influenced by temperature, while crystallized honey has a non-Newtonian behavior 21. The other two forms, anhydrous α- d-glucose and anhydrous β-glucose, are stable at temperatures between 50 and 80 ☌. Glucose can crystallize as α- d-glucose monohydrate at temperatures below 50 ☌. There are also other factors that act as seed crystals such as pollen, other carbohydrates, air bubbles, moisture content 20. Honey samples with a fructose/glucose ratio greater than 1.33 do not crystallize for a long time, while those with a ratio value of less than 1.11 crystallize very easily. The fructose/glucose ratio in honey determines the crystallization rate, thus affecting both physical and rheological properties. The botanical origin of honey influence honey viscosity due to the variation that occurs in terms of individual sugars as well as the colloidal material 19. The honey viscosity is influenced by the quality, processing stages of honey and temperature 18, and the botanical origin. its viscosity is not influenced by the shear rate applied 17. The most used adulteration agents are: sucrose 7, fructose, glucose 8, 9, inverted sugar syrup 9, 10, maltose 11, high fructose corn syrup 11, 12, beet syrup, cane syrup 13, rice syrup 14, 15, 16, corn syrup 10, 15, and barley syrup 15. Thus, its adulteration with concentrated sugar syrups at a lower cost often takes place, diminishing its nutritional and medicinal benefits 6. Due to its properties, there is a high demand for honey. It should not contain food additives or any other exogenous substance 5. Honey is a natural food product 1 produced by bees from the nectar of flowers or honeydew 2, being renowned for its sensorial 3, nutritional and medicinal properties 4. All parameters analyzed had a high regression coefficient for calibration (> 0.810) and validation (> 0.790), except for the elastic modulus. The viscoelastical parameters (η*-complex viscosity, Gʹ -elastic modulus and Gʺ-viscous modulus) and glass transition temperature (T g) were predicted in function of the chemical composition (moisture content, glucose, fructose, sucrose, maltose, raffinose, trehalose, turanose, melesitose, and F/G ratio) using the PLS-R (partial least square regression). Regarding the physicochemical parameters analyzed (moisture and sugar content), significant changes depending on the adulteration agent/degree used were observed. The authentic honey and adulterated ones behaved as a Newtonian fluid with a liquid-like behavior (Gʺ>Gʹ). There was studied the influence of different percentages of adulteration agent on steady state and dynamic state rheology but also on rheology in the negative temperature domain. The aim of this study was to assess the influence of different adulteration agents (agave, maple, corn, rice and inverted sugar) on honey rheology.
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