BIGELS CONTAINING NATURAL EXTRACTS AS FAT REPLACERS IN BEEF HAMBURGERS

Over the last decades, increasing concern regarding the nutritional quality of
foods has emerged due to the high prevalence of chronic non-communicable diseases,
particularly cardiovascular diseases. Therefore, reducing saturated fat intake has
become an important goal in food development. Bigels, structured systems formed by
the combination of oleogels and hydrogels, have gained attention as potential fat
replacers due to their solid fat-like structure. However, vegetable oils generally exhibit
lower oxidative stability than animal fats, increasing susceptibility to lipid oxidation. The
combination of bigels with natural antioxidants represents a promising strategy to
improve oxidative stability and extend the shelf life of meat products.This study aimed to
evaluate the application of bigels containing plant extracts (clove, oregano, and
rosemary), individually or in combination, as fat replacers in beef burgers and to
investigate their effects on physicochemical properties and oxidative stability. Bigels
were prepared by combining an oil phase composed of flaxseed oil and rice bran wax
with a gelatin-based aqueous phase containing plant extracts, followed by
homogenization using an Ultra-Turrax. Beef burgers were formulated with 70% beef,
20% fat or bigel, 8% water, and 2% salt, resulting in nine formulations. Texture profile
analysis (TA-XT Plus), color evaluation (MiniScan EZ), proximate composition analysis
(AOAC methods), and oxidative stability assessment by the thiobarbituric acid reactive
substances (TBARS) assay were performed during 13 days of storage.The incorporation
of bigel affected color parameters, increasing lightness compared with the control and
modifying hue and chroma values due to the presence of plant extracts and bigel
particles. All formulations exhibited perceptible color differences (ΔE > 2), with the
highest variation observed in the formulation without plant extracts. Protein content did
not differ significantly among treatments, whereas other proximate composition
parameters showed differences between the control and bigel-containing formulations.
Texture changes were mainly observed in hardness and chewiness, while the other
parameters remained relatively stable. TBARS values increased during storage in all
samples, with the highest lipid oxidation observed in the burger containing bigel without
extracts. The addition of plant extracts reduced oxidation levels, particularly clove
extract, indicating antioxidant activity. Overall, the incorporation of bigels influenced the
physicochemical characteristics and oxidative stability of beef burgers through
interactions among the meat matrix, structured lipids, and bioactive compounds. The use
of bigels containing natural extracts represents a promising approach for saturated fat
replacement in meat products, contributing to improved oxidative stability and potential
nutritional and technological benefits.