Emulsion gels structured with clementine pomace: a clean-label strategy for fat reduction

The mounting demand for healthier and more sustainable food formulations, in conjunction with the World Health Organization's (WHO) guidelines recommending a maximum intake of saturated fat equivalent to 10 % of daily calories, has precipitated the exploration of alternatives to conventional plastic fat, which has been shown to effectively substitute structured fats while concomitantly contributing to a reduction in the overall fat content. In this study, emulsion gels were developed using physically treated clementine pomace (freeze-dried, extruded, and homogenized) as a clean-label structuring agent that is rich in hydrocolloids (polysaccharides and proteins). The study's objective was to assess the impact of pomace treatment, concentration (5 %–6 %), and oil content (40 %–50 %) on the microstructure, rheological properties, bioactive compound content, and physical and oxidative stability of the emulsion gels. The analysis revealed that freeze-dried pomace resulted in the most physically stable gels, as evidenced by microstructural and oil loss analyses. Emulsion gels with homogenized pomace exhibited robust solid-like behavior and augmented viscoelasticity, particularly at 40 % oil content. Regarding bioactive compounds, extrusion resulted in an increase in the total phenolic content and antioxidant capacity, whereas freeze-drying preserved a greater proportion of carotenoids. The oxidative stability assessment indicated that most emulsion gels retained peroxide values below the established legal limits after a 30-day storage period at both 4 °C and 20 °C, suggesting that the presence of clementine pomace imparted antioxidant protection. These findings underscore the efficacy of freeze-dried and homogenized clementine pomace as effective structuring agents for emulsion gels, providing a viable strategy for replacing plastic fat in bakery, pastry, and spreadable food products.

This research was funded by grant (PID 2022-137587OB-C22) funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” and grant (FPU19/03803) funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”.

Peer reviewed