Designing Stable Mayonnaise: Rheological and Structural Performance Fortified with Antioxidant Star Fruit (Averrhoa carambola) Extract from Ultrasound-Assisted Extraction

TL;DR

Researchers used star fruit extract to create stable mayonnaise with improved antioxidant properties and good texture.

Contribution

A novel use of ultrasound-assisted star fruit extract to enhance mayonnaise stability and antioxidant content.

Findings

Mayonnaise enriched with star fruit extract showed high antioxidant activity and phenolic content.

The enriched mayonnaise maintained microstructural integrity and exhibited shear-thinning behavior.

The extract incorporation preserved emulsion stability and resulted in a solid-like gel structure.

Abstract

The preparation and characterization of phenolic extracts from Averrhoa carambola were performed to develop enriched mayonnaise-type emulsions, evaluating the effect on their physicochemical, rheological, and microstructural properties. Extracts were obtained by Ultrasound-Assisted Extraction (UAE) employing different ethanol:water ratios, followed by the analysis of their Total Phenolic Content (TPC) and Antioxidant Activity (AA). The 50:50 extract (AEt50) exhibiting the highest bioactivity was selected for the development of enriched mayonnaise, which was then subjected to stability, physicochemical, rheological, and microstructural analyses. Extraction yields ranged from 13% to 28%, with TPC values spanning 3251 to 4661 mg GAE/g of extract, and AA values between 49.25 and 81.67 µMol Trolox/g of extract. Subsequently, the strategic incorporation of the extract, coupled with pH adjustment, successfully maintained the pH of the final products at approximately 4.63 and preserved emulsion stability. This process resulted in a significant, dose-dependent increase in TPC and AA in the mayonnaise, with the highest concentration achieving nearly 9.0 mg GAE/g and the antioxidant activity de 60.0 μMol Trolox/g. The microstructural integrity was maintained, with all droplet sizes remaining under 4 µm, though a visible change in color (ΔE) was observed. All samples exhibited shear-thinning, non-Newtonian behavior, accurately fitted to the Ostwald–de Waele model (R2 > 0.982), and demonstrated a dominant elastic structure (G′ > G″) characteristic of high-quality solid-like gels. Thus, the incorporation of Averrhoa carambola extracts is a technically viable and effective alternative to develop stable food products enriched with functional bioactive compounds.

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