Functional Mimicry of Solid Shortenings via Synergistic Polymer–Lipid Emulgels: Engineering Structure–Quality Relationships in Steamed Bread Formulations

Abstract

The role of traditional shortenings is vital in modulating the stability of gas cells, water retention, and crumb structure in bakery products. Thus, replacing them with alternative structuring agents becomes significantly challenging. In the present study, novel synergistic polymer-lipid emulgels based on cassia gum powder (CGP), psyllium husk polysaccharide (PHP), and rice bran oil (RBO) were prepared to serve as functional shortening mimics and were further utilized in the formulation of a steamed bread (SB) system. Structural features and quality attributes of formulated SBs were evaluated using various techniques, such as surface microscopy, electrochemical impedance spectroscopy (EIS), moisture analysis, and colorimetric analysis. It was found that substituting the SB formulations with polymer-lipid emulgels induced physicochemical alterations, especially in terms of structural and quality parameters, largely dictated by the emulgel composition. Specifically, both too low and too high amounts of oil in the emulgel formulations drastically affected the crumb architecture. In this context, among the formulations, SB-CI2 (SB formulation prepared with 20% RBO) exhibited an optimal structure-quality equilibrium, as evidenced by a consistent porous crumb structure, high moisture content, and desirable impedance profiles and color attributes. The balanced polymer-lipid network of SB-CI2 promoted gas retention, trapping of the water molecules, and the formation of a coherent matrix, thereby facilitating the development of an organized crumb structure and improved quality characteristics. Notably, SB-CI2 could mimic the functionality of conventional shortenings while incorporating only a lower amount of actual oil, translating to 80% less oil incorporated into the SB matrix. These results revealed that these synergistic polymer-lipid emulgels could serve as tools for structuring the quality attributes of SB formulations and as an alternative for developing healthier bakery products with lower oil content while preserving the structural attributes.