{"id":1149,"date":"2026-09-30T09:42:10","date_gmt":"2026-09-30T12:42:10","guid":{"rendered":"https:\/\/wp.ufpel.edu.br\/bionano\/?page_id=1149"},"modified":"2026-09-30T09:42:10","modified_gmt":"2026-09-30T12:42:10","slug":"rice-starch-based-emulsion-gels-containing-lemon-and-oregano-essential-oils-structure-rheology-and-antimicrobial-performance","status":"publish","type":"page","link":"https:\/\/wp.ufpel.edu.br\/bionano\/producao-cientifica\/2026-2\/rice-starch-based-emulsion-gels-containing-lemon-and-oregano-essential-oils-structure-rheology-and-antimicrobial-performance\/","title":{"rendered":"Rice starch-based emulsion gels containing lemon and oregano essential oils: Structure, rheology, and antimicrobial performance"},"content":{"rendered":"
Francine Tavares da Silva, Maria Espert Tortajada, Gl\u00f3ria Caroline Paz Gon\u00e7alves, Rosane Lopes Crizel, Eliezer Avila Gandra, Mar\u00eda Teresa Sanz Taberner, Elessandra da Rosa Zavareze, Alvaro Renato Guerra Dias<\/p>\n
Abstract<\/h2>\n
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The growing demand for sustainable structured lipid systems has encouraged the valorization of agro-industrial by-products as functional food ingredients. This study prepared and characterized rice starch-based emulsion gels containing rice bran oil, rice lecithin, and essential oils (EOs). The base formulation consisted of rice bran oil (40%, w\/w), water (40%, w\/w), broken-rice starch (14%, w\/w), and rice lecithin (6%, w\/w). Sicilian lemon (Citrus limon<\/em>) essential oil (LEO) and oregano (Origanum vulgare<\/em>) essential oil (OEO) were incorporated at 10% and 20% (w\/w, based on dry starch mass). Gas chromatography\u2013mass spectrometry identified D-limonene (61.3%) and carvacrol (64.1%) as the major compounds in LEO and OEO, respectively. Confocal laser scanning microscopy showed a heterogeneous distribution of fluorescent lipid-rich domains in all formulations. The samples remained visually stable during refrigerated storage, whereas oil loss after centrifugation depended on EO type, concentration, and storage time. All formulations exhibited non-Newtonian shear-thinning behavior and a predominantly elastic response, with apparent viscosity data being satisfactorily described by the Carreau model. The OEO 20% formulation showed lower hardness, zero-shear viscosity, and storage modulus than the other formulations. The emulsion gels containing EO exhibited antimicrobial activity against Staphylococcus aureus<\/em> and Escherichia coli<\/em>. OEO 20% produced the greatest reduction in S. aureus<\/em> counts, while all EO-containing formulations reduced E. coli<\/em> counts to below the limit of quantification. These results demonstrate that EO type and concentration affected the physical, rheological, and antimicrobial properties of rice starch-based emulsion gels and provide a basis for selecting formulations for future evaluation in food matrices.<\/div>\n<\/div>\n