Application of oil/water microemulsions containing lavender or bay leaf essential oil to preserve freshly squeezed orange juice

Abstract This study investigated the effects of microemulsions (MEs) containing lavender (LEO) and bay leaf essential oils (DEO) as natural preservatives for freshly squeezed orange juice (FOJ). For this purpose, MEs of LEO with starch (LN) and soy protein (LS), and MEs of DEO with amylopectin (DA) and gum arabic (DG), at a concentration of 0.5%, were added to the FOJ, and the storage stability of the products was examined. Yeast-mold counts of LS, DA, and DG samples were lower than the control at the end of 28 days of storage at 4 °C. Based on the kinetic study, MEs exhibited an inhibitory effect on B. cereus , S. aureus , and E. coli strains, with no significant inhibition observed for the A. acidoterrestris strain during 60 min of incubation. ME addition resulted in a significant increase in total phenolic content in FOJ, ranging from 23.3% to 85.9%. Camphor, linalyl acetate, lavandulyl acetate, and nerol were distinctive volatiles of FOJ with LEO based MEs. DEO based MEs can be distinguished by alpha-terpinene, pinocarvone, linalyl propionate, eugenol, methyl eugenol, and beta-elemene. DEO demonstrated a superior preservative effect at the same concentration, without negatively impacting the aromatic properties of FOJ, compared to LEO.