03822nam a2200193 a 450000100080000000500110000800800410001910000200006024501630008026001300024350000260037352031250039965300160352465300190354065300150355970000200357470000170359470000170361121538032023-12-11       2023    bl uuuu     u00u1 u    #d1 aMAZZA, K. E. L.  aEffect of freeze-drying and oven-drying on the physical-chemical properties of marjoram essential oil beads produced by ionic gelation.h[electronic resource]  aIn: CONFERÊNCIA INTERNACIONAL DE PROTEÍNAS E COLOIDES ALIMENTARES,9., 2023, Rio de Janeiro. Anais... Campinas, Galoác2023  aPOSTER 157711. CIPCA.  aEssential oils have become popular across several industries due to their flavor, fragrance, and biological activity. Marjoram essential oil (Origanum majorana L., family Lamiaceae) (MEO) is of special interest due to its antimicrobial activity against a wide range of microorganisms. However, before food application, MEO should be stabilized by microencapsulation techniques in order to protect it from adverse processing and storage conditions. Depending on the microencapsulation technique, drying processes could be applied to reduce particles? water content, aiming to increase their shelf life. This impacts particles? morphology, structure, and essential oil content. The present study evaluated the effect of freeze-drying and oven-drying on the physical-chemical properties of marjoram essential oil beads produced by ionic gelation. Microencapsulation was carried out by extrusion?dripping of the emulsions prepared with 1.25 g/100mL sodium alginate and 1.25 g/100mL WPI, using a 22G gauge syringe coupled to a vacuum system, in a 0.175 mol/L CaCl2 gelling bath. The samples were dried in a freeze-dryer for 24h or in a hot air circulation drying oven, at 60 ºC for 24h. The following physical-chemical properties were evaluated after drying: encapsulation efficiency, chemical composition by GC-MS and GC-FID, moisture content, thermal degradation by thermogravimetric analysis (TGA), and morphology applying scanning electron microscopy (SEM). The drying method influenced the encapsulation efficiency. Freeze-dried samples retained 51.25% of MEO, while oven-dried samples retained only 33.75% of MEO, which could be attributed to the higher temperature used in the oven dryer. Samples showed similar chemical profiles, with differences in major compounds contents: sabinene (Freeze-dried (FD): 152.46 ± 2.04 mg/g vs Oven dried (OV): 196.59 ± 2.37 mg/g), gamma-terpinene (FD: 25.51 ± 0.72 mg/g vs OV: 340.08 ± 9.62 mg/g), trans-sabinene hydrate (FD: 212.06 ± 10.4 mg/g vs OV: 32.95 ± 2.02 mg/g), and terpinen-4-ol (FD: 258.45 ± 14.6 mg/g vs OD: 14.37 ± 5.0 mg/g). The drying process also affected the samples? water content (OV: 1.5% vs FD: 4%). Thermal degradation started for the freeze-dried and oven-dried beads at similar temperatures (T onset of 127 ºC and 132 ºC, respectively), suggesting that both drying methods did not change the sample?s chemical native structure. Results indicated that the microencapsulated beads could be added to food products that undergo thermal processing below these temperatures. SEM analysis revealed that oven-dried beads had a denser and more uniform surface with fewer cracks and smaller inner pores compared to freeze-dried ones. Freeze-dried beads had a softer structure with larger, aerated pores and thinner walls. The present study showed that each method resulted in beads with specific physical-chemical and morphological characteristics, OD beads demonstrated better morphological features and lower moisture, while FD beads presented higher MEO retention. Additional research is needed to investigate MEO beads? release profile in a food matrix.  aDried beads  aIonic gelation  aMorphology1 aCOSTA, A. M. M.1 aBIZZO, H. R.1 aTONON, R. V.