Modification of palm-based oil blend via interesterification: Physicochemical properties, crystallization behaviors and oxidative stabilities

• Published in: Food chemistry Vol. 347; p. 129070
• Main Authors: Zhang, Zhen, Ye, Jing, Lee, Wan Jun, Akoh, Casimir C., Li, Aijun, Wang, Yong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.06.2021
• Subjects: Biocatalysis; Crystallization; Enzymatic interesterification; Esterification; Fatty Acids - chemistry; Kinetics; Lipase - metabolism; Oleic Acid - chemistry; Oxidation-Reduction; Oxidative stability; Palm Oil - chemistry; Properties; Rheology; Specialty fats; Stearic Acids - chemistry; Thermodynamics; Enzymatic interesterification; Specialty fats; Properties; Oxidative stability
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.129070

•Interesterified fats was obtained from palm-based oils via CIE and EIE.•EIE fats had lower SFC profiles and faster crystallization rate compared to that of CIE fats.•Molecular distillation reduced the tocopherol concentration in EIE fats which consequently affected the oxidative stability. Interesterification is widely employed as an effective technique to modify oils and fats. This study utilizes palm-based oil (palm olein: palm kernel oil: palm stearin, 5:3:2, w/w/w) as the raw material for the interesterification process performed in a pilot-scale packed bed reactor. Enzymatic interesterification (EIE) was catalyzed by Lipozyme TL IM (813.0 g) at 60℃ with reaction flow rate of 100 mL/min. Chemical interesterification (CIE) was catalyzed using sodium methoxide (0.3 wt%) as catalyst at 105 °C for 30 min. The results showed that the EIE fats had lower solid fat content tendency compared to that of CIE fats. The crystallization onset temperature was higher in EIE fats (23.09℃) compared to that of CIE (19.08℃). The results were consistent with the crystallization kinetics whereby the Avrami K constants of EIE fats were higher than that of CIE fats at various temperatures, indicating rapid crystallization and instant nucleation. Linear growth mechanism was dominant and the crystals formed were smaller in size as observed using polarized light microscope. The interesterified fats exhibited the presence of β and β′-crystals. While most of the tocopherol content was retained after EIE (386.18 ug/g), the molecular distillation process reduced the tocopherol concentration (110.01 ug/g) which consequently affected the oxidative stability. The findings in this work contribute to the fundamental understanding on the differences between CIE and EIE fats and provides data to support the preparation of modified fats via EIE that shows great potential as a controllable technique for industrialization.