EFFECT OF STORAGE TEMPERATURE AND DURATION ON RHEOLOGICAL AND THERMAL CHARACTERISTICS OF SUPEROLEIN OLEOGELS
DOI: https://doi.org/10.21894/jopr.2022.0024
Received: 17 August 2021 Accepted: 2 March 2022 Published Online: 9 May 2022
The study was conducted to investigate the effects of storage temperature and duration on the rheological and thermal characteristics of superolein oleogels derived from 3% w/w of polyglycerol behenic acid ester (PBA), 3% w/w of sunflower wax (SFW) and 8% w/w of fully hydrogenated palm-based monoacylglycerols (MGHO). The results indicated that the storage modulus (G’), loss modulus (G”) and critical stress values were much higher for all the oleogels when stored at 5°C. At 15°C, the rheological parameters for SFW and MGHO oleogels were gradually increased during storage. From the thermal analysis, the peak intensity at approximately 20°C also gradually increased during storage, demonstrating the marked increase in the rheological parameters were due to the crystallisation of the triacylglycerol (TAG) in the superolein during the three-day storage. This effect was not observed for PBA oleogels, showing that the PBA inhibited or delayed crystallisation of the superolein molecules at 15°C. However, an extended storage study revealed that the PBA actually delayed and did not inhibit the crystallisation of the superolein. At 25°C, all the oleogels were highly unstable with poor thermal and rheological properties. The results suggested that 15°C was a more suitable temperature for the storage of superolein oleogels.
KEYWORDS:1 Malaysian Palm Oil Board,
6 Persiaran Institusi, Bandar Baru Bangi,
43000 Kajang, Selangor Malaysia.
2 Department of Food Technology,
Faculty of Food Science and Technology,
Universiti Putra Malaysia, 43400 Serdang,
Selangor, Malaysia.
* Corresponding author e-mail: tancp@upm.edu.my