2.5. Thermal oxidation measured with differential scanning
calorimeter (DSC)
The oxidative stability of oleogel and emulgels were measured using a
204F-1 Phoenix differential scanning calorimeter (Netzsch-Garätebau
GmbH, Selb, Germany) to determine the oxidation induction time (OIT) of
samples. The test followed parameters in previous research (Hyatt,
Zhang, & Akoh, 2021; Zhang, Willett, Hyatt, Martini, & Akoh, 2021)
with slight modifications for both sample types. Oleogels were analyzed
using 10 ± 0.5 mg aliquots placed in aluminum crucibles with pierced
caps against a pierced blank empty crucible. Emulgel samples were
analyzed against a pierced blank crucible which held an equivalent
amount of water to offset interference caused by water present in the
emulgel (Pollastri, Porter, McIntosh, & Simon, 2000). Samples were
heated from 40 to 105 °C at a rate of 20 °C min−1under constant nitrogen flow at 50 mL min−1. At 105
°C, after a 3 min stabilization, gas flow was switched to oxygen at 50
mL min−1. The OIT of the sample was calculated as the
onset time of the exothermic peak subtracted from stabilization time (3
min) and heating time (2.5 min). All experiments were carried out in
triplicate and results were reported as mean ± SD.