Summary The stability of vitamin A in Refined Bleached Deodorised Palm Olein (RBDPOL) was studied for 24 months. Vitamin A decreased with time, temperature and thermal treatment (frying/cooking). RBDPOL fortification was observed over several temperature ranges, using PET, nylon and HDPE commercial packaging materials. After 24 months, the following vitamin A contents of 39–43 IU g−1 (39–45%) at 16–20 °C; 35–40 IU g−1 (43–49%) at 24–29 °C; and 28–39 IU g−1 (45–73%) at 24–45 °C were detected at the respective temperature ranges. Results showed stability of vitamin A fortified RBDPOL vegetable oil was not stable over typical shelf life (12 months). Depletion of vitamin A accelerated when the RBDPOL vegetable oil was subjected to high temperature thermal treatment.

Until now, no literature exists to explain about the impact of time, and environmental parameters, when using typical commercial grade transparent linear low density polyethylene (LLDPE) packaging for protecting vegetable cooking oil during typical shelf-life conditions. We tested long-term impact of temperature and illuminance (light: 100 to 150 lux and darkness <1 lux) on refined bleached deodorized palm olein (RBDPOL), fortified with vitamin A. Results showed degradation of fortified RBDPOL with 70 ppm vitamin A was  approximately 15% at 18-22oC in Light, 10% at 18-22oC in Darkness, 19% at 32-33oC in light and 17% 32-33oC in darkness. Similar trend was observed at 45 ppm vitamin A. Exposure to heat and light impacted vitamin A degradation, but is primarily attributed to temperature, irrespective of packaging. This investigation builds on our previous work (Silalahi et al., 2017), and confirms the impact of challenging environmental conditions on vegetable cooking oil shelf-life over long time periods.

Total Polar Compound (TPC) analysis was used to evaluate fry life cycle of oils and shortenings with differing fatty acids compositions, and to understand if longer trisaturated material (Tribehenin), could influence total fry life, during protracted, semi-continuous deep frying simulations. Results showed, when TPC reached 25% max, the TOTOX and FFA revealed correlated values. However, both FFA and Totox were deemed unreliable indicators of oil quality. TPCs were more acutely accurate, especially during oil filtration and top-up procedures, where peak TPC onset showed stronger correlation for assessing oil degradation. Unsaturated frying oil, SBO (PUFA based), resulted with the shortest fry life of 132 fry-cycles; POL (MUFA based) 138 fry-cycles and MPS (MUFA based + Tribehenin) achieving up to 146 fry-cycles, suggesting Tribehenin may apparently extend fry life longevity.

Moringa oleifera seed oil (MSO) from Lombok was extracted by n‐hexane and evaluated after refining by several degumming methods to understand the impact of individual tocopherol retention and compared to extra virgin olive oil (EVOO) and high oleic palm oil (HOPO). MSO achieved an Oxidative Stability Index (15.8 h); EVOO (11.7 h) HOPO (8.83 h), based on two factors; the degree of unsaturation and total tocopherols, which did not accurately correlate with oxidation stability. The presence of tocopherol type affected the efficiency of heat stability in MSO, which is caused by a significant level of δ‐tocopherol (13.5 ppm), which was retained, through effective water degumming. Whereas, δ‐tocopherol in EVOO was not detected. This strongly suggests δ‐tocopherol contributes effectively against heat oxidation and thereby improved the overall stability of MSO. Novelty impact statement Several novelties are identified in this work, which at the time, could not be found within the literature: first, the type of phosphatide in Moringa Oleifera is in hydratable form. Hence, secondly, we propose the appropriate degumming method for Moringa Oleifera seed oil is by water degumming. And third, the particular tocopherol type most impacting the oxidative stability performance of Moringa Oleifera was identified as δ‐tocopherol.

Observations about the impact of environmental parameters and time, on fortified vegetable oil, using typical commercial grade linear low density polyethylene (LLDPE) packaging during typical shelf-life conditions, are minimal. We tested the long-term (12 months) impact of temperature and illuminance (light: 100 to 150 lux and darkness <1 lux) on refined bleached deodorized palm olein (RBDPOL), fortified with vitamin A, and without antioxidant. Results showed degradation of fortified RBDPOL with 70 ppm vitamin A was  approximately 19% at 18-22oC in Light, 18% at 18-22oC in Darkness, 38% at 32-33oC in light and 24% 32-33oC in darkness. A similar trend was observed at 45 ppm vitamin A. Exposure to both heat and light impacted vitamin A degradation, but was primarily attributed to prolonged exposure at elevated temperature, irrespective of the packaging material. This short study validates extensive research by Silalahi et al., (2017), doi:10.1111/ijfs.13462 on the impact of environmental effects of fortified vegetable frying oil, during extensive storage life periods.