Vitamin A Is Rapidly Degraded in Retinyl Palmitate-Fortified Soybean Oil Stored under Household Conditions

Abstract

Oil fortification with retinyl palmitate is intended to lower the prevalence of vitamin A deficiency in populations at risk. Although the stability of vitamin A in vegetable oil has been shown to depend on environmental factors, very little information is known about the stability of vitamin A in preoxidized vegetable oils. The present study investigated the stability of retinyl palmitate in mildly oxidized (peroxide value < 2 mequiv O2/kg) and highly oxidized (peroxide value > 10 mequiv O2/kg) soybean oil stored under domestic and retail conditions. Soybean oil was filled in transparent bottles, which were exposed to cold fluorescent light at 22 or 32 °C for 56 days. Periodic oil sampling increased the headspace, thereby mimicking consumer handling. Loss of retinyl palmitate in soybean oil by a maximum of 84.8 ± 5.76% was accompanied by a decrease of vitamin E by 53.3 ± 0.87% and by an increase of the peroxide value from 1.20 ± 0.004 to 24.3 ± 0.02 mequiv O2/kg. Fortification of highly oxidized oil with 31.6 IU/g retinyl palmitate led to a doubling of the average decrease of retinol per day compared to fortification of mildly oxidized oil. In conclusion, oil fortification programs need to consider the oxidative status of the oil used for retinyl palmitate fortification.

The stability of vitamin A in fortified palm olein during extended storage and thermal treatment

“…Pignitter et al . (,b) have previously shown a tendency for a compound decrease of retinol when compared to a mildly oxidised oil; this and the aforementioned factors may explain another mechanism by which means the vitamin A in RBDPOL vegetable oil will be rapidly depleted during any subsequent domestic heating application.…”

“…We believe the presence of these high peroxide compounds are a concomitant factor, initially onset through extended exposure to high environmental temperature for extended periods. These also may have contributed and influenced the decomposition of vitamin A (Laillou et al ., ; Pignitter et al ., ,b). In the event of fulfilling vitamin A fortification requirements for intervention programmes, the PV level may need to be monitored if exceeding beyond acceptable level of 10 meq kg −1 (Pignitter et al ., ).…”

“…Additionally, there is known to be a negative effect on vitamin A, when exposed to oxygen and ultraviolet light (Hariyadi, ; Andarwulan et al ., ; Hemery et al ., ). Other factors affecting stability of vitamin A during storage are acidity, temperature, moisture and impurities (Atwood et al ., ; Hariyadi, ; Pignitter et al ., ,b).…”

“…A PV level of <2 meq kg À1 has been proposed as a key parameter at the time of production . Concomitantly, the quality of vegetable oil (assessed by PV) prior to fortification has been shown to have a dramatic effect on the stability of retinyl palmitate (Andarwulan et al, 2014); the same authors have shown that where a vegetable oil is oxidised through elevated levels of peroxides, it will significantly impact the loss of vitamin A (Viana et al, 2007;Pignitter et al, 2014a). Hydroperoxides are very unstable and decompose into a series of aldehydes, ketones, hydrocarbons, alcohols and many more reaction products as the oil oxidation process continues.…”

Purification of β‐carotene 15,15′‐monooxygenase from pig intestine and its enzymatic hydrolysis of pigment in soybean oil

“…The deficiency of vitamin A is a major public health problem, which is a leading reason for preventable blindness in children and increases the risk of disease and death from severe infections. In recent years, vitamin A fortified edible oil has been proved to be the most effective intervention measure to reduce vitamin A deficiency (Pignitter et al, 2014). Vitamin A fortified soybean oil currently sold in the market usually uses retinol and palmitate or acetic esterification to form a stable ester compound, which is then added to vegetable oil, and the reaction process is complicated.…”