Effect of different antioxidants on lycopene degradation in oil‐in‐water emulsions

Abstract

There is interest in incorporating lycopene into foods because it is a natural pigment and can also play a role in preventing disease. Therefore, the effect of the addition of various antioxidants in lycopene containing oil-in-water emulsions stabilized with Tween 20 at acidic pH was studied in order to determine protection systems against lycopene oxidation. In this model, EDTA showed pro-oxidant activity while other chelators like citric acid and tripolyphosphate showed no effect. The free radical scavengers, propyl gallate (PG), gallic acid (GA), and a-tocopherol all had the ability to decrease lycopene oxidation with a-tocopherol being the most effective. The combination of 1 mM atocopherol and 10 mM GA was more effective than the individual antioxidants. Addition of ascorbic acid to the combination of a-tocopherol and GA system accelerated lycopene loss. These results suggest that by the proper selection of free radical scavenging antioxidants, lycopene stability in oil-in-water emulsions could be significantly improved.Practical applications: Evidence that dietary lycopene decreases the risk for a number of health conditions has generated new opportunities for addition of lycopene to functional foods. A successful strategy to deliver lycopene into foods is by means of oil-in-water emulsions. However, lycopene may decompose thus causing nutritional loss and color fading. In order to prevent this, the effectiveness of various antioxidants and their combinations in Tween 20 stabilized oil-in-water emulsions was studied. Overall, lycopene oxidation in oil-in-water emulsions could be significantly reduced by the proper selection of free radical scavengers. This fact is of interest to food industry for increasing the shelf-life of lycopene containing functional foods where the lycopene is dispersed in the food in the form of an oilin-water emulsion.

Effects of antioxidants on the stability of β-Carotene in O/W emulsions stabilized by Gum Arabic

“…Figure 4 showed the stability of β-carotene in the diluted reference solution at 4°C, the degradation of β-carotene in solutions was slower with the presence of α-tocopherol, the main reason might be that the preferential oxidation of α-tocopherol could inhibit the oxidation of β-carotene since α-tocopherol was oxidized prior to β-carotene. Similar phenomena were found in the study on lycopene emulsions (Bou et al 2011). Compared with α-tocopherol, the degradation of β-carotene in solutions was faster with ascorbyl palmitate and TBHQ, especially at low concentration.…”

Inhibition of β-carotene degradation in oil-in-water nanoemulsions: Influence of oil-soluble and water-soluble antioxidants

“…4). Under certain conditions, ascorbic acid can act as a pro-oxidant due to its ability to convert ferric ions to the more reactive ferrous ions, which can decompose lipid hydroperoxides into free radicals (Bou, Boon, Kweku, Hidalgo, & Decker, 2011). However, no pro-oxidant activity of ascorbic acid was observed in the current study.…”

Lycopene as a natural antioxidant

“…In the same sample, however, numerous products of lycopene oxidation were also observed. In the study of Bou et al [6] in this issue of EJLST free radical scavengers, propyl galate, gallic acid and a-tocopherol all had the ability to decrease lycopene oxidation with a-tocopherol being the most active.…”