Influence of trace metals, acids and ethanol in food-simulating liquids on the retention of alpha-tocopherol in low-density polyethylene film.
The retention of alpha-tocopherol (vitamin E) in low-density polyethylene (LDPE) film was investigated when in contact with different food-simulating liquids. Variations of the aqueous food simulants approved by the EU for testing of interactions between packaging materials and food, and an alternative fatty food simulant (95% aqueous ethanol) were used to study the influence of trace metals and acids, as well as variation in pH and ethanol concentration, on the stability of alpha-tocopherol in the LDPE film. The presence of trace metals in aqueous media accelerated loss of alpha-tocopherol from the film, while the addition of citric or ascorbic acid counteracted this loss. In contact with aqueous ethanol at a concentration of 50% or higher, the loss of alpha-tocopherol from the film was total. However, with solutions containing less than 50% ethanol, the antioxidant was almost completely retained in the film, unless the temperature was increased from 6 to 40 degrees C. For contact with solutions containing ethanol or trace metals, an increase in temperature resulted in a greater loss of alpha-tocopherol from the LDPE film.
Wessling
C
C
SIK-Swedish Institute for Food and Biotechnology, Göteborg, Sweden. carolina.wessling@sik.se
Nielsen
T
T
Leufvén
A
A
D000143:Acids / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019343:Citric Acid / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D018857:Food Packaging; D007501:Iron / Q000737:chemistry; D020959:Polyethylene / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014131:Trace Elements / Q000737:chemistry*; D014810:Vitamin E / Q000737:chemistry*
D000143:Acids; D000975:Antioxidants; D002614:Chelating Agents; D012997:Solvents; D014131:Trace Elements; D014810:Vitamin E; D019343:Citric Acid; D000431:Ethanol; D003300:Copper; D020959:Polyethylene; D007501:Iron; D001205:Ascorbic Acid