Results of a study conducted by food scientists at the University of Virginia indicate if clear packaging is expected to be as protective as opaque materials, especially for pathogen-friendly foods such as meat and fresh vegetables, it will involve more work.
Consumers generally prefer transparent or translucent packaging materials, for the security they experience if they can scrutinize the food they are to consume. This has resulted in a movement from older forms of packaging, towards clear polymers like high density polyethylene (HDPE) and polyethylene terephthalate (PET).
Interestingly, several foods and beverages undergo harmful oxidation reactions in florescent lights that they are diplayed under. Reactions occur because the photosensitisers in the product, such flavanoids and cholorophyl, absorb certain wavelengths of UV or visible light. This chemical reaction leads to not only an off-odour, but also to destruction of vitamins and nutrients.
When examining clear packaging for milk, the team observed the chemical changes that occur during photo-oxidation when the product was packaged in a range of single and multi-layers of iridescent film. The oxidation process was then observed by using gas chromatography, a process that involves separating complex mixtures by moving the product along a stationary material.
The study concluded that film over-wraps reduce the production of volatile and odour-active compounds in milk, compared to milk with no over-wrap, and that multi-layer over-wraps are more effective than single-layer. However, none of the over-wraps are as effective as a complete light block, such as foil.
Consumers generally prefer transparent or translucent packaging materials, for the security they experience if they can scrutinize the food they are to consume. This has resulted in a movement from older forms of packaging, towards clear polymers like high density polyethylene (HDPE) and polyethylene terephthalate (PET).
Interestingly, several foods and beverages undergo harmful oxidation reactions in florescent lights that they are diplayed under. Reactions occur because the photosensitisers in the product, such flavanoids and cholorophyl, absorb certain wavelengths of UV or visible light. This chemical reaction leads to not only an off-odour, but also to destruction of vitamins and nutrients.
When examining clear packaging for milk, the team observed the chemical changes that occur during photo-oxidation when the product was packaged in a range of single and multi-layers of iridescent film. The oxidation process was then observed by using gas chromatography, a process that involves separating complex mixtures by moving the product along a stationary material.
The study concluded that film over-wraps reduce the production of volatile and odour-active compounds in milk, compared to milk with no over-wrap, and that multi-layer over-wraps are more effective than single-layer. However, none of the over-wraps are as effective as a complete light block, such as foil.
