Tests dispute 'nutritional superiority' of milk in lightproof bottles

In 2013 Tristan Pang, then aged 11, won a Niwa Auckland City Science and Technology Fair award for his science project "Triple Layer Milk Bottle - is it effective?"

Flashback four years when Tristan Pang, then aged 11, won a Niwa Auckland City Science and Technology Fair award for his science project "Triple Layer Milk Bottle - is it effective?" on the new light-proof Anchor milk bottles compared to the normal semi-transparent bottles.

The Auckland youngster, who started at Auckland University as a 12-year-old, carried out three lots of testing on the triple-layer Anchor bottles for taste, light and acidity and found no difference in the first two experiments compared to standard bottles - but that milk degraded faster in the triple layer bottle during acidic testing.

Despite claims light-proofed containers protect the vitamins in milk, Consumer NZ testing reveals there's little difference in nutrient content between major milk brands.

Fonterra-owned Anchor launched light-proof bottles four years ago, in response to research showing light can cause damage to vitamin B2 and A according to the company website.

However, Consumer NZ testing of five trim milk brands - Anchor, Homebrand, Meadow Fresh, Pams and Signature Range - shows miniscule differences in vitamin A and B2 content. Meadow Fresh sells its milk in "semi-opaque" bottles and the other three brands have transparent containers.

Consumer NZ chief executive Sue Chetwin says the tiny differences between the brands had no significant impact on the overall vitamin intake of a person eating a balanced diet.
"When we asked Fonterra for evidence of the nutritional superiority of milk stored in a light-proof bottle, it agreed there wasn't any," says Ms Chetwin.

"We think consumers reading the company's claims about vitamin content might be misled into thinking Anchor milk in light-proof bottles has a dietary advantage over its competitors."

Fonterra has now changed the description on the Anchor website to refer to the taste difference of milk in light-proof bottles instead of a nutritional benefit.

"There's little excuse for a company the size of Fonterra to be using claims that are unclear or may potentially mislead consumers," says Ms Chetwin.

Consumer NZ tested varieties of trim milk as experiments referred to on Anchor's website concluded lower-fat milk was the most susceptible to vitamin A degradation.