Frozen fruit and vegetables may be more nutritious than fresh: Research
Two new studies investigating the nutritional content of the most commonly bought supermarket fruit and vegetables have revealed that frozen products have higher levels of certain vitamins and some antioxidants than their fresh counterparts - after three days of storage. The analyses of more than 40 tests revealed that in 66% of cases fruit and vegetables that had higher nutritional levels of vitamins and antioxidant-type compounds after storage – including Vitamin C, polyphenols, anthocyanins, lutein and beta-carotene.
“Our data concluded that the concentrations of antioxidant compounds measured in frozen resembled those observed in corresponding fresh produce prior to refrigerated storage," explained Professor Graham Bonwick from the University of Chester - who led one of the studies.
"However, unlike frozen, some fresh produce concentrations exhibited a decrease during refrigerated storage to levels below those observed in the corresponding frozen produce," he said. "The effects were most noticeable in soft fruits.”
Both of the independent reports were commissioned by the British Frozen Food Federation, and were carried out by researchers at Leatherhead Food Research and the University of Chester.
Dr Rachel Burch of Leatherhead Food Research - author of the second study - said the results "demonstrate that frozen can be nutritionally comparable to ‘fresh’ produce."
"We must disregard the mistaken opinion that ‘fresh’ food is always better for us than frozen food,” she said.
Study details
The two studies involved researchers purchasing fresh and frozen fruit and vegetable samples from each of the four main UK supermarket chains. The team then stored each product for three days - as might be the situation for a consumer who conducts a bi-weekly shop.
After storage, the researchers prepared composite samples from each produce type and analysed each sample for antioxidant-type compounds including : vitamin C, polyphenols, anthocyanins, lutein and beta- carotene.
| Vitamin C | Total Polyphenols | Lutein | Beta-Carotene | Anthocyanins |
Broccoli | Fozen | Fresh | Frozen | Frozen | n/a |
Carrots | Frozen | Frozen | Frozen | Frozen | n/a |
Brussels sprouts | Frozen | n/a | Frozen | Frozen | n/a |
Spinach | Fresh | Fresh | Frozen | Frozen | n/a |
Peas | Comparable | Frozen | Frozen | Fresh | Frozen |
Green Beans | Frozen | Frozen | Comparable | n/a | Frozen |
Cauliflower | Fresh | Frozen | n/a | n/a | Frozen |
Sweetcorn | Frozen | Frozen | n/a | n/a | Frozen |
Blueberries | Frozen | Frozen | Fresh | Fresh | Frozen |
Raspberries | Comparable | Fresh | Frozen | Frozen | Frozen |