Just one brand of frozen vegetables on supermarket shelves - Talley's - uses 100% New Zealand-grown vegetables.
The rest - including Wattie's and McCain - supplement local produce with vegetables from China, Vietnam, South America, and the United States.
Not that consumers would know from looking at the packet - all products meet New Zealand's food safety regulations but none need country-of-origin labelling. Studies indicate more than 75% of people prefer New Zealand-made food.
It is not hard to monitor where food comes from. Dunedin company Oritain has developed ways to pinpoint exactly where a fruit or vegetable is grown by analysing the microscopic "fingerprint" left by soil and rain.
Director Helen Darling said it was the "forensic science" of food - and testing was inexpensive and straightforward.
"Consumers want to know where their food comes from. There's a need for transparency."
Both Wattie's and McCain say on their labels: "Packed in NZ from local and imported ingredients."
Wattie's said 90% of its vegetables were locally grown but it sourced baby corn from Thailand and its cauliflower and broccoli could come from China, Ecuador, Guatemala or Spain.
McCain said its broccoli and cauliflower were sometimes imported from the US, Chile, China and Vietnam, as were 5% of peas they used.
A company spokesman said he could not be more specific because the numbers were changeable.
Horticulture NZ chief executive Peter Silcock said companies knew ingredient sources and it was disappointing they were not passed on to the consumer.
- Herald on Sunday
