Marie Dubois, a student from France, carried out research into the effect of cooking on the composition and colour of New Zealand grown yams during her four month placement in the Food Group at Lincoln University.
Marie is in her third year of study in Food Innovation at the University of West Brittany (Quimper). Each student in this course is required to spend a semester in an English speaking country working on a research project.
While at Lincoln University, Marie built on previous research on New Zealand grown yams by studying the changes in composition and colour that happen when red, yellow and apricot coloured yams are baked and boiled.
“We already know that the colour of a food influences the consumers’ first judgement and the purchasing preference,” said Marie
“However, if the consumer is going to buy the product twice, the memory of the taste is important.”
The acidity of yams can influence the consumers’ appreciation. The tangy taste of yams when cooked reflects the levels of compounds called oxalates that are naturally present in the yams.
“What I found was that no matter what the original yam colour was they all changed to yellow when they were cooked. I also discovered that boiling did not reduce the vitamin C content but baking did, and that cooking, by either method, reduces the soluble but not the insoluble oxalate levels.
Oxalates are present as part of plants’ defence systems against disease but are not needed by the human body. However, they are important to study because people who have a tendency to develop kidney stones should limit their intake of foods containing high levels of oxalate.
Maire said that she really enjoyed being in New Zealand
“I didn’t spend all my time in study. I went on a bus trip around the South Island and enjoyed seeing the landscape and ski fields. I enjoyed practicing English. I think I need to stay longer to speak English very well, but I improved my English during my placement. I enjoyed living with a New Zealand family. I hope come back one day.”
Marie’s work at Lincoln University was supervised by Dr Geoffrey Savage.
FOR FURTHER INFORMATION CONTACT
Janette Busch, Technical Writer
Lincoln University, Canterbury
Tel: 64 3 325 2811 ext 8114
Email: Janette Busch