13 November 2024 Training food science students on modern methods vital for future of local producers

A walnut grown in New Zealand and a walnut grown across the world. Could you tell the difference?

Identifying the unique properties of our local produce is an increasingly important part of food production in New Zealand. In their final lecture for the year, a group of Lincoln University Food Science students got a taste of how contemporary testing methods could gather data with less resources, which could help small businesses compete in the global market.

Department of Wine, Food and Molecular Biosciences Lecturer Shaoyang Wang said traditionally sensory testing was done using descriptive analysis testing, which required training a group of individuals how to identify different components of food sensations and rate it using an objective metric.

Big companies could afford to train testers, but that was not an option for smaller businesses, he said.

A more contemporary method called projective mapping, a rapid profiling method, has proven to be more accessible. It instead accounted for the wide range of subjectivity between each tester.

“A human’s perspective is almost all subjective.”

That subjectivity could be an issue with descriptive analysis testing, as each tester had to be taught how to communicate what they were experiencing.

Originating from psychology research, the biggest advantage of projective mapping was how food scientists could invite ordinary consumers to conduct experiments rather than professional evaluators.

Giving the students experience with projective mapping meant they would be capable of conducting the tests in the future, wherever they ended up after graduating.

In the test, the students used keywords to describe the sensations they noticed in each type of walnut and placed it on a grid. Walnuts that were similar ended up being clustered together, and outliers were easily identified.

Lincoln University partnered with Trickett's Grove Walnuts and Walnuts New Zealand to ensure there were enough walnuts to go around to all the students. About 9kg of walnuts — 1kg of each variety — were brought in for the workshop.

Walnuts New Zealand General Manager Kevin Parish said graduates having experience with projective mapping would be beneficial for the industry.

“Training students with practical tools that help businesses is always a good thing, especially tools which can visually explain the differences in various products and services.”

Walnuts New Zealand used projective mapping to assess where it was perceived in the market. It was also useful to see which characteristics consumers identified in their product compared to their competitors’.

Student Yixuan Yan said the locally produced walnuts were easily identified and had the significant advantage of being fresh.

“Compared with imported walnuts, the freshness of locally produced walnuts is far better than that of imported walnuts, because the walnuts do not require a long time of transportation.

“The freshness can directly affect the taste and aroma of walnuts.”

The lack of training required for projective mapping also challenged one of the students, Eric Gao, who had trouble picking out the different flavours.

“I found this test a bit more challenging for me, because I don’t usually eat walnuts and have no idea what they are supposed to taste like.”

Despite that, he still managed to pick out the New Zealand walnuts, as they were slightly more nutty and fresher.

He felt the knowledge of projective mapping would help him be competitive in his future career.