U of A PhD student derives preservative, other health benefits from mango seeds

Pete Yee

Working with mango kernels has been a fruitful endeavor for University of Alberta PhD student Christina Engels with the Department of Agricultural, Food, and Nutritional Science. Engels has discovered a way to extract a specific substance from leftover kernels, unearthing an inexpensive, all-natural preservative and capitalizing on a food trend.

According to Engels, the mango product industry produces juice and dried mangoes, but discards millions of mango seeds every year. Engels was determined to find a way to recycle these by-products.

“The basic idea behind this project is to use the leftover kernel, to find a good application for it,” Engels said.

What she discovered were tannins, a plant compound that has anti-microbial activities acting as defence mechanisms against pathogens such as Listeria, a bacterial strain that infected luncheon meat last summer, killing 21 Canadians. Since the substance is extracted from a so-called waste product in the age of processed foods and growing obesity rates, Engels believes demand will grow for what is an inexpensive, natural product.

“At the moment, there’s a trend towards more organic and natural foods. This presents a natural alternative to existing synthetic preservatives,” Engels noted.

The mango preservative can be used on products that are most susceptible to rot and require very particular storing techniques, such as dairy products. However, this discovery won't be hitting the dairy section of grocery stores just yet.

“There will be other nutritionists to work with it, to make sure there is no negative impact on humans, but it will be available sometime in the near future,” Engels said.

If this substance passes rigorous nutritional testing, she said that it could also be used in the washing water of fresh-cut lettuce or put directly into fruit juices. For Engels, the practical uses of mangoes continue to add up; she described a process that involves extracting fat from the mango kernels and using it to replace the fat from cream in ice cream. In addition, other research has found anti-oxidant activity as well, which is linked to cancer-reducing properties. However, these discoveries also demand further examination.

Though she has been enjoying the fruits of her labour, Engels says her work does not end here; this is only a pit-stop during her quest to learn and discover more.

“I’ve been getting so much positive feedback. It’s really nice that it affects people outside of my lab,” Engels noted. “Now I want to go deeper and find out why they have this ability. That’s the thesis of my PhD project.”