Older adults have unique nutritional needs, and food science professor Lisa Duizer is looking at ways to make their meals healthier as part of U of G’s Agri-food for Healthy Aging research group.
Mealtime is particularly important in long-term care facilities, she says, because that’s when most residents get to socialize with each other. Making foods that are appealing from a visual, taste and texture perspective makes mealtime more enjoyable.
Our nutritional requirements change with age, says Duizer. “We start to lose muscle mass, so our protein needs are greater because we need to maintain that muscle mass.” The elderly also become deficient in micronutrients. Her work aims to enhance vitamin and mineral content in food.
Aging also causes our taste buds to lose functionality and our sense of smell to diminish, which can affect our ability to taste flavours.
Duizer studies the sensory experience of eating that begins as soon as we see food. The appearance of food helps us decide whether we want to eat it. “When you eat the food, it may look great, but if it doesn’t have the right taste and flavours associated with it, you won’t eat it again,” she says.
Texture also plays a role in food’s appeal. Since pureed food is often served in long-term care facilities, she helped develop tips for making it more appetizing. “Nobody enjoys eating pureed foods,” she says. “It really is not the most pleasant sensory experience. When you take away all the textures and you’re just left with the taste and flavours, things don’t taste right.”
Some food manufacturers restructure their pureed food so that it looks more like its original shape. Duizer sees 3D printing as the next step in making pureed food look more realistic.
Adding thickening agents, such as guar gum, xanthan gum, pectin and starches can also help pureed food retain its shape but it’s important that the thickener doesn’t make the food look too shiny, which can put off consumers.
To make foods more nutritious, the researchers tried substituting ingredients for more nutritious ones, such as swapping green peppers for red peppers, or using white beans instead of kidney beans. “We’re hoping that it would lead to increased nutrient intake and improved nutrition in the older adult population,” says Duizer.
The researchers also studied vitamin and mineral powder additives. They interviewed chefs, nutrition managers and dietitians at long-term care facilities to find out which foods would be most appropriate for the powder. “We added them to soups, mashed potatoes and oatmeal,” she says. “The powder went very well into those kinds of products.”
A panel of 65-year-old taste testers enjoyed the foods that contained the nutrient powder. Their sensory capabilities were also tested to find out if there was a link between their senses and the foods they liked.
“We weren’t successful in finding that relationship,” says Duizer. “Food is more complex than that. Memory is really important and familiarity is really important.” But our memories of what foods used to taste like can be deceptive, since it’s hard to remember flavours from childhood and food manufacturers change their recipes over time.
The food research team helps develop new meal solutions and then presents their ideas to long-term care facilities to see if they work. “We can do all the research in the world but if it’s not practically relevant, it’s never going to go anywhere,” she says. “We go to them and interview them and ask questions of the residents, the cooks and the dietitians just to make sure we’re on the right track with what we’re trying to do.”