Fries to control glucose release? New enzyme-inhibiting process may make potatoes healthier

16 Jun 2022 --- Scientists have uncovered a new enzyme-inhibiting process that may present opportunities to improve the nutrition profile in potatoes. A new process may make potatoes more appealing for all.

Dr. Amy Lin, Principal Investigator and lead of the Food Carbohydrate Program at the Singapore Institute of Food and Biotechnology Innovation (SIFBI), tells NutritionInsight how the process works and what it all means.

“The process technique changes how fast dietary glucose is released from potatoes into our body,” says Lin. “Current laboratory data gives us confidence it will help manage glucose generation.”

“Our team revealed that toggling the accessibility of two digestion enzymes in the small intestine is a successful strategy to make dietary glucose slowly and continuously released from potatoes,” Lin further explains.

A variety of cooked potato types can be used, ranging from fries to roast potatoes.Key lies in calcium solution
From baked potatoes to french fries, potatoes have long been a worldwide dietary staple. However, though rich in iron and other micronutrients, potatoes are also rich in starch and that can pose problems for people suffering from diabetes or those trying to control their weight.

The newly discovered process works by inhibiting two digestive enzymes, a-amylase and a-glucosidase, both of which are in the small intestine. 

This keeps the enzymes from breaking down the potato starches too quickly and slows the release of starch and production of glucose, which can be considerable if a large amount of potatoes are consumed. 

The process is done by soaking, or blanching potatoes in water with a calcium solution which the US Food and Drug Administration (FDA) has already designated as generally safe for human consumption. 

This ingredient reacts with naturally occurring pectin within the potato and creates a temporary barrier between the enzymes and the starch molecules. Not only does this prevent glucose spikes, it can also make people feel full longer. This finding is in line with a recent study conducted in the UK, revealing shakes containing potato and rice protein are better than whey protein at managing blood glucose levels and reducing spikes in insulin.

Targeting blood glucose
The process does not stop the digestion of the potato. Rather, it slows the process down, giving the body more time to process the glucose and prohibiting spikes in glycemia. 

“We used processed potatoes to make some oriental cuisines like potato curry,” says Lin. “This process will suit French fries because it will enhance the desirable texture attributes.” 

Since the process essentially pre-cooks the potatoes, treated potatoes are not shelf-stable but could be frozen and then cooked or further processed for dishes such as roasted potatoes, hash browns, soups or stir-fry. 

Initial taste tests had good results in terms of digestibility and texture, the study reveals.

What this means for the consumerThe process can be done on a large scale or at home in the kitchen.
Lin states that one of the best aspects of this process is the ease with which it can be done. Researchers cut the potatoes into cubes and blanched them in a hot, 500 parts per million (ppm) solution for 30 minutes to achieve the desired effect. 

“The process is suitable for large-scale production and is also feasible for consumers to operate in a home kitchen,” says Lin. 

This could also hold opportunities for female athletes as a recent study revealed that potatoes can be just as effective as many sports nutrition products in recovery from training and exercise. In addition, potatoes have also been found to reduce salt retention and may ease some of the symptoms of hypertension. 

Diabetes is a complicated disease,” concludes Lin. Lin hopes to have clinical trials to test exactly how effective the process may be for those who have diabetes or some forms of malnutrition.

Potatoes – while not considered a conventional health staple – are still tapping into the field of functional foods. “Rescued” potato fruit water as a byproduct of the potato starch industry has presented a new source of new functional proteins, according to separate research conducted last summer.

By William Bradford Nichols