Natural enzyme could reduce peanut allergens, say scientists

Although still in early stages, the research has revealed that the polyphenol oxidase (PPO) enzyme can be used to reduce a reaction between antibodies- in allergy sufferers- and allergens in peanuts.

This could be good news for the food industry, which has faced tougher new allergen labeling rules since January 1 this year. These require that food manufacturers identify, "in plain, common language"​, the presence of any of the eight major food allergens, including peanuts.

And the nation's Food Allergy & Anaphylaxis Network (FAAN) estimates that 11 million people in the US - or 1-in-25 Americans - are affected by food allergies, with around 3 million suffering from allergies to peanuts or tree nuts.

But scientists at the US Department of Agriculture's (USDA's) Agricultural Research Service (ARS) now hope that their new research could be the start to the development of a safer peanut.

PPO is an enzyme found naturally in certain fruits and vegetables that brown after they are sliced, such as apples, bananas, lettuce and potatoes. Responsible for this browning action, which occurs through oxidization, PPO has also been found to trigger a certain chemical reaction when added to peanut extracts.

Peanut allergens- the components in peanuts that trigger allergic reactions- are proteins, explained ARS scientist Si-Yin Chung. And when PPO is added to ground-up peanut extracts it causes these proteins to link up, a process that affects the allergenic properties of the allergens.

When the structure of the peanut proteins, or allergens, is changed, this prevents these from binding with certain antibodies, a process that normally leads to an allergic reaction.

"Our research has shown that such structural changes reduced the allergenic properties of peanut allergens,"​ said Chung, although he pointed out that this effect was confirmed for only two of the eight allergens found in peanuts.

However, Chung cautions that although his tests so far have been positive, it is not yet clear if the process will be effective in reducing the severity of an allergic reaction in peanut allergy sufferers.

"The test for the reduction in peanut allergenicity was performed in a test tube. Animal studies are now needed to confirm whether a similar effect could occur in humans,"​ he told FoodNavigator-USA.com.

"The importance of this finding is that it provides insight into how to reduce the allergenic properties of peanut allergens, and that it could lead to future development of hypoallergnic peanut products,"​ he said.

"These products would not be meant for people who are allergic to peanuts, but to reduce the risk and severity of an allergic reaction caused by accidental ingestion of peanut products,"​ he added.

If animal tests prove successful, Chung explained that the next step in his research would be to examine whether the process would affect a peanut's taste and shelf life.

Chung's is not the first attempt to reduce the danger of peanuts and other foods to allergy sufferers.

Investigating a range of processing methods for peanuts, researchers from North Carolina A&T University last year discovered that one fermentation method reduced the detectable level of major allergenic proteins by as much as 70 per cent, without causing any adverse effects on the sensory quality of the final product.

"It is hoped that careful control of the process conditions may enable complete modification of allergenic proteins into non-allergenic and readily soluble proteins,"​ said Jianmei Yu, a researcher on the study.

"This finding is good news to the food industry in general, where peanuts are used as an ingredient in food product development and food preparation,"​ added the researcher.

And scientists at Wageningen University in The Netherlands last year identified and localized genes that are involved in the allergenicity of apples.

Partially because of the results of this study and the use of modern technologies such as marker assisted breeding and reduction in gene activity, the future may bring new 'less-allergenic' apple varieties onto the market targeted at allergic consumers.