The allergenic potential of food products can be a critical issue for many consumers, and has led to a whole range of 'free from' products made specifically to help consumers with allergies or intolerances. But new techniques in the processing and structuring of foods and food ingredients could soon mean that the targeted removal or modification of allergens is possible.
Whether it be by UV light, the use of specialised enzymes or acids, or specific alterations to the cooking and preparation of foods – researchers are developing a whole host of ways to reduce the allergenic potential of foods without removing the offending ingredient, that could soon help to create allergen free peanut butter, for example.
Food allergies are caused by an adverse immune response, usually to a food protein, when the immune system identifies a protein as harmful. Estimates of global incidence vary however it is known that allergies to common foods (including milk, fish, peanuts, and some vegetables) are growing rapidly. The global incidence of childhood food allergy is now believed to be at around 6%.
In recent years the sector of the food industry catering to allergy-sufferers – the ‘free-from’ market – has developed rapidly, with a recent Global Industry Analysts Inc (GIA) report predicting that the global market for food allergy and intolerance products will surpass $26 billion US dollars (€11.2 billion) by 2017.
Which such a high growth in the number of people with allergies and a proliferation of ‘free from’ alternatives, the market is poised for strong growth.
However, one area, still in its infancy, is that of modifying raw ingredients to remove allergenic proteins, or structuring foods in new ways that reduce the impact of these allergens.
Researchers from the United States Department of Agriculture (USDA) recently suggested that the use of tannic acid could help to reduce the allergic potential of products that contain peanut proteins. The US based researchers revealed that complexes formed by tannic acid and peanut proteins do not release allergens in the acidy range of the human digestive system – meaning the solution has potential for reducing the allergic potential of foods that contain peanuts.
“The data suggests that the allergen-bound complexes may be stable under gastric and intestinal conditions, and ultimately pass through without causing an allergic reaction,” said the researchers, who added that their findings open up new possibilities for low-allergen peanut products
Other research has suggested that adding polyphenols such as caffeic, chlorogenic and ferulic acids to liquid peanut butter could reduce the levels of major peanut allergens.
Alternatively, researchers from North Carolina A&T State University, USA, have suggested that a new enzymatic treatment process using alpha-chymotrypsin or trypsin enzymes could effectively reduce allergen levels in roasted peanuts by up to 100%: “Results from this study indicate the potential for producing peanuts with reduced allergenicity using post-harvest processing approaches such as food grade enzymatic treatment,” said research leaders Mohamed Ahmedna and Jianmei Yu.
Meanwhile scientists at the University of Florida, USA, suggest that exposing peanuts to bursts of pulsed ultraviolet light (PUV) can reduce their allergenic potential by up to 90%. The research found that releasing the concentrated bursts of PUV transforms the allergenic proteins, meaning they cannot be recognised by the human immune system.
“We believe the allergen can be controlled at the processing stage, before the product even goes to the shelf,” said the researchers.
The way in which foods and ingredients are cooked can also play a huge role in allergenic potential. For example, research has shown that allergenic proteins are significantly higher in peanuts that have been roasted, when compared to those that are fried or boiled. The team behind the findings also said that the proteins from boiled and fried peanuts did not bind as easily with human immunoglobulin E (IgE) compared to the proteins from roasted peanuts, meaning the potential for allergic reactions was lowered both by the actual number of allergenic proteins present and also by the lower ‘reactivity’ of these proteins.