THERE is a simple way to produce safer peanuts that are less likely to trigger life-threatening allergic reactions. The problem is that they might not taste so good after the processing.
In the US alone, an estimated 1.5 million people suffer from nut allergies. But now food engineers have discovered that the maturation, curing and roasting of peanuts increases their allergen content, so by tweaking these processes the nut industry may be able to make them safer.
Unfortunately, many of the proteins and sugars blamed for allergies are thought to give roasted peanuts their distinctive, rich flavour. 鈥淚t will be a trade-off,鈥� says Si-Yin Chung, head of the team that discovered the link between processing and allergy at the US Department of Agriculture鈥檚 Southern Regional Research Center in New Orleans, Louisiana.
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Three processes give roasted peanuts their special flavour. The first, maturation, simply involves leaving the peanuts to ripen in the field. 鈥淚mmature peanuts taste bad,鈥� says Chung. In the second 鈥� curing 鈥� the nuts are dehydrated by warming them to between 35 and 70 掳C. Finally, they are roasted at around 160 掳C for about 20 minutes.
At each of these stages, the researchers exposed the nuts to antibodies from people with peanut allergies. The more antibodies that bind, the more allergens are present, giving Chung a way to rate the nuts鈥� 鈥渁llergenicity鈥�. He found that each process creates additional compounds called advanced glycation end adducts 鈥� pairings between proteins and carbohydrates that are thought to be more allergenic than either alone. The results will be published in the Journal of Agricultural and Food Chemistry.
Many of these substances enrich flavour, so getting rid of them could destroy the taste. But Chung is hopeful that modifications to processing could minimise the allergenicity of roasted peanuts while keeping most of the taste. Curing below 60 掳C, for example, doesn鈥檛 generate new allergens.