The study, published in Food Chemistry investigated the use of enzymatic treatments to reduce the levels of allergens in peanut kernels, using two major peanut allergens (Ara h 1 and Ara h 2) as indicators of effectiveness.
The researchers found the treatment of roasted peanut kernels with alpha-chymotrypsin or trypsin enzymes for 1 to 3 hours significantly increased the solubility of peanut protein, whilst reducing Ara h 1 and Ara h 2 in kernel extracts by 100 per cent and 98 per cent respectively.
“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 senior authors Drs. Mohamed Ahmedna and Jianmei Yu from North Carolina A&T State University in Greensboro.
Consumption of peanuts or peanut containing food products can cause severe and even fatal allergenic reactions.
“While avoidance is the best way to guard against manifestation of allergy, the ubiquitous use of peanuts and peanut products by the food industry makes it very hard for allergic individuals to avoid accidental ingestion,” said the researchers.
“Therefore, it would be useful to reduce the level of allergens in peanuts that are mixed with other food ingredients,” they added.
Enzymatic processing is an approach that has worked to reduce or eliminate allergenicity in certain foods and ingredients, said Dr Ahmedna and his colleagues.
They noted examples of enzyme treatment used to remove allergens include production of hypoallergenic rice by a two-stage enzymatic proteolysis process and the development of hypoallergenic whey protein hydrolysate.
An enzymatic treatment process was reported to effectively reduce Ara h 1 and Ara h 2 in roasted peanut kernels by up to 100 per cent under optimal conditions.
Upon treatment with alpha-chymotrypsin solution, protein solubility increased, whilst detectable/extractable levels of Ara h 1 and Ara h 2 decreased in both blanched and non-blanched peanuts, said Dr Ahmedna and his co-workers.
They noted that the blanching of kernels enhanced the effectiveness of enzyme treatment in roasted peanuts.
Chymotrypsin treatment of blanched, roasted peanuts resulted in reduction of detectable soluble allergens by as much as 100 per cent.
“In fact, Ara h 1 and Ara h 2 levels in blanched peanut kernels were non-detectable … at enzyme concentration of 0.1–0.15 per cent,” said the authors.
Trypsin treatment of roasted peanuts also significantly reduced Ara h 1 and Ara h 2 while increasing the soluble proteins in both blanched and non-blanched soluble extracts, they added.
“The optimum enzyme treatment conditions for roasted peanut kernels consists of 5 minutes of blanching prior to incubation of peanut kernels in 0.12 per cent enzyme for 3 hours … Under these conditions, Ara h 1 and Ara h 2 were not detectable in soluble peanut protein extracts,” said Dr Ahmedna and his co-workers.
“The results confirm that our enzyme treatment process degrades the allergens into smaller peptides which may or may not retain their IgE binding and other allergenic properties in the soluble fractions of treated whole roasted peanuts,” said the researchers.
However, they added that because the results presented in the current study are from in vitro tests only, the allergenic potential of the enzyme treated extracts must be further tested in vivo to confirm any reduction in allergenicity.
Source: Food Chemistry
Published online ahead of print, doi: 10.1016/j.foodchem.2011.01.074
“Enzymatic treatment of peanut kernels to reduce allergen levels”
Authors: J. Yu, M. Ahmedna, I. Goktepe, H. Cheng, S. Maleki
Correction: This article has been changed from the initial version, published March 2, 2011, in which we incorrectly identified Soheila Maleki as the senior researcher. As stated in the article above, Dr Mohamed Ahmedna from the North Carolina A&T State University led the research. Apologies.