Allergenicity, antioxidant activity and ACE-inhibitory activity of protease hydrolyzed peanut flour

Regularly consuming peanuts has been reported to have many health benefits. Peanut flour, a by-product of peanut oil processing, has higher protein and dietary fiber contents than peanut kernels, but its application as protein source in foods and dietary supplement is limited due to the fear of peanut allergy. This study indicates that hydrolysis of peanut flour (12% lipid) up to 4 h with Alcalase lowered the immunoreactivity of both soluble and insoluble portions of peanut flour, generated peanut flour hydrolysate (PFH) with good in vitro antioxidant and ACE-inhibitory activities. Importantly, the fraction smaller than 5 kDa did not bind IgE of peanut allergic patients, but exhibited higher ACE-inhibitory activity than the crude PFH. Thus, peanut flour could be an inexpensive protein source of antioxidant and anti-hypertensive ingredient. These findings are important for the value added application of peanut flour. However, studies with food and animal/human models are needed to confirm the benefits.