Influence of high-intensity ultrasound on the IgE binding capacity of Act d 2 allergen, secondary structure, and In-vitro digestibility of kiwifruit proteins

• Published in: Ultrasonics sonochemistry Vol. 71; p. 105409
• Main Authors: Wang, Jin, Wang, Jun, Kranthi Vanga, Sai, Raghavan, Vijaya
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2021; Elsevier
• Subjects: Circular dichroism spectroscopy; High-intensity ultrasound; IgE binding capacity; In-vitro digestibility; Kiwifruit allergy; Original; Secondary structure; Kiwifruit allergy; Circular dichroism spectroscopy; High-intensity ultrasound; IgE binding capacity; Secondary structure; In-vitro digestibility
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2020.105409

[Display omitted] •16-min ultrasound caused a 50% reduction in the IgE binding capacity of Act d 2.•In-vitro digestibility of kiwifruit proteins increased up to 77% with ultrasound.•Ultrasonication led to a loss of alpha-helixes and an increase in beta-sheets.•Digestibility and allergenicity strongly associated its protein secondary structure. Kiwifruit can trigger allergic reactions that can lead to death, causing public health concerns worldwide. In the present study, we treated kiwifruit samples with high-intensity ultrasound (20 kHz, 400 W, 50% duty cycle) for 0 to 16 min to evaluate its effect on the IgE binding capacity of kiwifruit allergen Act d 2, secondary structure and in-vitro digestibility of kiwifruit proteins. The changes in the protein solubility and microstructures of kiwifruit were also analyzed. The results showed that treatment with powerful ultrasound caused a significant disruption in the microstructure of kiwifruit tissues, leading to the changes in the secondary structures of proteins, including a loss of alpha-helixes and an increase in beta-sheet structures. These structural changes were due to the ultrasound treatment, especially 16 min of treatment, resulted in a 50% reduction in Act d 2 allergen content and significantly improved in-vitro digestibility up to 62% from the initial level of 35%. Furthermore, the solubility of the total proteins present in kiwifruit samples was significantly decreased by 20% after 16-min ultrasound processing. The results of this work showed that high-intensity ultrasound treatment has a potential application in reducing the allergenicity of kiwifruit or related products.