Effect of Thermal and High Electric Fields on Secondary Structure of Peanut Protein

Abstract

This study evaluated the effect of the thermal and high electric field stresses on the secondary structure conformation of peanut protein using Fourier transform infrared spectroscopy. The amide I region between the wavelengths 1700-1600 cm-1 of the spectra were studied for different thermal and high electric field treatments. Within thermal treatments, both hot air roasting and microwave processing treatments were evaluated. Hot air treatments were performed at temperatures of 50, 75, and 100°C from 15, 30, and 45 min while the microwave treatments were conducted at the same temperatures, but for 5, 10, 15, and 20 min. Three experimental conditions were evaluated for the electric field intensity of 10, 15, and 20 kV for 60, 120, and 180 min. Changes were observed at 1654-1650 cm-1 , indicating conformational changes in the α-helix secondary structure. Similar changes were observed at various other wavelengths indicating changes in the 3/10 helix, β-sheets and random coils present in the protein. With an increase in the treatment time, the secondary structure reorganizations increased with the creation of new random coils and aggregated strands. Curve-fitting using Gaussian band shapes further supported the observations. In vitro protein digestibility studies were also performed and the protein changes also supported the observations from the spectra.

Peanut Allergy: Characteristics and Approaches for Mitigation

“…The effect of PEF treatment in peanut protein has also been explored recently. FT‐IR spectra showed significant alteration in protein structure (α‐helixes, β‐sheets, β‐turns, and random coils) as an effect of PEF treatment (Vanga et al., ). Thus, in general, PEF can also induce alterations in the structure and immunogenicity of food allergens.…”

“…Besides the major/potent peanut allergens, research indicates that some other minor allergens can also potentially cause life-threatening symptoms, while other allergens may only cause oral symptoms (Arkwright, Summers, Riley, Alsediq, & Pumphrey, 2013;Mittag et al, 2004;Petersen et al, 2014). Specific features of these proteins such as structure, digestibility, solubility, resistance to heat and digestion, and other functional properties such as glycosylation and enzymatic activity impart immunological sensitization and are the basis for the varying IgE reactivity, thus, allergenicity (Besler, 2001;Bøgh & Madsen, 2016;Huby, Dearman, & Kimber, 2000;Platts-Mills & Woodfolk, 2011;Vanga et al, 2016;Vanga et al, 2017). The peanut allergenic individuals also possess an 86% risk of being sensitized toward other nut allergies due to cross-reactivity Maloney, Rudengren, Ahlstedt, Bock, & Sampson, 2008).…”

“…Besides IgE epitopes, protein structure also plays a critical role and functions in the allergenic potential of proteins (Chruszcz et al, 2011, Nesbit et al, 2012, Dyer et al, 2018Maleki, Kopper et al, 2000;Maleki et al, 2003, Maleki, 2004, Maleki & Hurlburt, 2004. Therefore, the alteration in allergen structure subsequently alters its physicochemical properties such as solubility and digestibility, which in turn plays a significant role in altering the immunoreactivity (Apostolovic et al, 2013;Mikiashvili & Yu, 2018;Plundrich et al, 2015;Szymkiewicz & Jędrychowski, 2009;Vanga et al, 2016). The degree of alteration of allergens depends on the types and conditions of processing.…”

Effects of the Varietal Diversity and the Thermal Treatment on the Protein Profile of Peanuts and Hazelnuts

“…ese processing methods may induce protein modification, altering its intrinsic allergenicity through protein aggregation via disulfides or other interchain covalent bonds; all structural changes at the protein level may induce a concomitant disappearance or appearance of new IgE-binding epitopes [10][11][12]. Several authors reported that the thermal treatment causes changes in the structure/conformation of proteins in different matrix [13][14][15], depending on the structural and chemical properties of the protein itself, the type of thermal processing and the operating conditions applied (temperature, pH, and time) [16][17][18][19].…”

Deodorization of Arthrospira platensis biomass for further scale‐up food applications

“…The percentage of incidence for β ‐sheet secondary structure in the control of A. platensis biomass was 38.5% (the most abundant), followed by random coil and α ‐helix, which represented 23.1% and 15.4%, respectively. The percentages of β ‐sheet and α ‐helix were similar to peanut protein and to α ‐chymotrypsin, trypsin, ribonuclease A and alcohol dehydrogenase …”