Effect of roasting history and buffer composition on peanut protein extraction efficiency

Abstract

Peanut is a major allergenic food. Undeclared peanut (allergens) from mis-formulation or contamination during food processing pose a potential risk for sensitized individuals and must be avoided. Reliable detection and quantification methods for food allergens are necessary in order to ensure compliance with food labelling and to improve consumer protection. The extraction of proteins from allergenic foods and complex food products is an important step in any allergen detection method. In this study, the protein extraction efficiency of various buffers prepared in-house and some extraction buffers included in some commercial allergen enzyme-linked immunosorbent assay (ELISA) test kits for peanut determination in food products were tested. In addition, the effect of roasting history on the extractability of peanut protein was investigated by the biuret and the bicinchoninic acid (BCA) assays. Elevated roasting temperatures in food processing were found to have a major impact on protein extraction efficiency by reducing protein yields of oil and dry roasted peanuts by 50-75% and 75-80%, respectively, compared with the raw material. Extraction buffers operating in the higher pH range (pH 8-11) showed best yields.

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

“…Here, we observed that increasing the pH of Tris·Cl bu er to 8, higher protein recoveries were obtained, speci cally 51% and 36% for raw and roasted peanuts, respectively. is evidence was also suggested by previous studies on processed peanuts, which confirmed that extraction solutions with pH ≥ 8.5 improved the protein recovery [18,26,27]. Besides the good observed results by Tris·Cl buffer for protein extraction of raw and treated peanuts, best recovery values were obtained with urea-TBS buffer.…”

“…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].…”

A quantitative sandwich ELISA for the detection of Anisakis simplex protein in seafood

“…With regard to A. simplex protein, the extractability and ELISA-detectability appeared to be greatly dependent on the pH-values of the buffers. Measurable A. simplex proteins were only obtained under basic conditions, which is congruent to an observation made for other allergens in a previous study [43]. The Tris-glycine extraction buffer was found to be optimal considering the yield of detectable A. simplex proteins from thermally treated samples.…”

Egg Allergen Detection

“…Protein solubilization and the modification of epitope configuration resulting from processing are challenges that need to be addressed during the development of immunoassays for processed foods. The solubilization of the target protein is a requirement to obtain successful immunoassay results [85,86]. Figure 16.4 shows solubility issues arising from a typical sample preparation prior to ELISA analysis.…”