title: Sequential extractions: A new way for protein quantification-data from peanut allergens.
abstract: Quantification of certain protein contents in the matrix is essential in protein analyses. The amount of total protein in the matrix can be determined by the Kjeldahl method. However, few methods can quantify certain protein contents in the matrix without extracting all of them in solution. Extracting all of the contents is difficult for proteins, especially relatively insoluble ones. A five-step sequential extraction method was developed for the quantification of certain proteins in defatted peanut flour based on the relationship between the extracted protein contents and the extraction times. The extracted proteins (i.e., total protein, Ara h 1, and Ara h 2) were quantitatively analyzed in each extraction of the same condition. An exponential equation was obtained between the extraction times and the respective amount of extracted protein as well as both the total protein and a particular protein. In particular, the amount of protein extracted each time can be a geometric sequence. If all proteins can be extracted with sufficient extraction times, the protein contents in the peanut matrix can be calculated using a mathematical summation formula. This sum should be all proteins in the matrix. The five-step sequential extraction method can provide a means to quantify certain proteins in the matrix.
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China; Department of Food Science, Nanchang University, Nanchang 330047, China.
authors.forename: Ningling
authors.initials: N
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China; Department of Food Science, Nanchang University, Nanchang 330047, China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China. Electronic address: wuzhihua@ncu.edu.cn.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Department of Food Science, Nanchang University, Nanchang 330047, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China.
authors.forename: Anshu
authors.initials: A
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Tong
authors.affiliation: State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China. Electronic address: chbgjy@hotmail.com.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Chen
mesh_terms: D000485:Allergens / Q000302:isolation & purification*; D010367:Arachis / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D010940:Plant Proteins / Q000302:isolation & purification*
chemical_list: D000485:Allergens; D010940:Plant Proteins
keywords: Ara h 1; Ara h 2; Peanut; Protein quantification; Sequential extraction