title: Microwave assisted direct saponification for the simultaneous determination of cholesterol and cholesterol oxides in shrimp.
abstract: A novel microwave-assisted direct saponification method for the simultaneous determination of cholesterol and cholesterol oxides in shrimp was developed and validated. Optimal saponification conditions, determined by means of an experimental design, were achieved using 500mg of sample and 20mL of 1mol/L KOH ethanol solution for 16min at 45°C at maximum power at 200W and magnetic stirring at 120rpm. Higher extraction of cholesterol oxides in a reduced saponification time (∼75 times) was achieved in comparison with the direct cold saponification method. The new method showed low detection (≤0.57μg/mL) and quantification (≤1.73μg/mL) limits, good repeatability (≤10.50% intraday and ≤8.56% interday) and low artifact formation (evaluated by using a deuterated cholesterol-D6 standard). Raw, salted and dried-salted shrimps were successfully analyzed by the validated method. The content of cholesterol oxides increased after salting and decreased after drying.
authors.affiliation: Department of Food Science, Faculty of Food Engineering, University of Campinas, 13083-862 São Paulo, Brazil.
authors.forename: Hugo A L
authors.initials: HAL
authors.lastname: Souza
authors.affiliation: Department of Food Science, Faculty of Food Engineering, University of Campinas, 13083-862 São Paulo, Brazil.
authors.forename: Lilian R B
authors.initials: LRB
authors.lastname: Mariutti
authors.affiliation: Department of Food Science, Faculty of Food Engineering, University of Campinas, 13083-862 São Paulo, Brazil. Electronic address: neurabragagnolo@gmail.com.
authors.forename: Neura
authors.initials: N
authors.lastname: Bragagnolo
mesh_terms: D000818:Animals; D016477:Artifacts; D002784:Cholesterol / Q000032:analysis* / Q000737:chemistry; D002849:Chromatography, Gas; D003445:Crustacea / Q000737:chemistry*; D005504:Food Analysis / Q000379:methods*; D007700:Kinetics; D057230:Limit of Detection; D008280:Magnetics; D008872:Microwaves; D010087:Oxides / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012492:Salts / Q000737:chemistry; D013696:Temperature
chemical_list: D010087:Oxides; D012492:Salts; D002784:Cholesterol
keywords: Direct saponification; Grey shrimp; Litopenaeus vannamei; Microwave-assisted; Oxysterol