Strategies for Accurate Quantitation of Volatiles from Foods and Plant-Origin Materials: A Challenging Task

• Published in: Journal of agricultural and food chemistry Vol. 67; no. 6; pp. 1619 - 1630
• Main Authors: Sgorbini, Barbara, Cagliero, Cecilia, Liberto, Erica, Rubiolo, Patrizia, Bicchi, Carlo, Cordero, Chiara
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 13.02.2019
• Subjects: Gas Chromatography-Mass Spectrometry - methods; Gas Chromatography-Mass Spectrometry - standards; Plant Extracts - analysis; Plants - chemistry; Solid Phase Microextraction - methods; Solid Phase Microextraction - standards; Volatile Organic Compounds - analysis; accurate quantitation of volatiles; gas chromatography−mass spectrometry; food volatiles; multiple headspace solid phase microextraction
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.8b06601

The volatile fraction of foods and of plant-origin materials provides functional information on sample-related variables, and gas-phase extractions are ideal approaches for its accurate chemical characterization. However, for gas-phase sampling, the usual procedures adopted to standardize results from solvent extraction methods are not appropriate: headspace (HS) composition depends on the intrinsic physicochemical analyte properties (volatility, polarity, partition coefficient(s)) and matrix effects. Method development, design, and expression of the results are therefore challenging. This review article focuses on volatile vapor-phase quantitation methods (internal standard normalization, standard addition, stable isotope dilution assay, multiple headspace extraction) and their suitability in different applications. Because of the analyte informative role, the different ways of expressing results (normalized chromatographic area, percent normalized chromatographic areas, and absolute concentrations) are discussed and critically evaluated with examples of quality markers in chamomile, process contaminants (furan and 2-methylfuran) in roasted coffee, and key-aroma compounds from high-quality cocoa.