Validation of a high-throughput method for the accurate quantification of secondary products of lipid oxidation in high-quality hazelnuts (Corylus avellana L.): A robust tool for quality assessment

Integrated Strategy for Informative Profiling and Accurate Quantification of Key-Volatiles in Dried Fruits and Nuts: An Industrial Quality Control Perspective

“…The accurate quantification of secondary products of lipid oxidation in walnuts was targeted to hexanal, heptanal, (E)-2-heptenal, octanal, (E)-2-octenal, nonanal, and decanal. The validated quantitative method [27], here extended to unsaturated congeners, verified the HS linearity operating on 0.250 g of ground material instead of the 1.750 g adopted for the profiling method. Under the established sampling conditions (see Section 2.5), analytes had MHE decay trends matching with recommended values (i.e., β < 0.8) and uncertainties below 20% of relative error.…”

“…A more detailed description of the MHS-SPME procedure is available in the referenced literature [27,37,40,41].…”

“…The current study combines optimized HS profiling conditions for the selected model samples, as indicated by the CCD screening, with a validated procedure for accurate quantitative assessment of secondary product of FAs hydroperoxides degradation [27].…”

“…As a general consideration, the profile of secondary products of lipid oxidation is dominated by hexanal followed by (E)-2-octenal, octanal, and nonanal. The impact of storage conditions along shelf life is illustrated by the histogram in Figure 5 where the hexanal equivalents were calculated by converting the amount of each target analyte to hexanal (ng/g), simplifying the evaluation of the oxidative status [27].…”

“…Visual inspection targets damaged kernels [e.g., insect-damaged, rotten, twin, and yellowed kernels [17,[19][20][21][22][23]], sensory evaluation reveals the presence of rancidity (taste and aroma) [24], categorization by morphological parameters (shape and kernel size/caliber) is used to direct transformation strategies, while moisture content (a w ) below established levels, guarantees microbial and mold stability. Chemical markers for QC include the quali-quantitative profiling of fatty acids methyl esters (FAMEs), targeted to both free FAs (FFAs) and esterified species (EFAs) [13,25,26], accompanied by the accurate quantification of secondary products of FAs hydroperoxides degradation (i.e., hexanal, heptanal, octanal, and nonanal) [27]. Additional parameters include the free acidity [25,28], the peroxide value (PV), and the Oxitest AOCS method [29].…”