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Plant sterol (PS) oxidation products (POP) derived from sitosterol and campesterol were measured in 15 foods cooked with liquid margarine without (control) and with added 7.5% PS. POP were analyzed using a GC–MS method. PS liquid vs. control margarine resulted in a higher median POP content per food portion (1.35 mg, range 0.08–13.20 mg versus 0.23 mg, 0.06–0.90 mg), a lower PS oxidation rate (0.63 vs. 1.29%) and lower oxidation susceptibility of sitosterol vs. campesterol. POP formation was highest in shallow-fried potatoes with PS liquid margarine (64.44 mg per portion food plus residual fat). Mean relative abundances of epoxy-, 7-keto-, 7-hydroxy- and triol-PS derived from sitosterol and campesterol were 40.0, 34.4, 21.5 and 4.0% with control vs. 44.1, 23.8, 29.6 and 2.4% with PS liquid margarine. In conclusion, PS liquid margarine increased POP content in foods with a POP profile characterized by a higher ratio of epoxy- to 7-keto-derivatives. [ABSTRACT FROM AUTHOR]

• A simple and "direct" method for phthalate analysis in vegetable oils is proposed. • Sample preparation involved only dilution with a suitable solvent. • Twenty-seven vegetable oils were analyzed by using GC × GC with triple quadrupole MS. • Nine vegetable oils were found to be contaminated by DPP, DEHP, DiNP, and DiDP. Phthalic acid esters (PAEs), known as phthalates, have a variety of industrial applications, mainly related to their ability to increase plastic softness, flexibility, and durability. With regard to toxicological aspects, several studies suggest that phthalates would act as endocrine-disrupting chemicals, and they have been correlated to several forms of cancer. Since the analysis of PAEs in food is challenging, the aim of this study was the development of a simple and direct method, with no sample preparation (only dilution with solvent), for the analysis of targeted phthalates in vegetable oils, by using cryogenic-modulation comprehensive two-dimensional gas chromatography combined with triple quadrupole mass spectrometry. The method was characterized by good repeatability values, limit of quantification values ranging between 0.06 and 2.10 mg/kg, accuracy values ranging from −9.2 to 10.4%, and a matrix effect ranging from −4 to 78%. The developed technique was used for the analysis of 27 vegetable oils. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are common flame retardants that are used in a wide variety of products. These compounds might migrate into and pollute food products. An analytical method involving an improved approach called the “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) method and ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) was developed to simultaneously measure trace levels of nine OPEs in milk powder. Separation of the nine OPEs was optimized on a reversed-phase column within 7 min. The stable isotope tri-n-butyl phosphate- d 27 (TBP- d 27 ) was used as an internal standard. This method was validated in terms of its linearity, sensitivity, precision, accuracy and matrix effects. Matrix-matched calibration curves were constructed with 1/ x 2 as the weighting factor for all of the target compounds resulting in coefficients of regression lines between 0.9938 and 0.9999. The average accuracy was between 73.5% and 110.2%. Intra- and inter-assay precisions for six replicates ranged from 3.9% to 8.9% or below 11%, respectively. The limits of detection (LODs) were in the range of 0.1–0.25 μg/kg, and the limits of quantification (LOQs) were below 1.5 μg/kg. Significant matrix effects have been observed, but suppression or enhancement of the signal was compensated for by the use of an isotopically labeled internal standard. This validated method was successfully applied to determine the concentrations of the OPEs in milk powder. [ABSTRACT FROM AUTHOR]

Fruit esters are regarded as key volatiles for fruit aroma. In this study, the effects of cold storage on volatile ester levels of ‘Hort16A’ (Actinidia chinensis Planch. var chinensis ) kiwifruit were examined and the changes in aroma perception investigated. Cold storage (1.5 °C) for two or four months of fruit matched for firmness and soluble solids concentration resulted in a significant reduction in aroma-related esters such as methyl/ethyl propanoate, methyl/ethyl butanoate and methyl/ethyl hexanoate. Levels of these esters, however, were restored by ethylene treatment (100 ppm, 24 h) before ripening. A sensory panel found that “tropical” and “fruit candy” aroma was stronger and “green” odour notes less intensively perceived in kiwifruit which were ethylene-treated after cold storage compared to untreated fruit. The key findings presented in this study may lead to further work on the ethylene pathway, and innovative storage and marketing solutions for current and novel fruit cultivars. [ABSTRACT FROM AUTHOR]

Highlights: [•] Application of yeast Hanseniaspora vineae in real wine co-fermentation. [•] H. vineae and spontaneous fermentations showed higher flavour intensity and diversity. [•] Genetic strains identification showed increased diversity compared to conventional treatment. [•] Increased formation of esters and decrease formation of alcohols may explain fruit intensity. [Copyright &y& Elsevier]

• Monitoring MCPD esters and glycidyl esters with HS–SPME–GC–MS instead of liquid injection–GC–MS. • Derivatization, derivatives extraction and desorption with automated equipment. • Employing PBS in the derivatization system for the protection of the SPME fiber. • Screening parameters of SPME fiber with DSD prior to optimization with CCD. • Alkaline hydrolysis is less stable than acidic hydrolysis of MCPD esters. This study aimed to develop a headspace solid-phase microextraction gas chromatography–mass spectrometry (HS–SPME–GC–MS) method for the quantification of 3-monochloropropane-1,2-diol fatty acid esters (3-MCPDEs) and 2-monochloropropane-1,3-diol fatty acid esters (2-MCPDEs), and semi-quantification of glycidyl fatty acid esters (GEs) in edible oils. A central composite design was implemented to optimize the derivatization temperature and extraction time, which were 100 °C and 80 min, respectively. HS–SPME coupled with in-situ derivatization was more straightforward (three steps) and sensitive, with a limit of detection of 16% (3.9 µg/L) and 11% (5.3 µg/L) higher than that of liquid injection method, for 3-MCPD and 2-MCPD, respectively. The recoveries of 3-MCPD and 2-MCPD were in the range of 91.1% to 102.1%, with a relative standard deviation ranging from 0.08 to 9.29%. The validated methodology was successfully applied to oil samples. Further efforts will focus on shortening the extraction time, as 80 min is relatively long. [ABSTRACT FROM AUTHOR]