Effect of Oral Physiology Parameters on In-Mouth Aroma Compound Release Using Lipoprotein Matrices: An In Vitro Approach.

Temporal aroma compound release during eating is a function of the physicochemical properties of the food matrix, aroma compounds, and oral physiology of individuals. However, the influence of each parameter on the release of each aroma component should be clarified. Two flavored lipoprotein matrices varying in composition were chewed in a chewing simulator that reproduced most of the physiological functions of the mouth. Aroma compound releases (butanoic acid, 2-heptanone, ethyl butyrate, 3-octanone, and 2-nonanone) were followed in real time by direct connection of the device to APCI-MS (atmospheric pressure chemical ionization mass spectrometry). Each oral parameter was controlled and decoupled using the in vitro device. The food matrix composition had only a low impact on aroma compound release, but the controlled oral parameters had significantly different influences on the release of aroma compounds according to their physicochemical characteristics. The release of certain compounds seemed more sensitive to bite force, while others seemed more sensitive to the shearing angle. The salivary flow rate primarily influenced the more hydrophobic compounds. Significant interactions were also observed between shear angle, salivary flow rate, and lipoprotein matrix composition, mainly for the release of the more hydrophobic volatile compounds; this needs further investigations to be clarified.

Salt release monitoring with specific sensors in "in vitro" oral and digestive environments from soft cheeses.

The objective of the present work is to demonstrate the interest and the feasibility of the measurement of NaCl concentrations in soft cheeses and in particular an in vitro digestion process by the use of chemical sensors. The analyzed matrices were the commercial Italian mozzarella cheeses and domestic cheese base models. The classification of mozzarellas was performed according to their salinity, while the breakdown of cheese base models has been followed both at initial steps of digestion in artificial mouth dispositive mimicking the oral sphere and in a gut-imitating digester (TIM-1). During the breakdown of soft cheese in the digester, the estimated values for Na(+) concentration using mono-Na-ISEs showed correlation coefficients values about 0.907 and 0.832 compared to Ionic Chromatography (IC) reference values, with an important relative error (about 30-40%). The use of ISE array system combining several electrodes, in particular electrodes showing more selectivity to Cl(-) and Na(+) ions, showed the best results for Na(+) concentration estimation, with good correlations both in calibration (R=0.962) and in validation (R=0.952) steps. For cheese digestion in the artificial mouth, good correlations for Na(+) concentration were observed using single Na-ISE compared to IC with coefficients ranking between 0.93 and 0.96 for both the calibration and validation steps. Moreover, a fair correlation between chloride ions measured with Cl-ISE2 and Na(+) (R=0.96) was found. The best results were obtained with the use of ISEs array combining, in particular, Cl(-) and Na(+) detections. The salinity of commercial mozzarella cheese samples, as far as originally utilized milk type (cow or buffalo), were also satisfactory determined with developed ISE array.

Representativeness of extracts of offset paper packaging and analysis of the main odor-active compounds.

Packagings often carry odors due to the support and printing inks. The aim of the investigation was to define a representative solvent-free extract of paper-based packaging materials printed by the offset process, for the identification of the odor-causing volatile compounds. Static headspace and solid-phase microextraction were the two applied extraction methods. Representativeness tests showed that the odor of the PDMS fiber extract gave satisfying odor similarities with the original packaging. The sample incubation was performed at 40 degrees C for 30 min, whereas the extraction time was 3 min at 40 degrees C. Extracts of both the nonprinted and printed papers of different batches were analyzed by gas chromatography-olfactometry. 4-Phenylcyclohexene was identified as the most potent compound contributing to the latex-like odor of the nonprinted paper. Among the 13 major odorants identified by mass spectrometry, 10 were aldehydes and ketones generated by oxidation of the printing ink resins. The ratio of odorants to interferences was too low for a possible detection of the key odorants by nonseparative techniques such as sensor arrays.