| Although the use of bag-in-box (BIB) for wine packaging has increased over the past decade, information on the effects of the semi-rigid package on the enological parameters of wine product, especially due to oxygen ingress, is limited. In this study, changes of enological parameters of BIB white wines were investigated as a function of storage time and temperature. The increase in browning during storage, as measured by absorbance at 420 nm (A420), correlated negatively with free and total SO2 contents. Total phenol content correlated negatively with total aldehyde content. Partial least squares (PLS) models derived from the Fourier transform infrared spectral data of wine samples predicted concurrently the wine enological parameters (A420, free SO2, total SO2, total phenol, and total aldehyde) and storage time, with acceptable accuracy.;Gas chromatography (GC) was also employed to analyze wine volatiles using a dichloromethane microextraction technique. Principal component analysis of the volatile fingerprints showed grouping trends that were influenced by storage time and temperature, and revealed that changes in chemical profiles were different for wines held at different temperatures. PLS regression of GC peak table data predicted accurately the enological parameters and storage time except for the SO2 at 22°C and total phenol at 45°C. When the entire chromatograms were used for PLS regression, storage time, color and total aldehyde were well predicted, while the predictions for free SO2, total SO2, and total phenol were acceptable.;Most of the mass transport studies in the literature have been focused on single compound diffusion in thermoplastic film. However, this approach is not realistic since the existence of multiple permeants may affect the diffusion behavior of the permeating compounds. In this research, an FTIR-ATR technique was developed to investigate the simultaneous diffusion of selected wine volatile compounds (2-octanone, hexyl acetate, octanal, limonene, and linalool) in a linear low density polyethylene film. Compared to the diffusion of the individual permeant, in the mixture solution, the diffusivity values of 2-octanone, hexyl acetate and limonene were lower while those of octanal and linalool were higher. Hansen solubility parameter concept was invoked to explain the diffusion behaviors of the permeants tested. |
