Authors
Title
Abstract
The objective of this study was the sensory and spectral assessment of spirits beverages, such as vodka, gin, whisky, and brandy that underwent a process of lyophilisation. Freezed samples of spirit beverages (-80 ºC) were lyophilized in an ALPHA1-4 LDC-1m (Christ company) lyophilizator. The process parameters were constant, i.e.: pressure: 63 Pa; safety pressure: 103 Pa; time: 1.5 h. The sensory analysis was conducted using a profiling method with uni-polar category scale. Infrared spectra of freeze-dried liquid materials were registered by a transmittance method with the use of KRS crystal plates in the classic spectral range of 4000 – 370 cm-1. The spectral data were analyzed by a discriminant analysis module of the Omnic 8 software. With the process parameters applied, ethanol was the first to evaporate and, therefore, the obtained mixtures were alcohol-free. Thus, the lyophilisation process can be a gentle way to remove ethanol and water from a mixture and, at the same time, to save other important ingredients, such as dyes, flavours, or aromas.
Keywords
freeze-drying, spirit beverages, FT-IR spectroscopy