Aroma components at various stages of litchi juice processing

Abstract

BACKGROUND: Considering the importance of flavour on the quality of litchi juice, a study was conducted on how processing and operating stages influence the aroma components of clear litchi juice during processing. RESULTS: The aroma fractions isolated by solid-phase micro-extraction were analysed by capillary gas chromatography-mass spectrometry. According to statistical analyses, the amount of total and seven characteristic aroma compounds (geraniol, citronellol, phenylethyl alcohol, D-limonene, nonanal, geranial and linalool) increased significantly after enzyme hydrolysis, but decreased significantly during the process of enzyme inactivation, ultra-filtration and sterilisation. CONCLUSION: The aromatic fraction of litchi juice decreased greatly during processing. The major losses in aromatic composition of clear litchi juice were related to the ultra-filtration and sterilisation processes. With regard to the retention of aroma, an ultra-filtration membrane with a larger pore size is better than a membrane with a smaller pore size, and a high-voltage pulsed electric field was better than thermal sterilisation. © 2009 Society of Chemical Industry.