Effects of different packaging materials on the qualities of Lapsang Souchong black tea during storage

Aiming to explore the effects of four commonly used tea packaging materials, including aluminum foil bag, kraft paper bag, aluminum foil-kraft paper bag, and corn fiber bag, on the qualities of Lapsang Souchong black tea during storage, samples were stored at 40 ℃ for eight weeks, and were taken for sensory evaluation and determination of contents of water, tea polyphenols, soluble proteins, free amino acids, and infusion color and aroma at the 1, 2, 4, 6 and 8 weeks. Orthogonal partial least squares-discriminant analysis (OPLS-DA) was used to compare the effects of different packaging materials on aroma components in detail. The results showed that the four kinds of packaging materials had effects on preventing the increase of water content and decrease of tea polyphenol, soluble protein and free amino acid contents. Aluminum foil-kraft paper bag had the best effect on the sample storage quality, and aluminum foil and kraft paper bags had similar effects, and corn fiber bag had the worst effect. However, compared with the unpackaged control tea samples, the protective effects of packaging materials on the above indicators were relatively limited. The packaging materials had obvious influence on aroma retention, and the aluminum foil-kraft paper had the best effect. The aroma sensory score increased first and then decreased, and the optimal aroma sensory of tea in four packaging materials appeared at different time points. This study showed that none of the four commonly used black tea packaging materials could effectively slow down the overall quality deterioration of Lapsang Souchong black tea in this storage model. It’s necessary to use some fresh-keeping measures for the preservation of Kungfu black tea as green tea and oolong tea.