The effect of packaging conditions and storage time on the volatile composition of Assam black tea leaf

Black tea leaf, vacuum packed in Assam and subsequently repacked in the UK in standard air packs, under vacuum or nitrogen-xushed, was stored for up to 48 weeks. The volatile composition of the tea was assessed at zero time, after 16 weeks and 48 weeks. Six compounds were identiwed as signiwcantly diverent at 16 and 48 weeks when compared with the zero time sample (p < 0.001). These were identiwed as hexanal, trans-2-octenal, trans, cis-2, 4-heptadienal, trans, trans-2, 4-heptadienal, β-cyclocitral and β-ionone, the level of these being at an increased level in the standard air pack and similar to the zero time sample in the vacuumdash and nitrogen-xushed packs. These results are consistent with oxidative deterioration of the tea during storage. Subsequent canonical variate analysis was carried out using these six volatiles. Results indicated clear discrimination between the samples, in particular between the standard air packs and the other samples. This overs the potential of using these compounds as indicators of tea aroma quality and as a means of distinguishing between tea samples based on exposure time in air.