Abstract:

Dried litchi was prepared by heat pump drying (HPD) at six different combinations of temperature and time or
hot air drying (HAD). Ttitratable acidity, rehydration ratio, total sugar, browning index, total phenols and volatile flavor
compounds of dried litchi by the two methods were analyzed. The results showed that the chemical and physical indexes,
except total phenol, of dried litchi processed by HPD was better than those of dried litchi processed by HAD. HPD-dried
litchi also had higher levels of volatile flavor compounds, including linalool, geraniol, citronellol and limonene.

Key words: litchi, heat pump drying, hot air drying, quality, gas chromatography-mass spectrometry (GC-MS)