Abstract:
This work aimed to assess the impact of sonication (US), osmosonication (US + OD) and vacuum-assisted
osmosonication (V + US + OD) pretreatments on the quality of Ghanaian garlic prior to relative humidity
convective drying. Hence, slices of fresh garlic subjected to US, US + OD and V + US + OD pretreatments were
dried and the following assessed: antioxidant activities, total phenolic content (TPC), total flavonoid content
(TFC), polyphenol oxidase (PPO) enzyme inactivation, rehydration ratio (RR), drying kinetics, energy consumption,
chromatographic fingerprinting, allicin content and Fourier-transform infrared (FT-IR) spectroscopy.
V + US + OD pretreatment gave the best results for antioxidant activities, TPC, TFC, RR and PPO enzyme
inactivation. It also recorded the shortest drying time and was more energy efficient. Finally V + US + OD
pretreatment maintained the chemical integrity of the finished product and recorded the highest content of
allicin. A general trend was however observed for all quality parameters assessed for the various pretreatment
methods as: V + US + OD > US + OD > US.
