Materials and Methods
Rawmaterials and preparation
The pennywort plants were freshly harvested, of commercial
maturity (2 to 4 mo), and obtained fromhigh altitude in Chiangmai,
Thailand. Upon arrival at the laboratory, they were washed with
running tap water to remove debris and damaged portions.
The leaves and petioles of pennywort were stripped from the
plant and extracted with water (1 : 1, w/v). This juice was filled
into a double layer of a LDPE stomacher pouch (Seward Limited,
West Sussex, U.K.) before HPP and filled into a retort
pouch (PET/nylon/aluminum/PP) (Royal Can Industries Co., Ltd.,
Bangkok, Thailand) before pasteurization and sterilization. Sucrose
10% was added to the juice before processing. The samples were
subjected to pasteurization (90 ◦C for 3 min), sterilization (121 ◦C
for 4 min) or HPP (400 MPa for 20 min at < 30 ◦C).