title: Total, Soluble and Insoluble Oxalate Contents of Ripe Green and Golden Kiwifruit.
abstract: Three bulk samples of two different cultivars of kiwifruit, green (Actinidia deliciosaL.) and golden (Actinidia chinensisL.) were bought ripe, ready to eat from a local market. The aim of the study was to determine the oxalate composition of each of the three fractions of kiwifruit, namely skin, pulp and seeds. The pulp consisted of 90.4% of the edible portion of the two cultivars while the skin and seeds made up a mean of 8.0% and 1.6% respectively. Total oxalate was extracted with 2.0 M HCL at 21 °C for 15 min and soluble oxalates extracted at 21 °C in water for 15 min from each fraction. The total and soluble oxalate compositions of each fraction were determined using ion exchange HPLC chromatography. The pulp of golden kiwifruit contained lower amounts of total oxalates (15.7vs.19.3 mg/100 g FW) and higher amounts of soluble oxalates (8.5vs.7.6 mg/100 g FW) when compared to the green cultivar. The skin of the green cultivar contained lower levels of insoluble oxalates (36.9vs.43.6 mg/100 g FW), while the seeds of the green cultivar contained higher levels of insoluble oxalates 106.7vs.84.7 mg/100 g FW.
authors.affiliation: Food Technology Department, Biotechnology School, International University, Ho Chi Minh City, 70000, Vietnam. nvhha@hcmiu.edu.vn.
authors.forename: Hà Vũ Hồng
authors.initials: HV
authors.lastname: Nguyễn
authors.affiliation: Food Group, Department of Wine, Food and Molecular Biosciences, Agriculture and Life Sciences, Lincoln University, Lincoln 7647, Christchurch, New Zealand. savage@lincoln.ac.nz.
authors.forename: Geoffrey P
authors.initials: GP
authors.lastname: Savage
keywords: golden kiwifruit (Actinidia chinensis L.); green kiwifruit (Actinidia deliciosa L.); total, soluble and insoluble oxalates