The vitamin C content of some kiwifruits ( Actinidia chinensis planch., variety hayward)

Abstract

Skin, outer pericarp, inner pericarp and core, respectively comprised 4·8, 43·7, 45·0 and 6·5% of a mean whole kiwifruit weight of 111·3 ± 1·3 g. Kiwifruit weights ranged from 99·0 to 125·3 g. Vitamin C content per 100 g edible flesh ranged from 37·8 to 53·6 mg with means of 43·7 ± 1·7 mg for total vitamin C,41·9 ± 1·5 mg for ascorbic acid (AA) and 1·7 ± 0·4 mg for dehydroascorbic acid (DHA). Vitamin C contents were found to be at least half previously reported contents, possibly due to losses during storage and transportation from New Zealand. Total vitamin C concentrations per 100 g of skin, outer pericarp, inner pericarp and core were 41·7 ± 3·1 mg, 42·9 ± 2·0 mg, 45·5 ± 2·3 mg and 42·3 ± 2·6 mg, respectively. Outer and inner pericarp contained similar concentrations of both AA with 40·7 ± 1·7 mg and 42·7 ± 2·1 mg, and DHA with 2·1 mg and 2·8 ± 0·7 mg per 100 g tissue, respectively. Skin and core contained lower concentrations of AA with 28·1 ± 2·4 mg and 31·1 ± 2·2 mg, and correspondingly higher contents of DHA with 13·5 ± 2·4 mg and 11·2 ± 1·3 mg per 100 g tissue, respectively. Whole fruit weight correlated with DHA concentration in both skin ( r = −0·644) and core ( r = −0·693).