Sugars, ascorbic acid, total phenolic content and total antioxidant activity in passion fruit (Passiflora) cultivars
Correspondence to Shiamala Devi Ramaiya, Department of Animal Science and Fisheries, Faculty of Agriculture and Food Sciences, Universiti Putra Malaysia Bintulu Sarawak Campus, 97008 Bintulu, Sarawak.
The levels of sugars, ascorbic acid, total phenolic content (TPC) and total antioxidant activity (TAA) were determined in fruit juices from seven passion fruit (Passiflora spp.) cultivars: P. edulis cultivars Purple, Frederick, Yellow, Pink, P. edulis f. flavicarpa, P. maliformis and P. quadrangularis (we also tested this cultivar's mesocarp).
Purple and Yellow P. edulis had significantly higher total sugar, 142.85 ± 0.17 g kg−1 and 139.69 ± 0.12 g kg−1, respectively, than other cultivars. Glucose and fructose content were higher in juice from vine-ripened fruits of Purple, Frederick and Yellow P. edulis, P. quadrangularis and P. maliformis. Sucrose content was significantly higher in juice of non-vine-ripened fruits of P. edulis (Pink) and P. edulis f. flavicarpa. Ascorbic acid, TPC and TAA were significantly higher in vine-ripened Purple and Yellow P. edulis; ranges were 0.22–0.33 g kg−1, 342.80–382.00 mg gallic acid equivalent L−1 and 409.13–586.70 µmol Trolox L−1, respectively. Based on principal component analysis (PCA) and cluster analysis, the main variables – °Brix, total sugar, glucose, fructose, ascorbic acid, TPC and TAA – formed the characteristics for the group comprising Purple and Yellow P. edulis.
Glucose, fructose, sucrose, ascorbic acid, TAA and TPC were quantified in passion fruit juices. Variation of the above variables in juices of Passiflora depends on the cultivar and ripeness.