Antioxidant and Colour in Selected Local Fruits

Abstract

Fruit pigments are associated with the presence of antioxidants. This study determined the content of antioxidant components (total phenolic content (TPC), ascorbic acid, beta carotene and lycopene) and colour in selected local fruits (papaya, watermelon, dragon fruit, wax apple, and jackfruit). The TPC, ascorbic acid, beta carotene and lycopene were determined spectrophotometrically. Ascorbic acid content was determined using the 2,6-Dichlorophenolindophenol (DCPIP) titration method. Colour was assessed by tristimulus colorimetry based on the reflection spectrum. Total soluble solids (TSS) were also determined. Papaya has TPC (61.86 mg GAE/100 g), ascorbic acid (31.14 mg/100 mL), lycopene (4.82 mg/100 g), beta carotene (19.98 mg /100 g), TSS (10.17 °Brix) and colour profile L*(41.30), a*(24.07), b*(26.48), chroma value (35.79) and hue angle (47.70°). Wax apple has TPC (94.20 mg GAE/100 g), ascorbic acid (11.13 mg/100 mL), lycopene (1.62 mg/100 g), TSS (10.00 °Brix) and colour profile L*(63.42), a*(0.42), b*(7.64), chroma value (7.66) and hue angle (86.69°). Dragon fruit has TPC (179.985 mg GAE/100 g), ascorbic acid (5.94 mg/100 mL), beta carotene (3.98 mg/100 g), TSS (10.30 °Brix) and colour profile L*(21.45), b*(0.66), chroma value (6.86) and hue angle (5.52°). Jackfruit has TPC (75.16 mg GAE/100 g), lycopene (2.31 mg/100 g), beta carotene (9.25 mg/100 g), TSS (20.43 °Brix) and colour profile L*(71.74), a*(5.79) and hue angle (82.98°). Watermelon has ascorbic acid (19.28 mg/100 mL), lycopene (36.55 mg/100 g), beta carotene (14.37 mg/100 g) and colour profile b* (12.36), chroma value (26.98) and hue angle (27.22°). The a* value has a significant positive correlation (p<0.05) with the content of ascorbic acid, lycopene, and beta carotene while the chroma value shows a negative correlation with the total phenolic content (p<0.05). The b* value showing a negative correlation with the total phenolic content (p<0.05). Local fruits can be a good source of nutrient, phytochemicals, and antioxidants.