QUALITY EVALUATION OF SIX RAMBUTAN HYBRIDS STORED AT 25 AND 10°C

The fruits of six hybrids selection of rambutan (Nephelium lappaceum L.) were characterized to identify those with marketing quality to promote their propagation, improvement and conservation in germplasm bank. Fruits were harvested from a MARDI’s farm at Bukit Tangga Station, Kedah. Assessments for physical changes comprise weight, thickness of flesh and skin, breadth, length, and flat shape of fruits, length of spinterns, and colour of skin and flesh. Chemical analysis includes total soluble solids, pH and titratable acidity. Sensorial quality was conducted by fifty panelists who graded each selection for colour, shape, sweetness, acidity and overall acceptability. The shape of six selections were ovoid, and with the following characteristics (in ranges); fruit weight, 29.16 to 42.38 g; fruit length, 41.80 to 47.59 mm; fruit breadth, 34.28 to 42.35 mm; fruit flat shape, 30.96 to 38.63 mm; thickness of the skin, 2.16 to 3.63 mm; thickness of flesh, 6.04 to 8.78 mm; and length of spintern, 0.71 to 1.21 cm. The fruits had high contents of total soluble solids (16.63 to 20.17°Brix), vitamin C (21.94 to 26.47 mg/100 g), pH (4.45 to 5.28) and total titratable acidity ranging from 0.17 to 0.32%. The fruits from GB 44 and IE 20 selections had better attributes of fruit weight (32.50 and 42.38 g) as compared to the other hibrids. The GB 44 hybrid contained total soluble solids (20.07°Brix), desirable traits for export markets. The hybrid GB 44 was most preferred by panelists for its sweetness, less acidic, easier removal of testa seed and crunchier and firmer texture compared to the others. Different temperatures had significant influence on the rambutan quality. Rambutan fruits can be stored at 10°C for 10 days, whereas at ambient condition, the quality remained good for only 2 days.