Correlation between Off-flavor and Morphology of Papaya (Carica papaya L.) Fruits

Abstract

Aims: To investigate the correlation between fruit morphology and off-flavor characteristics which are naturally present in papaya. Place and Duration of Study: Department of Food Science and Technology (Sensory Laboratory and Food Analysis Services Laboratory), Centre for Tropical Horticulture Study (Chemistry Laboratory) and Indonesian Centre for Rice Research of Indonesian Agriculture Ministry (Flavor Laboratory), between December 2014 and September 2015. Methodology: Morphology descriptions of 6 papaya varieties, i.e. “Carisya”, “Callina”, “Sukma”, “Merah Delima”, “Burung” and “Bangkok”; off-flavor description using Quantitative Descriptive Analysis; semi-quantification of volatile compounds by using Headspace Solid-Phase Micro-Extraction and Gas Chromatography-Mass Spectrometry have been conducted. Results: The stinky-sour odor had positive correlation with the presence of butanoic acid (r=0.879) and octanoic acid (r=0.876). The stinky-sour odor had negative correlation with the weight (r= -0.836), length (r= -0.873), flesh thickness (r= -0.887), and ripe peel color (r= -0.838) in accordance to the octanoic acid content which showed negative correlation to fruit weight (r= -0.871), length  (r= -0.830) and ripe peel color (r= -0.911). The stinky-sour odor as well as the concentration of butanoic and octanoic acid were most dominant in “Burung” and “Carisya” papayas. “Callina” and “Sukma” papayas had the weakest off- flavor intensity. Conclusion: The off-flavor perception of papaya was dominated by stinky-sour odor. The presence of octanoic acid might deliver synergism impact to butanoic acid in giving the perception of stinky-sour odor. High concentration of octanoic acid and strong intensity of stinky-sour odor were closely related to the small type of fruit weight (650 g or less), short size fruit (16.5 cm or less), thin flesh (less than 3 cm), and papaya varieties with orangish ripe peel color. These phenomena can be utilized in selection process in the field selection criteria to breed favorable papaya varieties.