Sensory and quality characteristics of ‘Ambrosia’ apples in relation to harvest maturity for fruit stored up to eight months

Abstract

‘Ambrosia’ apples are well recognized for their sweet fruity attributes and quality characteristics. Generally fruit are harvested to ensure optimal quality throughout the storage period, with little regard for sensory attributes. Therefore, this research was undertaken to explore the sensory characteristics associated with fruit harvested at four different maturities, treated with or without 1-MCP, and held under high or low O2 controlled atmosphere (CA) storage, for 0-, 5- and 8-months. Descriptive analysis was used to profile the textural (crispness, hardness, juiciness, skin toughness) and taste/flavor (sweetness, tartness, fruity ‘Ambrosia’ flavor, green flavor) attributes using a panel of six trained judges in duplicate. Quality indices (non-destructive fruit firmness, soluble solids, titratable acidity) were determined. Analysis of variance (ANOVA) and canonical discriminant analysis (CDA) were used to discern sensory (textural, taste/flavor) differences among the harvest maturities and storage times, incorporating flavor attributes (fruity ‘Ambrosia’ flavor, green flavor) that have not previously been reported. ANOVA and CDA revealed a decline in green flavor, tartness and hardness and an increase in fruity ‘Ambrosia’ flavor and sweetness, with increasing harvest maturity. Concomitantly, there was a systematic decline in ‘Ambrosia’ flavor and sweetness with increasing storage time. Although ‘Ambrosia’ flavor could be enhanced by postponing harvest, it was reduced with storage, especially with extended storage (8-months). Fruit textural characteristics (crispness, hardness, juiciness, skin toughness) were better after 5- rather than 8-months, and deteriorated quickly in the last three months. Textural attributes (crispness, hardness, juiciness) were positively correlated with each other, and negatively correlated with skin toughness. Skin toughness substantially influenced the perception of textural attributes. The work revealed the need for better analytical tools to quantify ‘Ambrosia’ flavor as well as to develop new instrumental methods to assess skin toughness and flesh juiciness.