RIPENING OF 'ALEXANDER LUCAS' PEARS FOLLOWING REGULAR ATMOSPHERE WITH OR WITHOUT 1-MCP TREATMENT COMPARED TO CONTROLLED ATMOSPHERE

Abstract

The aim of this research was to evaluate the effect of regular atmosphere (RA) with or without 1-MCP treatment, and of controlled atmosphere storage (CA), on the ripening of ‘Alexander Lucas’ pears from two harvest maturities. The treatments were: T1: regular atmosphere (RA) (0±0.1°C, 21.0 kPa O2 + <0.03 kPa CO2); T2: RA + 1-MCP (300 nl L-1); and T3: controlled atmosphere (CA) (0±0.1°C, 2.0 kPa O2 + <0.7 kPa CO2). Pears were picked at two harvest dates (Streif-Index of 0.15 and 0.08 for the first and second harvest, respectively). After three months of storage plus seven days at ambient conditions the fruit were evaluated for flesh firmness, skin colour (h°), total soluble solids (TSS), titratable acidity (TA), ethylene production, respiratory rate and internal flesh browning. Fruit stored in RA + 1-MCP maintained higher firmness and greenest fruits for both harvest dates. In addition, fruit from the first harvest date stored in RA + 1-MCP had higher TSS concentration. The respiratory rate was reduced and ethylene production was dramatically inhibited in fruit in RA + 1-MCP. Pears stored in CA showed high occurrence of internal flesh browning and highest yellowing in comparison to other storage conditions. ‘Alexander Lucas’ pears treated with 1-MCP and stored for three months in RA can be harvested at a more mature stage (Streif-Index of 0.08) without compromising the quality of the fruit. The storage of ‘Alexander Lucas’ pears for a period of three months in RA with application of 1-MCP maintained fruit quality and prevented occurrence of internal flesh browning in comparison to CA storage. However, fruit in RA treated with 1-MCP needed longer period of cold storage or at ambient conditions (shelf life) to develop a buttery texture and skin yellowing. Storage of ‘Alexander Lucas’ pears under CA increased fruit susceptibility to internal flesh browning.