EFFECT OF TEMPERATURE AND 1-METHYLCICLOPROPENE ON THE STORABILITY OF ‘ALEXANDER LUCAS’ PEAR | EFEITO DA TEMPERATURA E 1-METILCICLOPROPENO NA CONSERVAÇÃO DE PERA ‘ALEXANDER LUCAS’

English. The storage life of ‘Alexander Lucas’ pear is limited by the occurrence of internal storage disorders during controlled atmosphere. 1-Methylcyclopropene (1-MCP) can be used to delay pear ripening, however, its interaction with controlled atmosphere (CA) storage conditions is not well understood. ‘Alexander Lucas’ fruit were treated with 1-MCP at 300 nL L-1 for 24 h in air at -0.5 or 1.0 °C before storage. Fruit were kept at -0.5 or 1.0 °C in normal air or CA (2.0 kPa O2 plus <0.7 kPa CO2). After six months storage, superficial scald did not develop. The highest incidence of flesh browning (72.2 %) was scored in air-stored fruit at -0.5 °C without 1-MCP. Storage in air at 1.0 °C plus 300 nL L-1 1-MCP kept 88.8 % of the fruit healthy. In contrast, 1-MCP increased the incidence of flesh and core browning under CA conditions. 1-MCP and CA maintained greener skin color and higher titratable acidity. No significant differences were found in fruit firmness, total soluble solids and ascorbic acid content between the different treatments. In conclusion, the quality of ‘Alexander Lucas’ pear was best maintained during six months storage in normal air at 1.0 °C combined with 300 nL L-1 1-MCP treatment. The storage life of ‘Alexander Lucas’ pear is limited by the occurrence of internal storage disorders during controlled atmosphere (CA). 1-Methylcyclopropene (1-MCP) can be used to delay pear ripening, however, its interaction with CA conditions is not well understood. ‘Alexander Lucas’ fruit were treated with 1-MCP at 300 nL L-1 for 24 h in air at -0.5 or 1.0 °C before being stored. Fruit were kept at -0.5 or 1.0 °C in normal air or CA (2.0 kPa O2 plus <0.7 kPa CO2). After six months of storage, superficial scald did not develop in fruit. The highest incidence of flesh browning (72.2 %) was found in air-stored fruit at -0.5 °C without 1-MCP treatment. Storage in air at 1.0 °C plus 300 nL L-1 1-MCP produced 88.8 % of healthy fruit. In contrast, 1-MCP increased the incidence of flesh and core browning under CA conditions. 1-MCP and CA maintained greener skin color and higher titratable acidity. No significant differences were found for fruit firmness, total soluble solids and ascorbic acid content between the treatments. In conclusion, the quality of ‘Alexander Lucas’ pear was best maintained during six months storage under normal air at 1.0 °C combined with 300 nL L-1 1-MCP treatment.

Portuguese. O tempo de armazenamento da pera ‘Alexander Lucas’ é limitado pela ocorrência de distúrbios fisiológicos, principalmente quando em atmosfera controlada (AC). O 1-metilciclopropeno (1-MCP) pode ser usado para retardar o amadurecimento das peras, no entanto, sua interação quando usado em  AC não está bem compreendida, podendo por um lado, retardar o processo de amadurecimento e preservação da qualidade do fruto, mas por outro lado, podendo agravar a ocorrência de desordens fisiológicas em AC. Frutos da cultivar ‘Alexander Lucas’ foram tratados com 300 nL L-1 de 1-MCP por 24 h em armazenamento refrigerado (AR) nas temperaturas de -0,5 ou 1,0 °C, antes do armazenamento. Os frutos foram mantidos a -0,5 ou 1,0 °C em AR ou AC (2,0 kPa O2 + <0,7 kPa CO2). Após seis meses de armazenamento, não ocorreu escaldadura superficial. A maior incidência de escurecimento da polpa (72,2 %) foi observada em frutos armazenados em AR a -0,5 °C sem tratamento com 1-MCP. O armazenamento em AR a 1,0 °C mais 300 nL L-1 1-MCP manteve 88,8 % dos frutos sadios. No entanto, o uso de 1-MCP aumentou a incidência de escurecimento da polpa e do miolo quando em condições de AC. 1-MCP e AC mantiveram a coloração da casca mais verde e maior acidez titulável. Não foram encontradas diferenças na firmeza de polpa dos frutos, nos sólidos solúveis totais e na concentração de ácido ascórbico. Concluiu-se que, a qualidade da pera ‘Alexander Lucas’ se conservoumelhor durante seis meses de armazenamento em AR a 1,0 °C com a aplicação de 300 nL L-1 de 1-MCP.