Influence of 1-Methylcyclopropene and Storage Atmosphere on Changes in Volatile Compounds and Fruit Quality of Conference Pears

Abstract

Conference pears (Pyrus communis L.) were treated with 25 and 50 nL L(-1) 1-methylcyclopropene (1-MCP) at -0.5 degrees C for 24 h, then stored for up to 22 weeks in air (NA) and controlled atmosphere (CA). After 7 and 14 weeks of storage, fruits were retreated with 1-MCP. After 7, 14, and 22 weeks of storage, fruits were kept for up to 7 days at 20 degrees C in air for poststorage ripening. The effects of 1-MCP treatment declined with duration of storage in both storage atmospheres, indicating that retreatments had little additional effects on subsequent ripening. Ethylene production was lower and firmness was higher in 50 nL L(-1) fruits, while the 25 nL L(-1) dose was not very different from the control. Development of superficial scald was not prevented by 1-MCP treatments, but the severity of the symptoms was influenced. The 1-MCP effects were perceivable on texture (juiciness) and flavor. Control fruit and 25 nL L(-1) fruit reached their best sensory quality after 14 weeks of storage, while 50 nL L(-1) fruit reached the same sensory quality later, keeping a fresh flavor when the quality of control fruit declined and became watery or grainy. The fresh flavor in 50 nL L(-1) fruit was probably due to the presence below the odor detection threshold concentrations of the volatile compounds responsible for the "ripe pear" aroma, mainly of butanol and ethyl butanoate. CA prolonged or enhanced the effects of 1-MCP; 1-MCP cannot substitute for CA but can reinforce the CA effects.

Ethylene Production and Quality in 1-Methylcyclopropene Treated 'Abbé Fétel' Pears After Storage in Dynamically Controlled Atmosphere

“…A sample of 20 fruit was analysed for ethylene production (EP) and skin colour after 1, 3 and 7 d of shelf life and for flesh firmness at 1 and 7 d. EP was measured on single fruit put into a 1.7 L gastight glass jar for 1h at 20°C, sampling 1 ml of the headspace gas and analysing it by GC according to Rizzolo et al (2005). EP was expressed as pmol/kg/s.…”

Avaliação do uso de inibidores de etileno sobre a produção de compostos voláteis e de mangiferina em manga

“…[6][7][8][9][10] Em testes sensoriais, a preferência do consumidor pelas maçãs 'Anna' e 'Gala' mostrou-se controversa, enquanto que a aceitação de peras 'Conference' não foi afetada. 7,8 O mecanismo de ação pelo qual inibidores de etileno influenciam a biossíntese de compostos voláteis ainda é desconhecido, porém se acredita que algumas enzimas responsáveis pela formação de compostos odoríferos sejam inibidas. 19 Em melões e bananas 'Williams', a queda na produção de ésteres e concomitante elevação no conteúdo total de alcoóis sugeriram inibição da enzima álcool-aciltransferase.…”

“…4 AVG e 1-MCP afetaram a produção total de compostos voláteis (terpenos, cetonas, aldeídos, ésteres e alcoóis de baixo peso molecular) em banana, maçã, pera, melão e manga, sendo que alguns deles são componentes odoríferos característicos do aroma e do sabor destas frutas. [5][6][7][8][9][10] Em morango, pera, abacaxi e manga, inibidores de etileno também afetaram os teores de substâncias bioativas (ex. : vitamina C e flavonoides), 2,11,12 as quais são hoje amplamente valorizadas pela população devido às suas propriedades benéficas à saúde.…”

Effect of controlled atmosphere storage on production of volatiles and ethylene from cv. Zaosuli pears

“…The effects of low oxygen combined with considerably higher than normal CO 2 levels, accompanied by subsequent exposure to temperatures of 18°C, do not lead to a significant softening of the flesh. In contrast, the ripening of European pears is usually characterized by softening (Suwanagul, Richardson 1998;Argenta et al 2003;Hiwasa et al 2003) and changes in aroma (Rizzolo et al 2005;Chiriboga et al 2011;Makkumrai et al 2014), with corresponding changes in levels of sugars, organic acids and the production of volatiles.…”