Tuesday, August 9, 2016: 2:00 PM
Macon Room (Sheraton Hotel Atlanta)
European pears (Pyrus communis) are enjoyed by consumers when fruit have ripened to a buttery-juicy texture with full development of flavor. However, pears available to consumers are often irregular in their ripening capacity and eating quality. ‘d’Anjou’ pears are resistant to ripening at harvest and generally require exposure to ethylene gas or to chilling temperatures in order to develop the capacity to soften when purchased by consumers. After gaining the capacity to soften, however, ‘d’Anjou’ pear fruit may develop either buttery-juicy (melting) texture or dry-coarse (mealy) texture depending on pre- and postharvest conditions. The underlying cell metabolic mechanisms leading to melting or mealy texture are still not known. Flesh firmness (FF) is not always a good indicator of the potential for developing melting texture. In this study, we found that water soluble polyuronide (WSP) content was positively correlated with the development of melting texture, and an objective index for the melting texture (MTI) based on extractable juice content was developed. Fruit harvested at FF between 66 and 62 N developed a melting texture in 7d at room temperature following 3-5 months in regular air (RA) and 3-8 months in controlled atmosphere (CA) (1.5% O2 + < 0.05% CO2) at -1.1 °C. They developed a mealy texture after 6 months in RA and after 9 months in CA. Pears harvested at FF between 57 and 53 N had a shorter melting texture storage life, from 2-4 months in RA and 2-6 months in CA. Pears harvested with FF between 66 and 62 N developed better melting texture (determined by WSP, MTI, and sensory evaluation) after cold storage than those harvested between 57 and 53 N. Fruit harvested between 75 and 70 N developed good melting texture, but inferior flavor and unacceptable shriveling during storage. Fruit harvested with accumulated cold units (ACU) > 200 h tended to develop better melting texture than fruit with ACU < 200 h.