I. Introduction
William pears (known as ‘Bartlett’ pears in North America) are harvested as they mature and reach the specific firmness, starch, and sugar content. At that time, they are resistant to ripening and could fail to reach the best texture, color, and flavor. There exist very important post-harvest factors which should be considered in the supply chain during storage period [1]. Before pears are commercially available, temperature and ethylene conditioning are used to stimulate fruit ripening to improve eating quality [2]. After the harvest, fruit maturity is determined by various methods that include fruit firmness, sugar and starch content, ground color, ethylene emission, and others. Flesh firmness is considered a reliable maturity parameter [3], since it is easily measured and adequately reflects the overall physiological state of the fruit. Author Streif [4] proposed the method that employs an index calculated as [firmness/(soluble solids starch index)], in which firmness is given in Newtons (N), sugar content as the refractometer value in percentage Brix (%) and the starch content as the starch patterns on a scale from 1 to 10. The storage duration in the supply chain before the availability for purchase is also important. Normally, ‘William’ pears are ready to eat after 2.5 to 7 days of storage at 20 °C when firmness reaches 14 N [5]. Another study from [6] provides slightly different results for firmness measured at harvest of 84.15 N and after storage and additional 8 days of shelf life at 20 °C it reaches 26.68 N.