Morphological and Chemical Properties of Medlar (Mespilus Germanica L.) Fruits and Changes in Quality During Ripening

Abstract

Medlar has acquired increasing popularity in recent years for its edible fruits and some healing properties in modern medicine. Medlar fruits are often stored under non-cold conditions in straw. This study was conducted to determine morphological and biochemical characteristics of medlar fruits and changes in fruit quality occurring under ordinary storage conditions. For this purpose, eight types of medlar trees were evaluated. The trees were at a mature stage and productive. Morphological properties such as the fruit and seed weight (g), length, and width (mm) were measured after the harvest. Fruit soluble solid content (%) and pH values were determined at physiological maturity after harvesting, and the fruit soluble solid content was measured again at ripening (edible stage), after 25 days of storage under ordinary storage conditions (mean temperature of 10 °C and mean humidity of 65-70%). Leaf characteristics were also determined. The tree productivity was very different between the types, and it was determined to range from 5.9 and 17.8 kg. The fruit weight varied from 9.69 to 24.45 g, while the water content decreased nearly to the half of the harvest values in some genotypes. The soluble solid content changed depending on the water losses and increased during the ripening period. The seed numbers ranged from 1.7 to 4.7 among the types, and the seed weight varied from 0.12 to 0.45 g. The fruits were able to reach ripening maturity in three weeks under the ordinary storage conditions depending on the type. Thus, this method of storage is practical for the medlar producer, but the results clearly showed that the storage period was too short and that the fruit quality was negatively affected. Cold storage conditions are needed to ensure quality and a long selling time.

Medlar—A Comprehensive and Integrative Review

“…The differences in the number of DAFB result from the starting date of the accounting days (10 May, 10 June, 8 May, and 10 May, respectively) [1,34,35,44]. Only Sulusoglu-Durul and Unver [53] did not use the same measure for the ripening stage. However, 25 days after harvest, they observed the same changes as other authors, meaning darkening, softening, dehydration, and flavor development of the fruits.…”

“…Thus, the fruit is a climacteric one, harvested in October and November and stored (in cold, dark, and aerated conditions, optionally in straw) until it becomes edible in the winter; the complex ripening process is genetically determined [4,39,45]. The green and hard flesh of the fruit softens and changes its color to light brown [53]. The result of this process includes major changes in texture, color, flavor, and aroma [39], resulting in brown (the pulp darkens), softened, and sweeter fruit.…”

“…The result of this process includes major changes in texture, color, flavor, and aroma [39], resulting in brown (the pulp darkens), softened, and sweeter fruit. The inconveniences of this process include decreasing shelf-life and loss of marketable value [1,53]. Fruit shape may vary and generally include sub-globose or pyriform fruits crowned by foliaceous sepals [1,6].…”

“…However, 25 days after harvest, they observed the same changes as other authors, meaning darkening, softening, dehydration, and flavor development of the fruits. Moreover, out of all the research papers, Sulusoglu-Durul and Unver [53] are the only ones that mentioned tree productivity, which ranged between 5.9 and 17.8 kg (province of Kocaeli, in Northwestern Turkey). As a result, from various research articles, the main morphometric characteristics of Mespilus germanica L. plant parts (fruits and stone) are presented in Table 4.…”

“…The main difference between the genotypes is related to their average weight that ranged between 2.9± 0.1 g (at 39 DAFB, unripe stage) [36] and 40,80 g. Several authors [32,41,53] observed that even if there were important differences in fruit weight, diameter, and length (all these parameters being influenced by the genotype), there were no important differences by different years in measurement. Sulusoglu-Durul [53] observed that the fruit weight varied from 9.69 to 24.45 g and the seed numbers ranged from 1.7 to 4.7 among the genotypes. In addition, during the ripening period, some fruits lost their commercial value.…”