The role of hydrolases in the loss of firmness and of the changes in sugar content during the post-harvest maturation of Carica papaya L. var solo 8

Abstract

Fruit ripening is associated with many hydrolase activities involved in the softening of the fruit during the maturation. This study investigates the relationship between the loss of firmness along with the changes of sugar content and the enzymatic activities in Carica papaya L.var solo 8 during post-harvest storage. Three maturation stages (green immature: the fruit is entirely green, green mature: the fruit shows 1/32 yellow skin and fully mature: the fruit shows 1/8 yellow skin) have been selected and stored at 15, 22 and 28°C. The reduction of fruit firmness, total sugar contents, refractive index (% Brix) and enzymatic activities were measured. Low enzymatic activities (0.035 μmol/min/mg) were recorded in fruit harvested at the green immature stage with no significant (p≥0.05) effect on the softening while fruit harvested at the green mature and fully mature stages showed enzymatic activities 7 times as high as those of the green immature stage. These high enzymatic activities were responsible for the loss of firmness of the fruit. Accordingly, papayas at the green mature and fully mature stages displayed higher maxima of sugar content (4.8 g/100 g at 28°C at day 12, and 10.2 g/100 g at 22°C at day 8, respectively) at higher temperatures. Meanwhile in green immature papayas, the maximum was only 4.3 g/100 g at 22°C and day 12 of storage. The results show that the loss of firmness of the papaya was highly related to the hydrolytic enzyme activities and the sweet taste to the presence of simple sugars such as galactose liberated from the polysaccharide complexes.

Sensory acceptance and qualitative analysis of fruits in papaya hybrids

“…This, in turn, due to the decomposition of the cell walls, increases the sugar levels in the cell. Besides, according to Yao et al (2012), it can explain the magnitude and direction of the correlation observed between PF and SS (-0.65). A similar result for this correlation (-0.81) was described by Oliveira et al (2012), but the authors did not explain the origin of such correlation.…”

Tratamento Com Cloreto De Cálcio Na Pós-Colheita Retarda O Desverdecimento E a Perda De Firmeza Do Mamão Uenf/Caliman01

“…Por ser um fruto que apresenta quantidadestraço de amido na polpa, a variação no teor de SS após a colheita é muito pequena e, quando ocorre, é resultado da degradação da parede celular, que aumenta a liberação de pectina solúvel nos espaços intercelulares, contribuindo com um ligeiro aumento no teor de SS (YAO et al, 2014). Apesar de a infiltração de CaCl 2 nos frutos ter resultado em manutenção da FF e FM por mais tempo que o observado para os frutos do controle (Figuras 3A e 3B), a partir do 9º DAT, essas apresentavam valores iguais ao dos frutos do controle, sem contudo provocar aumento no teor de SS.…”

“…O fato de o mamão não apresentar variações no teor de SS durante sua pós-colheita (YAO et al, 2014), indica que esse atributo pode não ser adequado para diferenciar o efeito da infiltração de soluções de CaCl 2 na pós-colheita do mamão, como o indicado por Valero e Serrano (2010).…”

Correlation among PME activity, viscoelastic, and structural parameters for Carica papaya edible tissue along ripening

“…The limitations of papaya marketing and distribution are associated with the softening phenomenon derived from the natural ripening process. One of the main challenges in papaya trading is related to its shelf‐life duration (Fabi, Cordenunsi, Seymour, Lajolo, & do Nascimento, 2009), so that the proper ripe stage selection for commercialization is relevant in the transport and storage of the fruit aiming to preserve its quality (Miller & McDonald, 1999; Yao et al., 2014).…”