Studies On The Development Of Cuticle Membrane And Its Relationship With Fruit Cracking In Jujube Fruits

Jujube fruit cracking is a physiological phenomenon that occurs when rain falls during fruit development.Cracked fruit loses its commercial value and can cause huge economic losses.The changes of the cuticular membrane(CM)and mechanical properties during the development of jujube fruit were analyzed and the relationship between the characteristics of cuticular membrane(CM)in jujube fruit surface and the fruit cracking was clearly defined.In this study,three jujube varieties with different cracking properties were used as test materials.The development and biomechanical characteristics of the cuticle membrane were studied by enzymolysis and texture analysis.The composition,effects and mechanical properties of the cuticular membrane(CM)were studied.Understanding the role of CM deposition and surface expansion provides a reliable theoretical basis for understanding and controlling the factors such as CM synthesis,circulation and deposition that affect in the fruit cracking characteristics.The results show:1 The growth trend of the CM per unit area of the three varieties jujube was the same and all decreased after the expanding period.2 The main components of the outer wax of the three jujube fruits are the same but the proportions occupied by different components are different.The percentage of fatty acids and alcohols contained in outer wax of Popozao and Hupingzao was highest in young fruit period.The proportion of fatty acids in outer wax of Popozao,Banzao and Hupingzao were the highest in coloring period and full-red period.3 The ?ix/t of Hupingzao was significantly higher than that of Popozao and Banzao during the young period in the shoulder region.Moreover,the ?iy/t and ?ixy/t of Hupingzao was significantly higher than those of Popozao during the white-ripen period and the coloring period.?ix/t of Popozao and Banzao were significantly higher than Hupingzao duiring the young period in cheek region and ?ix/t of Hupingzao was significantly higher than those of the Popozao during white-ripen period and coloring period.The ratio of CM strain of different jujube varieties showed a difference.4 The width,length and area of the cuticles membrane of Popozao during the coloring period of the fruit shoulder region were significantly higher than those of Banzao and Hupingzao;the width of the CM of the Popozao in cheek region during the coloring period was significantly higher than that before the separation.However,the top region of the Popozao during the coloring period width,length and area accounted for the ratio before separation was significantly higher than Hupingzao;5 The pericarp break distance of Hupingzao at the shoulder region during the expanding period and coloring period were significantly higher than that of Popozao and Banzao.The pericarp toughness of Hupingzao in the cheek region during the coloring period was significantly higher than that of Popozao and Banzao.The brittleness of Popozao and Banzao in the top region was significantly greater than that of Hupingzao during the coloring period.Brittleness of Popozao during half-red period was significantly greater than Banzao and Hupingzao.The fruit-cracking rate of jujube significantly related to the pericarp breaking force and it significantly related to the pericarp brittleness.CM mass per unit area significantly negatively correlated with pericarp break force,pericarp break distance,pericarp toughness and significantly positively correlated with pericarp brittleness.There was a highly significant positive correlation between pericarp break force and pericarp toughness and pericarp brittleness and there was a significant negative correlation between pericarp toughness and pericarp brittleness.