Effect Of Organizational Structure And Material Changes On Jujube Fruit Cracking In Growth And Development Process

The jujube fruit cracking has become one of the problems to be solved in the current production, selecting easy cracking’Huping fruit’ as test materials in this study. The content of this paper include the observation of the growth and development of jujube fruit, the changes of the inclusion content, the changes of mineral elements content, the peel organizational structure characteristics as well as the law of the jujube cracking, in order to reveal the reasons of the fruit cracking and provide a theoretical basis in the production of the jujube fruit. The results showed that:1、The growth of jujube fruit can be divided into five periods:the first is young fruit period (7d-20d after full bloom, or july6-july20), the growth of the vertical and horizontal diameter is increased, and the change of fresh weight is increased very little. The second is fruit enlargement period(20d～50d after full bloom,or july20-august20), the fruit weight is significantly increased, and the growth of the vertical and horizontal diameter is significantly increased in the50d after flowering. The third is white ripening(50d-65d after full bloom,or august20-august31), the weight of the fruit increase slowly, and the peel appear on many white spots.The fourth is turning period(50d～75d after full bloom,or september1-september10), the growth of the vertical and horizontal diameter is increased little,the peel start coloring. The fifth is the mature period(75d～85d after full bloom,or september10-september21), the fruit peel is all colored,and the weight of the fruit slightly decreased.2、The cracking period of jujube fruit is generally from the turning period to the mature period of the fruit. Cracking generally starts from the stalk of the jujube fruit, and then spread to other parts. Generally the cracking rate in sunny side is higher than the shade side, the cracking rate in the periphery of the canopy is higher the inside of the canopy, the cracking of the big fruit is higher than small fruit.3、By studying the peel anatomical structure in the jujube fruit. The results showed that peel cells and pulp cells are small and neat, and the pulp tissue has cavity in young fruit period.The peel cells and pulp cells are increased, and the peel cells are less than the pulp cells in fruit enlargement period. The pulp cells are significantly increased in the mature period.4、By studying the changes of the cell wall structure substance of jujube fruit, the results showed that the contents of cell wall components (pectin, cellulose and hemicellulose) reaches a maximum in the55d after full bloom from the young fruit period to the mature period, than following by a downward trend. The content of the pectin and cellulose reaches a maximum in the85d after full bloom, and the content of the peel is higher the pulp. The content of the hemicellulose reaches a maximum in the85d after full bloom, and the content of the pulp is higher the peel.5、The content of sugar is increased until reaches a maximum in the85d after full bloom, the content of starch is increased and then decreased in the70d after full bloom..6、The content of the major mineral element in jujube fruit peel was ordered from large to small: potassium (K)> calcium>(Ca) magnesium(Mg)> iron(Fe)> zinc(Zn)> manganese(Mn). The content of mineral element Ca, Mg, Zn has been declining, the content of mineral element Mn, Fe become downward trend, in the55d after full bloom. By analysing these mineral elements in different tissue, the results showed the content of mineral element Ca, Mn around the shoulder is higher than the style in the55d after full bloom.The content of mineral element K, Mg around the style is higher than the shoulder in40d after full bloom. The content of mineral element Mg, Fe, Zn around the style is higher than the shoulder in65d,80d after full bloom.Conclusion:1、The structure substances of the cell wall of the peel include pectin, cellulose, hemicellulose, and Ca element, their contents were lower in the mature period, and due to changes the tough of the peel is less.2、The content of total soluble sugar reach maximum in the mature period, it can low the cell osmotic potential, and lead to absorb water favorably.3、The content of mineral elements of the peel (Mg、Mn、Fe、Zn) are unevenly distributed in the turning period and the mature period.4、The cracking begin in the turning period, and become the most serious in the mature period.