Study On Cut Flower Preservation By Different Treatments Of Low Molecular Weight Chitosan Extractions

Chitosan is a natural high polymer obtained by deacetylation reaction of chitin. The reserves are abundant in the nature. It has the characteristic forming the membrane and inhabited effect on growth of many microorganism. It is nontoxic, safety and it has been widely applicated inpreservation of many fruits and vegetables. But few papers was reported on cut flowers, so the preservation effects of chitosan on cut flowers were investigated in this study.The shrimp shell was used for extraction of chitosan in treating cut flowers in this study. The chitosan was extracted by acid and alkali hydrolysis method and further degraded with NaNO2 of different conditions. The preservation of Gladiolus hybridus Hort. treated with different concentrations of chitosan and Rose Chinensis treated with different degradations of chitosan, were investigated respectively.The factors of degradating conditions on the average viscosimetric molecular weight have different importance, the order was the following, reaction time>reaction temperature>dose of 10% NaNO2 CH3COOH concentration, and the best treatment is: 0.6 ml 10% NaNO2, 40C reaction temperature, 45 min reaction time and 1% CH3COOH concentration.Effects of chitosan solutions on the booming rate and vase life of cut flower of gladiolus treating with concentrations of 0.25 %, 0.5 %, 0.75 %, 1%, 1.25% chitosan were studied. The results indicated that the booming rate and vase life of cut flower of gladiolus treating with 1% chitosan were the best treatment.The base of cut rose was steeped in low- molecular weight Chitosan-Ca2+ complexes, and the outward morphology was evaluated and the physiological index was determined . The results showed that compared to CK(distilled water), the cut rose steeped in 0.1 % Chitosan-Ca2+ complexes A (degraded with 0.2mlNaNO2 for 15min) +0.05% SA extended vase-life of cut rose for 3 days at 28-31C. This fresh-keeping liquid with Chitosan-Ca2+ complexes could delay anthesis and maintain water balance, and delay the climacteric, and keep relative membrane permeability balance; Chitosan (degraded with 0.2rnlNaNO2) could delay the climacteric and the anthesis; But the Chitosan-Ca2+ complexes (degraded with2mlNaNO2 for 15min) were not stable, and had no obvious fresh-keeping effect on cut rose. At the same time, these complexes could inhibit the bacterial growth.Chitosan used as a cheap, nontoxic, noharmful preservative solution needs further investigation.