The Research And Development Of Bleached Shellac Preservatives For Fruits

In this research, SiOx, a kind of nano-powder material, was introduced for the first time in bleached shellac preservatives (BSP). As a replacement of chemical antibacterial, the mixed liquid of bamboo leaf extract and licorice extract was also applied for the first time in BSP. The problems in respiration, oxidative metabolism, synthesis of ethylene, damage from pathogenic bacteria and the bio-safety disposal for components of coating preservatives can be resolved by adding air permeability regulator, membrane strength regulator, antioxidant and natural antibacterial. Such efforts were made for the development of a multifunctional natural fresh preservative.Basing on the orthogonal experimental design and randomized complete-block design, comprehensive select was made for the optimum components and concentrations of preservatives. Finally, two BSP, BSP(CMH) and BSPN(CMH), were selectively confirmed under the best condition.Results based on different fruits with the BSP coated indicate that the respiratory strength can be held back remarkably and the storage period of fruits can prolonged twice to three times with two preservatives. BSPN(CMH) is fit for fruits in the condition with low oxygen and high carbon dioxide concentration, whereas BSP(CMH) is more suitable for those in the condition with low oxygen and low carbon dioxide concentration.The comparative experiments indicate: Better effects could be seen as BSP(CA) and BSPN(CA) in the former part and BSP(CMH) and BSPN(CMH) in the latter part. Generally speaking, BSP(CMH) and BSPN(CMH) achieve more advantages than BSP(CA) and BSPN(CA).Comparing with imported fruit wax based FMC890, each index of apples coated with BSPN(CMH) is better than those coated with FMC890. But the fruit decay index of oranges coated with BSPN(CMH) is obviously higher than those coated with BSP(CMH) and FMC890, thus it is known that effects of oranges treated by the three preservatives are ordered as: BSP(CMH),FMC890 and BSPN(CMH).It is showed that effects in preservation with BSP(CMH) and BSPN(CMH) were considerably better than those with chemical antibacterial adding BSP and imported fruit wax based FMC890. The two selected BSP can be widely used in preservation for different fruits with convincingly great prospects.