漂白紫胶/单宁酸复配涂膜对芒果常温贮藏的保鲜效果

Effect of Bleached Shellac/Tannic Acid Composite Coating on Mango Preservation at Room Temperature

为降低芒果常温贮藏的黑斑发生率和腐烂率,减缓营养物质流失,延长货架期,本实验制备了单宁酸-漂白紫胶复合保鲜剂,以单宁酸和漂白紫胶的质量分数作为响应变量,芒果的质量损失率和黑斑发生率作为响应值,通过响应面Central Composite试验设计对单宁酸-漂白紫胶天然保鲜剂进行配方优化,并检测了复合保鲜剂的理化指标。结果显示,单宁酸-漂白紫胶复合保鲜剂对芒果常温贮藏有明显的保鲜效果,确定了最优配比为漂白紫胶7.3%(质量分数,下同)和单宁酸0.3%,贮藏第18天,芒果质量损失率和黑斑发生率分别为24.38%和29.91%,与空白对照组相比,该最优配比复合保鲜剂减缓了芒果中可滴定酸、可溶性糖、可溶性固形物和抗坏血酸等营养成分的流失,抑制芒果腐烂,使芒果的贮藏货架期至少延长了8 d;且该复合保鲜剂的各项感官和理化指标,包括黏度、灼烧残渣、总砷和铅含量等均符合国家标准,说明此保鲜剂绿色、安全、无毒。

In order to reduce the incidence of black spots and decay as well as the loss of nutrients and to prolong the shelf life of mango fruit stored at room temperature,a tannic acid(TA)-bleached shellac composite preservative was prepared.The concentrations of TA and bleached shellac were used as the variables and the mass loss percentage and the incidence of black spots in mango fruit were used as the response values to optimize the formulation of the composite preservative using response surface methodology based on central composite design.Meanwhile,the physical and chemical indexes of the optimized formulation were tested.The results showed that the composite preservative could obviously prolong the shelf life of mango fruit at room temperature.The optimal proportions(m/m)of the ingredients were 7.3%bleached shellac,0.3%TA.The mass loss percentage and the incidence of black spots in mango fruit treated with the optimized preservative were 24.38%and 29.91%after 18 days of storage,respectively.Compared with the blank control group,the preservative significantly reduced the loss of nutrients such as titration acid,soluble sugar,total soluble solids and ascorbic acid in mangoes,delayed the decaying process and prolonged shelf life by at least 8 days.The sensory,physicochemical indexes of the preservative,including viscosity,ignition residue,total arsenic and lead content,were all in line with the requirements of the national standard,which indicates that the preservative is green,safe and non-toxic.