充入N_2和CO_2对贮藏橙汁品质的影响研究

Effects of Nitrogen and Carbon Dioxide on Quality of"Olinda"Valencia Orange Juice Stored at 15 ℃

主要探讨充入N2和CO2,并控制温度和压力条件下,贮藏橙汁的品质变化。研究结果表明:分别充入N2或CO2气体0.2、0.4MPa,15℃贮藏6个月,L值增加,a值、b值减少;与对照组比充气0.4MPa的两个处理组对色差值变化有一定抑制作用,橙汁可溶性固形物保存率在97%以上,菌落总数前期升高后期下降(总数<40CFU/ml),VC损失均小于6mg/100g,以0.4MPa、N2组的损失最小,0.4MPa、N2处理组主要香气成分保有量为1001μg/ml。由此可见,充气加压贮藏能够有效保持橙汁原有的风味和品质,综合各项指标测定结果以0.4MPa、N2处理组效果最好。

＂Olinda＂ Valencia orange juice was stored for 6 months in a container filled with N2 or CO2 to 0.2 or 0.4 MPa at 15 ℃. Quality changes of four＂ Olinda＂ valencia orange juice samples （sample P-1： N2, 0.4 MPa; sample P-2： CO2, 0.4 MPa; sample P-3： N2, 0.2 MPa; and sample P-4： C02, 0.2 MPa） during the storage were investigated. A slight increase of L^＊ value was observed in all the samples while the a^＊ and b^＊ values decreased dramatically. An obvious inhibition was found in color difference of the two orange juice samples stored under 0.4 MPa when compared to the control sample stored hermetically in a PET bottle at - 5 ℃. Over 97% of soluble solids were preserved in the orange juice samples and the total bacterial count showed a changing trend of first increase and then decrease and the loss of vitamin C was less than 6 mg/100 g during the storage, which was the least in the sample P-1. The content of major aroma components in the sample P-1 was 1001μg/ml. In general, the original quality and flavor of the orange juice can be preserved when stored under N2 or CO2 pressure environment.