Study On The Fruit Quality And Juice Processing Technology Of Hybrid Oranges

Juice processing characteristics, the conditions of solid phase micro-extraction (SPME) and adour component analysis, membrane separation, the optimal formula of 5 hybrid orange cultivars(Amacan, Nankou, Miyautiiyokan, Novo and Sweet orange) were studied in order to offer theoretical basis and guidance to utilization of hybrid oranges. The results are as follows:The fruit quality and juice processing characteristics of hybrid orange cultivars were showed that:1) the variation of the soluble solids content of orange juice ranged from 12.84%～14.21% with average value of 13.70%; 2) titratable acidity ranged from 0.51%to 0.84% with average value of 0.69%; 3) the five cultivars yielded 46.34% to 57.82% juices from fresh fruits with the average value of 52.52%. The juice yield for five cultivars ranked as following sequence:Amacan>Nankou> Miyautiiyokan> Novo> Sweet orange. The results indicates that Nankou and Amacan were better for juice processing because of high juice yield, high soluble solid, high titratable acidity, high reductive sugar content, and high scores in flavour and aroma evaluation.The SPME extracting efficiency of different fibers, exposure time, exposure temperature, NaCl amount, sample volume, and stirring rate were investigated using Miyautiiyokan juice as material. The optimal conditions were optimized through orthogonal test. The results showed that the optimal SPME parameters were:25% of NaCl,40 min of exposure at 40℃with 1 g sample amount. GC-MS analyses of aromatic compounds of 5 different hybrid orange juices were studied. It was showed that terpenes and aldehydes were the key aroma components. Aromatic compounds of Nankou, Amacan and Sweet orange were rich and the terpenes were prominate, while that of Novo and Miyautiiyokan were less because of the lack of odour.The technical conditions for Nankou juice ultrafiltration were at 40℃and 0.3 MPa, using 0.1% NaOH and 0.15% NaClO as scours for membrane washing, the recovery of membrane could reach to 90% after washing.The optimal reverse osmosis (RO) technical conditions for Nankou juice were at 40℃,1.0 MPa, and 1.5 m/s. Juice could be concentrated up to 33°Bx in this condition.The different washing method were compared after membrane flow reduced to 40%. The result showed that effect of 1%H2O2+0.15% NaClO was better than that of 0.1% NaOH. The recovery of membrane could reach to 96% after washing.The formula of the functional beverage of Nankou was studied through orthogonal design. The result showed that formula containing 15% of Nankou juice, 8% of sugar,0.16% of citric acid, and compound stabilizers with 0.04% of sodium alginate and 0.08% of CMC-Na was optimal.