Optimization of enzymatic clarification of green asparagus juice using response surface methodology.
Enzymatic clarification conditions for green asparagus juice were optimized by using response surface methodology (RSM). The asparagus juice was treated with pectinase at different temperatures (35 °C-45 °C), pH values (4.00-5.00), and enzyme concentrations (0.6-1.8 v/v%). The effects of enzymatic treatment on juice clarity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity were investigated by employing a 3-factor central composite design coupled with RSM. According to response surface analysis, the optimal enzymatic treatment condition was pectinase concentration of 1.45%, incubation temperature of 40.56 °C and pH of 4.43. The clarity, juice yield, and soluble solid contents in asparagus juice were significantly increased by enzymatic treatment at the optimal conditions. DPPH radical-scavenging capacity was maintained at the level close to that of raw asparagus juice. These results indicated that enzymatic treatment could be a useful technique for producing green asparagus juice with high clarity and high-antioxidant activity.


CONCLUSIONS
Treatment with 1.45% pectinase at 40.56 ° C, pH 4.43, significantly increased the clarity and yield of asparagus juice. In addition, enzymatic treatment maintained antioxidant activity. Thus, enzymatic treatment has the potential for industrial asparagus juice clarification.
College of Food Science and Technology, Nanjing Agricultural Univ, Nanjing 210095, PR China.
Xuehong
X
Chen
Feng
F
Xu
Weidong
W
Qin
Lihua
L
Ma
Yonghua
Y
Zheng
D027761:Asparagus Plant / Q000737:chemistry* / Q000254:growth & development; D001230:Aspergillus / Q000201:enzymology; D001628:Beverages / Q000032:analysis*; D055598:Chemical Phenomena; D002681:China; D004040:Dietary Carbohydrates / Q000032:analysis / Q000378:metabolism*; D005511:Food Handling; D016166:Free Radical Scavengers / Q000032:analysis; D005656:Fungal Proteins / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008956:Models, Chemical; D010858:Pigmentation; D018520:Plant Shoots / Q000737:chemistry* / Q000254:growth & development; D011096:Polygalacturonase / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D011786:Quality Control; D012995:Solubility; D013223:Statistics as Topic
D004040:Dietary Carbohydrates; D016166:Free Radical Scavengers; D005656:Fungal Proteins; D011134:Polysaccharides; D011096:Polygalacturonase