Thermal Inactivation Kinetics and Application of Phospho- and Galactolipid-Degrading Enzymes for Evaluation of Quality Changes in Frozen Vegetables

• Published in: Journal of agricultural and food chemistry Vol. 49; no. 5; pp. 2241 - 2248
• Main Authors: Kim, Myo-Jeong, Oh, Jae-Myung, Cheon, Sang-Hee, Cheong, Tae-Kyou, Lee, Sang-Hwa, Choi, Eun-Ok, Lee, Hyeon Gyu, Park, Cheon Seok, Park, Kwan Hwa
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.05.2001
• Subjects: Biological and medical sciences; Food Handling; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Galactolipids; Glycolipids - metabolism; Hot Temperature; Hydrolases - metabolism; Kinetics; Phospholipids - metabolism; Substrate Specificity; Vegetables - enzymology; Heat treatment; Thermal inactivation; Phospholipid; Phosphoric monoester hydrolases; Esterases; Spinacia oleracea; Inactivation; Thermal stability; Regulation(control); Dicotyledones; Angiospermae; Frozen product; Spinach; Vegetable; Galactolipase; Enzyme; Foodstuff; Carboxylic ester hydrolases; Chenopodiaceae; Phospholipase; Vegetable crop; Galactolipid; Quality control; Hydrolases; Spermatophyta; Catalyst activity
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf001379b

Lipid-acyl hydrolases (LAHases) play significant roles in lipid degradation during the storage of vegetables. In particular, spinach contains a large portion of galactolipids (59.5%) and phospholipids (22.4%) among its fat-soluble components, which are used as substrates for LAHases. Thermal inactivation of various LAHases, including phospholipases A, C, and D, phosphatase, and galactolipase, from spinach and carrot was investigated to optimize the blanching process prior to the frozen storage of vegetables. Thermostability of phospholipase C or galactolipase was greatest among the LAHases from both spinach and carrot. Galactolipase from spinach exhibited a D value of 3.39 × 102 s at 80 °C and a z value of 8.21 °C, whereas phospholipase C from spinach showed D 80 of 1.72 × 102 s with a z value of 9.26 °C. In the case of LAHases from carrot, the D 65 and z values of galactolipase were 6.66 × 102 s and 8.69 °C, respectively, whereas phospholipase C displayed D 85 of 3.12 × 102 s and a z value of 15.8 °C. Highly active and thermostable galactolipase and phospholipase C in spinach and carrot made it possible for them to be used as indicator enzymes for the determination of quality deterioration of the stored vegetables. Keywords: Blanching; lipid-acyl hydrolases; phospholipase C; galactolipase; thermal inactivation