The Effect of Ultrasonic Waves on Peroxidase Activity and Vitamin C Content of Green Bean

Subject Areas : Microbiology

M. Yolmeh ¹ , F. Salehi ² , M. Najafzadeh ³

1 - دانشجوی دکترای صنایع غذایی، دانشگاه کشاورزی و منابع طبیعی گرگان، گرگان، ایران
2 - عضو گروه پژوهشی افزودنی‌های غذایی، پژوهشکده علوم و فناوری غذایی، جهاد دانشگاهی، خراسان رضوی، ایران
3 - عضو گروه پژوهشی افزودنی‌های غذایی، پژوهشکده علوم و فناوری غذایی، جهاد دانشگاهی، خراسان رضوی، ایران

Received: 2016-05-14 Accepted : 2016-05-14 Published : 2016-05-21

Keywords: Green Bean, Peroxidase, Ultrasound Blanching, Vitamin C,

Abstract :

Introduction: The application of ultrasound in food processing is considered a novel technique, that can be used along with the conventional methods. This study evaluated the effects of the ultrasound blanching (USB) of green bean on residual peroxidase activity and vitamin C of green bean. Materials and Methods: Response surface methodology (RSM) was used to study the effect of process variables on the Ultrasound Blanching. Three independent variables including temperature (50-90°C), time (45-225 s), and duty cycle (0.2-0.8 s) were examined. Results: According to the results, the Linear-square models were more suitable than other models for both responses. All of the linear and quadric terms of time and duty cycle of residual Peroxidase activities have shown significant effects (P<0.05). However, the effect of quadric term of temperature was insignificant (P>0.05). On the other hands, the linear and quadric terms of temperature and time have shown significant effects (P<0.05) unlike the quadric terms of duty cycle (P<0.05) for vitamin C loss. Conclusion: According to the performed tests the range of the residual peroxidase activity and percent of vitamin C loss were 3.85-34.75 and 2.00-22.75, respectively. The results from this research demonstrated that USB is an effective technique for green bean blanching in comparison with the conventional method. The advantages of this technique include lower blanching time, less vitamin C damage and more peroxidase inactivation as compared to the conventional method at the same time.