تعيين شرايط بهينه‌ي فرايند سرخ كردن تحت خلا كدو حلوايي(Cucurbita moschata Duch)

Optimization of processing conditions in vacuum frying of Pumpkin(Cucurbita moschata Duch)

در اين پژوهش، استفاده از سرخ كردن تحت خلا جهت فرآوري كدو حلوايي استفاده گرديد و تاثير پارامترهاي فرآيند بــر ويژگي هاي محصول نهايي به منظور دستيابي به شرايط بهينه‌ي فرآيند مورد ارزيابي قرار گرفت. در ابتدا با انجام پيش آزمايش‌ها و بررسي پارامترهاي كيفي محصول، محدوده‌ي درجه حرارت 70 تا 140 درجه‌ي سانتي گراد، فشار 40 تا 140 ميلي بار و مدت زمان 3 تا 18 دقيقه در نظر گرفته شد و با استفاده از مدل آماري رويه‌ي پاسخ ، نمونه ها در درجه حرارت، فشار و زمان هاي طرح‌ريزي شده فرآوري گرديدند. نتايج حاصل، حاكي از آن بود كه محتوي رطوبت، چروكيدگي و تردي بافت محصول متاثر از درجه حرارت و مدت زمان فرآيند مي باشد و تغييرات رنگ محصول تنها با درجه حرارت فرآيند به طور معني داري (p?0.05) ارتباط دارد. بر اساس نتايج حاصل از آزمايش‌ها، شرايط بهينه‌ي سرخ كردن تحت خلا برش هاي كدو حلوايي دماي53/84 درجه‌ي سانتي گراد، فشار 40 ميلي بار و زمان 18 دقيقه تعيين گرديدند.

Nowadays, healthy food has become more popular, this research was aimed to develop fried snack from pumpkin ( cucurbita moschata duch ) which is also a healthy food for human. A vacuum frying machine in laboratory scale was used for snack production in order to optimize process parameters on vacuum frying of cucurbita moschata duch and study the relationship between process parameters ( including frying temperature, vacuum level and time) and the quality of the product. A range of pretests were done to obtain suitable ranges for main parameters. Considering the results of these pretests, variables assumed as 70- 140 for temperature, 40- 140 millibar for vacuum pressure and 3-18 mins for the processing time. In this research, for analyzing the results and studying the effect of these variables on the quality factors of the slices of pumpkin the response surface methodology and the central composite design were used. The results showed that moisture content, shrinkage and crispiness of pumpkin chips were significantly ( p? 0.05 ) affected by temperature and time of frying process. In this case, by increasing frying temperature and time of process, moisture content decreased while crispiness and shrinkage of the product increased. The Hunter ?E of products was significantly affected by the temperature of the frying process and by increasing the temperature. Based on the results, the optimal frying condition for pumpkin was as follows,vacuum pressure of 40 millibar, Temperature of 84.53 and 18 minutes for processing time. According to the results, this condition could be applied to produce pumpkin chips with lower moisture and shrinkage with good color and crispy texture along with good nutritional value.