بهینه‌سازی خشک‌کردن پاششی عصاره گیاه بادرشبو با استفاده از روش سطح پاسخ و تاپسیس

خشک‌کردن پاششی به‌طور متداول در تولید پودر گیاهان دارویی به‌کار می‌رود، کیفیت پودر به‌دست آمده وابسته به شرایط خشک‌کردن و ماده کمکی به‌کار برده شده است. هدف از این تحقیق بهینه کردن متغیرهای فرآیند همچون دمای هوای ورودی، نرخ جریان هوای فشرده و غلظت ماده کمکی بر روی محتوای رطوبتی، عملکرد خشک کردن، محتوای فنول کل، محتوای فلاونوئید کل و فعالیت آنتی‌اکسیدانی پودر عصاره گیاه بادرشبو می‌باشد. بدین منظور از دو روش سطح پاسخ و تاپسیس برای بهینه‌سازی و رتبه‌بندی هر یک از متغیرها استفاده شد. نتایج نشان داد که دمای هوای ورودی و نرخ جریان هوای فشرده بیشترین تاثیر را روی محتوای رطوبتی و عملکرد خشک‌کردن نمونه‌ها داشتند، در حالی‌که غلظت ماده کمکی اثر معنی‌داری بر محتوای فنل کل، فلاونوئید کل و فعالیت آنتی‌اکسیدانی نمونه‌ها داشت. بهترین تیمار در روش تاپسیس در دمای هوای ورودی °c 150، نرخ جریان هوای فشرده lit min1 7.5 و غلظت ماده کمکی 20 درصد به‌دست آمد. همچنین شرایط بهینه در روش سطح پاسخ در دمای هوای ورودی 152.5، نرخ جریان هوای فشرده 8.046 و غلظت ماده کمکی 20 درصد به‌دست آمد.

Optimization the SprayDrying Process of Moldavian Balm Plant Extract using Response Surface Methodology and TOPSIS Method

Introduction;Dracocephalum moldavica L. is an annual plant with blue or white flowers and fragrant leaves which belongs to the family of Lamiaceae with the height of up to 80 cm. This plant is native to Central Asia and is accepted in Central and Eastern Europe. In Iran, it is mainly grown in the province of West Azarbaijan and the Alborz Mountains. The essential oils and extracts derived from the secondary metabolisms which are mainly used in the pharmaceutical industry, dietary, cosmetic, flavoring and also as tea and beverage with sugar or honey. The liquid extract of the herb contains a high percentage of water, which should evaporate to increase shelflife, easy transport, handling and storage, the ease of standardization and preservation of the product quality. On the other hand, the active compounds of the extracts are affected by temperature, oxygen, light and enzymes. Therefore, because of the uses and benefits of herbal extracts, they need to be dried by a practical and effective method like spray drying. In literature still there are no studies taking into account to the comparisons between RSM and TOPSIS as two important optimization methods. So, as the main objective of the present work, the effects of moisture content, drying performance, total phenol content, total flavonoid content and antioxidant activity have been surveyed. Finally, the optimal point of each process variable was presented by two optimization methods.;Materials and Methods;Aerial parts of Moldavian balm plant were cleaned and drying of plant was carried out under shade and thin layer conditions. The extraction of Moldavian balm was obtained by maceration method using ethanol 50 % (v/v), plant to solvent ratio of 1/10 (w/v). After 48h, the extract was concentrated in a rotary evaporator (Buchi Rotavapor R205, Switzerland) to obtain a solid concentration of 6%. The used carrier was: Maltodextrin and apple pectin. Different ratios of carrier were prepared, then the ratio was added to distilled water and stirred by a magnetic stirrer. Finally, the solution was mixed with extract. The drying of Moldavian Balm plant extract was performed using a spraydryer (Büchi B191, Switzerland) with cocurrent flow regime. The powders provided by the spray drying were stored in refrigerator until they were needed for the experiment.;Results and Discussion;The results of variance analysis showed that the BoxBehnken design with the secondorder model has led to the meaningfulness of the model, insignificant of the Lack of Fit and the appropriate correlation coefficient for each of the responses. A total number of 15 experiments were conducted to investigate the effect of process variables such as inlet air temperature, compressed air flow rate and concentration of carriers on moisture content, drying performance, total phenolic content, total flavonoid content and antioxidant activity of Moldavian balm powder. Inlet air temperature and compressed air flow rate had the most significant effect on moisture content and drying performance, while Chemical properties of the powder affected by changing the concentration of carriers.;Optimization parameters of the spray drying process was performed using surface response and TOPSIS methods. The optimum predicted conditions in the response surface method and TOPSIS method were obtained at inlet air temperature, compressed air flow rate and concentration of carrier (152.5150°C), (8.0467.5 lit min1) and 20%, respectively.;Conclusions;By comparing two methods, it can be concluded that although they could provide the same optimum points, the RSM is more efficient. Because RSM offers a mathematical model that can be used at any desired point of variables to predict the output quantities as well as describing the process trend, while TOPSIS method is unable to predict the process trend and only provides the ranking of alternatives.