تاثیر ریزپوشانی کردن بر ویژگی‌های اسانس پوست پرتقال حاصل از پسماندهای کارخانجات آب پرتقال

مقدمه: اسانس پوست پرتقال که در صنایع مختلف به عنوان طعم دهنده استفاده می‌شود، به طور معمول دارای ثبات فیزیکی‌شیمیایی و حلالیت کمتری در آب است. در این تحقیق، تاثیر ریزپوشانی بر ویژگی‌های اسانس حاصل از پوست پرتقال رقم تامسون مورد بررسی قرار گرفت. مواد و روش‌ها: ابتدا پوست پرتقال در دمای 35 درجه سلسیوس به مدت 19 دقیقه تحت فراصوت در فرکانس 20 کیلو هرتز، با شدت 60 درصد قرار گرفت و سپس توسط دستگاه کلونجر اسانس آن استخراج شد. اسانس استخراج شده با استفاده از محلول‌های تهیه شده از بتاسیکلودکسترین و کازئینات سدیم در غلظت‌های 5 و 10% در آب، به روش خشک کردن انجمادی ریزپوشانی شد. سپس راندمان تولید، رطوبت، اندازه قطر ذرات، دانسیته توده، دمای انتقال شیشه‌ای، ترکیبات فنلی و قدرت گیرندگی رادیکال آزاد، ریزساختار و سینیتیک پایداری ریزکپسول‌ها تعیین شد. نتایج با استفاده از طرح آماری کاملاً تصادفی در 3 تکرار تجزیه شد. میانگین‌ها در سطح 0.05 با آزمون چند دامنه‌ای دانکن مقایسه شد.نتایج: نتایج نشان داد که ویژگی‌های ریزکپسول‌های تهیه شده با دیواره بتاسیکلودکسترین به جز دانسیته توده بالاتر از ویژگی‌ ریزکپسول‌های تهیه شده با دیواره کازینات سدیم بود (p<0.05). رطوبت و راندمان ریزکپسول‌ها با افزایش غلظت بتاسیکلودکسترین افزایش اما با افزایش غلظت کازینات سدیم کاهش یافت. با افزایش غلظت هر دو دیواره دانسیته توده افزایش و دمای انتقال شیشه‌ای و قدرت گیرندگی رادیکال آزاد کاهش یافت. نتایج حاصل از تعیین ریزساختار نشان داد که ریزکپسول‌های حاوی بتاسیکلودکسترین به شکل کروی، دارای تورفتگی و خلل و فرج زیاد و ریزکپسول‌های حاوی کازئینات‌سدیم دیواره‌ای نازک و یکنواخت بدون خلل و فرج بود. نتایج حاصل از بررسی پایداری ریزکپسول‌ها حاکی است که در طول نگهداری با افزایش رطوبت نسبی، مقدار dpph افزایش و با افزایش دما از 4 تا 25 درجه سلسیوس کاهش یافت.نتیجه‌گیری: ریزکپسول‌های اسانس تهیه شده با دیواره بتاسیکلودکسترین با غلظت 10 %، دارای خصوصیات فیزیکیشیمیایی بهتری نسبت به سایر دیواره‌ها بودند.

The effect of microencapsulation on characteristics of orange peel essential oil of extracted from by product of orange juice factories

Introduction: Orange peel essential oil is used in various industries as a flavoring component due to its excellent organoleptic properties. These compounds are generally rich in active and sensitive components (antioxidant and antimicrobial compounds). These compounds typically have low physicochemical stability and lower solubility in water. Therefore, the use of a method that can protect these compounds against environmental factors is of particular importance. Microencapsulation is one of the methods of protecting chemical compounds with biological activity. Since the microencapsulation process of the active compounds is influenced by the core and wall material and drying method, it is expected to use suitable wall materials such as sodium alginate and betacyclodextrin with a suitable drying method such as freeze drying lead to the production of stable microcapsules. The aim of this study was to produce microencapsulation of orange peel essential oil extracted from Thomson cultivar with walls of sodium caseinate and beta cyclodextrin by freezedrying method and to investigate its quantitative and qualitative characteristics. Materials and Methods: Orange peel was subjected to ultrasound at a frequency of 20 kHz with 60% intensity for 19 minutes at 35 °C and then its essential oil was extracted by Clevenger method. The extracted essential oil was finely Microencapsulate using betacyclodextrin and sodium caseinate at concentrations of 5 and 10% by freezedrying method at 70 ° C for 19 hours and then transferred to a freezedried dryer. Samples were dried in a freezedryer at 55 ° C with a pressure of 0.15 mm Hg (Azarpazhooh et al. 2018). Then the properties of capsulate essential oil including Microencapsulate efficiency, particle diameter size were used using laser light refraction method. moisture was measured using an infrared hygrometer at 105 ° C until reaching a constant weight. To determine the mass density, a specific volume of the sample, its weight and density were calculated by dividing the weight (g) by the volume of the sample (ml) in g/ cm3. The glass transition temperature was determined using a differential scanning calorimeter with a liquid nitrogen cooling system. To determine phenolic compounds, Folin–Ciocalteu method was used. The antioxidant activity of the samples was also measured using the DPPH test. Scanning electron microscopy was used to observe the microstructure of the prepared microcapsules. Stability kinetics of microcapsules were performed under different temperature and humidity conditions (temperature, 4 and 25 °C; relative humidity, 52 and 75% and storage time of 0, 7, 14, 21, 28, 35 and 42 days) in three replications. The results were analyzed using a completely randomized statistical design with 3 replications and MSTATC software.Results and discusses: The results of statistical analysis of data showed that the effect of wall material on all properties of microcapsules was significant (p <0.05). Thus, all the characteristics of microcapsules prepared with betacyclodextrin wall except mass density were significantly higher than the characteristics of microcapsules prepared with sodium casinate wall. The low production efficiency of microcapsules containing sodium caseinate is probably due to the instability of the initial emulsion. Also, the lower moisture of these microcapsules is another reason for the low efficiency. Microcapsules with 10% betacyclodextrin and 5% sodium caseinate had the highest and lowest moisture and efficiency, respectively. Therefore, the type and concentration of wall material effectively affects the efficiency and final moisture of the microcapsules. The bulk density of microcapsules with betacyclodextrin wall was lower than that of sodium caseinate. Because of their greater porosity, betacyclodextrincontaining microcapsules will take up more volume than sodium caseinate microcapsules. As a result, their bulk density is lower. The small particle size of microcapsules containing sodium caseinate is related to the effective emulsifying properties of sodium caseinate and its hydrophobic and hydrophilic components (Moghimi et al. 2016). The large particle size of betacyclodextrincontaining microcapsules may be due to the lack of ionization of betacyclodextrin, which tends to accumulate in water, there is no repulsive force to prevent particle aggregation (TorresAlvarez et al. 2020). Moisture and efficiency of microcapsules increased with increasing concentration of betacyclodextrin but decreased with increasing concentration of sodium caseinate. Also, with increasing the concentration of both walls, the density of the mass increased and the glass transition temperature and free radical scavenging decreased (p <0.05). Also, the glass transfer temperature of all microcapsules is higher than the ambient temperature. Therefore, none of the microcapsules prepared at ambient temperature reach the glass transition temperature, so it is not possible to release and transfer the core material out of the wall. As the concentration of both walls increased, the glass transition temperature decreased (p <0.05). The results of determining the microstructure of the microcapsuleed particles by electron microscopy showed that the resulting microcapsules did not have a definite geometric shape, which is probably due to the drying mechanism. Spherical capsules containing betacyclodextrin had a large indentation and pore, and microcapsules containing sodium caseinate had thin, uniform, nonporous walls. The results of the study of the stability of microcapsules indicate that during storage the amount of DPPH increased with increasing relative humidity but decreased with increasing temperature from 4 to 25 °C.Conclusion: Orange peel essential oil capsules prepared with 10% betacyclodextrin wall had better physicochemical properties than other walls.