درون پوشاني عصاره بابونه در نانو ذرات تهيه شده با روش رسوب با ضد حلال

Encapsulation of Chamomile Extract in Nanoparticles Prepared via Anti-solvent Precipitation Technique

در اين پژوهش اتانول به عنوان ضدحلال براي رسوب دادن محلول پروتئين آب پنير و توليد ذرات بدون هسته و ذرات بارگذاري شده با عصاره ي بابونه استفاده شد. بازده درون پوشاني براي نسبت وزني-وزني 1 به 20 عصاره به پروتئين، 81 درصد بدست آمد. به منظور بهبود پايداري نانوذرات، پروتئين به روش آنزيمي درهم تنيده شد. ذرات توليد شده در مقياس نانومتري و توزيع اندازه ذرات به صورت دونمايي بود. نتايج اسپكتروسكوپي فروسرخ (FTIR) مشخص كرد كه عصاره در درون پروتئين هاي آب پنير محصور شده و پيوند كوالانسي بين ديواره و ماده هسته اي ايجاد نشده است. مشاهده با ميكروسكوپ نيروي اتمي نشان داد كه ذرات تهيه شده از پروتئين هاي درهم تنيده شده به روش آنزيمي، داراي ارتفاع كمتري هستند. درهم تنيدن آنزيمي پروتئين ها به وسيله ي FTIR تاييد شد. پايداري نانوذرات در برابر هضم پپسيني در اثر درهمتنيدن مولكول هاي پروتئين، افزايش يافت. در هم تنيدن پروتئين هاي آب پنير به روش آنزيمي ساختار نانوذرات را بهبود بخشيد و متعاقبا پايداري آنها در محيط شبيه سازي شده دستگاه گوارش افزايش و سرعت رهايش عصاره در شرايط شبيه سازي شده معده كاهش يافت.

Background and objectives: Chamomile extract contains bioactive materials such as Terpenoids, α-bisabolol and Chamazulene and polyphenolic compounds including apigenin, quercetin and patuletin which have considerable antioxidant, anti-inflammatory, antimicrobial, anticonvulsant, anti-allergic, antifungal and anti-pyretic activities. However, incorporation of these active compounds into foods may cause quality defects including astringent taste and increased haze in beverages. They also act as substrates for browning reactions resulting in undesirable color changes in food products. As well, bioactive substances may undergo degradation by exposure to heating, light and oxygen during food processing operations and storage or in the gastrointestinal tract (acidic pH and enzymes). Nanoencapsulation of bioactive molecules is an efficient strategy to overcome these problems without any adverse effect on sensory characteristics and appearance of the final product. In the present research, it is aimed to encapsulate the chamomile extract into nanoparticles obtained from whey protein isolate (WPI) via anti solvent precipitation technique to be used for enhancing healt-promoting effects of beverages. Materials and methods: Whey protein solution was prepared by dissolving whey powder in bidistilled water. The solution was preheated in a water bath at 80 °C for 15 min. Then, whey proteins were inter-connected by using transglutaminase. The cross-linked protein solution was charged with absolute ethanol. Finally, nanoparticles were collected using centrifugation. Results: An encapsulation efficiency of ~81% was obtained in 1:20 mass ratio of extract-to- WPI. Light scattering measurement of hydrodynamic size of particles showed a bimodal pattern for all particles. Fourier transform infrared (FTIR) spectroscopy suggested that extract and whey proteins interacted via hydrogen bonds and hydrophobic interactions. Enzymatically crosslinking of proteins was revealed by FTIR spectroscopy. Conclusion: According to in-vitro tests carried out at a simulated gastro-intestinal media, it was observed that nano-particle structure was improved by crosslinking in whey proteins. Crosslinking of whey proteins slowed down the release rate of entrapped extract from particles in the simulated gastric fluid.