柚皮苷/柠檬苦素微胶囊的制备、结构分析及特性研究

Preparation,Structural Analysis and Properties of Naringin/Limonin Microcapsules

为提高柚皮中柚皮苷和柠檬苦素的生物利用度,降低其苦味,拓展其在食品开发中的应用,本研究以海藻酸钠-壳聚糖-氯化钙体系为壁材,采用锐孔造粒法微胶囊化柚皮苷/柠檬苦素,并以柚皮苷/柠檬苦素包埋率为响应值,通过单因素实验和响应面试验优化柚皮苷/柠檬苦素微胶囊的制备工艺。进一步通过扫描电镜(SEM)、傅里叶变换红外光谱仪(FTIR)、电子舌、热稳定性分析以及体外模拟消化试验对柚皮苷/柠檬苦素微胶囊的微观形态、分子结构、相对苦味强度、热稳定性及胃肠消化特性进行了研究。结果表明,微胶囊化最佳工艺条件为壁芯材比为8:3、壳聚糖质量分数为0.9%,氯化钙质量分数为3%,此时包埋率可达88.2%,与理论值的88.68%相对误差小于5%,说明该工艺准确可靠;扫描电镜证实海藻酸钠-壳聚糖-氯化钙体系组成的微胶囊结构能高效且紧实包裹柚皮苷和柠檬苦素,并且微胶囊表面无裂缝、孔洞和凹陷的现象。热稳定性和电子舌试验表明,柚皮苷和柠檬苦素的微胶囊化可以明显提高柚皮苷和柠檬苦素的稳定性,并且有效降低其苦味强度;体外模拟胃肠道消化缓释试验表明,微胶囊在模拟胃液中消化6 h后总体释放率才达31%左右,在模拟肠液中消化45 min时累计释放率已经超过75%,表明微胶囊化能有效促进柚皮苷/柠檬苦素在肠道内的生物转化与吸收,提高其利用率。本研究结果可为拓展柚皮苷/柠檬苦素在食品和医药领域的高值化利用提供依据。

This study aimed to improve the bioavailability of naringin and limonin,reduce their bitter taste,and extend its application for the development of food.Microencapsulated naringin/limonin was prepared by orifice granulation method with sodium alginate-chitosan-calcium chloride as wall material,respectively.The technology process was further optimized by single factor experiment and response surface methodology using the embedding rate of naringin/limonin as response value.The micro morphology,molecular structure,relative bitterness intensity,thermal stability,and in vitro digestibility of products were characterized by scanning electron microscope(SEM),Fourier transform infrared spectrum(FTIR),electronic tongue,thermal stability analysis and simulating digestion experiments,respectively.The results showed that the optimal conditions were the ratio of wall to core material was 2.67,the mass fraction of chitosan was 0.9%,and the mass fraction of calcium chloride was 3%,the embedding rate could reach 88.2%,which was less than 5%compared with 88.68%,indicating that the process was accurate and reliable.SEM confirmed that naringin/limonin was effectively and tightly wrapped with sodium alginate-chitosan-calcium chloride system,and there were no cracks,holes or dents on the surface of the microcapsule.The thermal stability and electronic tongue test confirmed that the microencapsulation of naringin/limonin could significantly improve the stability of naringin/limonin,and effectively reduce their bitter intensity.The sustained release test of simulated gastrointestinal digestion in vitro showed that the overall release rate of microcapsules was only about 31%after digestion in simulated gastric juice for 6 h,and the cumulative release rate was over 75%after digestion in simulated intestinal juice for 45 min.These results indicated that microencapsulation could effectively promote the biotransformation and absorption of naringin/limonin in the intestinal tract,and improve its utilization rate.The results of this study could provide a basis for expanding the high-value utilization of naringin/limonin in food and pharmaceutical fields.