Alginate-pomegranate peels' polyphenols beads: effects of formulation parameters on loading efficiency

Calcium alginate beads containing pomegranate peels' polyphenol extract were encapsulated by ionic gelation method. The effects of various formulation factors (sodium alginate concentration, calcium chloride concentration, calcium chloride exposure time, gelling bath time maintaining, and extract concentration) on the efficiency of extract loading were investigated. The formulation containing an extract of 1 g pomegranate peels in 100 mL distilled water encapsulated with 3 % of sodium alginate cured in 0.05 M calcium chloride for 20 minutes and kept in a gelling bath for 15 minutes was chosen as the best formula regarding the loading efficiency. These optimized conditions allowed the encapsulation of 43.90% of total extracted polyphenols and 46.34 % of total extracted proanthocyanidins. Microencapsulation of pomegranate peels' extract in calcium alginate beads is a promising technique for pharmaceutical and food supplementation with natural antioxidants.本研究采用离子凝胶法制备包埋石榴皮多酚提取物的海藻酸钙微球，并考察了海藻酸钠浓度、氯化钙浓度、氯化钙作用时间、凝胶浴维持时长及提取物投加浓度等多种配方因素对提取物包埋效率的影响。以包埋效率为核心评价指标，最终筛选得到最优配方：以100 mL蒸馏水溶解1 g石榴皮提取物，采用3%海藻酸钠作为包埋基材，在0.05 mol/L氯化钙溶液中固化20分钟，并置于凝胶浴中维持15分钟。该配方可实现总提取多酚43.90%的包埋率与总提取原花青素46.34%的包埋率。将石榴皮提取物微囊化于海藻酸钙微球中，是一种极具应用前景的技术，可用于天然抗氧化剂类医药及食品补充剂领域。