Abstract: In order to extend the shelf life of milk cake, a Pickering emulsion containing antimicrobial peptide MOp2 from Moringa oleifera seeds was applied as preservative to milk cake. In this experiment, the preservative effect of the Pickering emulsion on milk cake was determined by measuring peroxide value, texture properties, total viable count, coliform count, color difference and sensory attributes. The results showed that Escherichia coli was detected in the vacuum packaging group (control) after 28 days of storage, and the count of E. coli exceeded the safety limit after 35 days. The total viable count, peroxide value (POV), and color difference was significantly higher than those of the experimental group coated with the Pickering emulsion. The experimental group remained unspoiled for 42 days. Sensory quality remained stable during the first 35 days of storage, total viable count increased slowly, and E. coli was not detected in the experimental group. Significant differences in texture properties between the two groups were observed starting from the 21th day of storage. Sensory and physicochemical evaluation showed that compared with the control group, the Pickering emulsion prolonged the storage life of milk cake by one week, indicating its good preservative effect.

Key words: Pickering emulsion; antimicrobial peptide; milk cake; preservation; peroxide value

摘要： 为了延长乳饼的保质期，将一种含辣木籽抗菌肽MOp2的Pickering乳液作为保鲜剂应用于乳饼，通过测定过氧化值、质构、菌落总数、大肠杆菌、色差和感官指标确定Pickering乳液对乳饼的保鲜效果。结果表明：真空包装组（对照组）贮藏28 d时检出大肠杆菌，贮藏35 d时大肠杆菌超标，且菌落总数、过氧化值、色差显著高于涂抹Pickering乳液的实验组；实验组贮藏42 d内未出现腐败变质，其中前35 d感官品质较好，菌落总数增长较慢，未检测出大肠杆菌，在乳饼质构测定中，从21 d开始实验组与对照组呈现明显差异。综合感官与理化指标分析与对照组相比，Pickering乳液能将乳饼的贮藏时间延长1 周，保鲜效果显著。

关键词: Pickering乳液；抗菌肽；乳饼；保鲜；过氧化值