聚離胺酸-葡萄聚糖複合物 (複合物；ε-polylysine-dextran conjugate) 乃藉由梅納反應形成。選取食品中常見之六種格蘭氏陽性菌和陰性菌，藉由細胞被破壞後會造成菌體內部成分釋出，來探討複合物之抗菌性。結果顯示該複合物保留了大部份原有聚離胺酸之抗菌性。當添加聚離胺酸或複合物於菌體中，不論陽性菌或陰性菌釋出之物質在260 nm吸收光譜中有快速的增加；但因陽性菌或陰性菌之細胞壁結構不同，故吸收值有些不同。更進一步應用螢光染劑 (NPN) 探討菌體外膜通透性的影響，結果顯示聚離胺酸或複合物可加速NPN進入細胞中。另外，當此複合物添加於咖啡奶油球產品中時，發現兼具其保存效果及乳化功能，故應可有效運用於食品中。

ε-Polylysine-dextran conjugate is a compound conjugated with ε-polylysine (PL) and dextran through the Maillard reaction. The antimicrobialactivity of PL-dextran conjugate was investigated using six Gram-positive and Gram-negative bacteria. The integrity of the cell membranes of the
representative bacteria was determined by the amount of intracellular components released from the cells. It was found that the PL-dextran conjugate retained most of the original antimicrobial activity of PL.When treated with PL or the PL-dextran conjugate, the amount of releasing materials at absorbance of 260 nm quickly increased in both Gram-negative and positive bacteria, but the absorbance values were different due to the difference in cell structures. Furthermore, an outer membrane (OM) permeability assay was performed by fluorescent probe 1-N phenylnaphthylamine (NPN). The results showed that PL or PL-dextran conjugate rapidly increased the NPN uptake. In addition, the preservative effect and the emulsifying properties of the PL-dextran conjugate were also observed when it is applied in coffee whitner. These findings
indicate that the PL-dextran conjugate can be applied in the food processing industry.