Maizura M, Fazilah A, Norziah M H, Karim A A
Food Technology Division, School of Industrial Technology, University Sains Malaysia, 11800 Penang, Malaysia.
J Food Sci. 2007 Aug;72(6):C324-30. doi: 10.1111/j.1750-3841.2007.00427.x.
Edible films were prepared from a mixture of partially hydrolyzed sago starch and alginate (SA). Lemongrass oil (0.1% to 0.4%, v/w) and glycerol (0% and 20%, w/w) were incorporated in the films to act as natural antimicrobial agent and plasticizer, respectively. The films were characterized for antimicrobial activity, water vapor permeability (WVP), tensile strength (TS), percent elongation at break (%E), and water solubility (WS). Fourier transform infrared (FTIR) spectroscopy was conducted to determine functional group interactions between the matrix and lemongrass oil. The zone of inhibition was increased significantly (P < 0.05) by addition of lemongrass oil at all levels in the presence and the absence of glycerol. This indicates that the film containing lemongrass oil was effective against Escherichia coli O157:H7 at all levels. In the absence of glycerol, the tensile strength of film decreased as the oil content increased, but there was no significant (P > 0.05) difference in percent elongation. The percent elongation at break and WVP values for film with 20% glycerol was found to be increased significantly (P < 0.05) with an increase in lemongrass oil content. Addition of lemongrass oil did not have any interaction with the functional groups of films as measured by FTIR.
可食用薄膜由部分水解的西米淀粉和海藻酸钠（SA）的混合物制备而成。柠檬草油（0.1%至0.4%，v/w）和甘油（0%和20%，w/w）分别添加到薄膜中，作为天然抗菌剂和增塑剂。对薄膜的抗菌活性、水蒸气透过率（WVP）、拉伸强度（TS）、断裂伸长率（%E）和水溶性（WS）进行了表征。采用傅里叶变换红外（FTIR）光谱法测定基质与柠檬草油之间的官能团相互作用。在有甘油和无甘油的情况下，添加各水平的柠檬草油均显著增加了抑菌圈（P<0.05）。这表明含柠檬草油的薄膜在各水平下对大肠杆菌O157:H7均有效。在无甘油的情况下，薄膜的拉伸强度随油含量的增加而降低，但断裂伸长率无显著差异（P>0.05）。发现含20%甘油的薄膜的断裂伸长率和WVP值随柠檬草油含量的增加而显著增加（P<0.05）。通过FTIR测定，添加柠檬草油与薄膜的官能团没有任何相互作用。
