Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331, USA.
J Food Sci. 2012 Oct;77(10):E280-6. doi: 10.1111/j.1750-3841.2012.02887.x. Epub 2012 Sep 25.
This study investigated physicochemical, microstructural, and antibacterial properties of β-chitosan-kudzu starch composite films with addition of 0%, 20%, 60%, or 100% kudzu starch (w starch/w chitosan) in 1% chitosan solution. Molecular interactions between chitosan and kudzu starch and the crystal structure of the films were also determined. Adding 60% kudzu starch reduced water vapor permeability and solubility of pure β-chitosan film by about 15% and 20%, respectively, whereas mechanical strength and flexibility of the film were increased about 50% and 25%, respectively. Micrograph showed that β-chitosan film was totally amorphous, and the composite films generally became rougher with more starch added. Fourier transform infrared and X-ray diffraction spectra showed that the 2 film-forming components were compatible with each other. Pure β-chitosan film resulted in 9.5 and 11.5 log CFU/mL reduction in Escherichia coli and Listeria innocua based on plate count method, respectively. Addition of kudzu starch reduced the antibacterial activity of film, but still achieved 8.3 and 10.3 log CFU/mL reduction in E. coli and L. innocua, respectively when kudzu starch to chitosan weight ratio was 1:1. Reduced antibacterial activity might attribute to the interaction of amino groups in β-chitosan with the hydroxyl groups in kudzu starch. This study demonstrated that kudzu starch effectively improved water barrier of β-chitosan film, and the composite films retained strong antibacterial ability.
One percent of β-chitosan containing 60% kudzu starch (w/w chitosan) composite films possessed better mechanical and water barrier properties than pure β-chitosan films, and showed strong antibacterial activity against both Gram-positive and Gram-negative bacteria. The films may be used as wraps or coatings to prolong the shelf life of different foods or other similar applications.
本研究考察了在 1%壳聚糖溶液中添加 0%、20%、60%或 100%葛根淀粉（w 淀粉/w 壳聚糖）的β-壳聚糖-葛根淀粉复合膜的物理化学、微观结构和抗菌性能。还确定了壳聚糖和葛根淀粉之间的分子相互作用以及膜的晶体结构。添加 60%的葛根淀粉使纯 β-壳聚糖膜的水蒸气透过率和溶解度分别降低约 15%和 20%，而膜的机械强度和柔韧性分别提高约 50%和 25%。显微镜照片显示，β-壳聚糖膜完全无定形，随着添加的淀粉量增加，复合膜通常变得更粗糙。傅里叶变换红外和 X 射线衍射光谱表明，两种成膜成分相互兼容。基于平板计数法，纯 β-壳聚糖膜分别使大肠杆菌和无害李斯特菌减少了 9.5 和 11.5 log CFU/mL。添加葛根淀粉降低了膜的抗菌活性，但当葛根淀粉与壳聚糖的重量比为 1:1 时，对大肠杆菌和无害李斯特菌的减少仍分别达到 8.3 和 10.3 log CFU/mL。抗菌活性降低可能归因于β-壳聚糖中的氨基与葛根淀粉中的羟基之间的相互作用。本研究表明，葛根淀粉可有效提高 β-壳聚糖膜的水阻隔性，且复合膜保留了较强的抗菌能力。
含有 60%葛根淀粉（w/w 壳聚糖）的 1%β-壳聚糖复合膜比纯 β-壳聚糖膜具有更好的机械和水阻隔性能，并对革兰氏阳性菌和革兰氏阴性菌均表现出强烈的抗菌活性。该膜可用于包装或涂层，以延长不同食品的保质期或其他类似应用。
