摘要
为探索新型生物膜材料的制备方法及抗菌、抗氧化活性,以大豆分离蛋白为成膜基质,添加适量的增塑剂和丁香精油成分,制备可食性复合膜。研究丁香精油添加对膜的物理性能、抗氧化活性和抗菌活性的影响。结果表明,当丁香精油添加量在0～2.0%时,随着添加比例的增加,复合膜的抗拉强度和透明度降低,断裂伸长率和透湿性升高;添加丁香精油显著提高了大豆分离蛋白膜的抗氧化活力(P<0.05),具有很好的抑制肉中常见腐败菌和致病菌的效果,对革兰氏阳性菌单增李斯特菌和清酒乳杆菌的抑菌效果好于革兰氏阴性菌大肠杆菌和荧光假单胞菌,其中对单增李斯特菌抑菌效果最好。当丁香精油添加量为1.5%时,制备复合膜具有优良抗菌、抗氧化活性,且综合理化性能较佳。丁香精油可添加到大豆分离蛋白中制备具有抑菌抗氧化性能的可食性膜,此复合膜具有作为活性包装的潜力。
In this study, clove essential oil （CEO） concentrations ranging from 0 to 2.0%, incorporated in a soy protein isolate （SPI） film were used. Antibacterial activity, physical, mechanical, barrier, and antioxidant properties of SPI films were evaluated. The addition of clove essential oil to the film-forming emulsion led to an increase in the thickness of the films, which ranged between 47.37pm and 49.59pm. However, this effect was only significant at the highest level of CEO used （2%）. Thus, clove essential oil might contribute to the formation of a loose film matrix with increased thickness. In general, the moisture content value increased as CEO was incorporated into the SPI film, which is attributed to the breakup of the film network. The addition of CEO at a level of 2% （v/v） decreased the moisture content value significantly （P〈0.05）, which is attributed to an increase in the hydrophobicity of films. The incorporation of clove essential oil decreased the water solubility of SPI films with respect to control. The addition of CEO at a level of 2% （v/v） decreased the water solubility value significantly （P〈0.05）. In our study, a lower moisture content with minimum solubility was achieved for films formulated with 2% clove essential oil. The water vapor permeability （WVP） of CEO incorporated films were slightly increased from 13.5 to 19.07 g.mm/（m2.d.kPa） as the concentrations of CEO （P〈0.05）. Film without clove essential oil had a tensile strength of 22.48MPa. Tensile strengths were weaker for films containing CEO than for the control film, significantly （P〈0.05） decreasing as the oil concentration increased. Conversely, the elongation at break of SPI films increased significantly （P〈0.05） from 25.50% to 36.68%. Additionally, CEO incorporated films became darker and showed a higher green value. The antioxidant activity of SPI films with and without incorporated clove essential oil was determined. The results showed that 1,1-Diphenyl-2-picrylhydrazyl radical （DPPH） scavenging activity and reducing power of the SPI films was significantly increased （P〈0.05） with an increasing CEO concentration. The antibacterial activities of SPI films incorporated with clove essential oil against Gram-negative and Gram-positive bacteria were determined. This method is based on the measurement of the clear zone caused by the growth inhibition produced by a film disk containing the antimicrobial agent when put in direct contact with a bacterial culture. Films containing 1% of CEO were effective against all test microorganisms, and exhibited a strong inhibitory effect on the growth of Listeria monocytogenes and Lactobacillus sake, as evidenced by minimal growth around the film cuts. Inhibition was increased with an increasing concentration of essential oil. As expected, the films containing the highest oil content （2%） presented the greatest zone of inhibition （P〈0.05）. SPI films with CEO were significantly more effective against gram-positive bacteria （Listeria monocytogenes and Lactobacillus sake） than against gram-negative bacteria （Escherichia coli and Pseudomonas fluorescens）. The lower antibacterial activity against Escherichia coli and Pseudomonas fluorescens could be due to the higher resistance of gram-negative microorganisms to these compounds. Our results pointed out that the incorporation of clove essential oil as a natural antibacterial agent has potential for using the developed film as an active packaging.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2014年第4期247-254,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然基金-河南人才培养联合基金项目(C2003)
关键词
膜
物理特性
包装
丁香精油
抗氧化
抗菌
films
physical characteristics
packaging
clove essential oil
antioxidant activity
antibacterial activity
