基于2种色素的pH响应型指示膜的制备及性能研究

Preparation and Performance of pH Responsive Indicator Films Based on Two Pigments

目的色素是pH响应型指示膜的重要组成,其性质关系着智能指示膜的响应性能,为了探究不同色素对智能指示膜性能的影响。方法以紫草色素(AERE)和紫甘薯色素(ATH)为pH显色剂,以琼脂糖(AG)为成膜基质、甘油为增塑剂,采用流延法制备得到了AG-AERE和AG-ATH 2种体系pH响应型指示膜。采用FT-IR、SEM对指示膜的微观结构进行了表征,对指示膜的力学性能、水溶解性、水溶胀性、水蒸气透过性等进行了测定,同时还考察了其pH响应性、颜色稳定性及体系中染料迁移等性能。结果AG-AERE体系指示膜在4种实验条件下的颜色稳定性均好于AG-ATH体系指示膜,AG-ATH体系指示膜在不同pH区间的颜色响应变化值明显大于AG-AERE体系指示膜。结论AG-ATH体系指示膜对pH变化更为敏感,更适合作为pH响应型新鲜度指示膜,AG-AERE体系指示膜在水性和酸性食品模拟液中染料迁移较低,而AG-ATH体系指示膜在油脂类食品模拟液中几乎无染料迁移,更适合用于油脂类食品的指示包装。

Pigment is an important component of pH-responsive indicator films,and its properties are related to the response performance of intelligent indicator films.The work aims to investigate the influence of different pigments on the performance of intelligent indicator films.With Arnebia euchroma roots extract(AERE)and Anthocyanins(ATH)pigments as pH indicators,agarose(AG)as a film-forming matrix,and glycerol as a plasticizer,AG-AERE and AG-ATH pH-responsive indicator films were prepared by the casting method.The microstructure of the indicator films was characterized by FT-IR and SEM,and their mechanical properties,water solubility,water swelling,and water vapor permeability were measured.The pH-responsive properties,color stability,and dye migration of the two system films were also evaluated.Through experiments,it was discovered that the color stability of the AG-AERE indicator film was better than that of the AG-ATH indicator film under the four experimental conditions,and the AG-ATH indicator film had a larger color change in different pH ranges than the AG-AERE indicator film.The AG-ATH indicator film is more sensitive to pH changes and is more suitable as a pH-responsive freshness indicator.The dye migration of the AG-AERE indicator film is lower in water and acidic food simulant solutions,while the AG-ATH indicator film has almost no dye migration in oil-based food simulant solutions.Therefore,the AG-ATH indicator film was more suitable for indicating the freshness of oil-based foods.