基于天然色素的新型色敏指示膜的鱼新鲜度检测方法及其响应机理

Timeliness, safety and nondestructive detection are the key elements of intelligent packaging for fish freshness. Currently, the safety hazard of intelligent packaging is existed and the sensitivity of intelligent packaging for freshness detection is not high, which severely restrict its application in freshness intelligent detection of fish. Therefore, the freshness detection method based on natural pigments with high safety, high sensitivity and short response time is particularly necessary. This study uses tilapia fillets as the research object, in addition, three kinds of natural pigments (cyanidin, pelargonidin, delphinidin) which is sensitive to volatile compounds of fish are selected based on the previous study. This research investigates the reaction degree and mechanism of color change of different natural pigments to volatile organic compounds by means of GC-MS, scanning electron microscopy, infrared spectrometer and colorimeter; studies the changes of material structure, molecular structure, mechanical properties, water absorption rate after the reaction between volatile organic compounds, and indicative film composed of natural pigments by means of GC-MS, scanning electron microscopy, infrared spectrometer, physical properties and water vapor permeation meter; explores mechanism of volatile organic compounds of the tilapia fillets with indicative films composed of natural pigments. The relationship between the total color difference (△E) of the indicative film and the quality of tilapia is analyzed, and the comprehensive evaluation method of fish freshness is constructed. The results will be significant to reveal response mechanism of volatile organic compounds of the tilapia fillets with indicative films composed of natural pigments, and provide theoretical basis for the preparation of high sensitivity, low cost and biodegradable intelligent indicative film and the establishment of comprehensive evaluation method of fish freshness.

快速、安全和无损是新鲜度智能包装技术的关键。目前新鲜度智能包装存在安全隐患、灵敏度低，严重制约其在鱼类新鲜度智能化检测中的应用。因此建立一种基于色敏指示膜的高安全性、高灵敏度且快速响应的鱼新鲜度智能检测方法尤为必要。拟以罗非鱼为研究对象，在前期研究基础上选择3种对鱼肉挥发性物质响应较灵敏的天然色素，采用气质联用仪、扫描电镜、红外光谱仪等技术分析贮藏过程中，天然色素对鱼肉各特征挥发性物质的响应变化，探讨天然色素对特征挥发性物质的变色灵敏度；研究天然色素指示膜与挥发性物质反应后的物质结构、分子结构、机械性能、水分吸附率变化，探索两者间的响应机理；并分析指示膜色差值与品质的相关性，构建鱼新鲜度综合检测方法。本项目对揭示挥发性物质与天然色素指示膜的响应机理意义重大，为建立高灵敏性、低成本、安全的鱼新鲜度智能指示膜检测方法提供重要理论依据并具有较大应用价值。

快速、无损和安全是新鲜度智能包装技术的关键。目前新鲜度智能包装存在一定安全隐患、灵敏度不高等问题，严重制约其在鱼类新鲜度智能化检测的应用。因此，一种安全性高、灵敏度高且响应时间短的基于色敏指示膜的鱼新鲜度智能检测方法尤为必要。本项目以罗非鱼为研究对象，研究了冷藏和常温条件下鱼肉品质变化规律及品质劣变相关的特征挥发性物质，采用变色灵敏度较高的3种天然色素-矢车菊色素、天竺葵色素和飞燕草色素为天然色素代表，研究了其在不同pH值下的颜色变化及变色机制；采用细菌纤维素膜作为基底材料制备天然色素指示膜，采用气质联用仪、扫描电镜、红外光谱仪、X射线衍射等技术，分析了指示膜物理化学结构及天然色素与基底材料的相互作用，研究了天然色素指示膜表面形态、物质结构、分子结构、微观晶体结构、机械性能、水分吸附率和色差值的变化；将制备的天然色素指示膜（不同pH值、不同浓度的天然色素）用于罗非鱼片新鲜度检测，分析了天然色素的物质结构与各特征挥发性物质的关系，探讨了天然色素对特征挥发性物质的变色机理；根据贮藏期间天然色素指示膜色差值的差异建立与罗非鱼片新鲜度之间的相关性，通过指示膜颜色变化完成对罗非鱼片新鲜度的指示作用，构建高效、敏感、实时的罗非鱼片新鲜度综合检测方法。本项目按照计划执行，完成了申报书的所有内容，为制备高灵敏性、低成本、安全、可降解的鱼类新鲜度智能指示膜及检测方法提供理论依据并具有重要的应用价值。. 项目执行期间，共发表学术论文4篇，其中SCI学术论文3篇，中文核心期刊论文1篇；授权发明专利1项，授权实用新型专利4项。具有新鲜度指示功能的智能包装可加强销售链的管理，为消费者提供可视化的食品品质信息，保障鱼类产品食品品质和安全性。