食品科学 ›› 2021, Vol. 42 ›› Issue (3): 194-203.doi: 10.7506/spkx1002-6630-20200303-038

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基于甲基纤维素改性聚乙烯醇指示膜的制备、表征及对南美白对虾的鲜度指示

黄佳茵,周雅琪,陈美玉,李苑,吴甜甜,胡亚芹   

  1. (1.浙江大学生物系统工程与食品科学学院,智能食品加工技术与装备国家地方联合工程实验室,浙江省农产品加工技术研究重点实验室,南方果蔬保鲜技术集成科研基地,浙江省健康食品制造与品质控制国际合作基地,浙江 杭州 310058; 2.浙江大学馥莉食品研究院,浙江 杭州 310058;3.浙江大学宁波研究院,浙江 宁波 315100)
  • 发布日期:2021-02-25
  • 基金资助:
    国家自然科学基金面上项目(31871868)

Preparation and Characterization of Indicator Films Based on Polyvinyl Alcohol Modified by Methyl Cellulose and pH-Sensitive Dyes for Shrimp Freshness Monitoring

HUANG Jiayin, ZHOU Yaqi, CHEN Meiyu, LI Yuan, WU Tiantian, HU Yaqin   

  1. (1. National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Key Laboratory of Agricultural Products Processing Technology Research, Zhejiang Province, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Cooperation Base of Health Food Manufacturing and Quality Control, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, China; 2. Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China; 3. Ningbo Research Institute, Zhejiang University, Ningbo 315100, China)
  • Published:2021-02-25

摘要: 为实现水产品鲜度可视化实时监测,本研究以甲基纤维素(methyl cellulose,MC)共混改性聚乙烯醇(polyvinyl alcohol,PVA)为成膜基材,复配溴甲酚紫甲基红制备指示膜,比较基材配比对结构、物理及检测性能的影响,并应用于南美白对虾鲜度检测。结果表明:各组分相容性强,流变学结果表明m(MC)∶m(PVA)=3∶1时分子间作用力最强烈。MC的引入可改善PVA性能,当PVA和MC质量比为1∶3时,指示膜具有最高的抗拉强度((65.36±4.29)MPa)、疏水性能(水接触角(57.30±0.81)°)和阻隔性能。各指示膜均能对pH值响应,且具良好颜色稳定性。将性能最优的指示膜用于南美白对虾(4 ℃)鲜度检测,4 d时指示膜由红褐色转为紫褐色,对应次级鲜度;8 d时pH值和总挥发性盐基氮(total volatile basic nitrogen,TVB-N)含量分别达7.73±0.01和(60.90±7.00)mg/100 g,指示膜变为黑色,对应完全腐败。差异显著性分析表明指示膜颜色在不同鲜度区间具有明显差异,相关性分析表明指示膜色差值与pH值、TVB-N含量呈显著(P<0.05)或极显著(P<0.01)相关。鉴于伴随虾不同程度的腐败,指示膜可产生肉眼可辨的颜色变化,故可根据指示膜颜色对所保鲜虾类的鲜度等级进行划分,实现食品鲜度实时监控,具良好应用前景。

关键词: 指示膜;甲基纤维素;聚乙烯醇;鲜度检测

Abstract: In this study, indicator films were prepared using blends of methyl cellulose (MC) polyvinyl alcohol (PVA) as film-forming materials with the addition of bromocresol purple and methyl red. The effect of substrate composition on the structure, physical properties and detection performance of indicator films was investigated, and the application in shrimp freshness monitoring was also evaluated. The Fourier transform infrared (FTIR) spectroscopy results indicated strong compatibility among the film components and the rheological studies exhibited the strongest intermolecular force when the MC-to-PVA ratio was 3:1 (m/m). The introduction of MC could enhance the properties of PVA effectively, and the film with a MC-to-PVA ratio of 3:1 (m/m) had the highest tensile strength (65.36 ± 4.29) MPa and the strongest hydrophobic properties with a water contact angle of (57.30 ± 0.81)° as well as the best light and water vapor barrier performance. All the indicator films prepared in this study could response to pH change and showed good color stability. Furthermore, when it was applied to monitor shrimp freshness under refrigeration (4 ℃), on the fourth day, the color of the indicator film with the best properties changed from reddish brown to purple brown, indicating less fresh. On the eighth day, pH and total volatile basic nitrogen (TVB-N) content were 7.73 ± 0.01 and (60.90 ± 7.00) mg/100 g, respectively, and the color turned black, indicating severe spoilage. The film color was significantly different in response to various freshness degrees, and color difference was significantly correlated with pH and TVB-N content (P < 0.05 or 0.01). Considering the indicator film could produce color change discernible to naked eyes in response to different spoilage degrees, the freshness of preserved shrimps could be graded according to the film color. Therefore, the indicator film is promising for monitoring the freshness of food products in real time.

Key words: indicator film; methyl cellulose; polyvinyl alcohol; freshness monitoring

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