Koshy Rekha Rose, Reghunadhan Arunima, Mary Siji K, Pillai Prasanth S, Joseph Seno, Pothen Laly A
Postgraduate and Research Department of Chemistry, Bishop Moore College, Mavelikara, 690101, Kerala, India.
Postgraduate and Research Department of Chemistry, CMS College, Kottayam, 686001, Kerala, India.
Curr Res Food Sci. 2022 Apr 14;5:743-751. doi: 10.1016/j.crfs.2022.03.015. eCollection 2022.
Sensor films are finding wide range of applications. Different type of sensing films is fabricated for the identification of chemicals, ions, heavy metals, changes in the pH, etc. The present report is on the fabrication of pH sensitive films from completely natural sources-soy protein isolate, chitin nano whiskers and flower extract. The highly crystalline chitin nano whiskers (CNW) were extracted from prawn shell under neutral condition via steam explosion technique. Multifunctional Soy protein isolate (SPI) films were prepared by adding chitin nanowhisker and flower extract and its effect on thermal, mechanical and moisture properties of SPI film was investigated. The isolated CNW presented a needle like morphology with a diameter of 10-50 nm and a crystallinity index of 99.67%. The extracted chitin nanowhisker was used to prepare biodegradable films with soy protein isolate immobilized with anthocyanin from flower extract. The prepared Soy protein -chitin nanowhisker films was found to have a tensile strength of about 15.45 ± 0.97 MPa with 8% chitin nanowhisker addition. The addition of CTE was found to decrease the tensile strength of SPI-CNW film but was found to make the film pH sensitive. The developed indicator film showed visible color changes in acidic and basic medium and hence can be used to monitor the freshness of food materials.
传感薄膜正被广泛应用。人们制备了不同类型的传感薄膜用于识别化学物质、离子、重金属、pH值变化等。本报告介绍了用完全天然的原料——大豆分离蛋白、几丁质纳米晶须和花卉提取物制备pH敏感薄膜的方法。通过蒸汽爆破技术在中性条件下从虾壳中提取出高度结晶的几丁质纳米晶须（CNW）。通过添加几丁质纳米晶须和花卉提取物制备了多功能大豆分离蛋白（SPI）薄膜，并研究了其对SPI薄膜热性能、机械性能和吸湿性能的影响。分离得到的CNW呈现出针状形态，直径为10 - 50纳米，结晶度指数为99.67%。提取的几丁质纳米晶须用于制备可生物降解薄膜，该薄膜将大豆分离蛋白与花卉提取物中的花青素固定在一起。发现添加8%的几丁质纳米晶须时，制备的大豆蛋白-几丁质纳米晶须薄膜的拉伸强度约为15.45±0.97兆帕。发现添加CTE会降低SPI-CNW薄膜的拉伸强度，但会使薄膜对pH敏感。所开发的指示薄膜在酸性和碱性介质中呈现出明显的颜色变化，因此可用于监测食品原料的新鲜度。
