Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Center for Digital Agriculture, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
Food Chem. 2023 Mar 15;404(Pt A):134528. doi: 10.1016/j.foodchem.2022.134528. Epub 2022 Oct 10.
To address consumer-level food waste, and pollution from commercial plastics, we developed intelligent films using sodium alginate (SA), pectin (PC), cellulose nanocrystals (CNCs), and anthocyanins extracted from red cabbage (RCA). We also investigated two methods of reinforcing these films - cross-linking (CL), and the addition of CNCs. Both together and separately, these methods improved SA/PC films' mechanical properties and thermal stability. The optimal SA/PC/CNCs/RCA/CL films exhibited pH-dependent color-response properties and high water resistance. These were then tested as colorimetric freshness indicators for shrimp samples, both through seepage and the monitoring of volatile compounds. The colors of the indicators changed from lilac to dark green to greenish-yellow after storage at 25 °C for 72 h, whereas at 4 °C, they changed much more slowly over the same time period. This demonstrated the excellent potential of such films to reduce food waste by providing real-time warnings of pH variation resulting from spoilage.
为了解决消费者层面的食物浪费和商业塑料造成的污染问题，我们使用海藻酸钠 (SA)、果胶 (PC)、纤维素纳米晶体 (CNC) 和从紫甘蓝中提取的花青素开发了智能薄膜。我们还研究了增强这些薄膜的两种方法——交联 (CL) 和添加 CNC。这两种方法都可以提高 SA/PC 薄膜的机械性能和热稳定性。最佳的 SA/PC/CNC/RCA/CL 薄膜具有 pH 值依赖性的颜色响应特性和高耐水性。然后，我们将这些薄膜用作虾样品的比色新鲜度指示剂，通过渗滤和监测挥发性化合物进行测试。在 25°C 下储存 72 小时后，指示剂的颜色从淡紫色变为深绿色再变为黄绿色，而在 4°C 下，在相同的时间内变化要慢得多。这表明这种薄膜通过提供由变质引起的 pH 值变化的实时警告，具有减少食物浪费的巨大潜力。
