During recent years the use of smart colorimetric packaging films for monitoring food freshness has received widespread attention. However, their poor mechanical strength and hydrophilic properties are the major problems hindering the large-scale application. Here, we employed biodegradable cellulose and naphthoquinone dyes extracted from Arnebia euchroma (AENDs) to fabricate a novel colorimetric sensing film with high tensile strength of 227 MPa and hydrophobic properties (water contact angle of 112.2°) for real-time monitoring of the freshness of shrimp and pork. In addition, the effectiveness of the sensing film in detecting the freshness of shrimp and pork under 20 °C, 4 °C and-20 °C conditions was confirmed by measuring the total volatile basic nitrogen (TVBN) and total viable count (TVC). Visual observation confirmed that the sensing film clearly changed from rose-red to purple, then to bluish violet providing a good indication of spoilage, which correlated well with TVBN and TVC content in shrimp and pork measures by standard lab procedures. The colorimetric sensing film developed here would be promising in fabricating high mechanical strength and hydrophobic properties smart labels for visual monitoring the freshness of shrimp and pork.

近年来，使用智能比色包装薄膜来监测食品新鲜度已受到广泛关注。然而，它们差的机械强度和亲水性是阻碍大规模应用的主要问题。在这里，我们采用了从紫草中提取的可生物降解的纤维素和萘醌染料。（AENDs）制造一种新型比色传感薄膜，该薄膜具有227 MPa的高拉伸强度和疏水性（水接触角为112.2°），可实时监测虾和猪肉的新鲜度。此外，通过测量总挥发性碱性氮（TVBN）和总存活数（TVC），确认了传感膜在20°C，4°C和-20°C条件下检测虾和猪肉新鲜度的有效性。 。目视观察证实，感测膜从玫瑰红变为紫色，然后变为蓝紫色，可以很好地表明变质，这与通过标准实验室程序对虾和猪肉中的TVBN和TVC含量密切相关。