Herein, a new intelligent indicator with polylactic acid (PLA)/ polyethylene glycol (PEG)/calcium bentonite (CB) blend and Malva sylvestris, as a source of anthocyanins, was developed, characterized, and used for visual freshness monitoring of a variety of proteinous foods. Anthocyanins were incorporated successfully into PLA/PEG/CB with no significant change in the chemical structure of the indicator. The hydrophilic (water contact angle of 43.9°) indicator represented visual color changes from light red (at pH 2) to green (at pH 11). Moreover, PLA/PEG/CB-Malva indicator visually distinguished (ΔE > 5) fresh, medium fresh, and spoiled shrimp and fish roe (during 6 days at 4 °C), but discriminated only fresh and spoiled minced beef and chicken fillets (during 10 days at 4 °C), which were strongly correlated with the total volatile basic nitrogen of food samples. The PLA/PEG/CB-Malva indicator has a satisfying application for monitoring the freshness of various proteinous foods.

Industrial relevance text

This study showed that anthocyanins extracted from Malva Sylvestris can be used efficiently in food smart packaging. The incorporation of anthocyanins into polylactic acid has led to the production of a novel intelligent freshness indicator. The indicator revealed an appropriate response to the spoilage of different proteinous foods with the capacity to differentiate between fresh, medium fresh, and spoiled foods. This capability is an important feature in commercializing freshness indicators.

中文翻译：

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一种基于聚乳酸和花青素的卤色指示剂，用于肉末、鸡柳、虾和鱼子的视觉新鲜度监测

在此，开发、表征了一种以聚乳酸（PLA）/聚乙二醇（PEG）/钙膨润土（CB）共混物和锦葵作为花青素来源的新型智能指示剂，并对其进行了视觉新鲜度监测。蛋白质食物。花青素成功掺入 PLA/PEG/CB 中，指示剂的化学结构没有显着变化。亲水性（水接触角为 43.9°）指示剂代表了从浅红色（pH 2）到绿色（pH 11）的视觉颜色变化。此外，PLA/PEG/CB-Malva 指示剂在视觉上区分（Δ E > 5) 新鲜、中等新鲜和变质的虾和鱼子（在 4°C 下 6 天），但仅区分新鲜和变质的碎牛肉和鸡肉片（在 4°C 下 10 天），这与食品样品的总挥发性碱性氮。PLA/PEG/CB-Malva 指示剂在监测各种蛋白质食品的新鲜度方面具有令人满意的应用。

工业相关文本

这项研究表明，从锦葵中提取的花青素可以有效地用于食品智能包装。将花青素掺入聚乳酸中，产生了一种新型智能新鲜指示剂。该指标揭示了对不同蛋白质食品腐败的适当反应，能够区分新鲜、中等新鲜和腐败食品。这种能力是新鲜度指标商业化的一个重要特征。