Edible biopolymers are used as barrier coatings to preserve food products quality, but they have never been studied for use with green coffee beans. In the present work, biopolymeric coatings were developed and characterized in order to determine the treatment that would best retain the physical and sensorial properties of green coffee beans. The factors investigated were the type of biopolymer (starch and chitosan), pre-drying time (1 and 3 h) of the suspensions in an oven, and the number of immersions (1 and 2) of the green coffee beans in the suspensions. Tests were performed on coated beans (color and water content), films (contact angle with water and moisture), suspensions (rheological behavior after pre-drying), and beverages obtained from coated and roasted coffee beans (sensory quality). Contact angle and moisture analyses revealed that starch resulted in higher resistance to moisture than did chitosan treatments. Pre-drying for 3 h changed only the viscosity resulting from starch-based treatment. The treatment that entailed the use of starch, 3 h of pre-drying, and one immersion was the one that best retained color and water content characteristics of coated green coffee beans compared to control (uncoated green coffee beans). Moreover, neither biopolymer altered the sensory quality.

可食用的生物聚合物被用作阻隔涂层，以保持食品的质量，但是从未对它们与生咖啡豆一起使用进行过研究。在目前的工作中，开发了生物聚合物涂层并对其进行了表征，以确定可以最好地保留生咖啡豆的物理和感官特性的处理方法。研究的因素包括生物聚合物的类型（淀粉和壳聚糖），悬浮液在烤箱中的预干燥时间（1和3小时）以及生咖啡豆在悬浮液中的浸入次数（1和2）。对被覆咖啡豆（颜色和水含量），薄膜（与水和湿气的接触角），悬浮液（预干燥后的流变行为）以及从被覆咖啡豆和烘焙过的咖啡豆获得的饮料（感官品质）进行了测试。接触角和水分分析表明，淀粉比壳聚糖处理对水分的抵抗力更高。预干燥3小时仅改变了基于淀粉的处理所产生的粘度。与对照（未涂层生咖啡豆）相比，需要使用淀粉，预干燥3小时并浸入一遍的处理是涂层生咖啡豆的最佳保留颜色和含水量特征的处理。而且，两种生物聚合物均未改变感觉质量。一种浸入是与对照（未包覆生咖啡豆）相比，包覆生咖啡豆的最佳保留颜色和含水量特征的一种。而且，两种生物聚合物均未改变感觉质量。一种浸入是与对照（未包覆生咖啡豆）相比，包覆生咖啡豆的最佳保留颜色和含水量特征的一种。而且，两种生物聚合物均未改变感觉质量。