Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E-32004 Ourense, Spain.
Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolonia, 5300-253 Bragança, Portugal.
Molecules. 2020 Jan 30;25(3):614. doi: 10.3390/molecules25030614.
Tannins are polyphenolic compounds naturally found in vegetables. Their presence in nature has prompted their historical use in many different ways. The revision of their traditional utilization has allowed their further modification aiming for an industrial application. Sometimes these modifications have implied the addition of harmful substances such as formaldehyde, classified as a carcinogen of category B1. In other cases, these natural tannins have been replaced by synthetic compounds that threaten human and animal health and damage the environment. Therefore, currently, both academy and industry are searching for the substitution of these unsafe complexes by the increasing inclusion of tannins, natural molecules that can be obtained from several and diverse renewable resources, modified using harmless additives. To achieve promising results, cost-efficient and eco-friendly extraction methods have been designed. Once these green alternatives have been isolated, they have been successfully applied to many fields with very assorted aims of utilization such as coagulants, adhesives, floatation agents, tannings, dyes, additives, or biomolecules. Therefore, this review offers a global vision of the full process that involves the tannin's technological application including an overview of the most relevant tannin sources, effective extraction methods, and their utilization in very diverse fields.
单宁是天然存在于蔬菜中的多酚类化合物。它们在自然界中的存在促使人们以许多不同的方式对其进行历史应用。对其传统用途的修订使得人们能够进一步对其进行改性，以实现工业应用。有时，这些改性意味着添加甲醛等有害物质，甲醛被归类为 B1 类致癌物。在其他情况下，这些天然单宁已被合成化合物所取代，这些合成化合物会威胁人类和动物的健康，并破坏环境。因此，目前学术界和工业界都在通过越来越多地包含单宁来寻找这些不安全复合物的替代品，单宁是一种天然分子，可以从多种可再生资源中获得，并使用无害的添加剂进行改性。为了取得有希望的结果，已经设计了具有成本效益和环保效益的提取方法。一旦这些绿色替代品被分离出来，它们就已经成功地应用于许多领域，具有非常多样化的利用目的，如凝结剂、粘合剂、浮选剂、鞣剂、染料、添加剂或生物分子。因此，本综述提供了涉及单宁技术应用的全过程的全景视图，包括对最相关的单宁来源、有效提取方法的概述，以及它们在非常多样化的领域中的应用。
