Estudio de diferentes plantas autóctonas de Ecuador para su aplicación como conservantes naturales en productos alimenticios

Abstract

Este trabajo buscó determinar el potencial antioxidante y antimicrobiano de tres plantas medicinales nativas de Ecuador (Simira ecuadorensis, Piper carpunya e Ilex guayusa). Se obtuvieron cuatro extractos de cada una de ellas mediante diferentes procesos, denominándose como liofilizado (H2O), atomizado (ATOM), etanol (ETOH) y etanol-agua (ETOH-H2O). Se determinó su perfil volátil (GC-MS), se evaluó su antimicrobiana in vitro (frente a 20 bacterias patógenas y alterantes de alimentos) y aplicados a modelos alimentarios (pollo, pescado y arroz cocido). Se determinó su actividad antioxidante in vitro (fenoles totales, DPPH, FRAP, ABTS) y su efecto protector frente a la oxidación lipídica de hamburguesas de cerdo (Tbars). Destacaron las familias de monoterpenos, fenoles volátiles y alcoholes, que contienen compuestos como: 1-8 cineol, piperitona, cimeno, 1-hexanol, safrol, los cuales pueden ser los responsables de la actividad antioxidante y antimicrobiana. Los extractos de P. carpunya afectaron a ocho de las 20 bacterias, los de S, ecuadorensis a siete e I. guayusa a cinco. El extracto ETOH-H2O de S. ecuadorensis tuvo una notable actividad antimicrobiana en productos de pescado (hamburguesas y caldo), su extracto atomizado también frente a C. jejuni en caldo de pollo y el extracto ETOH-H2O de P. carpunya contra C. perfringens y bacterias psicrófilas en rissotto. La mejor capacidad antioxidante in vitro fue de S. ecuadorensis, seguida de P. carpunya e I. guayusa, las cuales tienen un efecto protector contra la oxidación lipídica en hamburguesas de cerdo durante un período de 14 días de almacenamiento en refrigeración. Estos resultados sugieren el potencial de estos extractos como aditivos naturales para la industria alimentaria.

Ecuador, due to its privileged geographical location covering the Andean Mountain range, coastal areas, Amazon rainforest, and islands, has exceptional biodiversity. Additionally, it holds a valuable legacy of ancestral knowledge regarding the use of medicinal plants by indigenous communities. Despite this, a large part of this cultural and natural heritage has not been studied or used, which represents a risk since important resources for society and science may be lost. Current scientific research has focused on exploring the potential of certain plants to prevent food deterioration and extend shelf life, opening vast possibilities given the existing species diversity. Furthermore, this coincides with emerging market trends, especially with the clean label concept in food processing, which implies the production of products with natural and recognizable ingredients, in response to the growing demand for healthy and conscious options by of consumers. Therefore, this thesis aimed to evaluate the chemical composition, as well as the antimicrobial and antioxidant capacity of extracts from three species of plants belonging to the Ecuadorian biodiversity and the Andean countries, using both in vitro methods and tests in food models to better understand its effectiveness and potential application in the food industry. The volatile profile of Simira ecuadorensis (guápala), Piper carpunya (guaviduca), and Ilex guayusa (guayusa) was investigated to identify the volatile compounds present in the plant and understand their potential use in the food industry. Four types of extracts were obtained: two extracted with water, one subsequently freeze-dried (H2O), and one spry-dried (ATOM); one extracted with ethanol (ETOH), and another with ethanol-water (ETOH-H2O). Gas chromatography determined that P. carpunya had the highest number of volatile compounds, followed by S. ecuadorensis and I. guayusa. Terpenes (monoterpenes) were the predominant compounds in all plants.