Physicochemical stability and quality of freeze-dried Tectona grandis L. for phytosanitary use

 

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Autoři: Luna-Fox, Sting Brayan, Bravo-Sánchez, Luis Ramón, Rivera-Barreto, Jannys Liseth, Guamán-Castillo, José Guillermo, Bermúdez del Sol, Abdel
Médium: artículo original
Stav:Versión publicada
Datum vydání:2026
Popis:Introduction. The development of phytosanitary products from plant extracts requires the establishment of quality and stability criteria to guarantee their efficacy and safety. Objective. To determine the specifications for the physicochemical quality control of a phytosanitary product based on a lyophilized aqueous extract of Tectona grandis leaves and to evaluate the stability under temperature-accelerated conditions that allow establishing its shelf life. Materials and methods. The research was conducted in the province of Pastaza, Ecuador, in the period January-May, 2024. Mature leaves of T. grandis were collected, dried, pulverized and subjected to ultrasound-assisted extraction. The aqueous extract was freeze-dried and evaluated for pH, electrical conductivity, moisture, total ash, total polyphenol content and antioxidant activity. Bowker’s method was applied to establish specification limits with seven replicates and 95 % confidence. Stability was evaluated by loss of antioxidant activity in accelerated storage (30, 40 and 50 °C), using kinetic models (zero, first and second order) and the Arrhenius equation to project shelf life at 4, 15 and 20 °C. Results. The product showed a pH of 5.46-5.48; conductivity 5.1-5.9 µS/cm; moisture of 13.4-14.9 %; total ash 12.83-13.25 %; polyphenols 55.33-57.93 mg EAG/100 g and an antioxidant activity of 17895.4-16526.2 mgEqTrolox/100g. The three kinetic models allowed adequate prediction of shelf life. Conclusions. The quality and stability specifications of the lyophilized extract of T. grandis were defined, which confirms its potential as a natural phytosanitary product.
Země:Portal de Revistas UCR
Instituce:Universidad de Costa Rica
Repositorio:Portal de Revistas UCR
Jazyk:Español
OAI Identifier:oai:portal.revistas.ucr.ac.cr:article/346
On-line přístup:https://revistas.ucr.ac.cr/index.php/ragromeso/article/view/346
Klíčové slovo:teca
fungicida agrícola
antioxidante
estabilidad acelerada
Arrhenius
Bowker
teak
agricultural fungicide
antioxidant
accelerated stability