PROPRIEDADES TÉRMICAS, BIOATIVAS E ANTIMICROBIANAS DOS FRUTOS DE CORDIA DICHOTOMA

• Autor(a) principal: Liu Hsuan Han
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFMS
• Texto Completo: https://repositorio.ufms.br/handle/123456789/8257
• topic: Cordia dichotoma, embalagens biodegradáveis, embalagens bioativas, fenólicos totais, análise térmica, atividade antimicrobiana

The fruit of Cordia dichotoma, consumed for centuries in Asia, was introduced to Brazil by Taiwanese immigrants in the 1990s. Various scientific articles indicate that the fruit has antimicrobial, antioxidant, and thermal resistance properties, which are interesting for the field of Food Science and Technology. This study aimed to evaluate the thermal, bioactive, and antimicrobial properties of Cordia dichotoma fruits, with the intention of assessing their potential use in obtaining natural bioactive and antimicrobial extracts for use in food packaging. The fruits were collected in Campo Grande-MS and taken to the Food Science Unit of UFMS, where they were cleaned and separated into peel and pulp. Both parts were lyophilized, obtaining lyophilized peel (LP) and lyophilized pulp (PP). Firstly, LP and PP were characterized in terms of their centesimal composition (moisture, proteins, carbohydrates, lipids, and ashes), with results expressed in g per 100 g-1. Subsequently, LP and PP were subjected to the evaluation of thermal properties: thermogravimetric behavior. TG/DTG curves were generated using the TGA-Q-50 Thermogravimetry equipment from TA Instruments. For the evaluation of bioactive and antimicrobial properties, extracts were prepared using water and solutions of ethanol and acetone in water at concentrations of 25, 50, 75, and 100%, v:v) to assess which would optimize the extraction of total phenolic compounds, with their antimicrobial activity evaluated later. The total phenolic compounds (TP) were quantitatively determined in the extracts, by colorimetry, and the results were expressed in mg gallic acid equivalent g-1. Subsequently, the ethanolic and aqueous extracts were evaluated for their antimicrobial properties against microorganisms of interest to the food industry: Bacillus cereus, Staphylococcus aureus, Salmonella spp., Escherichia coli, and Listeria monocytogenes. The disk diffusion method, proposed by Kirby-Bauer, was employed to determine the efficacy of the antimicrobial tests. The experimental design was completely randomized. All analyses were performed in triplicate. The results of phenolic compound content were subjected to ANOVA and the means compared by Tukey's test (p≤0.05). Regarding thermal analysis, the TG/DTG curve revealed four main events, with water loss at 109.4°C, decomposition of carbohydrates, lipids, and proteins at 370.06°C, decomposition of carbohydrates, lipids, and proteins at 520.70°C, and the remaining 9.066% of the mass corresponding to oxide residues. The results indicate that the fruit has thermal resistance up to 120oC. Regarding bioactive properties, it was observed that the 25% aqueous and ethanolic extracts showed greater extraction (p≤0.05) of TP compared to the other solvents tested, with the TP content in PP significantly higher (p≤0.05) than that observed in LP. The fruits also showed higher TP levels than other fruits of the same family. No antimicrobial activity was observed in the ethanolic and aqueous extracts against the microorganisms researched in this work. The results obtained indicate thermal resistance and antioxidant potential of the fruit for application in active biodegradable food packaging.