OTIMIZAÇÃO DA EXTRAÇÃO DE PRÓPOLIS VERDE PELA ATIVIDADE ANTIFÚNGICA E INCORPORAÇÃO EM BIOFILME DE QUITOSANA

O mercado de própolis brasileiro sofreu grande expansão, levando o setor de beneficiamento a buscar a melhor forma de produzir extratos com atividades biológicas. O objetivo deste trabalho foi otimizar a extração de própolis verde pela atividade antifúngica e realizar a incorporação em um biofilme de quitosana. Os extratos foram preparados utilizando etanol, acetona, acetato de etila e isopropanol, de acordo com três planejamentos, e a concentração inibitória mínima (CIM) e a concentração fungicida mínima (CFM) foram determinadas contra Candida albicans, Candida tropicalis e Candida glabrata. A partir da CIM, realizou-se a análise de superfície de resposta, para encontrar as condições ótimas de extração para cada planejamento. Os extratos otimizados foram incorporados em biofilmes de quitosana que, posteriormente, foram avaliados quanto a espessura, permeação de vapor de água, solubilidade em água e atividade anti-Candida. Verificou-se que todos os extratos testados apresentaram atividade antifúngica contra as três espécies de Candida. Destacou-se o extrato obtido com acetona/etanol que apresentou os menores valores de CIM e CFM (0,76 - 2,50 mg/mL). Observou-se que os pontos ótimos de extração de cada planejamento foram as misturas de: acetona/isopropanol, acetona/etanol e acetato de etila/isopropanol e os biofilmes incorporados com estes extratos mostraram poucas diferenças de espessura, permeabilidade de vapor e solubilidade em água em relação ao controle. O biofilme contendo extrato obtido por acetona/isopropanol foi o que demonstrou maior atividade anti-Candida. Estes resultados mostram a importância da otimização dos processos de extração de própolis para aplicação e desenvolvimento de produtos.

Effects of supplementation with kombucha and green banana flour on Wistar rats fed with a cafeteria diet

Introduction

With the increase of chronic diseases as a consequence of the population's eating habits, there is also a growing interest in foods rich in bioactive compounds capable of mitigating these diseases. Thus, this study aimed to evaluate the effects of supplementation with kombucha and green banana flour (GBF) on Wistar rats fed with cafeteria diet (CAF).

Methods

The animals were randomized into five groups of seven animals each, which were fed with the following diets: Treatment 1 (T1): Control treatment/commercial feed; Treatment 2 (T2): cafeteria diet (CAF); Treatment 3 (T3): CAF + kombucha; Treatment 4 (T4): CAF + green banana flour (GBF); Treatment 5 (T5): CAF + GBF + kombucha. Daily weight gain, daily food consumption, feed conversion, blood glucose, total cholesterol and fractions, triglycerides, liver enzymes, antioxidant activity, and body composition were evaluated.

Results

T5 presented lower feed intake and less weight gain. Liver histology revealed vacuolization in all treatments except T1, which was confirmed by the results of liver enzymes. There was no increase in blood glucose, and changes were observed in the lipid profile of the animals. T1 had the lowest body fat and the highest protein levels. Differences were observed for the antioxidant capacity in the liver of animals among treatments.

Conclusion

The intake of cafeteria diet altered the lipid and liver profile of the animals and the consumption of kombucha and GBF did not prevent these changes. The high polyphenols level of kombucha did not exert a hepatoprotective effect as an antioxidant. However, this supplementation generated greater satiety in the animals, leading to less weight gain until the end of the experiment.

Antioxidant and antibacterial activity and preliminary toxicity analysis of four varieties of avocado (Persea americana Mill.)

Abstract The antioxidant and antibacterial activity and toxicity of natural products can change according to plant variety, as well as the part of the plant which is analyzed. In this study, peel, pulp and seed of four avocado varieties (Quintal, Fortuna, Margarida, and Hass) were analyzed for antioxidant and antibacterial properties and toxicity. There are few studies in the literature comparing these three first varieties. Antioxidant capacity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazil), ABTS [2,2'-azino-bis- (3-ethylbenzothiazoline-6-sulfonic acid)], and FRAP (Ferric Reducing Ability Power) methods, along with the content of phenolic compounds and flavonoids. Principal component analysis was applied for antioxidant tests. Antibacterial activity against food pathogens was assessed by the minimum inhibitory concentration and minimum bactericidal concentration tests. Toxicity was evaluated against Artemia salina and also by hemolytic activity. The ethanolic extract of Quintal variety peel presented the greatest antioxidant and antibacterial activity. This same extract showed no toxicity in the preliminary tests, and shows great potential for food industry application as an additive.