Solvent Mixture Optimization in the Extraction of Bioactive Compounds and Antioxidant Activities from Garlic (Allium sativum L.).

Garlic is a health promoter that has important bioactive compounds. The bioactive extraction is an important step in the analysis of constituents present in plant preparations. The purpose of this study is to optimize the extraction with the best proportion of solvents to obtain total phenolic compounds (TPC) and thiosulfinates (TS) from dried garlic powder, and evaluate the antioxidant activities of the optimized extracts. A statistical mixture simplex axial design was used to evaluate the effect of solvents (water, ethanol, and acetone), as well as mixtures of these solvents, after two ultrasound extraction cycles of 15 min. Results showed that solvent mixtures with a high portion of water and pure water were efficient for TPC and TS recovery through this extraction procedure. According to the regression model computed, the most significant solvent mixtures to obtain high TPC and TS recovery from dried garlic powder are, respectively, the binary mixture with 75% water and 25% acetone and pure water. These optimized extracts presented oxygen radical absorbance capacity. Pure water was better for total antioxidant capacity, and the binary mixture of water-acetone (75:25) was better for DPPH scavenging activity. These optimized extracts can be used for industrial and research applications.

Challenges of organic agriculture for the production of composts and vermicompost for the production of medicinal plants: a socioeconomic demand / Desafios da agricultura orgânica na produção de composto e vermicomposto na produção de plantas medicinais: uma demanda socioeconômica

Although the demand for organic fertilizers in agriculture is growing, it remains incipient in some production sectors, such as medicinal plant production, which does not possess specific technology for its development. Solid residues are highly contaminant to water sources, soil, populations and biodiversity but can potentially be used to produce organic composts and vermicompost, such production not only enables nutrient recycling but also acts on soil conditioning, increasing soil organic matter and improving its physical, chemical and biological characteristics, as well as strengthening organic production with an emphasis on medicinal plant production. In this context, recommendations for and applications of organic fertilizers available in the market were reviewed; in addition, the imminent socioeconomic demand for organic compost and vermicompost production was contextualized based on residues from coffee and sugarcane production and cattle farming for application to the medicinal plant production chain. It is concluded that although these sectors produce a considerable amount of residues, they are not being reused in formulation of organic composts and vermicompost, and commercial organic fertilizers recommended for medicinal plant production were not found. Thus, the formulation of vermicomposting and composting from the reuse of agricultural residues, are potential social, economic technologies and tools to be valued and disseminated to traditional and family farmers. (AU)

Embora a demanda por fertilizantes orgânicos na agricultura seja crescente, ela ainda é incipiente em alguns setores produtivos, como a produção de plantas medicinais, que não possui tecnologia específica para seu desenvolvimento. Os resíduos sólidos são altamente contaminantes para fontes de água, solo, populações e biodiversidade, mas podem ser potencialmente utilizados para a produção de compostos orgânicos e vermicomposto, tal produção não só possibilita a reciclagem de nutrientes, mas também atua no condicionamento do solo, aumentando a matéria orgânica do solo e melhorando seu aspecto físico, químico e características biológicas, além do fortalecimento da produção orgânica com ênfase na produção de plantas medicinais. Nesse contexto, foram revisadas as recomendações e aplicações dos fertilizantes orgânicos disponíveis no mercado; além disso, a iminente demanda socioeconômica pela produção de composto orgânico e vermicomposto foi contextualizada a partir dos resíduos da produção de café, cana-de-açúcar e pecuária para aplicação na cadeia produtiva de plantas medicinais. Conclui-se que embora esses setores produzam uma quantidade considerável de resíduos, eles não estão sendo reaproveitados na formulação de compostos orgânicos e vermicomposto, e não foram encontrados fertilizantes orgânicos comerciais recomendados para a produção de plantas medicinais. Sendo assim, a formulação de vermicompostagem e compostagem a partir do reaproveitamento de resíduos agropecuários, são potenciais tecnologias sociais, econômicas e ferramentas a serem valorizadas e disseminadas para os agricultores tradicionais e familiares. (AU)