Studies about preservative and antioxidant activity of essential oils have been encouraged in recent years, given their importance to food industry. The aim of the current study was to evaluate the antioxidant properties and antimicrobial activity of essential oils deriving from Syzygium aromaticum, Cymbopogon citratus and Lippia alba against lactic and pathogenic bacteria responsible for food-borne diseases. Essential oil antibacterial activity was assessed through disc diffusion and macrodilution tests conducted in a mixed lactic culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus (YF-L903) and of Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 6538), Salmonella enterica (ATCC 6017) strains. Based on the chromatographic analysis results, the essential oils shown to be composed of eugenol (79.41%) which was the prevalent compound in S. aromaticum, geranial (31.89%), neral (24.52%) and β-myrcene (25.37%) in C. citratus, as well as of geranial (33.80%) and neral (25.63%) in L. alba. The observed antibacterial activity confirmed the dose-dependent effect of these three oils on all the assessed bacteria; there was halo inhibition at concentration 20μL mL-1. The essential oil of S. aromaticum presented better antioxidant activity, with IC50 equal to 5.76μg mL-1 and antioxidant activity index of 6.94, and it was considered strong (AAI>2.0) in comparison to the other evaluated oils. This essential oil also presented excellent antioxidant activity at concentrations lower than the one required to inhibit lactic cultures. Based in this outcome, the essential oil from S. aromaticum can be used as preservative agent in processed food whose formulation presents lactic cultures.

Understanding the water requirement of forest species in the seedling stage supports cost reduction by eliminating unnecessary irrigation in addition to providing higher productivity. This study was carried out to evaluate the effect of the water regime on initial growth, leaf production and content and chemical composition of the essential oil of Eucalyptus globulus , during the first 120 days of cultivation. The experiment employed a completely randomized design and was carried out at the Instituto de Ciências Agrárias da Universidade Federal de Minas Gerais (ICA/UFMG), Montes Claros, MG. Treatments consisted of six different water regimes (50%, 75%, 100%, 125%, 150% and 175% of the reference evapotranspiration - ETo) with four replicates. Plant growth was evaluated by measuring linear dimensions - height, stem diameter and number of leaves. The essential oil was extracted from fresh leaves by hydrodistillation in a Clevenger apparatus. The present study demonstrated that irrigation depths corresponding to 75% of the ETo are responsible for increased growth of E. globulus and increased dry matter production of leaves. The lowest irrigation levels were responsible for the greatest essential oil content. The essential oil was analyzed by gas chromatography-mass spectrometry (CG- MS), and eucalyptol (40.84% to 55.72%) was reported to be the major compound for all treatments. Compounds such as β-myrcene, α-Gurgujeno, Alloromadendreno, Varidiflorene appear under specific irrigation conditions.

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The objective of this study was to investigate the phenotypic variability in Paspalum urvillei Steud. related to twelve zootechnical traits to better understand the diversity of 41 accessions from the USDA GRIN platform from seven countries. First, we performed a structure inference based on the phenotypic data, identifying two structure groups, and the majority of Brazilian accessions belonged to the first group. Then, we performed principal component analysis and principal coordinate analysis, making Violin plots for each trait within each structure group. Next, we performed spatial clustering of the accessions and utilized an unweighted pair group method with arithmetic mean clustering. In brief, the Brazilian P. urvillei breeding programs may be successful by importing USDA germplasm resources from the second phenotypic structure group.Keywords: cluster analysis, germplasm bank, forage RESUMO -Entendendo a extensão da variabilidade fenotípica em acessos de Paspalum urvillei Steud. do banco de germoplasma do USDA NPGS. O objetivo deste estudo foi investigar a variabilidade fenotípica de Paspalum urvillei em relação a doze características zootécnicas, a fim de compreender melhor a diversidade de 41 acessos da plataforma USDA GRIN de sete países. Primeiro foi realizada uma inferência de estrutura baseada nos dados fenotípicos, identificando dois grupos estruturados, onde a maioria dos acessos brasileiros é inferida ao primeiro grupo. Em seguida, examinou-se a análise de componentes principais e análise de coordenadas principais, foram feitos gráficos de violino para cada característica dentro de cada grupo estruturado. Por fim, foi realizado o agrupamento espacial dos acessos e o método de médias não ponderadas de grupos pareados. Em suma, o programa brasileiro de melhoramento de P. urvillei pode alcançar sucesso importando acessos do USDA inferidos ao segundo grupo estruturado.Palavras-chave: análise de agrupamento, banco de germoplasma, forragem