Chemical characterization and antimicrobial activity of essential oils from Croton grewioides Baill. accessions on the phytopathogen Xanthomonas campestris pv. campestris.

Croton grewioides Baill. is an aromatic species with proven bioactive properties. Considering the potential of the species, the aim of this study was to chemically characterize and evaluate the in vitro antibacterial activity of the essential oils of C. grewioides on Xanthomonas campestris pv. campestris. The essential oils of the accessions of C. grewioides were extracted by the hydrodistillation method and analyzed by gas chromatography - mass spectrometry. For determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the essential oils and of the compound eugenol, the microdilution method was used at concentrations that ranged from 125 to 4000 µg.mL-1. Streptomycin sulfate was used as a positive control (12.5 to 100 µg.mL-1). Growth kinetics and the membrane permeability trial were evaluated for the concentrations 2×, 1×, 1/2×, 1/4×, and 1/8× MIC of the essential oil CGR-108. The major compounds identified in the essential oils were eugenol, methyl eugenol, and methyl chavicol. The essential oil of the accession CGR-108 had a lower MIC (> 500 and < 1000 µg.mL-1) and MBC equal to <2000 µg.mL-1. For eugenol, MIC was obtained with contractions >250 and < 500 µg.mL-1 and MBC with >500 µg.mL-1 and < 1000 µg.mL-1. A loss of cell viability of the bacteria was observed after 30 min of exposure to the essential oil of the accession CGR-108 at the concentrations of 2× and 1× MIC, which was proven by the fluorescence intensity with propidium iodide. The essential oils of Croton grewioides Baill. and the compound eugenol show antibacterial potential on Xanthomonas campestris pv. campestris.

Development of alcohol vinegars macerated with ACAI (Euterpe precatoria Mart.) berries and their quality evaluations with emphasis on color, antioxidant capacity, and volatiles profile.

In this work, the Amazonian native acai fruit, a superfruit recognized worldwide, was used through a simple operation of maceration in alcohol vinegar to transform it into an attractive and functional product containing the acai natural colorant and its bioactive compounds. The variables studied were the proportion of alcohol vinegar to acai (8:2 and 1:1) and maceration period (7, 14, and 21 days). The final vinegar was subjected to the determination of color parameters, antioxidant capacity (DPPH, ABTS), total phenolics content (TPC), volatile compounds extracted by stir bar sorptive extraction and identified by gas-chromatography-mass spectrometry analysis. The alcohol vinegars macerated with acai presented the color according to the content of acai added and maceration period employed, whereas antioxidant capacity and TPC were comparable to vinegars elaborated from fruits and red wine. Sixty volatiles compounds classified into five chemical groups were identified. The principal volatile compounds which contributed to the aroma in the products were 3-methyl-1-butanol, phenylethyl alcohol, benzaldehyde, o-cymene, p-cymenene, isoamyl acetate, and ethyl acetate. The most attractive product regarding the parameters studied was obtained from the use of the proportion of 1:1 of alcohol vinegar:acai and maceration period of 14 days. This product retained the most similar color to acai in natura, the highest values for antioxidant capacity measured by ABTS and TPC while being rich in volatile compounds due to the contributions mainly of alcohols, esters, aldehydes, and terpenes. PRACTICAL APPLICATION: This work demonstrates the feasibility to produce an alcohol vinegar with an attractive color and functional properties by the addition of acai resulting in to a wide spectrum of chemical compounds of acai through a very simple operation of maceration during 14 days of a proportion of 1:1 of alcohol vinegar:acai.

Oil impact on the environment and aquatic organisms on the coasts of the states of Alagoas and Sergipe, Brazil - A preliminary evaluation.

The oil spill off the coast of the Brazilian Northeast region is one of the most significant global events regarding contamination and environmental impact in recent years. This work evaluates the effects of oil spills on the Northeast coasts between Alagoas and Sergipe states from October 2019 to January 2020. Analysis of some sampling points of seawater revealed the presence of Hg, Cd, Pb, and Cu in levels above the maximum concentration limits established by the Brazilian legislation. For water quality parameters, phosphorus, nitrite, and turbidity showed statistically different values. However, the chromatographic profiles of oil obtained from different beaches were quite similar. Seawater, fishes, and massunins (bivalve) presented the main polycyclic aromatic hydrocarbons: naphthalene, phenanthrene, fluoranthene, fluorene, and acenaphthalene. Therefore, the concentration of organic and inorganic contaminants determined in different environmental locations served as a subsidy to assess the effect of the preliminary oil spill on the Brazilian coast.

Volatile profiling and UHPLC-QqQ-MS/MS polyphenol analysis of Passiflora leschenaultii DC. fruits and its anti-radical and anti-diabetic properties.

Twenty-four phenolic compounds including daidzein, epicatechin and artepillin C were identified in Passiflora leschenaultii DC. fruit by UHPLC-QqQ-MS/MS analysis. The aroma profile has been studied using the HS-SPME/GC-MS which revealed 67 volatile compounds including 13 terpenes, 18 alcoholics, 15 esters, ketones and phenolic acids. Further, the proximate composition, anti-radical and anti-diabetic activities of fruit pulp were also determined. The fresh fruit pulp of P. leschenaultii registered higher total phenolic (691.90 mg GAE/g extract) and tannin (313.81 mg GAE/g extract) contents and it also exhibited maximum DPPH (IC50 of 6.69 µg/ml) and ABTS+ (9760.44 µM trolox equivalent/g extract) scavenging activities. The fresh fruit pulp showed a strong inhibition towards the α-Amylase and α-Glucosidase (IC50 of 32.20 and 19.81 µg/mL, respectively) enzymes. Thus, the work stipulates that phenolic compounds rich P. leschenaultii fruit can serve as a potential nutraceutical, antioxidative and anti-diabetic agent in food and pharmaceutical formulations.

Effect of spray drying on bioactive and volatile compounds in soursop (Annona muricata) fruit pulp.

Soursop is seasonal and highly perishable fruit, which limits its commercialization. Thus it is necessary to conserve its pulp so that it is available throughout the year. One of the most common forms of fruit preservation is by dehydration. This work had an objective to dehydrate soursop pulp by spray drying at optimum conditions and to analyze the retention of bioactive and volatile compounds in soursop powder, besides analyzing its antioxidant capacity. The total phenolics, carotenoids and flavonoids contents were determined, while volatile compounds were analyzed by Stir Bar Sorptive Extraction (SBSE) coupled with GC-MS system. The total content of the phenolic compounds and flavonoids in the fresh pulp were 160.28 mg of GAE/100 g and 87.17 mg of quercetin/100 g, respectively while for rehydrated dried powder their values were 158.95 mg of GAE/100 g and 85.17 mg of quercetin/100 g, respectively. The total phenolic compounds, flavonoids and antioxidant capacity did not show any significant difference (p < .05) between the fresh fruit pulp and dehydrated powder. A total of 85 volatile compounds were identified, of which 33 were esters, representing the major class of organic compounds, 15 were terpenes, 10 aldehydes, 7 acids, 5 alcohols, 5 lactones, 3 ketones, and 6 other compounds. Of the total 85 compounds, identified in soursop pulp, 58 compounds were identified in the rehydrated dried powder. The principal compounds for both samples were methyl (E)-2-hexenoate, methyl hexanoate and methyl (E)-2-butanoate, which contribute to soursop aroma according to their Odor Active Values (OAV). Considering that there was no significant difference (p < .05) between fresh pulp and the rehydrated dried powder in concentrations of bioactive compounds and even with the reduction in the concentration of the main volatile compounds while the OAVs of these compounds were relatively high, it is concluded that spray dried powder of soursop pulp retains its nutritional and aroma quality, besides maintaining the antioxidant capacity.