Abstract
Essential oils are volatile compounds commonly used by several industries, easily degradable, which restrains their applications. Therefore, we developed and validated a methodology for ...producing microcapsules loaded with orange essential oil, using a spray-drying process. The experimental design results showed that the combination between a low flow transfer rate (0.15 L h
−1
) of the colloidal suspension, a higher drying air flow rate (536 L h
−1
), and an inlet air temperature of 150 °C to the spray-dryer were the most important parameters for the atomization efficiency. The method optimization resulted in microcapsules with powder recovery between 7.6 and 79.9% (w w
−1
), oil content ranging from 8.9 to 90.4% (w w
−1
), encapsulation efficiency between 5.7 and 97.0% (w w
−1
), and particle sizes with a high frequency of distribution less than 4 μm. In these experiments, gelatin and lignin were evaluated as biopolymers of encapsulation. We also developed an analytical method using headspace gas chromatography. The matrix effects could be addressed by using matrix-matched calibration curves. The chromatographic analysis was linear and selective for
d
-limonene between 0.025 and 3.00 µg mL
−1
, with correlation coefficients higher than 0.99. The analytical method had limits of detection and quantitation of 0.024 and 0.073 mg g
−1
for gelatin and 0.039 and 0.119 mg g
−1
for lignin, respectively.
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.
The fungus
Beauveria bassiana
is widely used for pest control; however, biostability and dispersion for broth pulverization are limiting factors for its application in the field. In this context, ...formulation techniques such as microencapsulation are viable alternatives. The aim of this work is to optimize
B. bassiana
formulations by spray dryer and evaluate its stability and biological activity against
Spodoptera cosmioides
compared to ionic gelatinization formulations. The fungus was biocompatible with all evaluated biopolymers (lignin, cellulose, starch, humic substances, and alginate). The encapsulation by spray drying was optimized by factorial design in an inlet and outlet air temperature of 120°C and 68°C, respectively; aspirator rate of 35 m
3
·h
−1
, feed flow rate of 12 mL·min
−1
; and drying gas flow at 35 L·h
−1
. The ionic gelation capsules were obtained using a 0.5% quantity of conidia in a 1% sodium alginate solution dropped into a 0.5 mol·L
−1
CaCl
2
solution using a peristaltic pump. Spray drying provided smaller microcapsules than those by ionic gelation. Both techniques produced more stable conidia when exposed to temperature and UV-radiation than non-formulated
B. bassiana
. The formulations prepared by spray drying showed gains at aqueous dispersion. Biological assays against
Spodoptera cosmioides
showed a mortality rate of up to 90%. These results demonstrate the suitability of encapsulating
B. bassiana
conidia stably in aqueous dispersion without loss of viability and virulence.
Fruit processing waste, such as kernels (endocarp + seed) of avocado
Persea americana
Mill. (Lauraceae), could be used as raw material in the preparation of botanical insecticides. In light of this ...potential, this study assessed the insecticidal action of extracts and fractions from kernels of two avocado cultivars (Breda and Margarida) on
Bemisia tabaci
(Gennadius) (Hemiptera: Aleyrodidae) biotype B, an important pest species in tropical conditions. Ethanolic and aqueous extracts prepared from kernels of
P. americana
, regardless of the plant cultivar used, caused promising insecticidal activity to whitefly nymphs. Based on yield in crude extracts 10.32 and 9.85% (w/w), respectively, for cultivars Breda and Margarida, on the bioassay results with crude extracts and on the chemical profiles, the ethanolic extract of kernels of
P. americana
cv. Breda was chose for the continuation of the study. Thus, the ethanolic extract of kernels of cv. Breda (LC
50
= 197.84 ppm and LC
90
= 567.19 ppm) was selected and subjected to fractionation by the liquid-liquid partition technique. The hexane and dichloromethane fractions of this extract caused significant mortality of nymphs. The analysis using the ultraviolet (UV) and hydrogen nuclear magnetic resonance (
1
H NMR) showed the presence of long-chain aliphatic compounds (alkanols or acetogenins of Lauraceae), alkylfurans (or avocadofurans), and unsaturated fatty acids in these fractions, which are possibly related to bioactivity observed in
B. tabaci
, besides saccharides. The results show that kernels of
P. americana
are promising sources of compounds with insecticidal action for the control of
B. tabaci
biotype B, a great opportunity to transform environmental problems into eco-friendly solutions to agriculture.
HPLC-UV and MALDI imaging on citrus with citrus variegated chlorosis (CVC) showed higher concentrations of hesperidin in infected plants than in healthy ones. Display omitted
•MALDI imaging mass ...spectrometry was applied to study the tissue distribution of hesperidin.•HPLC-UV analyses of citrus with citrus variegated chlorosis (CVC) showed hesperidin was at higher concentration in leaves.•HPLC-UV analyses can screen many samples for CVC per hour using about 1mg of leaves.•Hesperidin has a role in plant–pathogen interaction, probably as a phytoanticipin.•Increase in hesperidin content can be related to induced defense mechanisms.
A high performance liquid chromatography-ultraviolet (HPLC-UV) method was developed for quantifying hesperidin and rutin levels in leaves and stems of Citrus limonia, with a good linearity over a range of 1.0–80.0 and 1.0–50.0μgmL−1 respectively, with r2>0.999 for all curves. The limits of detection (LOD) for both flavonoids were 0.6 and 0.5μgmL−1, respectively, with quantification (LOQ) being 2.0 and 1.0μgmL−1, respectively. The quantification method was applied to Citrus sinensis grafted onto C. limonia with and without CVC (citrus variegated chlorosis) symptoms after Xylella fastidiosa infection. The total content of rutin was low and practically constant in all analyses in comparison with hesperidin, which showed a significant increase in its amount in symptomatic leaves. Scanning electron microscopy studies on leaves with CVC symptoms showed vessel occlusion by biofilm, and a crystallized material was noted. Considering the difficulty in isolating these crystals for analysis, tissue sections were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) to confirm the presence of hesperidin at the site of infection. The images constructed from MS/MS data with a specific diagnostic fragment ion (m/z 483) also showed higher ion intensities for it in infected plants than in healthy ones, mainly in the vessel regions. These data suggest that hesperidin plays a role in the plant-pathogen interaction, probably as a phytoanticipin. This method was also applied to C. sinensis and C. limonia seedlings, and comparison with the graft results showed that the rootstock had an increased hesperidin content ∼3.6 fold greater in the graft stem than in the stem of C. sinensis seedlings. Increase in hesperidin content by rootstock can be related to induced internal defense mechanisms.
This study investigated the chemical composition and the antifungal activity of the essential oil extracted from the Hymenaea stigonocarpa fruit peel (HSFPEO) against Botrytis cinerea, Sclerotinia ...sclerotiorum, Aspergillus flavus and Colletotrichum truncatum. The HSFPEO obtained through hydrodistillation was analyzed with gas chromatography coupled to mass spectrometry. The antifungal activity was determined by the mean mycelial growth inhibition of the fungus treated with essential oils and growth control. The major constituents of HSFPEO were spathulenol (25.19%) and caryophyllene oxide (13.33%). HSFPEO demonstrated antifungal activity against all fungi tested in all concentrations evaluated in a dose-dependent behavior. The best results were observed against B. cinerea and A. flavus, in which the lowest concentration tested inhibited more than 70% of mycelial growth. Based on the current knowledge, this study describes for the first time the chemical composition and the antifungal activity of HSFPEO against the phytopathogenic fungi B. cinerea and C. truncatum.
The aim of this work was to quantify B-complex vitamins in pharmaceutical samples by surface enhanced Raman spectroscopy technique using gold colloid substrate. Synthesis of gold nanoparticles was ...performed according to an adapted Turkevich method. Initial essays were able to suggest the orientation of molecules on gold nanoparticles surface. Central Composite design was performed to obtain the highest SERS signal for nicotinamide and riboflavin. The evaluated parameters in the experimental design were volume of AuNPs, concentration of vitamins and sodium chloride concentration. The best condition for nicotinamide was NaCl 2.3×10−3molL−1 and 700μL of AuNPs colloid and this same condition showed to be adequate to quantify thiamine. The experimental design for riboflavin shows the best condition at NaCl 1.15×10−2molL−1 and 2.8mL of AuNPs colloid. It was possible to quantify thiamine and nicotinamide in presence of others vitamins and excipients in two solid multivitamin formulations using the standard addition procedure. The standard addition curve presented a R2 higher than 0.96 for both nicotinamide and thiamine, at orders of magnitude 10−7 and 10−8molL−1, respectively. The nicotinamide content in a cosmetic gel sample was also quantified by direct analysis presenting R2 0.98. The t-student test presented no significant difference regarding HPLC method. Despite the experimental design performed for riboflavin, it was not possible its quantification in the commercial samples.
Display omitted
•Gold nanoparticle colloid was employed for quantification of B-complex vitamins.•SERS signal of Thiamine-B1, Riboflavin-B2 and Nicotinamide-B3 were optimized by DoE.•B1 and B3 vitamins were simultaneously quantified by SERS in commercial samples.•There was not statistical difference to the reference method of analysis (HPLC).
The aim of our study was to produce and characterize poly-ε-caprolactone (PCL) nanospheres containing essential oils from
fruit and to evaluate their stability gains as well as their insecticidal and ...deterrent activities against whitefly (
). The PCL nanospheres exhibited a homogeneous spherical morphology, with particle diameters between 106.7 nm and 129.2 nm, pH of approximately 6, zeta potential (ZP) lower than -19.0 mV and encapsulation efficiency higher than 98%. Only 43% of the nanoencapsulated essential oil (NSEO) was degraded in response to ultraviolet light, whereas the essential oil (EO) degraded by 76% over the same period. In a free-choice test, the NSEO and EO reduced the number of whitefly eggs by approximately 70%. NSEO and EO at 1.5% killed 82.87% and 91.23% of 2nd-instar nymphs of whitefly, respectively. Although NSEO displayed lower insecticidal activity, it offers a greater advantage over the free EO, due to protection conferred by polymer against photodegradation. Therefore, its usage may optimize the maintenance of essential oils in the field through photoprotection and controlled release. Our results suggest that the EO of
fruit can be used for
management strategy; nevertheless, the benefits of NSEO require further evaluation at the field level.
A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of
...leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests.
is an important pest of several crops in South America, including soybeans. Adults cause severe defoliation in soybean plants, and damage is significant when cotyledons are attacked. This study ...evaluated feeding non-preference to
adults using 10 soybean genotypes, testing (i) 15-day-old whole plants and (ii) leaf disks of 60-day-old plants, through assessments of soybean attractiveness and leaf area consumed (LAC). Foliar contents of flavonoids and nutrients, and leaf trichome density were quantified for potential correlations with soybean resistance to adult of
. In the whole young-plant experiment, under free-choice conditions, the lowest LAC was observed in IAC 100 and PI 227687. In no-choice, PI 227687 and IGRA RA 626 RR showed lower LAC than the other genotypes. In the leaf disk test, in free-choice, the genotypes IAC 100, PI 274454, PI 227687, DM 339, and BR 16 were the least preferred by adult of
. In no-choice, PI 274454 was one of the least preferred, similarly to IGRA RA 626 RR, Dowling, and PI 227687. In the whole plant experiment, a high rutin content and low amounts of zinc, calcium, sulfur and manganese were associated with less consumption of
on leaves of resistant genotypes. In contrast, in the leaf disk test there was a significant influence of trichomes in soybean resistance to the pest. In conclusion, the PI lines herein assessed are also promising sources for developing cultivars resistant to
.
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