Application of nanoparticles entrapped orange essential oil to inhibit the incidence of phytopathogenic fungi during storage of agroecological maize seeds.

The demand for sustainable, healthy, and pesticide-free food has grown in recent years. Agroecological seeds cannot receive chemical treatment, as pesticides present toxicological and environmental risks, requiring the development of alternative methods for disease control, such as the use of essential oils. In this study, orange essential oil was extracted and encapsulated in zein nanoparticles by the nanoprecipitation method. The nanoparticles were tested for the antifungal activity on agroecological maize seeds and for the mycelial sensitivity of Stenocarpella macrospora. The synthesized nanoparticles presented good encapsulation efficiency (99 %) of orange essential oil rich in D-limonene, conferring high antioxidant activity to the loaded nanoparticles. The release profile indicated a pseudo-Fickian mechanism governed by diffusion, explained according to the Korsmeyer-Peppas model. The dynamic light scattering, and transmission electron microscopy showed spherical nanoparticles with particle size lower than 200 nm. The nanoparticles containing orange essential oil inhibited the incidence of Fusarium during the storage of agroecological maize seeds. The mycelial sensitivity against Stenocarpella macrospora showed that the encapsulated essential oil was more effective in inhibiting the fungus when compared to the non-encapsulated oil. Therefore, the nanoparticles containing encapsulated orange essential oil can be effectively applied as an antifungal material for the conservation of agroecological maize seeds, contributing to the development of sustainable agricultural biotechnology with pesticide-free products.

Antiparasitic potential of alternative treatments against larval stages of Lernaea cyprinacea.

This study evaluated the potential of alternative treatments against larval stages of Lernaea cyprinacea. For in vitro test, the nanoemulsified oils of Pinus sp. acicule and oleoresin were evaluated, along with Biogermex® (commercial product based on citrus biomass). For this, the motility of five larvae of the same stage (nauplii or copepodite) were evaluated in a 96-well microplate. Using the best results, on the in vivo test, fries of Rhamdia quelen were submitted to a long-term immersion bath (96 h) containing different concentrations of the product diluted directly in the water. It was possible to notice the antiparasitic potential of the oleoresin and the acicule of Pinus sp., as well as the citrus biomass extract against the parasites. The nanoemulsified oils successfully inhibited the development of nauplii (10 mg L-1 in 24 h) and the fries showed to be tolerant to the presence of the compound (LC50 96 h-16.74 mg L-1). The concentration of 30.5 mg L-1 of Biogermex® eliminated the copepodites within 24 h, being more efficient than Pinus sp. when tested at the same stage, at the times analyzed. The results obtained indicate a potential use of these compounds as prophylactic agents against L. cyprinacea.

Chitosan packaging functionalized with Cinnamodendron dinisii essential oil loaded zein: A proposal for meat conservation.

The nanoencapsulation of essential oils for biodegradable films functionalization is a viable alternative for the production of active food packaging. In this study, the Cinnamodendron dinisii Schwanke essential oil was nanoencapsulated using zein as wall material, and applied in chitosan matrix to produce an active nanocomposite film packaging for food conservation. The chemical composition of the Cinnamodendron dinisii Schwanke essential oil showed a variety of unexplored bioactive compounds, and 1,8-cineole was the major compound. The oil nanoencapsulation produced stable and homogeneous nanoparticles with zeta potential close to 30 mV and polydispersity index lower than 0.2. The nanoparticles size showed a size variation between 70 and 110 nm. The chitosan films obtained functionalized with nanoparticles demonstrated antioxidant activity and antimicrobial activity. The active packaging containing zein nanoparticles was efficient in the conservation of ground beef, stabilizing the deterioration reactions and preserving the color.

Antiparasitic effect of Mentha × villosa hydrolate against monogenean parasites of the Nile tilapia / Efeito antiparasitário do hidrolato de Mentha × villosa contra parasitas monogenéticos para Tilápia-do-nilo

ABSTRACT: This paper o evaluated different concentrations and exposure times of Mentha × villosa hydrolate for the control of monogeneans in Nile tilapia (Oreochromis niloticus). Mentha × villosa leaves (150 g) were homogenized and the hydrolate was obtained by hydrodistillation for 4 h in a Clevenger apparatus. Fifty tilapia were then divided into ten groups (five fish each) and subjected to therapeutic baths for 15 minutes in five different hydrolate concentrations (0, 10, 20, 40, and 80 ml.L-1;× 2 replicates). After a suitable hydrolate concentration was identified, another 50 tilapia were divided into ten groups (five fish each) and subjected to therapeutic baths at the identified hydrolate concentration for five different durations (0, 15, 30, 45, and 60 minutes;× 2 replicates). In both steps, the mucus and gills were analyzed to determine parasitological indices. The hydrolate concentration of 20 ml.L-1 showed an efficacy of 59.9% and the biggest decrease in pathogen prevalence, average abundance, and average infection compared to the control and the lowest concentration (10 ml.L-1). For duration, the best antiparasitic effects were achieved with the 60-minute therapeutic bath, as it resulted in 89.28% antiparasitic efficacy. Therefore, it was concluded that therapeutic baths of M. × villosa hydrolate at a concentration of 20 ml.L-1 for 60 minutes have satisfactory antiparasitic effects and could be used to control monogenetic infestations in the gills and mucus of Nile tilapia (O. niloticus).

RESUMO: Este trabalho teve como objetivo avaliar diferentes concentrações e tempos de exposição do hidrolato de Mentha × villosa para o controle de monogenéticos em Tilápia-do-nilo (Oreochromis niloticus). Folhas de Mentha × villosa (150 g) foram homogeneizadas e o hidrolato foi obtido por hidrodestilação por 4 h em aparelho de Clevenger. Em seguida, 50 tilápias foram divididas em dez grupos (cinco peixes cada) e submetidas a banhos terapêuticos por 15 minutos em cinco diferentes concentrações de hidrolato (0, 10, 20, 40 e 80 ml.L-1; × 2 repetições). Após a identificação de uma concentração de hidrolato adequada, outras 50 tilápias foram divididas em dez grupos (cinco peixes cada) e submetidas a banhos terapêuticos na concentração de hidrolato identificada por cinco durações diferentes (0, 15, 30, 45 e 60 minutos; × 2 repetições). Em ambas as etapas, o muco e as guelras foram analisados para determinar os índices parasitológicos. A concentração de hidrolato de 20 ml.L-1 apresentou eficácia de 59,9% e a maior redução na prevalência do patógeno, abundância média e infecção média em relação ao controle e a menor concentração (10 ml.L-1). Para a duração, os melhores efeitos antiparasitários foram alcançados com o banho terapêutico de 60 minutos, uma vez que resultou em 89,28% de eficácia antiparasitária. Portanto, concluiu-se que banhos terapêuticos de hidrolato de M. × villosa na concentração de 20 ml.L-1 por 60 minutos têm efeitos antiparasitários satisfatórios e podem ser usados para controlar infestações monogenéticas nas brânquias e muco da Tilápia-do-nilo (O. niloticus).

Effects of Tagetes minuta essencial oil on Lucilia cuprina third instar larvae.

The activity of Tagetes minuta essential oil (TMEO) was tested against third instar larvae (L3) of the Australian blowfly Lucilia cuprina. We have determined the potential of the T. minuta EO as a new biopesticide candidate. To test this, groups of 20 L3 were placed on filter paper impregnated with ranging concentrations (from 0.19 to 6.36 µL/cm2) of TMEO, solubilized in acetone. Data show in this article is related to research article "Tissue damage and cytotoxic effects of Tagetes minuta essential oil against Lucilia cuprina" Chaaban et al., 2019. Thus, data of cuticle damage, color changes in L3 body and decrease in L3 motility were recorded 24 and 48 h after TMEO contact.

Tissue damage and cytotoxic effects of Tagetes minuta essential oil against Lucilia cuprina.

The blowfly Lucilia cuprina has great medico-sanitary and veterinary importance due to the ability of its larval form to develop in decaying organic matter, parasitizing vertebrates. Fly eradication is challenging and the essential oil (EO) of Tagetes minuta (TMEO) have been reported to have therapeutic properties. This study aimed to determine the activity of EO from the aerial parts of T. minuta against third instar larvae (L3) of L. cuprina. Groups of 20 L3 were placed on filter paper, which were impregnated with varying concentrations (0.19; 0.39; 0.79; 1.59; 2.38; 3.18; 4.77; and 6.36 µL/cm2) of TMEO solubilized in acetone, ethanol or Tween 20. Histological tissue damage of TMEO was measured in L3 after 24, 48 and 96 h of exposure. Dihydrotagetone (67.64%), trans-ocimene (16.23%), trans-tagetone (10.14%) and verbenone (2.98%) were obtained as major compounds of TMEO. Lethal concentrations of 50%, 24 and 48 h after TMEO exposure were 1.02 and 0.73 µL/cm2 for acetone; 3.37 and 1.75 µL/cm2 for ethanol; and 7.46 and 6.11 µL/cm2 for Tween 20, respectively. TMEO had a significant L3 mortality of 96.6% in acetone, 48 h after contact. Cuticle abnormalities were observed, as well as the loss of digestive tract architecture and vacuolization in fat bodies. TMEO presented time and concentration-dependent effects against L. cuprina. As our study demonstrated a strong insecticide activity of TMEO, we consider that it could be developed into an ecofriendly product against L. cuprina.

Cellulose nanocrystals from rice and oat husks and their application in aerogels for food packaging.

This study describes the valorization of rice and oat husks by obtaining cellulose nanocrystals for the production of aerogels for food packaging applications. Commercial cellulose was used as a control sample. Nanocrystals from cellulose were obtained by enzymatic hydrolysis and mechanical treatment at high pressure. The morphology, particle size, functional groups, crystallinity, and thermal properties of the cellulose nanocrystals were analyzed. The morphology, functional groups, crystallinity, water absorption capability, and zeta potential of aerogels were also analyzed. Cellulose nanocrystals show different structural properties and crystallinity depending on the source of the cellulose. The average diameter of the nanocrystals varied from 16.0 to 28.8 nm. The aerogels prepared with cellulose nanocrystals showed a porous and uniform structure with a water absorption capacity between 264.2% and 402.8% at 25 °C. The aerogel of oat cellulose nanocrystals showed a larger pore size than that of eucalyptus cellulose nanocrystals, and this may have influenced the lowest water absorption capacity of the aerogels of eucalyptus cellulose nanocrystals. These results show that agroindustrial residues have promising applications in various industrial fields and could be used as aerogel absorbers of water in food packaging.

Identification of Ellagitannins and Flavonoids from Eugenia brasilienses Lam. (Grumixama) by HPLC-ESI-MS/MS.

The grumixama (Eugenia brasiliensis Lam.), also known as Brazilian cherry, is a fruit native to Brazil. This study identified the flavonoids in the flesh and seeds and ellagitannin in the flesh of purple and yellow varieties. The physicochemical characteristics and antioxidant capacity of these fruits were also evaluated. Anthocyanins and flavonols were found in high levels in the flesh of purple (32-180 mg 100 g(-1) FW) and yellow grumixama (13-41 mg 100 g(-1) FW), respectively. The major flavonoids identified were cyanidin 3-glucoside and quercetin aglycone. Furthermore, ellagitannins were found in high levels in the flesh of purple (82-243 mg ellagic acid equiv 100 g(-1) FW) and yellow grumixama (92 mg ellagic acid equiv 100 g(-1) FW) and seeds (2220-2905 mg ellagic acid equiv 100 g(-1) FW). The ellagitannin profiles of both varieties were first characterized in which pedunculagin isomers, strictinin isomers, and ellagic acid galloyl hexoside were the major ellagitannins identified. In summary, both varieties of the grumixama fruit as well as the seeds could be good sources of bioactive compounds, mainly ellagitannins.

Revisão: biotecnologia de microalgas / Review: microalgae biotechnology

Esta revisão de literatura teve como objetivo apresentar informações relacionadas com a biotecnologia de microalgas. Além do histórico e da importância das microalgas, foram abordadas as principais aplicações, composição bioquímica da biomassa algal, bioprodutos, tipos de cultivo e meios de cultura. Os temas revisados nesse trabalho evidenciaram que a biotecnologia de microalgas vem se desenvolvendo em função dopotencial de industrialização de biomassa algal como suplemento alimentar. A biomassa destina-se às mais diversas aplicações como produção de proteína unicelular, lipídios, corantes, enzimas, antibióticos, carboidratos e vitaminas. Pode-se concluir que além da diversidade de aplicações, as microalgas estão relacionadas com cultivo de curto período de crescimento, pois se desenvolvem em poucos dias, requerendo cuidados simples e dispensam a utilização de agrotóxicos.

Teor de clorofila e perfil de sais minerais de Chlorella vulgaris cultivada em solução hidropônica residual / Chlorophyll content and minerals profile in the microalgae Chlorella vulgaris cultivated in hydroponic wastewater

O cultivo de microalgas representa uma potencial fonte de biomassa rica em clorofila e sais minerais como: fósforo, ferro, manganês, cobre, zinco, magnésio e cálcio. Este experimento teve como objetivo avaliar a composição de minerais, bem como determinar o teor de clorofila a e b da microalga Chlorella vulgaris cultivada em solução hidropônica residual em três diferentes concentrações comparadas com um cultivo controle. Os resultados mostraram que os teores de clorofila a e b da microalga não apresentaram diferença significativa entre os cultivos. Com relação à composição dos sais minerais, a Chlorella cultivada na solução residual mais concentrada apresentou valores superiores quando comparada com a cultivada nos demais cultivos. Dessa forma, a biomassa da Chlorella vulgaris demonstrou ser uma potencial fonte de clorofila e de sais minerais, quando cultivada em solução hidropônica residual, possibilitando a utilização desse resíduo de forma sustentável.

The microalgaes cultive represents a potential source of biomass rich in chlorophyll and minerals as: P, Fe, Mn, Cu, Zn, Mg and Ca. This research was aimed at evaluating the composition of minerals, as well as, determining the content of chlorophyll a and b from the microalgae Chlorella vulgaris cultivated in hydroponic wastewater in three different concentrations compared with the control cultive. The results showed that the contents of chlorophyll a and b of the microalgae did not show significant difference between the cultives. In relation to the composition of the minerals, the Chlorella cultivated in the most concentrated wastewater, showed higher values when compared with the one cultivated in the others cultures. In this manner, the Chlorella vulgaris biomass demonstrated to be a potential source of chlorophyll and minerals, when cultivated in hydroponic wastewater, allowing the use of this residue in a sustainable way.