Chemical composition, nutritional value and bioactive compounds in six uvaia accessions

A New Single-Step Approach Based on Supramolecular Solvents (SUPRAS) to Extract Bioactive Compounds with Different Polarities from Eugenia pyriformis Cambess (Uvaia) Pulp

This work employed supramolecular solvents (SUPRAS) made up of octanoic acid, ethanol, and acidified water (pH ~ 3) to extract and concentrate bioactive compounds from Eugenia pyriformis Cambess (uvaia) pulp. At first, the SUPRAS phase characterization demonstrated the spherical aggregates' formation with an internal hydrophobic structure and an external hydrophilic media. Subsequently, the simultaneous production and extraction (SUPRAS-SPE) method was employed in the solid-liquid extraction (SLE) of uvaia pulp. The extracts were evaluated through Folin-Ciocalteu reducing capacity, antioxidant activity (DPPH assay), total carotenoid content (TCC), and total flavonoid content (TFC). The results showed that reducing the ethanol concentration in the SUPRAS composition boosted the TCC extraction while increasing the ethanol presence, promoting a high TFC yield. Moreover, the SUPRAS-SPE method was compared with the ex situ method (SUPRAS-ES), where the solvent was previously produced and then applied to the SLE. Both methods were evaluated concerning their EE% and thermal degradation. The SUPRAS-SPE method increased the EE% of uvaia pulp bioactive compounds compared to the SUPRAS-SE method, providing a suitable microenvironment to extract, concentrate, and stabilize carotenoids from uvaia pulp, offering a sustainable alternative to obtain valuable compounds.

Phenolic compounds profile of optimised green and eco-friendly extracts of Eugenia pyriformis leaves: an alternative for antioxidant and antibacterial applications

The Eugenia pyriformis Cambess (uvaia) is a well-known source of bioactive compounds. This study investigated the efficiency of Ultrasound-Assisted Extraction (UAE) and Enzyme-Assisted Extraction (EAE) in obtaining uvaia leaf extracts with high antioxidant and antibacterial activity. In a first step, different variables of the leaves were employed to define the best conditions for obtaining the extract with the highest total phenolic content. In a second step, the optimised extracts were characterised. In total, twenty-four phenolic compounds were identified through LC-ESI-MS/MS. The EAE in optimised conditions showed a higher amount of total phenolic compounds and antioxidant potential. It was possible to note an analogous potential of antibacterial activity of the extracts, which showed action mainly against Gram-positive bacteria. These findings suggest that the aqueous extracts of uvaia leaves are feasible, economic, and sustainable alternatives for adding value to uvaia leaves, which are an agricultural residue that is generally underutilised.

Brazilian native fruit pomace as a source of bioactive compounds on starch-based films: Antimicrobial activities and food simulator release

The bioactive compounds extraction from fruit pomace is an ecological alternative for these abundant and low-added-value by-products. This study aimed to evaluate the antimicrobial potential of pomace extracts from Brazilian native fruits (araçá, uvaia, guabiroba and butiá) and the effect on physicochemical, mechanical properties and the migration of antioxidants and phenolic compounds from starch-based films. The film with butiá extract had the lowest mechanical resistance (1.42 MPa) but the highest elongation (63 %). In comparison, uvaia extract had less impact on film mechanical properties (3.70 MPa and 58 %) compared to the other extracts. The extracts and films showed antimicrobial activity against Listeria monocytogenes, L. inoccua, B. cereus and S. aureu. Approximately 2 cm inhibition halo was noticed for the extracts, while films ranged from 0.33 to 1.46 cm inhibition halo. Films with guabiroba extract had the lowest antimicrobial activity (0.33 to 0.5 cm). The phenolic compounds were released from the film matrix in the first hour at 4 °C with maintenance in the stability. The fatty-food simulator showed a controlled release of antioxidant compounds, which can assist in controlling food oxidation. Brazilian native fruit has shown to be a viable alternative to isolate bioactive compounds and produce film packaging with antimicrobial and antioxidant activities.

Quality Attributes and Metabolic Profiles of Uvaia (Eugenia pyriformis), a Native Brazilian Atlantic Forest Fruit

The uvaia is a native Brazilian Atlantic Forest Myrtaceae fruit with a soft pulp, ranging from yellow to orange, with a sweet acidic flavor and sweet fruity aroma. Uvaias present consumption potential, but their physicochemical characteristics are still understudied. In this context, we describe herein the metabolites of uvaia that have been determined by nuclear magnetic resonance spectroscopy. We screened 41 accessions and selected 10 accessions based on their diversity of physicochemical attributes, i.e., their fresh mass, height, diameter, yield, seed mass, total soluble solids, and titratable acidity. Twenty-six metabolites were identified, including sugars, acids, and amino acids. The results of this study comprise the most complete report on sugars and acids in uvaias. The relevant metabolites in terms of abundance were the reducing sugars glucose and fructose, as well as malic and citric acids. Furthermore, this study represents the first description of the uvaia amino acid profile and an outline of its metabolic pathways. Uvaia quality attributes differ among accessions, demonstrating high variability, diversity, and several possibilities in different economic areas. Our findings may help in future breeding programs in the selection of plant material for industries such as food and pharmaceuticals.

Branched-Chain Volatiles in Fruit: A Molecular Perspective

Branched-chain volatiles (BCVs) constitute an important family of fruit volatile metabolites essential to the characteristic flavor and aroma profiles of many edible fruits. Yet in contrast to other groups of volatile organic compounds important to fruit flavor such as terpenoids, phenylpropanoids, and oxylipins, the molecular biology underlying BCV biosynthesis remains poorly understood. This lack of knowledge is a barrier to efforts aimed at obtaining a more comprehensive understanding of fruit flavor and aroma and the biology underlying these complex phenomena. In this review, we discuss the current state of knowledge regarding fruit BCV biosynthesis from the perspective of molecular biology. We survey the diversity of BCV compounds identified in edible fruits as well as explore various hypotheses concerning their biosynthesis. Insights from branched-chain precursor compound metabolism obtained from non-plant organisms and how they may apply to fruit BCV production are also considered, along with potential avenues for future research that might clarify unresolved questions regarding BCV metabolism in fruits.

Effect of in vitro digestion on the bioaccessibility and bioactivity of phenolic compounds in fractions of Eugenia pyriformis fruit

Uvaia is a Brazilian fruit species that has great economic and nutritional potential, in addition to being a good source of compounds of biological interest. In this study, we evaluated for the first time the influence of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolic compounds from two fractions of uvaia (edible and seed). It was observed that the content of total phenolic compounds was about 3 times higher in the seed (undigested extract), but reduced significantly after intestinal digestion (-50.08%). In turn, the total flavonoid content was about 5 times higher in the undigested seed extract. After intestinal digestion, the flavonoid content increased in the edible fraction (+109.49%) and decreased in the uvaia seed (-70.20%). The heatmap analysis showed that after intestinal digestion, there was an increase in the relative intensity of the flavonoids, while phenolic acids reduced their intensity. The antioxidant capacity of the undigested extract was 4-7 times greater for the seed, but decreased after intestinal digestion (-8.04-27.23%), while the antioxidant capacity of the edible fraction increased by 72.12-107.89% in this same stage of digestion. Thus, the content of phenolic compounds and antioxidant capacity were higher in the uvaia seed, and the bioaccessibility of the bioactive compounds in this fruit were dependent on the fraction and digestive phase evaluated. These results can contribute to the establishment of uvaia as a novel ingredient for preparations with functional claims.

Chemical characterization of Eugenia stipitata: A native fruit from the Amazon rich in nutrients and source of bioactive compounds

Eugenia stipitata is a fruit native to the Brazilian Amazonian region, belonging to the Myrtaceae family whose chemical composition has been little evidenced. In this study, we evaluated for the first time the nutritional composition, bioactive compounds and antioxidant properties of two fractions of this fruit. It was observed that the edible fraction had a higher content of minerals such as K, Ca and Mg (827.66 ± 14.51; 107.16 ± 1.54; and 75.65 ± 1.28 mg 100 g^-1 dw, respectively), sucrose (38.01 ± 2.94 mg g^-1 dw), fructose (17.58 ± 0.80 mg g^-1 dw), and maltotetraose (1.63 ± 0.09 mg g^-1 dw). In this same fraction, about 30 volatile compounds were found, mainly biciclo(3.2.1)octan-3-one, 6 (2-hydroxyethyl)-, endo-; butanoic acid, 2-methyl-, hexyl ester and p-ocimene. In turn, the seed had the highest number of compounds identified by ESI-LTQ-MS/MS (including vanillic acid, gallic acid hexoside, catechin hexoside, luteolin hexoside, among others), higher content of phenolics (142.43 ± 0.82 mg GAE g^-1 dw), flavonoids (43.73 ± 0.23 mg CE g^-1 dw), and antioxidant capacity (139.59 ± 2.47; 447.94 ± 2.70; and 100.07 ± 10.50 µM TE g^-1 dw for DPPH, ABTS, and ORAC, respectively). These results suggest that Eugenia stipitata has excellent nutritional value and great functional potential, and may contribute to a greater commercial exploitation of this fruit, not only in food, but also in the pharmaceutical and cosmetic industries.

Volatile Compounds and Physicochemical Quality of Four Jabuticabas (Plinia sp.)

The jabuticaba is a native Brazilian fruit that has aroused worldwide interest in terms of its nutritional composition and biological activity. However, research on the profile of volatile compounds (VOCs) emitted by these fruits is rare. This study presents the first identification of VOCs from four jabuticaba species. The aim of the study was to characterize the aromatic profile of the following species: ‘Sabará’ (Plinia jaboticaba), ‘Escarlate’ (Plinia phitrantha × Plinia cauliflora), ‘Otto Andersen’ (Plinia cauliflora), and ‘Esalq’ (Plinia phitrantha). The analysis was performed by headspace solid-phase microextraction combined with gas chromatography/mass spectrometry (SPME-GC-MS). Multivariate analysis techniques applying the partial least squares-discriminant analysis (PLS-DA) and heatmap were used to compare the results. Fruit quality parameters were determined in terms of fresh mass (g), skin color, soluble solids, and titratable acidity. A total of 117 VOCs was identified including terpenoids, esters, alcohols, aldehydes, alkanes, ketones, and carboxylic acids, with 36 VOCs common to all four species. Terpenes were the majority for all jabuticabas with smaller contributions from other volatile classes, especially β-cubebene, β-elemene, and D-limonene for the ‘Otto Andersen’ jabuticaba.

Geographical discrimination of uvaia (Eugenia pyriformis Cambess) by principal component analysis

BACKGROUND

The international marketing of native Brazilian fruits may benefit from research into discrimination between plants with particular properties. Plants with certain characteristics have strong potential for use in agroindustry and for the development of new processed products. In the current study, 12 uvaia plants (Eugenia pyriformis Cambess), native to Brazil, were geographically discriminated by chemometric methods, using nutritional composition, physicochemical characterization, bioactive compounds, and antioxidant capacity data.

RESULTS

Uvaia fruits presented good nutritional value, with a high moisture and carbohydrate content. All fruits presented a pH value lower than 4, being classified as highly acidic, and the total soluble solids (°Brix) ranged between 2.90 and 9.80. Some plants had a higher vitamin C content, and all the plants had a high bioactive compound content (phenolic and flavonoids) and antioxidant capacity in 1,1-difenil-2-picrilhidrazil (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Hydroethanolic solution was the best extraction solvent tested when compared with water and ethanol. Using principal component analysis, it was possible to discriminate among the plants in five different groups; however, just one group was responsible for higher antioxidant compound content.

CONCLUSION

In this work, 12 native uvaia plants were discriminated by their geographical origin using a chemometric approach. Genetic improvement based on natural selection could be accomplished with some of the plants to improve the quality of uvaia pulp and to develop new cultivars. © 2019 Society of Chemical Industry.

Junior R, Gazim ZC. Biocidal potential of Eugenia pyriformis essential oil in the control of Rhipicephalus (Boophilus) microplus in the free-living cycle

ABSTRACT: Brazil has one of the largest commercial cattle herds in the world, which naturally coexist with an enormous number of parasitic species. Southern cattle tick, Rhipicephalus (Boophilus) microplus, is among these species, interfering with animal productivity and causing losses to the beef and dairy cattle sector. The use of chemical acaricides in the control of this mite has resulted in the emergence of resistant populations. In this sense, alternative control measures using plants as sources of botanical acaricides have shown to be effective. Eugenia pyriformis Cambess is a Brazilian plant with antioxidant and antimicrobial activity; however, there are no reports on its acaricidal activity in the literature. The present study aimed to evaluate the acaricidal and larvicidal potential of E. pyriformis leaf essential oil (EO) on southern cattle tick at different stages of the reproductive cycle. E. pyriformis leaves were collected and dried, and had their EO extracted by hydrodistillation (3h) using a modified Clevenger apparatus. Chemical analysis was performed by gas chromatography coupled with mass spectrometry (GC/MS), and 32 compounds belonging to the sesquiterpene class were identified: hydrocarbons (17.98%) and oxygenated forms (81.96%), with spathulenol (43.65%) and caryophyllene oxide (12.17%) as the most common. The EO was evaluated by the Adult Immersion Test at the concentrations (500.00 to 3.12mg/mL) in which the following parameters were measured: mortality of females (%), hatchability of eggs (%), and product efficiency (%). Larvae were assessed by the Larval Packet Test at concentrations ranging from 25.00 to 0.00004mg/mL. Lethal concentrations (LC) required for killing 50 and 99.9% of adult females and larvae were determined using Probit analysis. LC50 and LC99.9 of EO were 0.06 and 24.60mg/mL and 1,208.80 and 2,538mg/mL for larvae and adult females, respectively. Action of the EO in the free-living cycle of R. (B.) microplus larvae was another parameter assessed. To this end, the larvae were deposited in pots containing Brachiaria decumbens and, after migration to the leaf apex, a solution containing LC99.9 (24.60mg/mL) of the EO was sprayed. After 24h, 72.25% of the larvae had died, indicating stability of the EO when subjected to uncontrolled temperature and humidity conditions. The mechanism of action through which the EO killed the larvae and adult females was investigated by the Bioautographic Method, which showed inhibition of 3.15mg/mL of the EO on the acetylcholinesterase (AChE) enzyme. The results found in the present experiment indicate that E. pyriformis essential oil is an alternative in the control of southern cattle tick in the larval (parasitic) and free-living cycle (non-parasitic) stages under field conditions.