Recovery of Bioactive Ellagitannins by Ultrasound/Microwave-Assisted Extraction from Mexican Rambutan Peel (Nephelium lappaceum L.).

Rambutan (Nephelium lappaceum L.) is a tropical fruit from Asia which has become the main target of many studies involving polyphenolic analysis. Mexico produces over 8 million tons per year of rambutan, generating a huge amount of agro-industrial waste since only the pulp is used and the peel, which comprises around 45% of the fruit's weight, is left behind. This waste can later be used in the recovery of polyphenolic fractions. In this work, emerging technologies such as microwave, ultrasound, and the hybridization of both were tested in the extraction of phenolic compounds from Mexican rambutan peel. The results show that the hybrid technology extraction yielded the highest polyphenolic content (176.38 mg GAE/g of dry rambutan peel). The HPLC/MS/ESI analysis revealed three majoritarian compounds: geraniin, corilagin, and ellagic acid. These compounds explain the excellent results for the biological assays, namely antioxidant activity evaluated by the DPPH, ABTS, and LOI (Lipid oxidation inhibition) assays that exhibited great antioxidant capacity with IC50 values of 0.098, 0.335, and 0.034 mg/mL respectively, as well as prebiotic activity demonstrated by a µMax (maximum growth) of 0.203 for Lactobacillus paracasei. Lastly, these compounds have shown no hemolytic activity, opening the door for the elaboration of different products in the food, cosmetic, and pharmaceutical industries.

Co-microencapsulation: a promising multi-approach technique for enhancement of functional properties.

Co-microencapsulation is a growing technique in the food industry because it is a technique that, under the same fundamentals of microencapsulation, allows the generation of microcapsules with a longer shelf life, using a smaller number of encapsulating materials and a smaller amount of active compounds, while having a greater beneficial activity. This responds to consumer demand for higher quality foods that limit the use of ingredients with low nutritional content and provide beneficial health effects, such as probiotics, prebiotics, vitamins, fatty acids, and compounds with antioxidant activity. The combination of two or more active compounds that achieve a synergy between them and between the encapsulating materials offers an advantage over the well-known microencapsulation. Among the main active compounds used in this process are probiotics, prebiotics, fatty acids, and polyphenols, the main combination being that of probiotics with one of the other active compounds that enhances their benefits. The present review discusses the advantages and disadvantages of the different encapsulating materials and techniques used to obtain co-microencapsulants, where the main result is a higher survival of probiotics, higher stability of the active compounds and a more controlled release, which can lead to the generation of new foods, food supplements, or therapeutic foods for the treatment of common ailments.

Early Optimization Stages of Agave lechuguilla Bagasse Processing toward Biorefinement: Drying Procedure and Enzymatic Hydrolysis for Flavonoid Extraction.

Agave lechuguilla agro-waste is a promising renewable material for biorefining purposes. The procurement of added-value co-products, such as bioactive phytochemicals, is required to improve bioprocesses and promote the bio-based economy of the productive areas of Mexico. In this study, we aimed to evaluate the effect of post-harvest management and enzymatic pretreatment as the first stages of the A. lechuguilla valorization process. Four drying methods were compared, and enzymatic hydrolysis was optimized to obtain a flavonoid-enriched extract applying ultrasound-assisted extraction. In both experiments, the total phenolic (TPC) and flavonoid (TFC) contents, HPLC-UV flavonoid profiles, and radical scavenging capacity (DPPH) were considered as response variables. The results demonstrated that light exposure during the drying process particularly affected the flavonoid content, whereas oven-dehydration at 40 °C in the dark preserved the flavonoid diversity and antioxidant functionality of the extracts. Flavonoid glycoside recovery, particularly anthocyanidins, was 1.5-1.4-fold enhanced by enzymatic hydrolysis using the commercial mix Ultraflo© under optimized conditions (pH 4, 40 °C, 180 rpm, and 2.5 h) compared to the unpretreated biomass. The extraction of flavonoids from A. lechuguilla bagasse can be carried out using a scalable drying method and enzymatic pretreatment. This study confirmed the potential of this agro-waste as a source of marketable natural products.

Compuestos fenólicos de Tagetes lucida Cav. con efecto antibacteriano por daños a la membrana / Phenolic compounds of Tagetes lucida Cav. with antibacterial effect due to membrane damage

Tagetes lucida Cav. (Asteraceae = Compositae) se usa para tratar infecciones estomacales. El estudio se centró en evaluar la composición y el efecto antimicrobiano de un extracto de T. lucida Cav. La planta se extrajo con etanol al 10% p/v, y la composición del extracto se analizó por Rp-HPLC-MS. El efecto antibacteriano se evaluó contra Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa y Salmonella choleraesuis utilizando métodos de difusión por disco, microdilución y bioautografía. Los ensayos de sytox y cometa fueron utilizados para evaluar el mecanismo de acción. De esta forma, se detectaron nueve compuestos fenólicos en el extracto de T. lucida. El extracto exhibió actividad solo en S. aureus (MIC de 4.000 mg/ml). La bioautografía reveló que los compuestos fenólicos podrían actuar sinérgicamente. Las pruebas de sytox y cometa mostraron una acción antibacteriana del extracto sobre la membrana bacteriana y el ADN de esta cepa bacteriana.

Tagetes lucida Cav. (Asteraceae=Compositae) is used for treating stomach infections. The study focused on evaluating the composition and antimicrobial effect of an extract of T. lucida Cav. The plant extracted with ethanol at 10% w/v, and the extract composition analyzed by Rp-HPLC-MS. The antibacterial effect was evaluated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella choleraesuis using disk diffusion, microdilution and bioautography methods. The sytox and comet assays were used to evaluate the mechanism of action. In this way, nine phenolic compounds were detected in the extract of T. lucida. The extract exhibited activity only on S. aureus (MIC of 4.000 mg/ml). The bioautography revealed that the phenolic compounds could act synergistically. The sytox and comet tests showed an antibacterial action of the extract on the bacterial membrane and DNA of this bacterial strain.

Impact of extraction techniques on antioxidant capacities and phytochemical composition of polyphenol-rich extracts.

In this work, impact of extraction methods (maceration, decoction, MAE, and UAE) on TPC, antioxidant activity, and the mass fraction of phenolics in several plant extracts (Punica granatum, Juglans regia, Moringa oleifera, and Cassia fistula) was investigated. The results showed that, despite the nature of matrix, the highest values of TPC in all samples were obtained by MAE as follows: PP (18.92±0.11), ML (15.19±0.11), HL (12.69±0.16), and WS (12.80±0.11) mg GAEg-1 respectively, and exhibited potent antioxidant activity (from 0.28±0.01 to 5.34±0.02mgGAEg-1), representing sources of powerful antioxidants. The LC-MS2 analysis revealed a wide range of phenolics, highlighting their content in phenolic acids, flavonoids and lignans. The presence of different phenol molecules demonstrated that the extraction method had influence on phytochemical profile. Finally, due to its high extraction efficiency, MAE was the more effective extraction technique.

The complete biodegradation pathway of ellagitannins by Aspergillus niger in solid-state fermentation.

Our research group has found preliminary evidences of the fungal biodegradation pathway of ellagitannins, revealing first the existence of an enzyme responsible for ellagitannins degradation, which hydrolyzes pomegranate ellagitannins and it was called ellagitannase or elagitannin acyl hydrolase. However, it is necessary to generate new and clear information in order to understand the ellagitannin degradation mechanisms. This work describes the distinctive and unique features of ellagitannin metabolism in fungi. In this study, hydrolysis of pomegranate ellagitannins by Aspergillus niger GH1 was studied by solid-state culture using polyurethane foam as support and pomegranate ellagitannins as substrate. The experiment was performed during 36 h. Results showed that ellagitannin biodegradation started after 6 h of fermentation, reaching the maximal biodegradation value at 18 h. It was observed that ellagitannase activity appeared after 6 h of culture, then, the enzymatic activity was maintained up to 24 h of culture reaching 390.15 U/L, after this period the enzymatic activity decreased. Electrophoretic band for ellagitannase was observed at 18 h. A band obtained using non-denaturing electrophoresis was identified as ellagitannase, then, a tandem analysis to reveal the ellagitannase activity was performed using Petri plate with pomegranate ellagitannins. The extracts were analyzed by HPLC/MS to evaluate ellagitannins degradation. Punicalin, gallagic acid, and ellagic acid were obtained from punicalagin. HPLC/MS analysis identified the gallagic acid as an intermediate molecule and immediate precursor of ellagic acid. The potential application of catabolic metabolism of ellagitannin hydrolysis for ellagic acid production is outlined.