Guillermo Martínez-Ávila

Bioactive phenolic compounds: Production and extraction by solid-state fermentation. A review

Interest in the development of bioprocesses for the production or extraction of bioactive compounds from natural sources has increased in recent years due to the potential applications of these compounds in food, chemical, and pharmaceutical industries. In this context, solid-state fermentation (SSF) has received great attention because this bioprocess has potential to successfully convert inexpensive agro-industrial residues, as well as plants, in a great variety of valuable compounds, including bioactive phenolic compounds. The aim of this review, after presenting general aspects about bioactive compounds and SSF systems, is to focus on the production and extraction of bioactive phenolic compounds from natural sources by SSF. The characteristics of SSF systems and variables that affect the product formation by this process, as well as the variety of substrates and microorganisms that can be used in SSF for the production of bioactive phenolic compounds are reviewed and discussed.

Ultrasound-assisted extraction of phenolic compounds from Laurus nobilis L. and their antioxidant activity.

Bay leaves (BL) (Laurus nobilis L., Family: Laureceae) are traditionally used to treat some symptoms of gastrointestinal problems, such as epigastric bloating, impaired digestion, eructing and flatulence. These biological properties are mainly attributed to its phenolic compounds. In this paper, ultrasound-assisted extraction of phenolic compounds from Laurus nobilis L. (Laureceae) was studied. Effects of several experimental factors, such as sonication time, solid/liquid ratio and concentration of solvent on extraction of phenolic compounds were evaluated through a randomized complete block design with factorial treatment arrangement (3(3)). The best extraction conditions were: 1g plant sample with 12 mL of 35% ethanol, for 40 min, obtaining a yield of phenolic compounds of 17.32±1.52 mg g(-1) of plant. In addition, free radical-scavenging potential of DPPH and lipid oxidation inhibition, by linoleic acid peroxidation of the selected extract was measured in order to evidence their antioxidant properties. Results indicated that high amounts of phenolic compounds can be extracted from L. nobilis by ultrasound-assisted extraction technology.

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.

Macromolecular and functional properties of galactomannan from mesquite seed (Prosopis glandulosa).

In this work, galactomannans from Prosopis glandulosa seeds were evaluated for their chemical composition and functional properties for potential industrial applications. In addition, those characteristics were compared with the commercial galactomannan guar gum. Mannose and galactose were the two most abundant carbohydrates present in P. glandulosa seeds, which represent 95.32% of total carbohydrates present in this material. Galactomannans from mesquite seed (GMS) yield was 16.53% and presented a M/G ratio of 2:1, which was higher than value observed for guar gum (1.6:1). The results obtained from functional properties showed that GMS has considerable potential to be considered as a food additive.

Moringa plants: Bioactive compounds and promising applications in food products

Moringa plants have an extensive range of bioactive compounds that can be obtained from different vegetative structures, such as leaves, seeds, stems and pod husks. These bioactive molecules include carbohydrates, phenolic compounds, oils and fatty acids, proteins and functional peptides and have great potential to be used in several formulations of food products. This report collects recent information concerning bioactive molecules in other species of the Moringaceae family, different from Moringa oleifera. Thus, this document aims to describe these bioactive compounds and their functional properties on foodstuffs. In addition, more suitable methodologies applied for their extraction and characterization are reviewed. Finally, an overview of patents required to protect Moringa-derived products and processes is provided.

Phenolic Compounds Recovery from Grape Fruit and By- Products: An Overview of Extraction Methods

Phenolic compounds are considered as bioactive compounds having beneficial effects on human health. Because of their biological properties, they have wide applications on pharmaceutical and food industries, and for this reason, it is important to identify most appropriate procedures, which permits the standardization for recovery of these compounds from several plant materials including grapes. Grape fruit and by-products are excellent sources of bioactive compounds such as pigments, organic acids, and phenolic compounds. Several convectional and emerging technologies have been evaluated in order to recover phenolic compounds from grape fruits and wastes such as chemical, physical, and biotechnological techniques, which offer different advantages related to economic, environmental, time-saving, and yield aspects. Nowadays, there is no updated information, which provides an overview about the techniques applied of these bioactive compound recovery in order to obtain high-quality and high-activity extracts rich in phenolic compounds from grape fruit and by-products. This chapter offers relevant aspects related to the techniques employed during the last five years by researches for phenolic compound recovery from grapes.

Evaluation of Biochemical Components from Pterophylla beltrani (Bolivar & Bolivar) (Orthoptera: Tettigoniidae): A Forest Pest from Northeastern Mexico

Abstract. Insects are a biotic resource used for human medicine, nutrition, and industry. Many are a potential source of compounds such as proteins, peptides, secondary metabolites, and polymers like silk, chitin, and chitosan for industry and biotechnology. The Mexican katydid, Pterophylla beltrani Bolivar & Bolivar, is an important insect pest that defoliates oaks (Quercus spp.) and other trees where it feeds and becomes abundant during summer in forests in Northeast Mexico. Several strategies based on extracts of compounds and sustainable metabolites for use as raw material have been proposed for its control and use. Antioxidant, chitin, and chitosan content of P. beltrani were analyzed. Extracted aqueous residue was evaluated for effect on fungal growth, and chitosan was evaluated to supplement the growth of entomopathogenic fungi. Aqueous extract from P. beltrani flour contained phenolic compounds (1.08 ± 0.049 GAE mg g-1) that had little anti-fungal effect against three species of fungi, but did inhibit the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin. Yield of chitin was 11.8% and produced 58.8% chitosan, indicating the insect is a potential source of biochemical compounds. This could help support sustainable management of this pest.

Free Radical-Scavenging Capacities, Phenolics and Capsaicinoids in Wild Piquin Chili (Capsicum annuum var. Glabriusculum)

The total phenolic compounds content, free radical-scavenging capacity and capsaicinoid content in populations of wild Piquin chili (C. annuum) were studied. Aqueous and hydroalcoholic extracts from nine ecotypes were evaluated. High contents of phenolic compounds and free radical-scavenging capacities were observed for both extracts; however, the values that were found for the hydroalcoholic phase were substantially higher. LC-MS analysis allowed for the detection of 32 compounds, where apigenin-8-C-glucoside followed by vanillic acid 1-O-β-o-glucopyranosylester (Isomer I or II) and 7-ethoxy-4-methylcoumarin were the most widely distributed; they were found in more than 89% of the ecotypes. The diversity of identified phenolic compounds was different among ecotypes, allowing them to be distinguished by chemical diversity, free radical-scavenging capacities and heat Scoville units. The total capsaicinoid content was higher in Population I (23.5 mg/g DW) than in Populations II and III, which had contents of 15.3 and 10.7 mg/g DW, respectively. This variability could lead to phytochemical exploitation and the conservation of the natural populations of wild chili.

UPLC-ESI-QTOF-MS2-Based Identification and Antioxidant Activity Assessment of Phenolic Compounds from Red Corn Cob (Zea mays L.)

In this study, the extraction of phenolic antioxidants from red corn cob was carried out using ultrasound-assisted extraction (UAE). The solid:liquid ratio and extraction time were evaluated when obtaining these bioactive compounds. The total phenolic contents were evaluated using the Folin Ciocalteu method, while the antioxidant activity was measured by ABTS•+ and DPPH• assays. The amount of phenolic compounds ranged from 215.17 ± 33.49 to 527.33 ± 103.79 GAE mg/100 g and, overall, high solid:liquid ratios and time periods release more phenolic compounds. Moreover, the red corn cob extracts showed higher radical scavenging capacity according to the results obtained using the ABTS•+ technique compared to the DPPH• test. The coupling of liquid chromatography and mass spectrometry assay allowed the determination of 11 phenolic compounds, including phenolic acids and flavonoids. Thus, our results demonstrated for the first time the potential of red corn cob as a source of bioactive compounds, which might be included in food and pharmacological preparations.