Diana B. Muñiz-Márquez

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.

Enhancement of fructosyltransferase and fructooligosaccharides production by A. oryzae DIA-MF in Solid-State Fermentation using aguamiel as culture medium

The aim of this work was to improve the production of fructosyltransferase (FTase) by Solid-State Fermentation (SSF) using aguamiel (agave sap) as culture medium and Aspergillus oryzae DIA-MF as producer strain. SSF was carried out evaluating the following parameters: inoculum rate, incubation temperature, initial pH and packing density to determine the most significant factors through Box-Hunter and Hunter design. The significant factors were then further optimized using a Box-Behnken design and response surface methodology. The maximum FTase activity (1347U/L) was obtained at 32°C, using packing density of 0.7g/cm(3). Inoculum rate and initial pH had no significant influence on the response. FOS synthesis applying the enzyme produced by A. oryzae DIA-MF was also studied using aguamiel as substrate.

Phenolic content and antioxidant capacity of extracts of Laurus nobilis L., Coriandrum sativum L. and Amaranthus hybridus L.

Extraction of polyphenols of Laurus nobilis L. (Lauraceae), Coriandrum sativum L. (Apiaceae) and Amaranthus hybridus L. (Amaranthaceae) was carried out by solid–liquid extraction. The effect of ethanol concentration and the extraction time were determined to obtain the maximum of polyphenols. Three different methods, DPPH radical scavenging, ABTS radical cation scavenging and lipid oxidation inhibition, were tested to determine the antioxidant capacity in the extracts. The results indicate that L. nobilis has a high antioxidant potential: 94.73%, 47.71% and 76.86% for DPPH, ABTS and lipid oxidation inhibition, respectively. On the other hand, C. sativum and A. hybridus showed 13.69% and 10.16% in DPPH assay, and 9.22% and 14.96% in ABTS assay, while it did not show any antioxidant capacity in the lipid oxidation inhibition method under the experimental conditions. In addition, the phenolic compounds in the extracts were also characterized by High Performance Liquid Chromatography (HPLC) analysis.

Influence of thermal effect on sugars composition of Mexican Agave syrup

Agave syrup is a fermentable by-product from the Agave industry that is used for pulque production, a typical Mexican fermented beverage. However, to date, the information available on its physicochemical composition is scarce, with this study being one of the first contributions on the subject. Here the influence of thermal treatment at 121ºC/15 min on the physicochemical composition of agave syrup was studied. The chemical composition based on sugar content was evaluated by thin-layer chromatography and high-performance liquid chromatography. In addition, the mass spectrum is also presented. Results showed that thermal treatment promoted a change in the chemical composition of the agave syrup, particularly in sugar concentration favoring a high sucrose concentration after the sterilization process. Fructose, glucose in particular, and kestose (GF2) were detected in both samples. The presence of prebiotics such as GF2 suggests that agave syrup may be used in food and nutraceutical industries as a functional beverage.

Microplate Quantification of Total Phenolic Content from Plant Extracts Obtained by Conventional and Ultrasound Methods

INTRODUCTION There is increasing interest in phenolic compounds around the world because of their potential positive impact on human health. Phenolic compounds are largely found in fruits and vegetables. Extraction of phenolic compounds is a very important step in their recovery. The newly developed technique of ultrasound-assisted extraction (UAE) appears to be an advantageous alternative compared with conventional techniques, because it is simple and environmental friendly. The potential of UAE needs to be evaluated in each plant in order to demonstrate its efficiency. OBJECTIVE The objective of the present study was to compare a conventional method and UAE on the extraction efficiency of phenolic compounds from Jatropha dioica, Fluorensia cernua, Turnera diffusa and Eucalyptus camaldulensis plants and evaluate the in vitro anti-oxidant potential. METHODS Validation of the new method was carried out using mixed-model methodology and regression analysis. Feasibility of this new method was shown and applied using several plants extracts obtained by different extraction methods from semi-arid Mexican plants, which were characterised by high levels of polyphenols. Additionally, the anti-oxidant potential of these extracts was determined by 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. RESULTS Results showed that the new microplate method can be used to determine total phenolic content in plant extracts. Additionally, an alternative extraction method by ultrasound was less efficient compared with the conventional method. CONCLUSION The tested plants are good candidates to obtain nutraceuticals and functional food ingredients.

Enzymes for Fructooligosaccharides Production: Achievements and Opportunities

Abstract Microbial enzymes find application in enzymatic reactions for the production of fructooligosaccharides (FOS). Demands for an alternative healthy sweetener and multifunctional FOS have prompted investigators to explore microorganisms for microbial enzyme production as well as to develop bioprocesses for the production of high-fructose syrup and oligosaccharides based on transfructosylation of sucrose or hydrolysis of inulin. Fructosyltransferases have been characterized in several molds, yeasts, and a few bacteria. Recently, there has been a growing interest in finding novel enzyme producers by using agroindustrial media in both submerged and solid-state fermentation. This review discusses current knowledge on production, properties, and applications of microbial enzymes involved in the production of fructooligosaccharides and considers recent advances in the field. It also describes a comprehensive and illustrative analysis on basic and applied aspects of fungal enzymes, different substrates of microbial growth, and fundamental biotechnological and catalytic aspects to illustrate the potential of these biocatalysts in the food and bioprocessing industries.

Bioactive compounds from bay leaves (Laurus nobilis) extracted by microwave technology

Abstract Laurus nobilis leaves contain flavored and bioactive components with relevant biological properties for human health that are attributed to an abundant presence of highly bioactive secondary metabolites. However, the separation process for these bioactive molecules from plant matrix is seriously limited by the presence of a physical barrier (cell wall). Thus, the use of novel extraction procedures to enhance their release is particularly important. In this work, the potential use of microwave-assisted extraction (MAE) as a tool to improve the extraction efficiency of bioactive compounds from bay leaves and their characterization was evaluated. The effects of irradiation time (3, 6 and 9 min) and aqueous ethanol concentration (0, 25 and 50%) on the extraction of phenolic compounds were evaluated. A response surface methodology was applied to determine the best extraction conditions by MAE. The maximum total phenolic compound under the best conditions (9 min time irradiation and aqueous ethanol 50%) was 10.63±0.91 mg gallic acid equivalent/g plant using MAE. Also, the antioxidant potential of the extracts obtained was evaluated.

Chapter 5 – Extraction of Bioactive Phenolic Compounds by Alternative Technologies

Extraction of bioactive phenolic compounds (BPCs) from plants, fruits, and their by-products is a topic of interest in the last two decades. The main reason is due to the human health benefits associated with BPC consumption. Alternative extraction technologies have found new applications in the field because of advantages in terms of operational simplicity, safety, and high yields in comparison to conventional extraction technologies. This chapter examines the advances in the research done on BPC extraction using alternative extraction technologies. Modifications to improve the performance of alternative extraction technologies are presented and discussed with focused attention on ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), fermentation-assisted extraction (FAE), and enzyme-assisted extraction (EAE). In addition, the important parameters influencing its performance, the basic theory of reactions present, and the direct effect of alternative extraction technologies on BPCs are included. A list of advantages and drawbacks of the alternative extraction technologies on BPC extraction with regard to conventional extraction technologies is summarized. Finally, a perspective and general conclusion are presented.

Microbial Production of Bioactive Pigments, Oligosaccharides, and Peptides

Abstract Increasing globalization and internationalization have been a key trend in the microbial production of bioactive metabolites in recent years. Pigments produced by microalgae, bacteria, and yeasts, such as chlorophylls, xanthomonadins, and carotenoids, as well as oligosaccharides produced by filamentous fungi, such as fructooligosaccharides and galactooligosaccharides, and bioactive peptides, is expanding due to their importance for pharmaceuticals and food, because these natural compounds have functional properties and health benefits in contrast to other synthesized ingredients. Scientific studies have shown that synthetic compounds exhibit toxicity and carcinogenicity in the human body. On the other hand, production of bioactive compounds by fermentation has a number of advantages. One of the most important is the easy availability of raw materials, in addition other aspects, such as low production costs, yields and purification process, and the green technology should be considered in the generation of these bioactive compounds. The aim of this chapter is to discuss the microbial production of pigments, including types and characterization, coloring properties, and applications, as well as the microbial production of oligosaccharides and bioactive peptides, recent studies, bioengineering aspects, chemical and physical characteristics, and industrial applications.