Glaucia Maria Pastore

Potential applications of laccase in the food industry

Abstract Laccase is a widely studied enzyme because of its potential use in several areas such as textile, paper and pulp industries. This review presents the potential application of this enzyme in the food industry. Laccase can be used in bioremediation, beverage (wine, fruit juice and beer) processing, ascorbic acid determination, sugar beet pectin gelation, baking, and as biosensor and to improve food sensory parameters. Laccase could increase productivity, efficiency and quality of food products without a costly investment and has the advantage of being a mild technology.

Phenolic compounds and total antioxidant potential of commercial wines

Abstract Growing evidence of the role of free radicals and antioxidants in health and ageing has focussed great interest on these compounds. The relationship between the total antioxidant potential and the phenolic content of commercial wines was evaluated. A close relationship between total phenolic content and total antioxidant potential for all wines was observed. Capillary zone electrophoresis showed that, in red wines, gallic acid was the highest of the phenolic acids and (+)-catechin and (−)-epicatechin were the next most abundant phenolics. Also, these compounds were strictly correlated with the total antioxidant potential of wines. Total antioxidant potential, by bleaching of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations, using gallic acid as standard, could be a practical and simple measurement to evaluate the characteristics of different wines. Furthermore, capillary electrophoresis is a powerful and high-performing tool for evaluating principal antioxidant wine components.

Atividade antioxidante de frutas do cerrado

Annona crassiflora (araticum), Solanum lycocarpum (lobeira), Eugenia dysenterica (cagaita), Caryocar brasilense (pequi) and Swartzia langsdorfii (banha de galinha) are tropical fruits consumed mainly by native people in the Brazilian Cerrado (second biggest biome of Brazil). In this study, pulp, seed and peel of the fruits were extracted using ethanol and water. Some of the extracts showed a high content of total phenols and were screened for their potential as antioxidants using the in vitro model 2,2-diphenyl-1-picryl hydrazyl (DPPH). The best results were found for aqueous and ethanolic extracts of pequi peel (IC50 of 9,44 and 17,98 µg.mL-1 respectively), etanolic extract of cagaita seeds (IC50 of 14,15 µg.mL-1), etanolic extract of araticum seeds and peel (IC50 of 30,97 and 49,18 µg.mL-1 respectively). This is the first report on the antioxidant properties of the extracts of cerrado fruit fractions. Owing to these properties, studies can be further extended to use them for possible applications as natural antioxidant for cosmetics, supplements and functional ingredients for food products as well as being able to represent a sustainable application of the natural sources in the Brazilian bioma cerrado.

Bio-oxidation of Terpenes: An Approach for the Flavor Industry

The terpenes are secondary metabolites of plants that are produced, in part, as a defense against microorganisms and insects in addition to their pollinator-attractive properties.1 In mammals, terpenes contribute to stabilizing cell membranes, participate in metabolic pathways, and act as regulators in some enzymatic reactions.2 Members of this class of chemicals have carbon structures which can be decomposed into isoprene (C5H8) residues and are classified, based on the number of carbons in the molecule, as monoterpenes (ten carbons), sesquiterpenes (fifteen carbons), diterpenes (twenty carbons), triterpenes (thirty carbons), and tetraterpenes or carotenes (forty carbons).3 The simpler terpenes (monoand sesquiterpenes) are the major constituents of essential oils and are widely used in the perfumery industry, while diand triterpenes are less volatile and are obtained from plant gums and resins.4 Carotenes are synthesized by bacteria, algae, fungi, and green plants and comprise more than 600 known structures.5 The most important terpenes and their oxygenated derivates (terpenoids) cited in this study may be seen in Figures 1-3. Terpenes are a good starting material for the synthesis of many fine chemicals due to their similar carbon skeleton. R-(+)-Limonene (2), for example, is the most abundant monocyclic monoterpene in nature, and it represents more than 90% of the orange peel oil; thus, it is an inexpensive precursor.6,7 The oxygenated derivatives of limonene, e.g. carveol (24), carvone (25), perillyl alcohol (26), menthol (39), and R-terpineol (29), are recognized for their pleasant fragrances,8 and some of them also present bioactivity against certain types of tumor cells, not only preventing the formation or progression of cancer but also regressing existing malignant tumors.9,10 R-(6) and -pinene (7), in turn, are found in high concentrations in turpentine, a paper and pulp industry residue, and they are, therefore, also available in bulk at a low price. These bicyclic monoterpenes are used as a fragrance substance that is used to improve the odor of industrial products and are also precursors of important flavor compounds, such as terpineols, borneol (45), camphor (46), citronellol (11), geraniol (14), menthol (39), verbenol (48), and verbenone (49).6,7 The tetraterpene -carotene (62), an orange pigment found mainly in tropical vegetables, is a precursor of norisoprenoid ionones, molecules responsible for desirable fruity and floral flavors.7,11 Volatile carotenoid breakdown products have been long known as important flavor compounds.12

The use of endophytes to obtain bioactive compounds and their application in biotransformation process.

Endophytes are microorganisms that reside asymptomatically in the tissues of higher plants and are a promising source of novel organic natural metabolites exhibiting a variety of biological activities. The laboratory of Bioaromas (Unicamp, Brazil) develops research in biotransformation processes and functional evaluation of natural products. With the intent to provide subsidies for studies on endophytic microbes related to areas cited before, this paper focuses particularly on the role of endophytes on the production of anticancer, antimicrobial, and antioxidant compounds and includes examples that illustrate their potential for human use. It also describes biotransformation as an auspicious method to obtain novel bioactive compounds from microbes. Biotransformation allows the production of regio- and stereoselective compounds under mild conditions that can be labeled as “natural,” as discussed in this paper.

Recent progress of propolis for its biological and chemical compositions and its botanical origin.

Propolis is the generic name given to the product obtained from resinous substances, which is gummy and balsamic and which is collected by bees from flowers, buds, and exudates of plants. It is a popular folk medicine possessing a broad spectrum of biological activities. These biological properties are related to its chemical composition and more specifically to the phenolic compounds that vary in their structure and concentration depending on the region of production, availability of sources to collect plant resins, genetic variability of the queen bee, the technique used for production, and the season in which propolis is produced. Many scientific articles are published every year in different international journal, and several groups of researchers have focused their attention on the chemical compounds and biological activity of propolis. This paper presents a review on the publications on propolis and patents of applications and biological constituents of propolis.

Selection of microorganisms for biosurfactant production using agroindustrial wastes

Biosurfactant production by some bacterial isolates using molasses, milk whey and cassava flour wastewater (manipueira) as substrates was evaluated and compared with the production in conventional medium. Isolates growing in manipueira medium decreased the surface tension around 42%, the highest reduction among all the substrates tested. From the eleven isolates tested, eight were able to decrease the surface tension to levels below 30 mN/m using manipueira as substrate. The isolates LB5a, LB2a, LB262, LBB and LB1a that gave surface tension about 26 mN/m were identified as Bacillus sp. Natural manipueira (high solids content) and decanted manipueira (no solids) were investigated as culture media for biosurfactant production by selected microorganisms. Natural manipueira medium showed minimum surface tension of 28 mN/m (LB5a isolate) whereas for decanted manipueira the lowest value was 26 mN/m (isolate LB2a). Average diameter of growth on manipueira agar was 7.2 cm for isolate LB5a suggesting a high growth capacity on this substrate. Manipueira comprises a potential alternative culture medium for biosurfactant production by the selected isolates.

Biosurfactant production by Bacillus subtilis using cassava-processing effluent

A cassava flour-processing effluent (manipueira) was evaluated as a substrate for surfactant production by two Bacillus subtilis strains. B. subtilis ATCC 21332 reduced the surface tension of the medium to 25.9 mN/m, producing a crude biosurfactant concentration of 2.2 g/L. The wild-type strain, B. subtilis LB5a, reduced the surface tension of the medium to 26.6 mN/m, giving a crude biosurfactant concentration of 3.0 g/L. A decrease in surfactant concentration observed for B. subtilis ATCC 21332 seemed to be related to an increase in protease activity. The biosurfactant produced on cassava effluent medium by B. subtilis LB5a was similar to surfactin.

Microbial transformation of sucrose and glucose to erythritol

SummaryTwo strains of osmophilic yeast which were isolated from honey-comb, produced good yields of erythritol as a main product. These strains were identified as Trichosporonoides sp., 150-5 and 331-1.From the fermentation studies with these strains using glucose and sucrose as substrate, strain 331-1 produced more erythritol as the sole polyhydric product,with trace quantities of glycerol, than strain 150-5.

Characterization of monoterpene biotransformation in two pseudomonads

Aims:  To study the metabolic profile of Pseudomonas rhodesiae and Pseudomonas fluorescens in water–organic solvent systems using terpene substrates for both growth and biotransformation processes and to determine the aerobic or anaerobic status of these degradation pathways.