Ana Paula Dionísio

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.

Biotechnological production of bioflavors and functional sugars

Bioaromas e oligossacarideos sao duas classes de substâncias que podem ser produzidas biotecnologicamente por meio de bioprocessos microbiologicos. Estes compostos tem atraido o interesse das industrias farmaceutica e de alimentos nao so devido as suas propriedades tecnologicas (adocantes/fibras ou aromatizantes, respectivamente), mas tambem como consequencia de outras propriedades funcionais como, por exemplo, beneficios na promocao da saude. O uso de residuos agroindustriais como substrato em processos biotecnologicos parece ser uma alternativa valiosa para superar os altos custos de manufatura envolvidos nas fermentacoes industriais. Este manuscrito faz uma revisao dos mais importantes avancos na producao biotecnologica de bioaromas e oligossacarideos. O uso de alguns residuos agroindustriais nestes processos tambem sao citados e discutidos, mostrando que esta e uma tendencia crescente na biotecnologia.

Ionizing radiation effects on food vitamins: a review

Ionizing radiation has been widely used in industrial processes, especially in the sterilization of medicals, pharmaceuticals, cosmetic products, and in food processing. Similar to other techniques of food processing, irradiation can induce certain alterations that can modify both the chemical composition and the nutritional value of foods. These changes depend on the food composition, the irradiation dose and factors such as temperature and presence or absence of oxygen in the irradiating environment. The sensitivity of vitamins to radiation is unpredictable and food vitamin losses during the irradiation are often substantial. The aim of this study was to discuss retention or loss of vitamins in several food products submitted to an irradiation process.