Frontiers in Bioactive Compounds

Due to the unique extraction process, extra virgin olive oils conserve numerous substances, which are often excluded from other vegetable oils during the extraction and refining steps. Previous works showed that fatty acids profile of lipids are important for the dietary. In the last five decades many researchers demonstrated that monounsaturated fatty acids are involved in prevention of diseases such as the metabolic syndrome and cardiovascular ones. Moreover, vitamin E is active against weakened immunity, aging, environmental toxic substances, diabetic syndrome symptoms, enhancing the health status from different points of view, such as cardiovascular and neoplastic ones. Hydroxytyrosol has many effects; it is an antiinflammatory compound, with antibacterial, antioxidant and cardioprotective properties. However, not all extra virgin olive oils are equal. Inside the market category “extra virgin” there is a wide number of products ranging from the highest quality to the standard quality ones. In 2012 the European Commission approved three health claim applicable to the extra virgin olive oil but they are still scarcely used by the producers.

Wine contains several hundreds of compounds, most of them with impact on quality attributes and health benefices. Among these compounds, phenolic compounds play a significant role in sensory properties of wines as well as in antioxidant properties. Phenolic compounds are highly efficient compounds displaying antioxidant properties and preventing human cardiovascular diseases, also. Furthermore, the polyphenolic compounds are capable of quenching free radicals, thereby inhibiting the oxidation process of low density lipids (LDL). This effect about LDL could reduce the risk of atherosclerosis, cardiovascular diseases, heart attack, cancer, DNA degradation etc. Moderate drinking of red wine is beneficial against coronary disease and several forms of cancer. The phenolic compounds thought to be responsible are catechins and tannins. Catechins are powerful antioxidants, preventing cellular damage. Resveratrol and quercetin may improve the immune system, prevent towards heart diseases, inhibit cancer formation, and even prolong life. The amino acids are essential nutrients and have various benefits on human body such as muscle maintenance, tissue repair, and immunity. Amino acids yield biogenic amines that have allergenic or toxic effects on humans. Beneficial nitrogen compounds such as melatonin and serotonin are also found in red wines. Among vitamins, only vitamins B1, B2 and B12 are present in wines.

Most of the biological processes, either normal or pathological, are based on molecular recognition. Molecular recognition, defined as the ability of one molecule (host) to “recognize” another molecule (guest), which presents complementarity, mainly through bonding interactions and molecular geometry, may be exploited in the analytical sciences, as long as the specific interaction produces a detectable change that can be measured by an instrument. The most impactful and acknowledged analytical use of molecular recognition has been recorded in separation sciences, namely in solid phase extraction and affinity chromatographic applications, but also in optical and electrochemical chemo- and biosensing. In living organisms the molecular recognition system is represented by natural receptors, characterized by the highest affinity and specificity, being the natural targets for toxins and mediators of physiological processes. By consequence, a large variety of bioelements, such enzymes, antibodies, nucleic acids, and cells were investigated in the last decades, being integrated in various separation and sensing devices which were successfully applied in biomedical and environmental analyses or monitoring. However, their isolation, purification, stability and cost are critical issues. Therefore, the development of artificial biomimetic receptors, such as cyclodextrins and derivatives, calixarenes, ligands (valinomycine, crown-ethers, etc.), aptamers, and molecularly imprinted polymers focused the attention of many research groups. The most recent achievements in the field of analytical sciences based on molecular recognition, such as separation techniques (solid phase extraction, chromatography, electrophoresis), and sensing (electrochemical, optical, etc.) are revised.

The Mediterranean diet has largely demonstrated its health benefits which are related to the intake of antioxidants. Besides the health benefits, antioxidants influence in the organoleptic characteristics, the quality and the preservation of foods and beverages.

Although a variety of methods have been described to detect antioxidants and to evaluate the antioxidant capacity of foods, field experiments still represent a challenge. In this context, electrochemical techniques can represent an advantage thanks to higher sensitivity, short experimental times and inherent portability. In this chapter, the electrochemical sensors dedicated to the analysis of antioxidants will be presented. Particular attention will be paid to voltammetric sensors. The methods used to improve their selectivity and sensitivity by modifying the surface using chemical or biological materials will be described. The new developments obtained thanks to new nanomaterials and nanostructured films will be evidenced. Finally, the advantages of multisensor systems based on electrochemical sensors will be described.

Biosensors are promising analytical tools for the determination and characterisation of bioactive compounds in wines, providing fast, sensitive and costeffective detection, assisting in the assessment of quality, sensory and safety attributes of wines. In this chapter, some of the most representative, recent examples of biosensors for the detection of polyphenols, biogenic amines, mycotoxins and allergens in wine are discussed, emphasizing the wealth of biosensing strategies and the particularities of wine as a complex analytical matrix.

This chapter provides a review of the most recent works in electronic sensory system for characterization of Bioactive Compounds. Focus is placed on the food applications and those compounds that are good for health. This chapter reviews the main electronic sensory techniques, from electronic noses to sensors and biosensors devices used for Bioactive Compound Characterization. The chapter demonstrates that although Bioactive Compounds are difficult to detect with sensor systems due to their high molecular weight and low volatility of the compounds and therefore few references are found in the literature, it is important to stand out that these systems could be a promising field for research and developing of industrial instruments applied to real contexts.

Cell membranes are essential for life, since they compartmentalize cells, the basic unit of living matter, and mediate their symbiosis with the environment. In many events in which cells participate, interaction with biomolecules such as polysaccharides, proteins and peptides, is crucial. In spite of the developments in physics, chemistry and biology in the last century, the study of cells and bioactive biomolecules interacting “in vivo” is still elusive. Therefore, simplified models are employed to obtain fundamental knowledge from these systems. In this chapter, the use of Langmuir monolayers as cell membrane models made to interact with biomolecules is described. Firstly, a brief introduction on the nature of nanostructured Langmuir monolayers is provided. In particular, we describe technical aspects related to the experimental setup and procedures to guide novice researchers in the field. We also describe the fundamentals and possibilities of the most useful techniques applied to film characterization. In the final section, examples are given of Langmuir monolayers successfully employed to obtain relevant molecular-level information from systems involving biomolecules. Trends in the field are discussed as motivation for innovative research to bridge the gap between biology (and medicine) and the physicochemical framework used in cell membrane modeling.

The vegetal extracts are complex blends of chemical compounds from various classes: polyphenols, carotenoids, vitamins, essential oils, etc. It is known that these components are highly sensitive to the action of oxygen, light radiations and high temperature. These factors contribute to the degradation of bioactive compounds and implicitly to the decrease of their biological potential. Therefore, the encapsulation of bioactive compounds in different matrices is required in order to prevent the aforementioned shortcomings.

The purpose of this review is to synthesize the newest information about the biocomponents’ encapsulation. The encapsulation of bioactive compounds, ensures the stability of the volatile compounds during thermic processing, the protection of bioactive components against environmental factors, the increase of the solubility of bioactive compounds, the controlled release of bioactive components, etc. Various techniques are used for the encapsulation of bioactive compounds, some of them being: emulsification, coacervation, gelation, extrusion, spray drying, spray cooling, etc.