Phenolics in Foods: Extraction, Analysis and Measurements

Abstract

The increasing consumers demands to acquire healthier fruits and vegetables as well as the urgency in looking to natural compounds with antioxidant activity and enhanced antimicrobial activity against antibiotic-resistant pathogenic bacterial strains have encouraged a quick expansion of research studies about enhanced phenolic extraction and identiication methods. Considering the importance of phenolics as natural compounds with antioxidant and antimicrobial activity, this chapter aims to present the most updated information about extraction methods, ranging from the traditional to the most advanced processes, as well as the access to the modern methods used in the identiication and quantiication of phenolics. The main goal of this chapter is to provide the reader with a broad view on the diferent protocols used to extract, identify and quantify phenolic compounds from diferent kinds of foods, including fruits and vegetables.Keywords: phytochemicals, extraction, determination, colorimetric methods, HPLC, HPLC-MS IntroductionThe growing resistance of pathogenic bacterial isolates against the traditional chemical antibiotics as well as the resurgent of old disappeared diseases associated with the constant consumers' demanding of healthier, nutritious and safe food has led the researchers to focus on searching for new, safe and efective molecules. One class of such molecules is the class of polyphenols. Polyphenols are a ubiquitous class of compounds largely present in plants as their secondary metabolites, which are synthesized during their normal development [1] in response to several stressful biotic and abiotic factors [2,3]. This class of compounds are a much diversiied group derived from the amino acids phenylalanine and tyrosine and The results from the last decade's research have shown that polyphenols have important beneicial properties for human health, including antioxidative, antiaging, antibacterial and antimutagenic [7][8][9][10][11]. Moreover, the recent evidence of their interaction with proteins, DNA and other biological molecules has enhanced their exploitation for the production of new natural product-derived therapeutic agents. Despite these advantages, several limitations still persist, particularly those related with their extraction eiciency, which afects the large-scale use of some of these substances. The diiculties in screening, extracting, separation and purifying these compounds have increased the development of new and modern methods to address these limitations. In this context, the aim of this chapter is to present an updated review about sources, technologies and methods that have been developed until now to improve the extraction, detection, separation and full characterization of such beneicial compounds, with special emphasis to their possible application in the design of nutraceuticals and functional food products. Foods as natural resources of phenolicsPolyphenols have been exhaustively studied in their diferent natural matrices such as fruits, vegetables, teas, algae a...

Qualitative and Quantitative Analysis of Polyphenols in Lamiaceae Plants—A Review

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Plant Phenolics and Phenolic-Enriched Extracts as Antimicrobial Agents against Food-Contaminating Microorganisms

“…Byproducts of antioxidative plants generated through agro-and food industrial processes are excellent sources of bioactive phenolic materials with antimicrobial effects [5]. Physical and chemical extractions are common methods to obtain these active compounds from plants, but solid-state fermentation and enzyme assisted extraction procedures using carbohydrase active microorganisms or enzymes, can also be useful approaches [6][7][8].…”

Effective treatments of jojoba and jatropha hulls to obtain phytochemical compounds for industrial, nutritional, and pharmaceutical uses

“…This occurs when a single extraction method is low as we would expect, thus a mixture of extraction processes could be the optimum effective method for extraction of different polyphenols in extracts (Alfredo 2016). According to these reports and to our last study in this field, we used different treatments because as can be seen in the examined hull biomass (Figs 1 and 2), these are composed of cellulose, hemicellulose, lignin, and other minor components.…”