This contribution provides a review of the topic of insoluble-bound phenolics, especially their localization, synthesis, transfer and formation in plant cells, as well as their metabolism in the human digestive system and corresponding bioactivities. In addition, their release from the food matrix during food processing and extraction methods are discussed. The synthesis of phenolics takes place mainly at the endoplasmic reticulum and they are then transferred to each organ through transport proteins such as the ATP-binding cassette (ABC) and multidrug and toxic compound extrusion (MATE) transporter at the organ’s compartment membrane or via transport vesicles such as cytoplasmic and Golgi vesicles, leading to the formation of soluble and insoluble-bound phenolics at the vacuole and cell wall matrix, respectively. This part has not been adequately discussed in the food science literature, especially regarding the synthesis site and their transfer at the cellular level, thus this contribution provides valuable information to the involved scientists. The bound phenolics cannot be absorbed at the small intestine as the soluble phenolics do (5%–10%), thus passing into the large intestine and undergoing fermentation by a number of microorganisms, partially released from cell wall matrix of foods. Bound phenolics such as phenolic acids and flavonoids display strong bioactivities such as anticancer, anti-inflammation and cardiovascular disease ameliorating effects. They can be extracted by several methods such as acid, alkali and enzymatic hydrolysis to quantify their contents in foods. In addition, they can also be released from the cell wall matrix during food processing procedures such as fermentation, germination, roasting, extrusion cooking and boiling. This review provides critical information for better understanding the insoluble-bound phenolics in food and fills an existing gap in the literature.

https://www.mdpi.com/1420-3049/21/9/1216/pdf

Insoluble-Bound Phenolics in Food.

Bound phenolic compounds and antioxidant properties of whole grain and bran of white, red and black rice.

Phenolic compounds are important functional bioactive substances distributed in various food plants. They have gained wide interest from researchers due to their multiple health benefits. There are two forms of phenolic compounds: free form and bound form. The latter is also called bound phenolics (BPs), which are found mainly in the cell wall and distributed in various tissues/organs of the plant body. They can either chemically bind to macromolecules and food matrixes or be physically entrapped in food matrixes and intact cells. Various isolation methods, including chemical, biological, and physical methods, have been employed to extract BPs from plants. BPs have been shown to have strong biological activities, including antioxidant, probiotic, anticancer, anti-inflammation, antiobesity, and antidiabetic effects as well as beneficial effects on central nervous system diseases. This review summarizes research findings on these topics to help in better understanding of BPs and provide comprehensive information on their health effects.

Review of Distribution, Extraction Methods, and Health Benefits of Bound Phenolics in Food Plants.

Black rice (Oryza sativa L.): a review of its historical aspects, chemical composition, nutritional and functional properties, and applications and processing technologies.

Extractable and non-extractable bound phenolic compositions and their antioxidant properties in seed coat and cotyledon of black soybean (Glycinemax (L.) merr)

The revisited levels of free and bound phenolics in rice: Effects of the extraction procedure.

Species of the Vibrio genus are commonly reported as agents of food poisoning outbreaks associated with fish consumption. The objective of this study was to assess the antimicrobial activity of the essential oils of Origanum vulgare and Ocimum basilicum against Vibrio parahaemolyticus and Vibrio vulnificus, as well as to assess their addition to fillets of Mugil platanus and sensorial acceptance among consumers. The antimicrobial activity was analyzed by the disc diffusion test and minimal bactericidal concentration (MBC). M. platanus fillets, experimentally contaminated, were marinated for 24 hours in a solution containing 1.0% and 1.5% of essential oil of O. vulgare. For the sensory analysis, samples marinated in 1.5% of O. vulgare oil were prepared and offered to 100 testers. The oil of O. basilicum shows no antimicrobial activity, so its application would be ineffective; for such reason the subsequent tests were not performed. However, the essential oil of O. vulgare produced inhibition halo diameters ranging from 24.6 to 34.1 mm, on average, and the MBC ranging from 3.9% to 15.6%. When added to the product, the essential oil of O. vulgare eliminated the microorganisms that were experimentally inoculated. In the sensorial analysis, samples marinated in 1.5% of O. vulgare essential oil obtained an average of 6.82 of acceptance note among consumers.

/pdf/antimicrobial-activity-of-essential-oils-of-origanum-vulgare-4rbd40df5g.pdf

ANTIMICROBIAL ACTIVITY OF ESSENTIAL OILS OF Origanum vulgare AND Ocimum basilicum AGAINST Vibrio parahaemolyticus AND Vibrio vulnificus AND ADDITION OF THESE OILS ON Mugil platanus FILLETS

Patrícia Gomes Vivian

Papers

The revisited levels of free and bound phenolics in rice: Effects of the extraction procedure.

ANTIMICROBIAL ACTIVITY OF ESSENTIAL OILS OF Origanum vulgare AND Ocimum basilicum AGAINST Vibrio parahaemolyticus AND Vibrio vulnificus AND ADDITION OF THESE OILS ON Mugil platanus FILLETS