Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review

While use of synthetic antioxidants (such as butylated hydroxytoluene and butylated hydroxyanisole) to maintain the quality of ready-to-eat food products has become commonplace, consumer concern regarding their safety has motivated the food industry to seek natural alternatives. Phenolic antioxidants can inhibit free radical formation and/or interrupt propagation of autoxidation. Fat-soluble vitamin E (α-tocopherol) and water-soluble vitamin C (L-ascorbic acid) are both effective in the appropriate matrix. Plant extracts, generally used for their flavoring characteristics, often have strong H-donating activity thus making them extremely effective antioxidants. This antioxidant activity is most often due to phenolic acids (gallic, protocatechuic, caffeic, and rosmarinic acids), phenolic diterpenes (carnosol, carnosic acid, rosmanol, and rosmadial), flavonoids (quercetin, catechin, naringenin, and kaempferol), and volatile oils (eugenol, carvacrol, thymol, and menthol). Some plant pigments (anthocyanin and anthocyanidin) can chelate metals and donate H to oxygen radicals thus slowing oxidation via 2 mechanisms. Tea and extracts of grape seeds and skins contain catechins, epicatechins, phenolic acids, proanthocyanidins, and resveratrol, all of which contribute to their antioxidative activity. The objective of this article is to provide an overview of natural antioxidants, their mechanisms of action, and potential applications.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1541-4337.2011.00156.x

Natural antioxidants: sources, compounds, mechanisms of action, and potential applications

http://www.ipb.pt/~htgomes/FCT115275/Ref23.pdf

Sub- and supercritical fluid extraction of functional ingredients from different natural sources: Plants, food-by-products, algae and microalgae: A review

Phenols, proanthocyanidins, flavones and flavonols in some plant materials and their antioxidant activities

Supercritical extraction and fractionation of natural matter is one of the early and most studied applications in the field of supercritical fluids In the last 10 years, studies on the extraction of classical compounds like essential and seed oils from various sources: seeds, fruits, leaves, flowers, rhizomes, etc, with or without the addition of a co-solvent have been published Supercritical extraction of antioxidants, pharmaceuticals, colouring matters, and pesticides has also been studied The separation of liquid mixtures and the antisolvent extraction are other processes that can perform very interesting separations Mathematical modelling has also been developed and refined for some of these processes The objective of this review is to critically analyze traditional and new directions in the research on natural matter separation by supercritical fluids extraction and fractionation

Supercritical fluid extraction and fractionation of natural matter

Comparison of antioxidative and synergistic effects of rosemary extract with α-tocopherol, ascorbyl palmitate and citric acid in sunflower oil

High pressure extraction of vitamin e-rich oil from silybum marianum

The antioxidant and antimicrobial effects of commercially available oil-soluble rosemary extracts VivOX 20 and VivOX 4 were investigated against lipid oxidation and microbial growth in vacuum-packed chicken frankfurters. The content of the main active ingredient, carnosic acid, in extracts was 20% and 4% (w/w), respectively. For comparison, the activity of commercially available preservative Robin LI LS was also tested. The control was chicken frankfurters made without test additives. Antioxidant activity tests were performed at 3 storage temperatures (4, 12, 25 °C), using the Rancimat method. Antimicrobial effect was investigated by aerobic plate count. Results showed that both rosemary preparations possess antioxidant and antimicrobial properties that may make them useful in the food industry. In chicken frankfurters with added VivOX 20 and VivOX 4, higher oxidative stability was exhibited at all storage temperatures, as in frankfurters with Robin LI LS. Addition of VivOX 20, VivOX 4, and Robin LI LS also significantly reduced the aerobic plate count, compared to controls, stored at 4 or 12 °C.

Antioxidant and Antimicrobial Activity of Rosemary Extract in Chicken Frankfurters

In present work, the purification of crude rosemary extract with supercritical fluids is presented. Carbon dioxide was used as a solvent. The crude extract was prepared from rosemary with conventional extraction process. The supercritical CO 2 extraction of crude extracts was performed at pressures 10 and 20 MPa and temperatures 35 and 60 °C. The best results were obtained at pressure 10 MPa and temperature 35 °C. The content of carnosic acid in the samples before and after high pressure extraction was identified by high performance liquid chromatography. The content of carnosic acid in purified extract is higher compared to crude extract. The antioxidative efficiency of extracts was determined by measuring peroxide value. Activity of purified rosemary extracts is higher compared to crude extracts.

Davorin Bauman

Papers

Comparison of antioxidative and synergistic effects of rosemary extract with α-tocopherol, ascorbyl palmitate and citric acid in sunflower oil

High pressure extraction of vitamin e-rich oil from silybum marianum

Antioxidant and Antimicrobial Activity of Rosemary Extract in Chicken Frankfurters

Isolation and concentration of natural antioxidants with high-pressure extraction

Solubility of some solid triazine herbicides in supercritical carbon dioxide