Measurement of Antioxidant Capacity of Meat and Meat Products: Methods and Applications

At present, a wide variety of analytical methods is available to measure antioxidant capacity. However, this great diversity is not reflected in the analysis of meat and meat products, as there are a limited number of studies on determining this parameter in this complex food matrix. Despite this, and due to the interest in antioxidants that prevent oxidation reactions, the identification of antioxidants in meat and meat products is of special importance to the meat industry. For this reason, this review compiled the main antioxidant capacity assays employed in meat and meat products, to date, describing their foundations, and showing both their advantages and limitations. This review also looked at the different applications of antioxidant properties in meat and meat products. In this sense, the suitability of using these methodologies has been demonstrated in different investigations related to these foods.

Attenuating Fibrotic Markers of Patient-Derived Dermal Fibroblasts by Thiolated Lignin Composites

<div> <div> <div> <p>Engineering composite biomaterials requires the successful integration of multiple feed- stocks to formulate a final product for functional improvement. Here we engineered biomaterial scaffolds to attenuate the fibrotic phenotype exhibited by high scarring (HS) patient-derived der- mal fibroblasts (hdFBs) by valorizing lignosulfonate from waste feedstocks of lignin. We utilized phenolic functional groups of lignosulfonate to impart antioxidant properties and the cell binding domains of gelatin to enhance cell adhesion for poly(ethylene glycol)-based scaffolds. Highly ef- ficient chemoselective thiol-ene chemistry was utilized for the formation of composites with thio- lated lignosulfonate (TLS) and methacrylated fish gelatin (fGelMA) in the PEG(poly (ethylene gly- col))-diacrylate matrix. Antioxidant properties of lignosulfonate was not altered after thiolation and the levels of antioxidation were comparable to a well-known antioxidant, L-ascorbic acid, as evi- denced by DPPH (2,2-diphenyl-1-picrylhydrazyl) and TAC (Total Antioxidant Capacity) assays. Unlike porcine gelatin, fGelMA remained liquid at room temperature and exhibited low viscosities, resulting in no issues of miscibility when mixed with PEG. PEG-fGelMA-TLS composites signifi- cantly reduced the differential of five different fibrotic markers (COL1A1, ACTA2, TGFB1 and HIF1A) between HS and low scarring (LS) hdFBs, providing the potential utility of TLS in a bio- material scaffold to attenuate fibrotic responses. </p> </div> </div> </div>

Recent Advances in Antioxidant Capacity Assays

This work presents a survey of the important antioxidant capacity/activity assays applied for a diversity of samples including plant extracts, foods, biological material, etc. The published materials are critically discussed, emphasizing the recent findings in the field. New and emergent antioxidant capacity assays, such as nanoparticles-based assay, are also presented. The discussion includes chemical-based methods as well as biochemical and cellular assays. Chemical methods detailed are radical/ROS-based scavenging assays (the trolox equivalent antioxidant capacity (TEAC/ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC) assays, chemiluminescence methods, total radical-trapping antioxidant parameter (TRAP), total oxy radical scavenging capacity (TOSC), and β-carotene bleaching assays), non-radical redox potential-based assays (ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), nanoparticle-based methods and electrochemical methods), metal chelation capacity and total phenolic content tests. The biochemical-based assays and in vivo assays discussed include the oxidation of low density lipoprotein (LDL), the thiobarbituric acid reactive substances (TBARS) and the cellular antioxidant activity (CAA) assays. While a direct link between the antioxidant capacity and health benefits is still a matter of debate, the antioxidant testing methodologies presented in this chapter remain valuable for the high efficiency and cost-effective evaluation of antioxidants, from compound discovery to quality control.

In Vitro Comparison of the Bioactivities of Japanese and Bohemian Knotweed Ethanol Extracts

Knotweed is a flowering plant that is native to temperate and subtropical regions in the northern hemisphere. We evaluated Japanese (Reynoutria japonica Houtt.) and Bohemian (Fallopia x bohemica) knotweed rhizome and flower ethanol extracts and compared them in terms of their biological activities. The specific polyphenols were identified and quantified using HPLC/DAD, and the antioxidant activity was determined using 2,2-diphenly-1-picrylhydrazyl (DPPH) and cellular antioxidant capacity assays. The anticancer activity was evaluated as the difference between the cytotoxicity to cancer cells compared with control cells. The antimicrobial activity was determined using bacteria and yeast. The antidiabetic activity was tested as the ability of the extracts to inhibit α-amylase. Both rhizome extracts were sources of polyphenols, particularly polydatin and (−)-epicatechin; however, the cellular assay showed the highest antioxidant capacity in the flower extract of F. bohemica. The PaTu cell line was the least sensitive toward all knotweed extracts. The flower extracts of both species were less toxic than the rhizomes. However, the activity of the tested extracts was not specific for cancer cells, indicating a rather toxic mode of action. Furthermore, all used extracts decreased the α-amylase activity, and the rhizome extracts were more effective than the flower extracts. None of the extracts inhibited bacterial growth; however, they inhibited yeast growth. The results confirmed that rhizomes of Reynoutria japonica Houtt. could become a new source of bioactive compounds, which could be used for the co-treatment of diabetes and as antifungal agents.

Chemopreventive Effects and Antioxidant Capacity of Combined Leaf Extracts of Sesamum angustifolium (Oliv.) Engl. and Hibiscus articulatus on Rhabdomyosarcoma

Sesamum angustifolium (Oliv.) Engl. and Hibiscus articulatus contain compounds that have antimutagenic properties. The rise in rhabdomyosarcoma in paediatrics and prognosis of the disease in infants compared to adults calls for newer, less toxic alternatives in treatment of the disease. The aim of this study was to determine the anticancer activity and antioxidant capacity of combined leaf extracts of Sesamum angustifolium (Oliv.) Engl. and Hibiscus articulatus (SAHA), against rhabdomyosarcoma (RMS) using rhabdomyosarcoma (RD) cell line and mouse (L20B) cell line. Cytotoxicity, morphology, apoptosis induction, and antioxidant capacity assays were done. Of the four solvents used for extraction, the dichloromethane SAHA extract was the most cytotoxic with IC50 of 106 μg/mL after doxorubicin, the reference anticancer drug with IC50 of 0.8 μg/mL. The SAHA extracts had a stronger cytotoxicity effect on the cancerous RD cells than on normal L20B cells. Morphological assessment showed untreated cells maintained their normal striated appearance of muscle cells whereas cells treated with doxorubicin or SAHA extracts exhibited cell shrinkage, loss of surface adherence, reduced cell density along with cell debris, which is a characteristic of apoptosis. Normal L20B cells when treated with doxorubicin or SAHA extracts, maintained their cell shape, and remained adherent to the surface. The apoptotic enzyme caspase-3 was induced in a concentration dependent manner upon treatment of the RD cells with SAHA extracts or doxorubicin. Induction of caspase-3 was ten times less in treated L20B cells compared to the RD cells. Low induction of caspase-9 enzyme was observed in both treated RD and L20B cells. Treatment of both RD and L20B cells with SAHA extracts or doxorubicin resulted in increased activity of peroxidase and reduction of oxidative stress. Results of the study show that the SAHA extracts are potential sources of compounds that may serve as useful agents for treatment of rhabdomyosarcoma.

Antioxidant Activity and Polyphenolic Content of North Macedonian Wines

The purpose of this study was to evaluate comparatively the polyphenolic content and the antioxidant activity of selected regional red and white wine varieties, produced in the Republic of North Macedonia. The polyphenolic content was evaluated by measuring the total polyphenol, total flavonoid, total tannin and total anthocyanin contents and the antioxidant activity by applying the DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric-reducing antioxidant power) and CUPRAC (cupric ion-reducing antioxidant capacity) assays. Statistical analysis of the results showed that all white wines examined (Smederevka, Temjanika and Zhilavka) belong to the same group, two red wines (Vranec and Kratoshija) belong to another group while the Stanushina red variety shows distinct differences from the other red wines examined.

Investigation of Antioxidant and Elastase Inhibitory Activities of Geum urbanum Aerial Parts, Chemical Characterization of Extracts Guided by Chemical and Biological Assays

This study presents the bioguided chemical investigation of the 80% aqueous methanol extract of Geum urbanum aerial parts. Liquid–liquid partitioning of this extract in solvents of increasing polarity combined with biological screening showed that the ethyl acetate (EtOAc) soluble fraction was the most active part of the extract. This fraction was chemically profiled by a 13C nuclear magnetic resonance (NMR)-based dereplication method, resulting in the identification of 14 compounds. The dereplication process was followed by the purification of unknown and minor compounds of the EtOAc fraction. A new glycosylated phenol, namely, 3-(3,4-dihydroxyphenyl)propyl-α-l-rhamnopyranoside, together with 6 known compounds were isolated. Their structures were elucidated by spectroscopic methods including NMR and high-resolution electrospray ionization mass spectrometry. The antioxidant activity of fractions and isolated compounds were evaluated by 2,2,1-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging, and by cupric ion reducing antioxidant capacity assays. In parallel, their enzyme inhibitory property against human neutrophil elastase was assessed. Four subfractions, essentially containing polyphenols and triterpenes, exhibited a significant elastase inhibitory activity and an ellagitannin showed a very high radical scavenging activity.

ABTS/PP Decolorization Assay of Antioxidant Capacity Reaction Pathways

The 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical cation-based assays are among the most abundant antioxidant capacity assays, together with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-based assays according to the Scopus citation rates. The main objective of this review was to elucidate the reaction pathways that underlie the ABTS/potassium persulfate decolorization assay of antioxidant capacity. Comparative analysis of the literature data showed that there are two principal reaction pathways. Some antioxidants, at least of phenolic nature, can form coupling adducts with ABTS•+, whereas others can undergo oxidation without coupling, thus the coupling is a specific reaction for certain antioxidants. These coupling adducts can undergo further oxidative degradation, leading to hydrazindyilidene-like and/or imine-like adducts with 3-ethyl-2-oxo-1,3-benzothiazoline-6-sulfonate and 3-ethyl-2-imino-1,3-benzothiazoline-6-sulfonate as marker compounds, respectively. The extent to which the coupling reaction contributes to the total antioxidant capacity, as well as the specificity and relevance of oxidation products, requires further in-depth elucidation. Undoubtedly, there are questions as to the overall application of this assay and this review adds to them, as specific reactions such as coupling might bias a comparison between antioxidants. Nevertheless, ABTS-based assays can still be recommended with certain reservations, particularly for tracking changes in the same antioxidant system during storage and processing.