Novel antioxidants in food quality preservation and health promotion

Transcriptomic responses of Caco-2 cells to Lactobacillus rhamnosus GG and Lactobacillus plantarum J26 against oxidative stress

Oxidative stress is the basic reason for aging and age-related diseases. In this study, we investigated the protective effect of 2 strains of lactic acid bacteria (LAB), Lactobacillus rhamnosus GG and L. plantarum J26, against oxidative stress in Caco-2 cells, and gave an overview of the mechanisms of lactic acid bacteria antioxidant activity using digital gene expression profiling. The 2 LAB strains provided significant protection against hydrogen peroxide (H₂O₂)-induced reduction in superoxide dismutase activity and increase in glutathione peroxidase activity in Caco-2 cells. However, inactive bacteria had little effect on alleviating oxidation stress in Caco-2 cells. Eight genes related to oxidative stress-FOSB, TNF, PPP1R15A, NUAK2, ATF3, TNFAIP3, EGR2, and FBN2-were significantly upregulated in H₂O₂-induced Caco-2 cells compared with untreated Caco-2 cells. After incubation of the H₂O₂-induced Caco-2 cells with L. rhamnosus GG and L. plantarum J26, 5 genes (TNF, EGR2, NUAK2, FBN2, and TNFAIP3) and 2 genes (NUAK2 and FBN2) were downregulated, respectively. In addition, the Kyoto Encyclopedia of Genes and Genomes indicated that some signaling pathways associated with inflammation, immune response, and apoptosis, such as Janus kinase/signal transducers and activators of transcription (Jak-STAT), mitogen-activated protein kinase (MAPK), nuclear factor-κB, and tumor necrosis factor, were all negatively modulated by the 2 strains, especially L. rhamnosus GG. In this paper, we reveal the mechanism of LAB in relieving oxidative stress and provide a theoretical basis for the rapid screening and evaluation of new LAB resources.

Enzymatic synthesis of lipophilic lutein-PUFA esters and assessment of their stabilization potential in EPA-DHA rich fish oil matrix

The objective of the present study was to synthesize ω-3 polyunsaturated fatty acid esters of lutein and to evaluate if esterification can stabilize the both bioactive molecules. Both ω-3 polyunsaturated fatty acid and lutein are prone towards auto-oxidation in their free form. Free lutein extracted from the marigold petals was enzymatically esterified using Candida antarctica NS435 Lipase B, with the ω-3 long-chain polyunsaturated fatty acids. The lutein esters were purified, characterized and finally assessed for their protective role against oxidative degradation in bulk fish oil matrix. The antioxidative effect of these esters was compared with commercial antioxidants of natural origin, i.e., α-tocopherol and a synthetic antioxidant, i.e., tert-butylhydroquinone, at a dosage of 200 mg/L. Both free lutein and lutein-polyunsaturated fatty acid ester had significantly promoted the oxidative stability of bulk fish oil. But based on dose-response relationship, lutein-polyunsaturated fatty acid ester was found to be more efficient than free lutein, in protecting fish oil from secondary oxidation, thereby augmenting their shelf life. Given the high nutraceutical value, potent antioxidative potential and organic origin, it is only relevant to incorporate lutein esters as natural preservative and stabilizers in edible oils.

Potential of Liquid Extraction Surface Analysis Mass Spectrometry (LESA-MS) for the Characterization of Polymer-Based Materials

Liquid extraction surface analysis mass spectrometry (LESA -MS) is a direct analysis method suitable for the analysis of polymers. It is based on a fast and efficient extraction of polymer components, such as non-intentionally added species (NIAS), post-polymerization residues, or additives, and residues resulting from specific uses followed by their MS detection. In comparison with batch methods, it is a “green” method, using negligible volumes of organic solvents, and it is cost-effective, avoiding lengthy sample preparation procedures. It can be used for the detection of known molecules (targeted analysis), identification of unknown species (exploratory analysis requiring MS/MS) and semi-quantative analysis, if standards are available. The to-date applications of LESA-MS in the field of polymer science are reviewed and critically discussed taking into account the hands-on experience from the authors’ laboratory. Future possibilities of LESA applications are highlighted.

Comparative Phytochemical Analysis and Antioxidant Activities of Tamalakyadi Decoction with Its Modified Dosage Forms

Background and Objective

Tamalakyadi decoction (TD) is a classical formulation mentioned in authentic traditional medicine text Sarasankshepaya under nasal diseases and used as a remedy for allergic rhinitis. It consists of 12 plant ingredients. Decoction preparations are widely used in Sri Lankan traditional system and considered effective and safe for treating many disorders. However, decoctions have to be used only in fresh state due to shorter shelf life and loss of stability. This decoction preparation method leads to decreasing the patient compliance and is also time consuming. Hence, the objective of the present study was to convert TD to consumer friendly novel dosage form, namely, freeze dried, spray dried, and traditional ganasara forms.

Methodology

Therefore, we compared the phytochemical constituents and antioxidant activities of TD with its modified dosage forms. The chemical comparison of four dosage forms comprises phytochemical screening, TLC and HPTLC fingerprint profiles and the antioxidant activities by DPPH free radical scavenging activity, Ferric reducing antioxidant power (FRAP), total polyphenol content (TPC), and total flavonoid content (TFC).

Results

Phytochemical screening revealed the presence of alkaloids, saponins, tannins, steroids, flavonoids, phenols, and terpenoids in all dosage forms. However, the saponins, alkaloids, flavonoids, terpenoids, and steroids were more prominent in TD and freeze dried preparation than the other two preparations. HPTLC fingerprint pattern of freeze dried dosage was more similar with HPTLC fingerprint pattern of TD in terms of number of peaks and their intensity compared to that of spray dried and ganasara dosage forms. Antioxidant activities such as DPPH, FRAP, TPC, and TFC were higher in decoction and freeze dried preparation than in spray dried and ganasara preparation.

Conclusion

Freeze dried TD is the most suitable ready to use preparation having similar chemical properties and antioxidant activities to TD.

Purification and identification of an antioxidant peptide from perilla seed (Perilla frutescens) meal protein hydrolysate

This study aimed to obtain antioxidant peptides from perilla seed meal (PSM), which is normally discarded as an industrial waste during seed oil extraction. PSM protein was hydrolyzed using trypsin and fractionated by ultrafiltration. Molecular weight fraction (<3 kDa) with the highest antioxidant activity was purified using prep-HPLC and analytical HPLC. The purification fold of the peptide (fraction V) obtained from PSM protein hydrolysate on DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power was 1.79-, 1.59-, and 1.81-fold, respectively, after the three-step purification procedure. The sequence of the purified peptide from fraction V that exhibited free radical scavenging activity and reducing power was identified as Ile-Ser-Pro-Arg-Ile-Leu-Ser-Tyr-Asn-Leu-Arg (1,330.77 Da). These results demonstrate that PSM protein, a by-product from the oil seed extraction, can be used as a source of natural antioxidant peptides for food and/or nutraceutical applications.

Liposomes for delivery of antioxidants in cosmeceuticals: Challenges and development strategies

Antioxidants (AOs) play a crucial role in the protection and maintenance of health and are also integral ingredients in beauty products. Unfortunately, most of them are sensitive due to their instability and insolubility. The use of liposomes to protect AOs and expand their applicability to cosmeceuticals, thereby, is one of the most effective solutions. Notwithstanding their offered advantages for the delivery of AOs, liposomes, in their production and application, present many challenges. Here, we provide a critical review of the major problems complicating the development of liposomes for AO delivery. Along with issues related to preparation techniques and encapsulation efficiency, the loss of protective function and inefficiency of skin permeability are the main disadvantages of liposomes. Corresponding development strategies for resolving these problems, with their respective advantages and drawbacks, are introduced, discussed in some depth, and summarized in these pages as well. Advanced liposomes have a vital role to play in the development and delivery of AOs in practical cosmeceutical product applications.

Antioxidant properties and instrumental quality characteristics of spray dried Pangasius visceral protein hydrolysate prepared by chemical and enzymatic methods

Fish protein hydrolysates are digested form of protein with various bioactive properties where, the cleavages of molecular bonds of proteins can be broken by the enzymatic and chemical process. In this study, antioxidant properties of spray dried protein hydrolysate prepared from Pangasius viscera by using enzymatic (papain and pepsin), and chemical methods (hydrochloric acid and sodium hydroxide) were evaluated. Among the different treatments, pepsin-derived visceral protein hydrolysate showed the maximum antioxidant activity when used at higher concentrations. Essential amino acids (EAA) and hydrophobic amino acids are higher in papain-derived visceral protein hydrolysate. In pepsin-derived visceral protein hydrolysate, major proportion was contributed by glycine (Gly), glutamine (Glu), proline (Pro), and asparagine (Asp). Higher amount of aromatic amino acids are found in alkali-derived FVPH. Scanning electron microscopy (SEM) images of pepsin fish visceral protein hydrolysate showed better globular structure than the other treatments. It can be concluded that among the different treatments, the visceral protein hydrolysate prepared with pepsin had better overall quality regarding antioxidant properties and papain in nutritional point of view.

Direct screening of food packaging materials for post-polymerization residues, degradation products and additives by liquid extraction surface analysis nanoelectrospray mass spectrometry (LESA-nESI-MS)

Materials in direct contact with food should be monitored for the presence of species able to migrate into food. A direct method based on liquid extraction surface analysis nanoelectrospray mass spectrometry (LESA-nanoESI-MS) was developed for the analysis of the migrating species from a polymer film. Different types of molecules: post-polymerization residues, degradation products (oligomers resulting from polymer recycling, products of polymer oxidative degradation) and anti-oxidant additives (vitamin E) were demonstrated to be detected and identified, and determined quantitatively if relevant calibration standards are available. The method was validated by a comparison a standard method based on with bulk extraction mass spectrometry. It offers considerable advantages over the latter in terms of drastically reduced analysis time and solvent consumption. Also, LESA-nanoESI-MS produced simpler spectra (limited to compounds able to migrate into food) than Direct Analysis in Real Time (DART).

Antimicrobial and Antioxidant Performance of Various Essential Oils and Natural Extracts and Their Incorporation into Biowaste Derived Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Layers Made from Electrospun Ultrathin Fibers

In this research, the antibacterial and antioxidant properties of oregano essential oil (OEO), rosemary extract (RE), and green tea extract (GTE) were evaluated. These active substances were encapsulated into ultrathin fibers of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from fruit waste using solution electrospinning, and the resultant electrospun mats were annealed to produce continuous films. The incorporation of the active substances resulted in PHBV films with a relatively high contact transparency, but it also induced a slightly yellow appearance and increased the films opacity. Whereas OEO significantly reduced the onset of thermal degradation of PHBV, both the RE and GTE-containing PHBV films showed a thermal stability profile that was similar to the neat PHBV film. In any case, all the active PHBV films were stable up to approximately 200 °C. The incorporation of the active substances also resulted in a significant decrease in hydrophobicity. The antimicrobial and antioxidant activity of the films were finally evaluated in both open and closed systems for up to 15 days in order to anticipate the real packaging conditions. The results showed that the electrospun OEO-containing PHBV films presented the highest antimicrobial activity against two strains of food-borne bacteria, as well as the most significant antioxidant performance, ascribed to the films high content in carvacrol and thymol. Therefore, the PHBV films developed in this study presented high antimicrobial and antioxidant properties, and they can be applied as active layers to prolong the shelf life of the foods in biopackaging applications.

Bioactive food derived peptides: a review on correlation between structure of bioactive peptides and their functional properties

The presence of bioactive peptides has already been reported in many foods such as milk, fermented products, plant and marine proteins. Bioactive peptides are sequences between 2 and 20 amino acids that can inhibit chronic diseases by modulating and improving physiological functions, so these peptides contribute in holding the consumer health. Also, bioactive peptides can affect pro-health or functional properties of food products. Fractionation of the protein hydrolysate revealed a direct relationship between their structure and functional activity. So, this review focuses on different factors effecting on bioactive peptide structures, biological and functional properties such as antihypertensive, antioxidative, hypocholesterolemic, water-holding capacity, foaming capacity, emulsifying properties and solubility. Also, this review looks at the identified bioactive peptides from food protein sources as potential ingredients of health promoting functional foods.

Recovery of Antimicrobials and Bioaccessible Isoflavones and Phenolics from Soybean (Glycine max) Meal by Aqueous Extraction

Soybeans display strategic potential in food security as a source of protein and functional bioactives for human consumption. Polyphenols and other bioactive compounds can be recovered after an aqueous extraction from soybean meal, a byproduct of soy oil refining. The objective of the present study was to compile and quantify compounds from soybean oil refinery by-products, providing information about valuable bioactive phytochemicals, their bioaccessibility and potential bioactivities. Genistin, daidzin, glycitin and malonylgenistin were the predominant isoflavones, and the overall bioaccessibility of their glycosidic forms was of nearly 75%. Sixteen phenolics were identified and caffeic acid, 5-caffeoylquinic chlorogenic acid and hesperidin were the most predominant. Approximately 30% of gallic acid, syringic acid, vanillic acid and myricetin were released and the antioxidant capacity of aqueous extract was enhanced after simulated in vitro gastro intestinal digestion. The ability of aqueous soybean meal extract to inhibit lipid peroxidation was higher than natural and synthetic food antioxidants. Antimicrobial activity against several foodborne pathogens and antitumoral activity towards human glioblastoma cell line were also observed, but the aqueous extract showed no cytotoxicity to healthy murine cells. Compounds derived from the aqueous soybean meal extract have the potential to be used as health promoting agents.

Hemp (Marijuana) reverted Copper-induced toxic effects on the essential fatty acid profile of Labeo rohita and Cirrhinus mrigala

Heavy metals pollution affects the nutritive value of fish. This study examined if the inclusion of dietary hempseed (HS) and hempseed oil (HO) in the diet of the fish could revert the copper-induced toxic effects on muscle fatty acid profile of rohu (Labeo rohita) and mrigal (Cirrhinus mrigala). Fingerlings of both species were exposed to a sub-lethal concentration of copper i.e., 20% of LC₅₀ (1.34 ppm for rohu and 1.52 ppm for mrigal) for 96 h for 30 days. Following exposure, fish were maintained on graded levels of HO (1, 2 and 3%) or on HS (5, 10 and 15%) for 50 days. Copper exposure showed a significant effect on the fatty acid composition of both species; increased their saturated (SFA) to unsaturated (USFA) and altered their omega-3/omega-6 (ω-3/ω-6) ratios. However, feeding graded levels of hempseed products reverted the toxic effects of copper on the fatty acid profile of both the species, significantly increased muscle total fatty acid contents, improved ω-3/ω-6 ratios, and decreased SFA / USFA ratio in % inclusion dependent manner. Furthermore, hempseed product showed a species-specific effect on USFA. The ω-3/ω-6 ratios decreased in the muscle of C. mrigala whereas an increasing trend with an increase in hempseed product % inclusion was observed in L. rohita. Moreover, HS showed a higher impact on both species as compared to HO. With the findings of this study, hempseed product could be recommended as a feed ingredient for enhancing the essential fatty acid contents of fish which in turn can have a good impact on consumer health.

Characteristics of herring marinated in reused brines after microfiltration

Brines after herring marinating pose a serious financial problem to the industry and natural environment. Paradoxically, the brine waste containing biological active compounds like proteases and peptides being responsible for marinade quality is discarded with sewage. Results show that the reuse of brine without filtration is not possible because of increase in the bacterial count and lipid oxidation in marinated herring. The desired parameters of marinades were achieved using brine permeate-50 µm free of the suspension and lipids. The best quality and sensory parameters of marinated herring meat were obtained using permeate-0.22 brine, which not contain microorganisms and lipids, and also a high activity of proteases. Reuse of brine allows reducing by half the losses of protein hydrolysis products (PHP) from meat to brine and for reverse diffusion of PHP and peptidases to meat. The marinades produced with the newly-developed method had up to 25% more PHP, up to 20% lower hardness, 10–20% higher activity of proteases, 40–97% lower indices of lipid oxidation, and 5% higher scores in sensory assessment, compared to the marinades produced with fresh brine. The inexpensive and easy to perform microfiltration of brine affords the possibility of increasing the quality and nutritional value of marinades and minimizing both waste volume and production costs.

Optimization of the Antioxidant Potentials of Red Pitaya Peels and Its In Vitro Skin Whitening Properties

In this study, response surface methodology (RSM) was employed for the optimization of the antioxidant potentials of red pitaya peels using independent variables: temperature (45–65 °C), ethanol concentration (70–90%, v/v) and time (80–120 min) through its responses, which were DPPH scavenging activity, ferric ion reducing antioxidant power (FRAP), and beta-carotene bleaching (BCB) inhibition, respectively. In Vitro anti-tyrosinase and vitamin C content assays were carried out spectrophotometrically to determine the skin whitening efficacy of the optimized red pitaya peel extract. A gas chromatography-mass spectrometry (GC-MS) analysis was employed to identify the chemical constituents present in the optimized extract. The optimized conditions were ethanol 82% (v/v) for 103 min at 56 °C with values of 75.98% for DPPH, 7.45 mM Fe2+/g dry weight for FRAP and 93.29% for BCB respectively. The in vitro anti-tyrosinase and vitamin C content evaluation of the optimized extract showed a good tyrosinase inhibition of 66.29% with IC50 of 24.06 µg/mL while the vitamin C content was 5.45 mg/g of the extract. The GC-MS analysis revealed the presence of thirty phytoconstituents with l-(+)-ascorbic acid 2,6-dihexadecanoate being the most abundant with a peak area of 14.66%. This study evidently suggests the potential of red pitaya peels to be exploited as a natural skin whitening agent in the cosmeceutical and pharmaceutical formulations.

Production of antioxidant peptide fractions from a by-product of tomato processing: mass spectrometry identification of peptides and stability to gastrointestinal digestion

In this study, proteins were extracted from tomato seeds, the main by-product of tomato processing. The incubation for 138.62 min coupled with 3% alcalase was observed to be optimum to produce a tomato seed protein hydrolysate (TSPH) with the highest antioxidant properties. Under these conditions, predicted TSPH activities were 62.99% scavenging of DPPH radicals and 54.81% reduction of phosphomolybdate. Separation of TSPH by ultrafiltration provided three fractions (UF1-UF3) of which, UF3 (< 3 kDa) showed the strongest activity (73.15% DPPH scavenging and 60.1% phosphomolybdate reduction). UF3 was further separated by RP-HPLC into sub-fractions F1-F6. Biological testing found that F2 and F4 were the most active in scavenging DPPH radicals (60.36 and 21.23%) and reducing phosphomolybdate (57.3 and 48.0%). LC-ESI-MS/MS analysis showed that the higher activity of F2 might be explained by the presence of more peptides that contained tyrosine and histidine, known to enhance antioxidant activity through hydrogen or electron transfer. In the simulated gastrointestinal digestion test, peptides in F2 were more resistant compared to those in F4. These findings indicate that peptide fraction F2 might be more useful in the formulation of functional foods because of its greater antioxidant activity and resistance to digestion.

Storage stability of egg sticks fortified with omega-3 fatty acids

BACKGROUND

Egg sticks fortified with omega-3 polyunsaturated fatty acids (ω-3 PUFAs) were developed by replacing egg yolk with salmon, algae, and flax oils. Egg sticks were cooked before analysis. Quality indicators for storage stability under different packaging and temperature were determined throughout a 28-day storage. Egg sticks were vacuum and non-vacuum packed. Further, both packaging treatments were divided into two storage temperatures of 4 and 10 °C. Quality indicators were determined every 7 days, including pH, syneresis, texture, color, microbial growth, proximate composition, fatty acid profile, and lipid oxidation.

RESULTS

Vacuum-packed egg sticks stored at 4 °C had slower degradation over time than all other treatments; however, they also had higher syneresis, harder texture, and higher anaerobic growth. Although vacuum packaging slowed lipid oxidation, it had limited effect on prevention of ω-3 PUFAs degradation; whereas refrigeration (4 °C) seemed to prevent degradation of ω-3 PUFAs better than it could slow lipid oxidation.

CONCLUSION

Based on the results, it can be concluded that both vacuum packaging and refrigeration at 4 °C decrease degradation of egg sticks developed in the present study during storage. Under these conditions, egg sticks may maintain stability for at least 21 days of storage. © 2017 Society of Chemical Industry.

Physicochemical, antioxidant and sensory characteristics of sponge cakes fortified with Clitoria ternatea extract

Bakery products are a food appreciated by consumers all over the world. There is a great opportunity to incorporate more bioactive compounds to enhance its quality. The objective of this study was to utilize the advantage of CTE in the production of sponge cake. The five different levels of CTE (0, 5, 10, 15 and 20%, w/w) was incorporated into sponge cake. The sponge cakes were evaluated for physicochemical (color, volume, water activity, total phenolic content, and antioxidant properties) and texture characteristics as well as consumer acceptance. Addition of CTE into the sponge cakes increased the polyphenol content and antioxidant activity concomitant with reduced lipid peroxidation. Increasing hardness, adhesiveness, gumminess, and chewiness and decreasing cohesiveness, springiness and resilience of cakes were seen when increasing percentage of CTE in the cake. A significant decrease was observed in the lightness, redness and yellowness in the cake containing CTE. No differences were found in overall acceptability between the control and the cake containing CTE. The findings suggest that CTE could be a potential source for development of sponge cakes with more effective antioxidant properties.

Buchanania obovata: Functionality and Phytochemical Profiling of the Australian Native Green Plum

The green plum is the fruit of Buchanania obovata Engl. and is an Australian Indigenous bush food. Very little study has been done on the green plum, so this is an initial screening study of the functional properties and phytochemical profile found in the flesh and seed. The flesh was shown to have antimicrobial properties effective against gram negative (Escherichia coli 9001&mdash;NCTC) and gram positive (Staphylococcus aureus 6571&mdash;NCTC) bacteria. Scanning electron microscopy analysis shows that the antimicrobial activity causes cell wall disintegration and cytoplasmic leakage in both bacteria. Antioxidant 2,2-diphenyl-1-picrylhydrazyl (DPPH) testing shows the flesh has high radical scavenging activity (106.3 &plusmn; 28.6 &mu;M Trolox equivalant/g Dry Weight in methanol). The flesh and seed contain a range of polyphenols including gallic acid, ellagic acid, p-coumaric acid, kaempferol, quercetin and trans-ferulic acid that may be responsible for this activity. The seed is eaten as a bush food and contains a delphinidin-based anthocyanin. The green plum has potential as a functional ingredient in food products for its antimicrobial and antioxidant activity, and further investigation into its bioactivity, chemical composition and potential applications in different food products is warranted.

Antityrosinase and antioxidant properties of mung bean seed proanthocyanidins: Novel insights into the inhibitory mechanism

This study investigated the structure, antioxidant activity, antityrosinase activity and mechanism of proanthocyanidins from mung bean seed [Vigna radiata (L.) Wilczek]. The structural composition were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), electrospray ionization-full-mass spectrometry (ESI-Full-MS), and high-pressure liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) techniques. The mung bean seed proanthocyanidins were composed of procyanidins, prodelphinidins, and their rhamnosides. According to enzyme kinetic analysis, these compounds were potent, reversible, and mixed-type inhibitors of tyrosinase. They inhibited the enzyme activity by interacting with enzyme as well as substrates. The results of molecular docking showed that the interaction between mung bean seed proanthocyanidins and tyrosinase was driven by hydrogen bond, hydrophobic and electrostatic interactions. In addition, mung bean seed proanthocyanidins were demonstrated as powerful antioxidants. Therefore, this study confirmed a novel tyrosinase inhibitor and would lay a scientific foundation for their utilization in pharmaceutical and food industries.

Antioxidant Activity of Coconut (Cocos nucifera L.) Protein Fractions

Coconut cake is an abundant and good potential edible protein source. However, until now it has not been extensively used in the food industry. To promote its usage, the characterization, nutrition value and antioxidant activity of coconut cake protein fractions (albumin, globulin, prolamine, glutelin-1 and glutelin-2) were studied. Results revealed that all the albumin, globulin, glutelin-1 and glutelin-2 fractions showed a high nutrition value. The prolamine, glutelin-1 and glutelin-2 all exhibited good radical scavenging activity and reducing power, and the globulin and prolamine showed high ion chelating ability (89.14-80.38%). Moreover, all the fractions except glutelin-2 could effectively protect DNA against oxidative damage. Several peptides containing five to eight amino acids with antioxidant activity were also identified by LC-MS/MS from the globulin and glutelin-2 fractions. The results demonstrated that the coconut cake protein fractions have potential usages in functional foods.

Simple and rapid silver nanoparticles based antioxidant capacity assays: Reactivity study for phenolic compounds

A single-step, rapid (10 min), sensitive silver nanoparticles (AgNPs) based spectrophotometric method for antioxidant capacity (AOC) assay has been developed. The assay is based on the ability of natural polyphenols to reduce Ag(I) and stabilize the produced AgNPs(0) at room temperature. Localized surface plasmon resonance (LSPR) of AgNPs at ≈420 nm is then measured. Using different conditions of pH (8.4) and temperature (45 °C) a further assay based on the production of AgNPs with selectivity for flavonols was also developed. The reactivity of the two AgNPs based assays vs. 15 polyphenols belonging to different chemical classes and 9 different samples has been studied and compared with ABTS, Folin and AuNPs based methods for AOC. The proposed assays had good reproducibility (RSD ≤ 13) and are simple, sensitive and cost effective. Moreover, used in conjunction with the classical AOC assays, can improve the information on the polyphenolic pool of food samples.

Nanomaterial-Based Sensing and Biosensing of Phenolic Compounds and Related Antioxidant Capacity in Food

Polyphenolic compounds (PCs) have received exceptional attention at the end of the past millennium and as much at the beginning of the new one. Undoubtedly, these compounds in foodstuffs provide added value for their well-known health benefits, for their technological role and also marketing. Many efforts have been made to provide simple, effective and user friendly analytical methods for the determination and antioxidant capacity (AOC) evaluation of food polyphenols. In a parallel track, over the last twenty years, nanomaterials (NMs) have made their entry in the analytical chemistry domain; NMs have, in fact, opened new paths for the development of analytical methods with the common aim to improve analytical performance and sustainability, becoming new tools in quality assurance of food and beverages. The aim of this review is to provide information on the most recent developments of new NMs-based tools and strategies for total polyphenols (TP) determination and AOC evaluation in food. In this review optical, electrochemical and bioelectrochemical approaches have been reviewed. The use of nanoparticles, quantum dots, carbon nanomaterials and hybrid materials for the detection of polyphenols is the main subject of the works reported. However, particular attention has been paid to the success of the application in real samples, in addition to the NMs. In particular, the discussion has been focused on methods/devices presenting, in the opinion of the authors, clear advancement in the fields, in terms of simplicity, rapidity and usability. This review aims to demonstrate how the NM-based approaches represent valid alternatives to classical methods for polyphenols analysis, and are mature to be integrated for the rapid quality assessment of food quality in lab or directly in the field.

Role of Dietary Antioxidants in the Preservation of Vascular Function and the Modulation of Health and Disease

In vascular diseases, including hypertension and atherosclerosis, vascular endothelial dysfunction (VED) occurs secondary to altered function of endothelial nitric oxide synthase (eNOS). A novel redox regulated pathway was identified through which eNOS is uncoupled due to S-glutathionylation of critical cysteine residues, resulting in superoxide free radical formation instead of the vasodilator molecule, nitric oxide. In addition, the redox sensitive cofactor tetrahydrobiopterin, BH₄, is also essential for eNOS coupling. Antioxidants, either individually or combined, can modulate eNOS uncoupling by scavenging free radicals or impairing specific radical generating pathways, thus preventing oxidative stress and ameliorating VED. Epidemiological evidence and dietary guidelines suggest that diets high in antioxidants, or antioxidant supplementation, could preserve vascular health and prevent cardiovascular diseases (CVDs). Therefore, the purpose of this review is to highlight the possible role of dietary antioxidants in regulating eNOS function and uncoupling which is critical for maintenance of vascular health with normal blood flow/circulation and prevention of VED. We hypothesize that a conditioned dietary approach with suitable antioxidants may limit systemic oxidation, maintain a beneficial ratio of reduced to oxidized glutathione, and other redox markers, and minimize eNOS uncoupling serving to prevent CVD and possibly other chronic diseases.

Enzymatic alkylsuccinylation of tyrosol: Synthesis, characterization and property evaluation as a dual-functional antioxidant

This work reports a novel approach to generate a new group of tyrosol-based amphiphilic lipid alkylsuccinylated tyrosol by lipase-catalyzed succinylation of tyrosol with alkylsuccinic anhydrides of varying alkyl chain lengths, in high yields (80-95%). The structures of the compounds were confirmed by MS, FTIR &¹H NMR; and their properties were characterized by Temperature-Ramp FTIR, DSC & CMC measurements. The synthesized compounds integrate water-soluble phenylethanoid and hydrophobic alkyl into one molecule thus are endowed with dual functions: retaining the antioxidant property of tyrosol and entailing tyrosol with new surface-active property. The DPPH activity of tyrosol (13.77%) was significantly enhanced by 2-dodecen-1-ylsuccinylated tyrosol (16.01%). Compared to tyrosol-based emulsions (76.63%), the lipid oxidation is reduced to 21.57% and 42.32% in 2-octen-1-ylsuccinylated/2-dodecen-1-ylsuccinylated tyrosol emulsions, respectively. This work brings new members to the library of functional lipid excipients and open a novel and effective synthetic pathway for derivation of phenyl alcohols.

Potential Use of Tuna (Thunnus albacares) by-product: Production of Antioxidant Peptides and Recovery of Unsaturated Fatty Acids from Tuna Head

Tuna by-products were subjected to enzymatic hydrolysis with Alcalase (enzyme to substrate ratio 1 : 200 w/w; 60 °C; pH 6.5, 120 min) rendering a tuna protein hydrolysate (TPH) with 9.24 % degree of hydrolysis (DH). The antioxidant capacity of TPH determined by the methods of ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) were similar and 10 times lower than the result obtained by oxygen radical absorbance capacity (ORAC). The total amino acid profile indicated that 42.15 % are composed of hydrophobic amino acids and 7.7 % of aromatics, with leucine being found in the highest quantity (17.85 %). The fatty acid profile of the oil recovered by centrifugation of the TPH – as determined by a gas chromatograph – was characterized by a high percentage of polyunsaturated fatty acids (PUFAs) (39.06 %), mainly represented by the fatty acids ω3, docosahexaenoic acid (27.15 %) and eicosapentaenoic acid (6.05 %). The simultaneous recovery of unsaturated fatty acids and antioxidant peptides can add value to tuna by-products, assisting in the efficient management of fishing industry waste.

Improving pork burgers quality using Zingiber officinale Roscoe powder (ginger)

Pork burgers were evaluated for physical-chemical characteristics, fatty acids profile, lipid oxidation, antioxidant capacity, microbiological growth and sensory evaluation during storage time of seven days at 4°C as function of three formulations as only meat (control, B) and meat added with ginger powder at the percentage of 1 and 2% (BG1 and BG2). BG1 and BG2 were less redness than control ones with incremented yellow hue. These modifications in color parameters did not modify sensory characteristics of burgers. PUFA were incremented (both PUFAω3 and PUFAω6) by the addition of ginger. Furthermore, BG1 and BG2 burgers showed to be less sensitive to lipid oxidation and to possess an increase in antioxidant capacity. Microbial growth evaluation of total aerobic count and Pseudomonas spp. showed that ginger powder delayed in time the bacterial contamination. Results highlighted that the presence of ginger led to an enhanced shelf life and health characteristics of burgers (increasing peroxidisability, ratio hypocholesterolemic/hypercholesterolemic and ratio ω3/ω6; reducing atherogenicity and thrombogenicity).

Effect of Supercritical Carbon Dioxide Extraction Parameters on the Biological Activities and Metabolites Present in Extracts from Arthrospira platensis

Arthrospira platensis was used to obtain functional extracts through supercritical carbon dioxide extraction (SFE-CO₂). Pressure (P), temperature (T), co-solvent (CX), static extraction (SX), dispersant (Di) and dynamic extraction (DX) were evaluated as process parameters through a Plackett–Burman design. The maximum extract yield obtained was 7.48 ± 0.15% w/w. The maximum contents of bioactive metabolites in extracts were 0.69 ± 0.09 µg/g of riboflavin, 5.49 ± 0.10 µg/g of α-tocopherol, 524.46 ± 0.10 µg/g of β-carotene, 1.44 ± 0.10 µg/g of lutein and 32.11 ± 0.12 mg/g of fatty acids with 39.38% of palmitic acid, 20.63% of linoleic acid and 30.27% of γ-linolenic acid. A. platensis extracts had an antioxidant activity of 76.47 ± 0.71 µg GAE/g by Folin–Ciocalteu assay, 0.52 ± 0.02, 0.40 ± 0.01 and 1.47 ± 0.02 µmol TE/g by DPPH, FRAP and TEAC assays, respectively. These extracts showed antimicrobial activity against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Overall, co-solvent was the most significant factor for all measured effects (p < 0.05). Arthrospira platensis represents a sustainable source of bioactive compounds through SFE using the following extraction parameters P: 450 bar, CX: 11 g/min, SX: 15 min, DX: 25 min, T: 60 °C and Di: 35 g.