In vitro release and antioxidant activity of Satsuma mandarin (Citrus reticulata Blanco cv. unshiu) peel flavonoids encapsulated by pectin nanoparticles

The flavonoids of citrus peel extracts (CPE) were encapsulated by pectin nanoparticles (PNs), in an attempt to control the releasing property and improve their antioxidant activity. The physiochemical properties of the obtained PNs were characterised. Flavonoid composition in CPE before and after encapsulation were determined. In vitro release profiles and antioxidant activity of CPE were further evaluated. Results showed the size of spherical PNs obtained was 271.5 ± 5.3 nm. Interestingly, in simulated gastric fluid (SGF), 73% flavonoids were released from the naked CPE after 2 h, while only 28.78% from the CPE‐loaded PNs (E‐PNs). The releasing rate of flavonoids reached 91.47% from E‐PNs after 24 h in the simulated intestinal fluid (SIF). Moreover, DPPH and ABTS assay revealed that E‐PNs showed higher antioxidant activity than blank PNs and free CPE. These data showed that the controlled release of CPE might potentially increase its bioaccessibility and there was a synergistic effect between citrus PNs and CPE on the antioxidant activity.     

Influence of industrial sterilisation,freezing and steam cooking on antioxidant properties of green peas and string beans

We found that peptides or amino acids constituted the main fractions of water‐soluble nitrogenous compounds in green peas and string beans (44% and 79%, respectively). Their proportion increased after processing, especially in frozen peas and beans (61% and 95%, respectively). The content of phenolic compounds was decreased more after industrial processing (by 40% in peas and 50–70% in beans) than after cooking (by 20% in peas and 0–35% in beans). Antiradical activity against ABTS^?+ (2,2′‐azino‐bis[3‐ethylbenzothiazoline‐6‐sulphonic acid]) was much higher in aqueous extracts of peas and beans (33 and 45 μmol Trolox g^?1 d.m., respectively) than in aqueous acetone extracts (approximately 17 μmol Trolox g^?1 d.m. in both). In most cases, the activity decreased after processing. Both aqueous and acetone extracts of peas showed equal activity against DPPH^? (2,2′‐diphenyl‐1‐picrylhydrazyl), whereas in the case of beans this activity was four times lower in aqueous than in acetone extracts. Both reductions and increases of these activities were noted after processing.     

Solid lipid nanoparticles as oral delivery systems of phenolic compounds: Overcoming pharmacokinetic limitations for nutraceutical applications

Drug delivery systems, accompanied by nanoparticle technology, have recently emerged as prominent solutions to improve the pharmacokinetic properties, namely bioavailability, of therapeutic and nutraceutical agents. Solid lipid nanoparticles (SLNs) have received much attention from researchers due to their potential to protect or improve drug properties. SLNs have been reported to be an alternative system to traditional carriers, such as emulsions, liposomes, and polymeric nanoparticles. Phenolic compounds are widespread in plant-derived foodstuffs and therefore abundant in our diet. Over the last decades, phenolic compounds have received considerable attention due to several health promoting properties, mostly related to their antioxidant activity, which can have important implications for health. However, most of these compounds have been associated with poor bioavailability being poorly absorbed, rapidly metabolized and eliminated, which compromises its biological and pharmacological benefits. This paper provides a systematic review of the use of SLNs as oral delivery systems of phenolic compounds, in order to overcome pharmacokinetic limitations of these compounds and improved nutraceutical potential. In vitro studies, as well as works describing topical and oral treatments will be revisited and discussed. The classification, synthesis, and clinical application of these nanomaterials will be also considered in this review article.     

In vitro antioxidant activity of papain‐treated grass carp (Ctenopharyngodon idellus) protein hydrolysate and the preventive effect on fish mince system

Antioxidant activities of papain‐treated grass carp protein hydrolysate (HP) were investigated using in vitro methods and in grass carp mince system. Lipid oxidation, colour changes and cooking loss in grass carp mince added with 0% (control), 0.5%, 1.0%, 2.0% and 4.0% HP during refrigerated storage (4 °C) for 8 days was studied. HP could chelate 50% of Fe²⁺ and scavenge 50% of hydroxyl radicals at the concentration of 0.81 and 8.12 mg mL^?1, respectively. And HP could effectively decrease peroxide values and inhibit the formation of thiobarbituric acid reactive substances in fish mince throughout storage (P < 0.05), at the application level range from 0.5% to 4.0%. In HP‐treated samples the formation of conjugate dienes (CDs) was retarded 5–30% at day 6 of storage compared to control. In addition, HP could significantly decrease cooking loss of fish mince samples, at the application level range from 1.0% to 4.0%.     

Hazel (Corylus avellana L.) leaves as source of antimicrobial and antioxidative compounds

Aqueous extracts of leaves of different hazel (Corylus avellana L.) cultivars (Cv. M. Bollwiller, Fertille de Coutard and Daviana), were analysed by reversed-phase HPLC/DAD for the definition of their phenolic composition. Antioxidant potential was assessed by the reducing power assay, and the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and β-carotene linoleate model system. Their antimicrobial capacity was also tested against Gram positive (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Eight phenolic compounds were identified: 3-, 4- and 5-caffeoylquinic acids, caffeoyltartaric acid, p-coumaroyltartaric acid, myricetin-rhamnoside, quercetin 3-rhamnoside and kaempferol 3-rhamnoside. A p-coumaric acid, three myricetin and one quercetin derivatives were also detected. The hazel leaves extract presented high antioxidant activity in a concentration-dependent way, in general with similar behaviour of all cultivars. Gram positive bacteria revealed to be very sensitive to hazel leaf extract (MIC 0.1 mg/ml for B. cereus and S. aureus and 1 mg/ml for B. subtilis). However, Gram negative and the fungi displayed much lower sensitivity, being P. aeruginosa and C. albicans resistant at 100 mg/ml. Cv. M. Bollwiller exhibited the most potent antimicrobial activity.     

The protective ability of Mediterranean dietary plants against the oxidative damage: The role of radical oxygen species in inflammation and the polyphenol,flavonoid and sterol contents

Ten hydroalcoholic extracts of edible plants from the Calabria region (Italy) were evaluated for their in vitro antioxidant and antiradical properties and in vivo topical anti-inflammatory activity. All the extracts had radical-scavenging and/or antioxidant properties, the most active plants being hawkweed oxtongue and viper’s bugloss. The best free radical (DPPH·)-scavenging activity was found in hawkweed oxtongue and chicory leaves extracts (IC₅₀ = 25 and 26 μg/ml, respectively). Hawkweed oxtongue, poppy and viper’s bugloss extracts showed the greatest inhibition of linoleic acid oxidation (IC₅₀ = 3 μg/ml). Viper’s bugloss and hawkweed oxtongue extracts had the greatest antioxidant effect on bovine brain peroxidation (IC₅₀ = 11 and 22 μg/ml). All the extracts also showed an anti-inflammatory effect: 300 μg/cm² provoked oedema reductions ranging from 18% to 43%. Cress was the most active plant. Chicory leaves contained the highest amount of phenolics (190 mg/g) whilst Rush crimps contained the highest amount of flavonoids (32.9 mg/g), followed by hawkweed oxtongue (15.8 mg/g). Cress contained the highest number of sterols. Among them, γ-sitosterol (12.2%) and ergost-5-en-3-ol (3β) (4.5%) were found to be the major constituents. Moreover, three of the identified molecules (stigmasta-5,23-dien-3β-ol, stigmasta-5,24(28)-dien-3-ol (3β,22E) and 9,19-cyclolanost-24-en-3-ol (3β)) were found in this plant only.     

Phenolic profile,antioxidant, anticholinesterase,and anti-tyrosinase activities of the various extracts of Ferula elaeochytris and Sideritis stricta

In this study, the antioxidant, anticholinesterase, and anti-tyrosinase properties of (hexane, acetone, methanol, and water) extracts of Ferula elaeochytris and Sideritis stricta were determined with the total phenolic and flavonoid contents. The phenolic profile of the methanol and water extracts was analysed using HPLC-DAD. Protocatechuic acid was found as the major phenolic compound in the methanol (116.3 ± 3.1 µg/g) and water extracts (69.4 ± 1.3 µg/g) of F. elaeochytris. Coumarins (253.9 ± 4.1 µg/g) and catechin hydrate (175.2 ± 2.9 µg/g) were the most abundant phenolic compounds in the methanol and water extracts of S. stricta. β-carotene–linoleic acid, DPPH^?, ABTS^?+, CUPRAC, and metal-chelating assays were used to evaluate antioxidant properties of the extracts. The methanol and water extracts of F. elaeochytris and the acetone and methanol extracts of S. stricta containing the highest amount of total phenolic and flavonoid contents showed the highest antioxidant activities in β-carotene–linoleic acid, DPPH^?, ABTS^?+, and CUPRAC assays. The enzyme inhibitory potential of extracts was investigated against key enzymes involved in neurodegenerative (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)) and skin (tyrosinase) disorders. In the cholinesterase inhibitory assays, the hexane extracts of two species exhibited the best activity against AChE, while the hexane extract of F. elaeochytris and the methanol extract of S. stricta observed to be the most active against BChE. As for anti-tyrosinase activity results of extracts, the only acetone and methanol extracts showed mild inhibitory activity for both species.     

Nutritional composition and antioxidant activity in hazelnut shells from US‐grown cultivars

The hard shell of a hazelnut is a major waste of the hazelnut industry. The chemical composition, phenolic compounds (total phenolics, tannins and condensed tannins), antioxidant activity (DPPH and ABTS free‐radical scavenging assays), and the relationships between phenolic compounds and antioxidant activities of the hazelnut shells from twelve US grown cultivars were investigated to for potential commercial development. Crude fibre accounted for over 85% of total carbohydrate. The shells contained high concentrations of phenolic compounds. Concentrations of phenolic constituents and ABTS^?+ ‐scavenging capacities were significantly higher (P > 0.05) in the Oregon cultivars than their Nebraska counterparts. There were significant positive correlations between ABTS^?+ scavenging capacities and the phenolic compounds, whereas DPPH^? ‐scavenging capacity demonstrated a weak negative correlation with ABTS^?+ scavenging capacity and the phenolics. The results suggest that hazelnut hard shell may serve as a potential source of natural antioxidants for food applications.     

梁汾醋对小鼠免疫增强作用及体外抗氧化活性

目的 以梁汾醋为研究对象,测定其中的主要成分及其含量并研究对小鼠的免疫增强作用和体外抗氧化活性。方法 通过比较研究低剂量与高剂量梁汾醋对小鼠免疫器官的脏器指数、NK细胞活性、淋巴细胞转化功能、迟发型变态反应和细胞因子变化等的影响,评价梁汾醋对小鼠免疫功能的作用。通过1,1-二苯基-2-苦肼基(1,1-diphenyl-2-picrylhydrazyl, DPPH)自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)(2, 2''-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS)自由基和羟基自由基清除实验,观察梁汾醋的体外抗氧化活性。结果 两个剂量的梁汾醋对小鼠的体重、脾脏指数和胸腺指数均无显著影响,但高剂量组能够显著提高小鼠的NK细胞活性、脾淋巴细胞的转化能力,有效缓解迟发型变态反应,促进细胞因子IL-10、 IL-12的释放,增加免疫球蛋白(IgA)的水平;梁汾醋表现出显著的清除DPPH自由基以及羟基自由基的能力,在一定浓度下清除率可达到100%,对于ABTS自由基也有较好的清除率,在浓度为120μg/mL时清除率达到76.73% ± 3.28%,并与浓度呈现量效关系。结论 摄入一定量的梁汾醋具有增强小鼠免疫功能的作用,且具有良好的抗氧化效果。     

Nutraceutical value and toxicological profile of selected red wines from Morocco

The polyphenolic composition, antioxidant properties and multielement profile of selected red wines from Morocco were evaluated. The polyphenolic contents resulted higher than those reported elsewhere for the same variety of wines; the highest quantity was found in Cabernet Sauvignon, followed by Merlot, and last by Syrah wine. All of the wines tested showed very similar anthocyanin and flavonol patterns: individual compound contents resulted generally higher in comparison to conventional wines. The content of trans-resveratrol was significantly higher than that of cis-resveratrol in all of the wine samples. Particularly, Merlot showed the highest concentration of trans-resveratrol while Syrah exhibited the highest levels of cis-resveratrol. Reducing capacity resulted higher than antiradical property for all of the wines. The metal concentrations were below the official limits. The elemental pattern of wines were very similar, excepted V, Mn, Fe, Cu, As and Mo, for which Syrah markedly differed from the other wine samples.     

Phenolic content,antioxidant and physico‐chemical properties of Sardinian monofloral honeys

In this study, fifty‐one monofloral Sardinian honeys from ten various floral origins were screened for their phenolic content, antioxidant activity, colour and electrical conductivity. The total phenolic amounts have been evaluated by Folin–Ciocalteu method, whereas quantification of several phenolic compounds (phenolic acids and flavonoids) has been carried out by HPLC‐DAD technique. The richest sample in phenolic compounds resulted strawberry tree honey with about 40 mg GAE/100 g, as well FRAP test and DPPH˙ test confirm that antioxidant activity of strawberry tree honey extract exceed both honey extracts and synthetic antioxidants like BHA and BHT. Among the studied phenolic compounds a total of five phenolic acids (ferulic, syringic, trans‐cinnamic, chlorogenic and p‐hydroxycinnamic) and nine flavonoids (catechin, kaempferol, rutin, quercetin, luteolin, apigenin, galangin, pinocembrin and pinobanksin) were identified. Our results show good correlations between total polyphenol amount and antioxidant activity and between colour and electrical conductivity.     

Polyphenolic compounds and antioxidant activity of CTC black tea of North-East India

Sixty black tea samples from different agro climatic zones of northeast India were assessed for biochemical constituents that determine quality and also influence organoleptic perception. The antioxidant activities such as α,α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging, lipid peroxidation inhibition, nitrite scavenging and super oxide scavenging, of the collected samples were analysed. Out of the four antioxidant activities, the super oxide scavenging activity was lowest and nitrite scavenging activity was highest. Theaflavin was significantly and positively correlated with nitrite scavenging and lipid peroxidation inhibition activities. Thearubigins showed a significant positive correlation only with nitrite scavenging activity. Correlations between relative antioxidant capacity index (RACI) and TF, TR and tasters’ quality were positive and significant. Tea tasters’ parameters were significantly and positively correlated with each other. Principal component analysis showed that Upper Assam, North Bank and South Bank produced better quality tea than other regions with respect to TF, TR, RACI and tasters’ quality.     

Antioxidant and other quality properties of reindeer muscle from two different Norwegian regions

The effects of origin, gender, age, and muscle type on chemical composition, colour, antioxidant status and sensory profile of reindeer muscles Longissimus dorsi (LD) and Semimembranosus (SM) from two production regions were investigated. For some variables, the comparison between reindeer and beef muscles was also included. Muscles from North Norway (NN) were darker and contained more myoglobin and moisture, and less protein and fat than muscles from Mid Norway (MN). Oxygen radical absorbance capacity (ORAC) was significantly higher in these muscles while the levels of antioxidant enzymes were significantly lower in contrast to MN muscles. Relative to male reindeer, muscles from females contained significantly more total phenols and showed higher antiradical power (ARP). Carcass weight and the sensory attributes colour, sharp and bitter flavour had higher scores for older animals. Considerable differences between LD and SM were revealed in sensory assessment. In comparison to beef reindeer meat was darker, had more myoglobin, total phenols, antioxidant enzymes, and higher ARP and ORAC values.