Structure–antioxidant activity relationships of flavonoids isolated from different plant species

In the course of our phytochemical studies of different plants from developing countries we isolated and structurally characterized several flavonoid derivatives (compounds 1–26), both aglycones and glycosides, typical of the species investigated. The aim of this study was to evaluate varieties of medicinal plants that were growing in developing countries, known in traditional medicine as anti-inflammatory remedies, with respect to their flavonoidic isolated constituents, assuming that their anti-inflammatory activity could be explained, at least in part, by the presence of antioxidant principles. The antioxidant activities of compounds 1–26 were evaluated by measuring their ability to scavenge the radical cation 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS⁺) and the superoxide anion, to inhibit β-carotene oxidation in a lipid micelle system, and to inhibit xanthine oxidase activity, showing some structure–activity relationships.     

Concentrations of phthalates in bottled water under common storage conditions: Do they pose a health risk to children?

Of recent concern is the migration of phthalates from plastic products such as Polyethylene Terephthalate (PET) bottles into the water contain. These concerns should be addressed, especially considering the steady growth of the consumption of bottled water and the toxicological effects of phthalates. In this regard, special attention should be paid to children's consumption because of their particular susceptibility to the effects of phthalates.The aim of this study was to determine the concentrations of phthalates, including dibutyl phthalate (DBP), butyl benzyl phthalate (BBP) and bis(2-ethylhexyl) phthalate (DEHP), in bottled water and to estimate the health risk of endocrine disrupting chemicals due to water intake in children for the first time.Migration of phthalates was investigated in PET-bottled water under various storage conditions using gas chromatography–mass spectroscopy. A phthalate exposure assessment was performed to characterize their risk to the children's health via a calculated hazard quotient (HQ).It seems that increase in the temperature and the duration of storage affect phthalate migration, but the level of DEHP in bottled water was always very low and does not exceed 26.83% of the U.S. EPA maximum concentration limit (MCL). In particular, phthalate migration was not substantial at low temperatures (< 25 °C) and freezing conditions and the most abundant phthalate (DEHP) was not more than 10.6% MCL.The estimated child intake ranged from 0.01 μg/kg/day for BBP to 0.24 μg/kg/day for DEHP. Estimated phthalate intakes are generally in the safe range and exposure decreased with increasing age. Toxicological risk assessment of the maximum concentrations measured revealed a maximum HQ of 0.012 in the worst condition. Furthermore, a negligible carcinogenic risk of 6.5 × 10^− 7 for DEHP was observed. Consequently, risk evaluation showed that bottled water is safe for consumption by children.     

Effects of mineral content of bovine drinking water: Does iron content affect milk quality?

The composition of water given to dairy cattle is often ignored, yet water is a very important nutrient and plays a major role in milk synthesis. The objective of this study was to study effects of elevated levels of iron in bovine drinking water on milk quality. Ferrous lactate treatments corresponding to 0, 2, 5, and 12.5 mg/kg drinking water concentrations were delivered through the abomasum at 10 L/d to 4 lactating dairy cows over 4 periods (1 wk infusion/period) in a Latin square design. On d 6 of infusion, milk was collected, processed (homogenized, pasteurized), and analyzed. Mineral content (Fe, Cu, P, Ca) was measured by inductively coupled plasma mass spectrometry. Oxidative stability of whole processed milk was measured by the thiobarbituric acid reactive substances (TBARS) assay for malondialdehyde (MDA) and sensory analysis (triangle test) within 72 h of processing and after 7 d of storage (4°C). Significant sensory differences between processed milks from cows receiving iron and the control infusion were observed. No differences in TBARS (1.46 ± 0.04 mg of MDA/kg) or mineral content (0.22 ± 0.01 mg/kg Fe) were observed. A 2-way interaction (iron treatment by cow) for Ca, Cu, and Fe concentrations was seen. While iron added directly to milk causes changes in oxidation of milk, high levels of iron given to cattle have subtle effects that initially may not be obvious.     

Evaluation of antioxidant activity of ten compounds in different tea samples by means of an on-line HPLC–DPPH assay

Tea (Camellia sinensis), a well-known traditional beverage in China, has drawn growing attention due to its various benefits to health. In this study, an on-line assay of coupling high performance liquid chromatography separation with 1,1-diphenyl-2-picrylhydrazyl free radical reaction system (HPLC–DPPH) was applied to evaluate the antioxidant activity of different teas. Twelve main chromatographic peaks were detected in tea, and they were identified as gallic acid, 3-galloyl-quinic acid, theobromine, (−)-gallocatechin, (−)-epigallocatechin, caffeine, procyanidin dimer, (−)-epicatechin, (−)-epigallocatechin gallate, (−)-gallocatechin gallate, 1,2,6-tri-galloyl-glucose and (−)-epicatechin gallate by comparing their retention times and DAD spectra with standard compounds respectively or with reference to our previous study. DPPH assay showed that ten out of twelve investigated compounds have free radical scavenging activity, and their contents were determined or estimated. Trolox equivalent antioxidant capacities (TEACs) of the ten active components were also determined. EGCG was the most potent antioxidant with a TEAC value of 5.822. Catechin components were the major contributors to the antioxidant activity of tea; they decreased during tea fermentation and led to the reduction of antioxidant activity. Different tea samples were scientifically classified and their antioxidant activities were comprehensively evaluated by on-line HPLC–DPPH assays coupled with principal component analysis and hierarchical clustering analysis. The results indicated that the combination of the on-line HPLC–DPPH assay, principal component analysis and hierarchical clustering analysis could be suitable for the bioactivity assessment and variety characterization of tea and its derived products. Additionally, a simple and rapid method for simultaneous capture of chemical quantitative analysis and bioactivity evaluation by determining contents of the bioactive compounds was firstly established. This method could provide a comprehensive evaluation of tea.     

How do different cooling temperatures affect the characteristics of set-type yoghurt gel?

The impact of cooling temperatures on gel characteristics of set-type yoghurts was investigated through 28 days of storage. Yoghurt samples were cooled at four different temperatures (−10 °C, −5 °C, 0 °C, 4 °C) after incubation until the central temperature of yoghurt cups reached 4 °C. Cooling temperature and storage period were determined as significant factors affecting the yoghurt gel characteristics (p < 0.05). Yoghurts cooled at 0 °C clearly differed from the other yoghurts in terms of gel firmness and consistency. Confocal images of yoghurts cooled at 0 °C showed more homogeneous protein matrix than the other samples. Microbial counts and the acidity of the yoghurt samples increased with storage period. Textural parameters, water holding capacity and susceptibility to syneresis increased until 14th day of storage and then decreased. Sensory analysis of yoghurt samples confirmed the results obtained by microbiological and textural measurements.     

Effects of different vinification technologies on physico-chemical properties and antioxidant activity of ‘Falanghina’ and ‘Bombino bianco’ wines

The present research was aimed to compare the traditional white vinification with a combined cryomaceration–vinification in reductive conditions, by evaluating their effects on chemical and physical indices and on antioxidant compounds of ‘Falanghina’ and ‘Bombino bianco’, two wine grape cultivars of southern Italy. According to the results, the two cultivars showed similar behaviour in response to the same vinification protocol. The processing conditions mainly affected physico-chemical characteristics such as titratable acidity, pH, SO₂, tartaric and malic acids, phenolic concentrations, and antioxidant activity. Titratable acidity decreased with cryomaceration due to the tartrate precipitation, whereas the malic acid was greatly extracted from pulps and skins. In the reductive conditions applied, the SO₂ was protected by the presence of ascorbic acid; thus, the wines exhibited higher free/total SO₂ ratio. Cryomaceration combined with vinification in reductive conditions allowed a greater extraction of phenolic compounds from skins and, consequently, a greater antioxidant activity compared to the traditional winemaking. This behaviour was due to both the protection exerted by the low temperatures and the solubilisation of proanthocyanidins and flavans reactive with vanillin favoured by the high free SO₂ content.     

Anthocyanin stability and antioxidant activity of spray-dried açai (Euterpe oleracea Mart.) juice produced with different carrier agents

Anthocyanin stability and antioxidant activity of powdered açai juice was evaluated throughout 120 days. Powders were produced by spray drying using four types of carrier agents: maltodextrin 10DE, maltodextrin 20DE, gum Arabic and tapioca starch. Samples were stored at different temperatures (25 and 35 °C) and water activities (0.328 and 0.529), in order to verify the effect of these conditions on anthocyanin degradation and antioxidant activity reduction. Anthocyanin degradation exhibited two first-order kinetics: the first one, with higher reaction rate constant, up to 45–60 days of storage, and the second one, after this period, with lower degradation rate. Both temperature and water activity negatively affected anthocyanin stability. Antioxidant activity also decreased with increasing water activity, but was higher for the powders stored at 35 °C. Maltodextrin 10DE was the carrier agent that showed the best pigment protection and the highest antioxidant activity, for all the conditions studied.     

Effect of high-pressure processing on flavonoids,hydroxycinnamic acids,dihydrochalcones and antioxidant activity of apple ‘Golden Delicious’ from different geographical origin

The influence of high-pressure processing (HPP) (400, 500 and 600 MPa at 35 °C for 5 min) on different classes of phenolic compounds and antioxidant activity (AA) of ‘Golden Delicious’ apple from two different growing regions, northeastern of Spain (lowland climate) (S-apples) and north of Italy (mid-mountain climate) (I-apples) was investigated. Total hydroxycinnamic acids, total dihydrochalcones and total flavan-3-ols content were higher in S-apple (untreated and HPP-treated) than in I-apples and total flavonols content was higher in I-apples. HPP affected phenolic compounds and AA depending on the apple geographical origin. 400 MPa/35 °C/5 min increased total flavonols (30%) and maintained total phenolic compounds determined by HPLC (TP-HPLC) in S-apples. The higher increase of TP-HPLC (54%) was achieved when I-apple was treated at 600 MPa. Untreated and HPP-treated I-apples displayed higher AA than S-apples. HPP (400 and 600 MPa) increased AA in I-apple. Positive correlations were found between TP-HPLC and AA (TP-FC, DPPH^·, ABTS^·+ and FRAP) in both Italian and Spanish apples.Industrial relevanceThe apples of cultivar ‘Golden Delicious’ are one of the most consumed fruits in the UE. High-pressure processing (HPP) of these fruits acquires great importance to obtain ingredients and apple functional foods highly demanded by consumers. For this, it is necessary to know the process variables and plant material that favor greater extraction of phenolic compounds and antioxidant activity characteristics. This paper provides useful results to help fruit processor to select the appropriate HPP conditions and the geographical origin of ‘Golden Delicious’ apple to obtain apple-based products with high content on different classes of phenolic compounds with beneficial health effects.     

Does u.v. light affect the total phenolic compound,anthocyanin, antioxidant capacity,and sensory profiles in wines?

In the study, by applying ultraviolet (u.v.) lights (254 nm) for 45 min to red wines from fermented Cabernet Franc, Cabernet Sauvignon, Merlot, and Petit Verdot (Vitis vinifera L.) grapes, we examined the total phenolic compound, total anthocyanin, and antioxidant capacity by four different methods, trans-resveratrol, (+)-catechin, gallic acid content, and the change in tasting profiles of the wines after application. According to the results of the research, the u.v.-C application has caused an increase in all parameters examined. If we talk about averages without distinguishing between varieties, after the application the total phenolic compound content of 3206 increased to 3356 mg gallic acid equivalent (GAE) per L and after u.v.-C application, the total anthocyanin content increased from 411 to 780 mg L⁻¹, the ABTS [2,2′-azinobis(3-ethyl-benzothiazoline-6-sulphonic acid)] value increased from 30 to 33 μmol trolox mL⁻¹, the DPPH ((2,2-diphenyl-1-picrylhydrazyl) level increased from 13 to 16 μmol trolox mL⁻¹, the FRAP (ferric reducing antioxidant power) level increased from 15 to 16 μmol trolox mL⁻¹, and the CUPRAC (cupric reducing antioxidant capacity) level increased from 40 to 45 μmol trolox mL⁻¹. The u.v. application affected trans-resveratrol the most among the phenolic compounds and an average increase of 12.99% was obtained. The rate of increase after u.v. application was 3.33% in (+)-catechin and 5.57% in gallic acid. The highest correlation between antioxidant activity measurement methods was measured to be 0.998 between FRAP and DPPH. In addition, u.v.-C application has had a positive effect on taste-based sensory profiles. In recent years, the search for a diet with a high antioxidant content has become even more important.     

Total antioxidant activity and trace elements in human milk: the first 4 months of breast-feeding

The content of many nutrients in breast milk are dependent on the nutritional status of the lactating woman. This is particularly true for fat and water-soluble vitamins, some of which have antioxidant properties. The aim of the study entertained herein was to evaluate the changes in total antioxidant status of human milk during the first 4 months of lactation, and to correlate such changes with the contents in specific antioxidant oligoelements (Cu, Zn, Mn and Se). Milk samples were collected from (31) lactating women recruited at the Service of Obstetrics of the Hospital de São João in Porto, after 1, 4, 8, 12 and 16 weeks after birth. The total antioxidant status (TAS) of human milk was measured by the Randox^® commercial kit and trace metals by ICP-MS (inductively coupled plasma-mass spectrometry). The results found for TAS and oligoelements under study show a decrease in the concentration of these parameters from 7 days to 4 months of breast-feeding and significant correlations (p < 0.05) were found between TAS and Cu, Zn and Se (not Mn). The decreases of Cu, Zn and Se were also correlated, but not proportional between them, suggesting diverse excretion mechanisms for all. Between primipara and multipara women, a significant difference was found only for Cu and Zn concentrations at 7 days of lactation, but not for the other metals or TAS. With respect to the mother’s age, no correlation was found, either for trace metal concentrations or TAS.     

Does the lipid membrane composition of arsonoliposomes affect their anticancer activity? A cell culture study

Sonicated arsonoliposomes were prepared using arsonolipid with palmitic acid acyl chain (C16), mixed with phosphatidylcholine (PC)-based or 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)-based, and cholesterol (Chol) with C16/DSPC/Chol 8:12:10 molar ratio. PEG-lipid (1,2-distearoyl-sn-glycero-3-phosphoethanolamine conjugated to polyethylenoglycol 2000) containing vesicles (PEGylated-arsonoliposomes; PC-based and DSPC-based) were also prepared. The cytotoxicity of these arsonoliposomes towards different cancer cells (human promyelocytic leukaemia NB4, Prostatic cancer PC3, human breast adenocarcinoma MDA-MB-468, human T-lymphocyte (MT-4) and also towards human umbilical vein endothelial cells (HUVECs) was evaluated by calculating the arsonoliposome-induced growth inhibition of the cells by the MTT assay. IC-50 values were interpolated from cell number/arsonoliposome concentration curves. The results reveal that all types of arsonoliposomes evaluated significantly inhibit the growth of most of the cancer cells studied (PC3, NB4, MT4) with the exception of the MDA-MB-468 breast cancer cells which were minimally affected by arsonoliposomes; in some cases even less than HUVEC. Nevertheless, for the same cell type the differences between the different types of arsonoliposomes were significant but not proportional to their stability, indicating that the formation of arsonoliposomes with very stable membranes is not a problem for their anticancer activity. Thereby it is concluded that arsonoliposome composition should be adjusted in accordance to their in vivo kinetics and the desired, for each specific application, biodistribution of As and/or encapsulated drug.     

Haloacetonitriles vs. regulated haloacetic acids: are nitrogen-containing DBPs more toxic?

Haloacetonitriles (HANs) are toxic nitrogenous drinking water disinfection byproducts (N-DBPs) and are observed with chlorine, chloramine, or chlorine dioxide disinfection. Using microplate-based Chinese hamster ovary (CHO) cell assays for chronic cytotoxicity and acute genotoxicity, we analyzed 7 HANs: iodoacetonitrile (IAN), bromoacetonitrile (BAN), dibromoacetonitrile (DBAN), bromochloroacetonitrile (BCAN), chloroacetonitrile (CAN), dichloroacetonitrile (DCAN), and trichloroacetonitrile (TCAN). The cytotoxic potency (%C1/2 values) ranged from 2.8 microM (DBAN) to 0.16 mM (TCAN), with a descending rank order of DBAN > IAN approximately BAN > BCAN > DCAN > CAN > TCAN. HANs induced acute genomic DNA damage; the single cell gel electrophoresis (SCGE) genotoxicity potency ranged from 37 microM (IAN) to 2.7 mM (DCAN). The rank order of declining genotoxicity was IAN > BAN approximately DBAN > BCAN > CAN > TCAN > DCAN. The accompanying structure-activity analysis of these HANs was in general agreement with the genotoxicity rank order. These data were incorporated into our growing quantitative comparative DBP cytotoxicity and genotoxicity databases. As a chemical class, the HANs are more toxic than regulated carbon-based DBPs, such as the haloacetic acids. The toxicity of N-DBPs may become a health concern because of the increased use of alternative disinfectants, such as chloramines, which may enhance the formation of N-DBPs, including HANs.     

Type 2 diabetes-related bioactivities of coffee: Assessment of antioxidant activity,NF-κB inhibition,and stimulation of glucose uptake

Coffee consumption is correlated with a lower risk for type 2 diabetes mellitus (T2D), though whether differences exist in the T2D-mitigating bioactivities of decaffeinated (RD) and regular (RR) coffee is unclear. We conducted cell-based experiments to determine whether different phenolic levels in RD and RR affect T2D-mitigating bioactivities. The total phenolic content and the chemical antioxidant activity were significantly higher in RD than RR. However, these coffees had comparable cellular antioxidant activity. Both coffees reduced activation of NF-κB, with RR being twice as strong as RD. They also both increased glucose uptake in human adipocytes by 2-fold. Of the bioactivities examined, only chemical antioxidant activity was related to total phenolic levels. The NF-κB inhibition was proportional to chlorogenic acid levels, though chlorogenic acids could not account for the full inhibitory effect of coffee. Thus, a matrix effect may exist, whereby components of coffee work together to provide bioactivities that ameliorate the T2D risk.     

Effects of “craft” vs. “traditional” labels to beer consumers with different flavor preferences: A comprehensive multi-response approach

Common definitions of craft-style beers emphasize that they are brewed by small, local breweries and that they have complex, novel and, often, bold flavors. In recent research conducted with declared craft beer drinkers who tasted beers in a blind condition, Jaeger et al. (2020) [FQAP, 103884] identified the existence of two preference segments. One segment (Craft-style Likers) preferred the characteristic complex, novel and bold flavors of many craft-style beers, while the other segment (Traditional-style Likers) preferred the less complex and milder flavors associated with traditional-style beers. In the present research, a multivariate response approach that included the evaluation of liking, sensory, holistic/conceptual, and cognitive/emotional/situational responses, as well as beer-related attitudes and behaviors, was used to assess the same set of six beers in a similar sample of declared craft beer drinkers (n = 122) as used in our previous study. However, beers were now labeled to reflect the style of the beer (craft vs. traditional) and the size (small vs. large) and regional origin (local vs. international) of the brewer. Results confirmed the existence of the same two preference segments. Although the effects of labeling the beers in accordance with their craft- vs. traditional-style natures did not influence sensory, holistic/conceptual or cognitive responses, they did influence emotional and situational responses. For craft-style beer likers, the information increased their positive emotions and the situational uses for craft-style beers, while for the traditional-style beer likers the labeling had a corresponding positive effect on their judgments of the traditional style beers. The results confirm previous findings on beer and product labeling, which show that sensory properties are less susceptible to extrinsic information effects than are affective, emotional and other, non-sensory product judgments. Implications for craft and traditional brewers are discussed and suggestions for future research presented.     

Role of reverse micelles on lipid oxidation in bulk oils: impact of phospholipids on antioxidant activity of α-tocopherol and Trolox

Phospholipids self-assemble in bulk oils to form structures such as reverse micelles that can alter the microenvironment where chemical degradation reactions occur, such as lipid oxidation. In this study, we examined the influence of phospholipid reverse micelles on the activity of non-polar (α-tocopherol) and polar (Trolox) antioxidants in stripped soybean oil (SSO). Reverse micelles were formed by adding 1000 μM 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) to SSO. The addition of DOPC reverse micelles had a prooxidant effect, shortening the lag phase of SSO at 55 °C. DOPC improved the activity of low α-tocopherol or Trolox concentrations (10 μM) but decreased the activity of high concentrations (100 μM). Hydrophilic Trolox had better antioxidant activity than hydrophobic α-tocopherol. Fluorescence steady state and lifetime decay studies suggests that differences in the antioxidant activity of Trolox and α-tocopherol could be due to differences in their physical location in DOPC reverse micelles. These results will improve our understanding and control of lipid oxidation in bulk oils.