Chemical characterisation of anthocyanins in tamarillo (Solanum betaceum Cav.) and Andes berry (Rubus glaucus Benth.) fruits

The anthocyanin composition of tamarillo (Solanum betaceum Cav., red variety) and Andes berry (Rubus glaucus Benth.) was determined by HPLC–PDA and HPLC–ESIMS. From the anthocyanin-rich extracts (AREs), pure compounds (1–7) were obtained by MLCCC (multilayer countercurrent chromatography) and further preparative HPLC, and their unequivocal structures were obtained by 1D and 2D NMR analyses. The new anthocyanin delphinidin 3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside-3′-O-β-d-glucopyranoside, as well as the known cyanidin-3-O-rutinoside, pelargonidin-3-O-rutinoside, and delphinidin-3-O-rutinoside were identified as constituents of tamarillo fruit. Although the anthocyanin composition of Andes berry had been reported before in the literature, the unequivocal structure elucidation of the major compound, cyanidin-3-O-α-l-rhamnopyranosyl-(1 → 6)-O-β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranoside, was achieved for the first time.     

Structure of a galactoarabinoglucuronoxylan from tamarillo (Solanum betaceum), a tropical exotic fruit,and its biological activity

Tamarillo (Solanum betaceum) is a tropical exotic fruit whose polysaccharides were extracted from the ripe pulp. After various purification steps, homogeneous fractions (designated PTW, STK-1000R and PF) were analyzed by sugar composition, HPSEC, methylation and NMR spectroscopy analysis. The results showed that the fraction PTW consisted of a linear arabinan with (1 → 5)-linked α-l-arabinofuranosyl units. Fractions designated as STK-1000R and PF contained galactoarabinoglucuronoxylans, with (1 → 4)-linked β-d-Xylp residues in the backbone, carrying branches exclusively at O-2. The polysaccharide in STK-1000R is less branched than that in the PF fraction (∼20.0% and 36.5%, respectively), with side-chains formed by (1 → 5)-linked α-l-Araf residues and (1 → 4)-linked α-d-GlcpA residues and with non-reducing end units formed by α-l-Araf, β-Arap, β-d-Galp, α-d-GlcpA and 4-O-Me-α-d-GlcpA. Intraperitoneal administration of the STK-1000R fraction in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that that fraction has an antinociceptive effect on inflammatory pain models.     

Characterization and thermal lability of carotenoids and vitamin C of tamarillo fruit (Solanum betaceum Cav.)

The carotenoids from yellow tamarillo were determined by high-performance liquid chromatography-photodiode array detection/mass spectrometry (HPLC-PDA/MS). Xanthophylls were found as esterified with palmitic and myristic acids. All-trans-β-cryptoxanthin esters and all-trans-β-carotene were the major carotenoids of tamarillo. Changes in carotenoid and vitamin C contents after thermal pasteurization of degassed and not degassed tomato tree nectars were studied. Zeaxanthin esters appeared to be the less thermo-labile carotenoids. Carotenoids degradation was not significantly influenced by dissolved oxygen level. However, thermal treatment induced 5,8-epoxidation and cis-isomerization. Retention of ascorbic acid was total under degassed conditions while losses of dehydroascorbic acid were not affected by the initial level of dissolved oxygen.     

Positive effects of glycosylated anthocyanin isolated from an edible berry fruit (Acanthopanax sessiliflorum) on its antioxidant activity and color stability

A major chromatographic peak of anthocyanin from ogaja (Acanthopanax sessiliflorum) fruit represented 95.4% of total absorbable compounds at 518 nm. The mass-to-charge ratio (m/z) of this colorant was determined to be 581 by LC-MS, which was identical to the molecular mass of cyanidin-3-O-sambubioside. After acid hydrolysis of the purified anthocyanin fraction, it was structurally confirmed by thin layer chromatography (TLC) and high-performance anion exchange chromatography (HPAEC) analyses. As a result, the sugar moieties linked to cyanidin were glucose and xylose. The purified cyanidin-3-O-sambubioside and cyanidin had greater antioxidant activities than l-ascorbic acid by both DPPH and ABTS methods. Cyanidin-3-O-sambubioside was more stable than cyanidin in the response to heat (80 °C), and both fluorescent and UV light. l-Ascorbic acid had an adverse effect on the color stability of anthocyanin. In this study, we demonstrated that glycosylation on anthocyanidin would provide an effective protection barrier for its color stability against the exposure to various food processing conditions.     

Antioxidant activity of polyphenol and anthocyanin extracts from fruits of Kadsura coccinea (Lem.) A.C. Smith

Polyphenols and anthocyanins were extracted from Kadsura coccinea fruit. The contents of total phenolics and anthocyanins, influences of pH and temperature on anthocyanins, and antioxidant activities of extracts were further analyzed. The results showed that the total phenolic content of peel extracts was superior to that of pulp extracts. The total anthocyanin content of peel extracts was 180 ± 2.91 mg/100 g of fresh peel tissues. K. coccinea anthocyanins were stable below pH 4, whilst high temperature and extended heating time induced their degradation. Metal-chelating capacity (MCC) assay indicated that no ortho-dihydroxy aromatic moiety existed in the B-ring of the anthocyanin molecules, but there might be a catechol group in the B-ring of the polyphenol molecules. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and reducing power of extracts decreased in the following order: peel polyphenol extracts > anthocyanin extracts > pulp polyphenol extracts. It would be worthwhile to introduce this rare fruit into more countries.     

Colour stability of anthocyanins from Isabel grapes (Vitis labrusca L.) in model systems

The influence of temperature, pH, the presence or absence of light, the presence or absence of oxygen and the presence or absence of tannic acid on the colour stability of anthocyanins from crude extract of Isabel grapes (Vitis labrusca L.) in food and model systems was studied. The spectrophotometric results (Δλ, ΔA) revealed interaction between the anthocyanins of the crude extract and tannic acid, suggesting copigmentation. In a model system, temperature, pH, the presence or absence of light, the presence or absence of oxygen and the presence or absence of tannic acid, significantly affected the half-life time of anthocyanins. The long half-time of the anthocyanins from Isabel grapes in a yoghurt model system indicates that these pigments are relatively stable in this food. In a rehydrated beverage model system at 4±1 °C, the presence of tannic acid (1:1, w/v) increased the half-life time by 187 h compared to the control samples.     

Isolation,identification, and antioxidant activity of anthocyanin compounds in Camarosa strawberry

This paper explores the bioactive composition of strawberry (Camarosa variety) [Fragaria × ananassa (Rosaceae Family)] describing its anthocyanin composition and measuring the antioxidant activity (AA) of isolated pigments.     

pH stability and influence of salts on activity of a milk-clotting enzyme from Solanum dubium seeds and its enzymatic action on bovine caseins

In this study we investigated the pH stability and effect of salts on the activity of a partially purified enzyme from Solanum dubium seeds as well as its hydrolytic power on caseins and caseins components. The seeds of S. dubium were blended and extracted using 50 g/L NaCl in 50 mmol/L acetate buffer, pH 5.0. The enzyme was then partially purified using ammonium sulfate. The results obtained showed that both NaCl and CaCl₂ enhanced the proteolytic activity of the enzyme and the enhancement was found to be significant when NaCl was used. Moreover, the stimulatory effect was found to be concentration dependent. The proteolysis of bovine whole casein and casein subunits by the enzyme during incubation was studied by SDS-PAGE. The results obtained revealed that both κ-casein and β-casein are the most susceptible to hydrolysis than α-casein. The three main casein components α-, β-, and κ-caseins were sensitive to the action of the enzyme and the order of hydrolysis obtained was κ- casein, β- casein, and α- caseins.     

Chemical composition,anthocyanins, non-anthocyanin phenolics and antioxidant activity of wild bilberry (Vaccinium meridionale Swartz) from Colombia

Berries of Vaccinium meridionale Swartz native to Colombia were analysed for chemical composition, total phenolic content, anthocyanin content, and antioxidant activity. In addition, high-performance liquid chromatography with photodiode array detection (HPLC–DAD) and HPLC-electrospray ionisation tandem mass spectrometry (ESI–MS/MS) were used to determine anthocyanin and phenolic composition. Anthocyanin content was 329.0 ± 28.0 mg cyanidin 3-glucoside equivalents/100 g (fresh weight) FW and total phenolic content was 758.6 ± 62.3 mg gallic acid equivalent/100 g FW. Cyanidin 3-galactoside was the major anthocyanin while the most abundant non-anthocyanin phenolic was chlorogenic acid.     

Chemical characterization and antioxidant capacity of berries from Clidemia rubra (Aubl.) Mart. (Melastomataceae)

The flora of Latin America attracts gaining interest as it provides a plethora of still unexplored or under-utilized fruits that can contribute to human well-being due to their nutritional value and their content of bioactive compounds. Clidemia rubra (Aubl.) Mart. is a shrub belonging to the family of the Melastomataceae that grows preferably in a tropical climate. This paper comprises a nutritional characterization of the berries from Clidemia rubra and provides data on the phenolic compounds as well as the antioxidant capacity of the fruit. Findings in macronutrients like protein, carbohydrates, and fat were comparable to that of common berry fruits. Clidemia rubra berries seemed to be a good source for dietary fibers and some minerals (Ca, Mn, and Zn). In contrast, contents of titratable acids and ascorbic acid were low. The polyphenolic profile was determined by using HPLC-MS/MS in comparison to standard compounds. Noteworthy amounts of cyanidin 3-O-rutinoside (39.43 ± 1.66 mg/100 g fresh weight (FW)), delphinidin 3-O-rutinoside (23.74 ± 1.18 mg/100 g FW), cyanidin 3-O-glucoside (11.68 ± 0.56 mg/100 g FW), and delphinidin 3-O-glucoside (6.08 ± 0.35 mg/100 g FW) were found. Non-anthocyanin phenolic constituents were phenolic acids (gallic, protocatechuic, p-hydroxy-benzoic, vanillic, and caffeic acid), flavan-3-ols (epigallocatechin, epigallocatechin gallate, and epicatechin gallate), and 11 different myricetin and quercetin derivatives of which quercetin 3-O-arabinoside (5.26 ± 0.16 mg/100 g FW) and quercetin 3-O-rhamnoside (5.06 ± 0.08 mg/100 g FW) were dominating. Anthocyanins and ascorbic acid were mainly responsible for the antioxidant capacity of Clidemia rubra berries assessed with the total oxidant scavenging capacity (TOSC) assay.     

Chemical characterization, bioactive compounds, and antioxidant capacity of jussara (Euterpe edulis) fruit from the Atlantic Forest in southern Brazil

Samples of fruit from the jussara palm plant (Euterpe edulis), collected in different regions of the state of Santa Catarina, Brazil, were analyzed for chemical composition, phenolic acids, anthocyanins, flavonoids and fatty acids profile. Results indicated that the jussara fruit has a high lipid content (18.45-44.08%), oleic acid (44.17-55.61%) and linoleic acid (18.19-25.36%) are the fatty acids found in the highest proportion, and other components were proteins (5.13-8.21%), ash (1.55-3.32%) and moisture (34.95-42.47%). Significant differences were found in the total phenolic, total monomeric anthocyanins and other flavonoids for the samples from the five cultivation regions. The fruit from region E harvested in summer, with high temperatures and medium altitudes, had the highest contents of total phenolics (2610.86 ± 3.89 mg 100 g⁻¹ GAE) and monomeric anthocyanins (1080.54 ± 2.33 mg 100 g^− 1 cy-3-glu). The phenolic compound included ferulic, gallic, hydroxybenzoic and p-coumaric acids, as well as catechin, epicatechin and quercetin. The results show promising perspectives for the exploitation of this tropical fruit with a chemical composition comprising considerable phenolic acids and flavonoids compounds and showing activity antioxidant.     

Carotenoids and antioxidant capacities from Canarium odontophyllum Miq. fruit

Carotenoids were isolated and identified from peel, pulp and seed fractions of Canarium odontophyllum Miq., and their antioxidant capacities were evaluated. all-trans-β-carotene was present in a large amount in peel (69.5 ± 1.0 mg/kg), followed by pulp (31.1 ± 0.76 mg/kg) and seed (15.1 ± 3.0 mg/kg). Additionally, 15-cis-β-carotene, 9-cis-β-carotene and 13-cis-β-carotenes were also major contributors to carotenoid contents in peel, pulp and seed fractions. Pulp exhibited excellent β-carotene bleaching activity, significantly higher than peel and seed; high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, whereas peel exhibited significantly higher scavenging activity of 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals. All the extracts exhibited good inhibitory effect against hydrogen peroxide-induced haemoglobin oxidation, ranging from 45.3 to 59.7%. This is the first report about carotenoids and antioxidant capacities from C. odontophyllum fruit, and indicates that this fruit can be explored and promoted as a potential source of natural antioxidants.     

Degradation kinetics and colour of anthocyanins in aqueous extracts of purple- and red-flesh potatoes (Solanum tuberosum L.)

The effect of pH and temperature on the stability and visual colour of aqueous anthocyanin (ACY) extracts from purple- and red-flesh potatoes was evaluated and compared to commercial ACY extracts from grape and purple carrot. Extracts from purple carrot and red-flesh potatoes showed higher stability than grape and purple-flesh potato extracts. Stability to pH (?3) and thermal degradation of extracts (pH 3) followed first-order kinetics. Changes in lightness and hue followed zero-order kinetics, while changes in chroma followed first-order kinetics. Degradation parameters such as t_1/2, k-, D-, z- and Q₁₀-values were determined. Extracts from red- and purple-flesh potatoes at pH 3 showed similar hues to FD&C Red #40 and red cabbage extracts, respectively. The visual colour of both potato ACY extracts was also affected by tinctorial strength. The use of purple- and red-flesh potatoes as a source of natural colorants shows potential use in the pH region around 3.     

Characterisation,extraction efficiency,stability and antioxidant activity of phytonutrients in Angelica keiskei

Phytonutrients in Angelica keiskei, a dark green leafy vegetable, were characterised and their extraction efficiency by different compositions of water/ethanol as well as stability at different temperatures was determined. A range in the content of lutein (205–265 mg/kg dry wt), trans-β-carotene (103–130 mg/kg dry wt), and total phenols (8.6–9.7 g/kg) was observed amongst Angelica keiskei grown in three different conditions. LC-ESI-MS/MS analysis identified chlorogenic acid, chalcones and the glucosides of luteolin and quercetin as the major phenolic compounds in Angelica keiskei. Only 46% of lutein was extracted by 70% of ethanol and no carotenoid was detected in 40% ethanol and 100% water extracts of Angelica keiskei. Major phytonutrients in Angelica keiskei were stable at −80 °C up to 12 months whilst β-carotene was significantly degraded at room temperature and 4 °C within 2 months and lutein at room temperature within 12 months.     

Quantitative analysis of phenolic components and glycoalkaloids from 20 potato clones and in vitro evaluation of antioxidant,cholesterol uptake,and neuroprotective activities

Potato (Solanum tuberosum L.) is one of the most important food crops in the world and provides essential nutrients. With an aim to develop potato varieties for functional food or nutraceutial applications, we have conducted metabolomic profiling, total phenolics, chlorogenic acid, anthocyanins, and glycoalkaloids analyses on 20 selected potato clones within the Canadian potato breeding program of Agriculture and Agri-Food Canada. Pigmented potatoes in general contain higher levels of phenolic components, including chlorogenic acid and anthocyanins. Levels of phenolics were retained with granulation processing of pigmented potato tubers, but glycoalkaloids were significantly reduced with granulation. The pigmented potatoes also have higher antioxidant activity reaching up to 35% of that for berries, measured as their potency in scavenging DPPH radicals. Extracts of the 20 potato clones (peel, tuber, and granule) were also evaluated for in vitro effects on liver LDL cholesterol uptake and protection of cortical neurons from cell death caused by oxygen glucose deprivation (OGD). These potato extracts in general showed mild activity in enhancing LDL cholesterol uptake in liver HepG2 cells, and also protected cortical neurons against OGD induced cell death, with extracts from granules of six of the potato clones showing significant neuroprotective effects. The bioactive components are not dependent on pigmentation of potato clones. These novel bioactivities identified in potatoes warrant in-depth investigations in the future. Taken together, our results provide further evidence for the enhanced health beneficial components in potato.     

Major anthocyanins and antioxidant activity of Nasturtium flowers (Tropaeolum majus)

Major anthocyanins, ascorbic acid content, total phenolic content, and the radical scavenging activity against ABTS and DPPH radicals in petals of orange Nasturtium flowers (Tropaeolum majus), were investigated. Anthocyanin (ACN) content in the petals was 72 mg/100 g FW and pelargonidin 3-sophoroside represented 91% of the total ACN content. The ascorbic acid content was 71.5 mg/100 g and the total phenolic content as determined by the Folin–Ciocalteau method was 406 mg GAE/100 g FW. The radical scavenging activities against ABTS and DPPH radicals were 458 and 91.87 μm trolox eq/g FW, respectively. The excellent free radical scavenging activities along with high phenolic and ascorbic acid content of Nasturtium flowers suggest that they could be source of natural pigments and antioxidants for applications in functional foods.     

Natural occurrence of free anthocyanin aglycones in beans (Phaseolus vulgaris L.)

The application of an improved method of extraction and purification has allowed the characterization of anthocyanins and free anthocyanidins in beans, Phaseolus vulgaris L. using LC-MS determination.