Comparison of Carotenoid Composition in Immature and Mature Grains of Corn (Zea Mays L.) Varieties

The objective of this study was to compare the carotenoid composition of sweet and waxy corn grains at the stage of milk and dough by reversed-phase high-performance liquid chromatography, using a C(30) column, connected to diode array detector and mass spectrometry. In the reverse phase 21 carotenoids were found, the major identified carotenoids were all-trans-lutein, all-trans-zeaxanthin, and all-trans-α- cryptoxanthin. Waxy corn grains showed significantly lower contents for total carotenoids ranging from 1.52 to 3.68 μg/g dry weight in three varieties, whereas sweet corn grains had higher carotenoid contents from 8.42 to 39.71 μg/g dry weight. The composition of the carotenoid pattern was somewhat different compared to literature data; this could be the results of genetic or environmental differences. Taking into account the usage of all-trans lutein and all-trans-zeaxanthin for the prevention of several pathologies, especially the age related macular degeneration, the immature sweet corn (e.g., “Jingtian 5” and “Jingtian 3”) might be interesting sources of a lutein and/or zeaxanthin extract that could add value to an underutilized biomass.     

Change in anthocyanin concentrations in red apricot fruits during ripening

Here we report on accumulation patterns of anthocyanins and of β-carotene during fruit maturation, between 82 and 125 days after flowering, of two apricot (Prunus armeniaca L.) cultivars, A3576 and A3751. Both cultivars displayed an intense red colour of the skin but differed in their genetic background. The pigments were extracted from skin and flesh, separately, and analysed using HPLC-DAD-MS. Out of three anthocyanins detected here, the major compound, cyanidin-3-O-rutinoside was present at 75%. The two minor compounds were cyanidin-3-O-glucoside and peonidin-3-O-rutinoside. This is the first time that peonidin-3-O-rutinoside has been detected in apricot fruit. During maturation, A3751 accumulated anthocyanins in both skin and flesh, whereas anthocyanins were present only in the skin of A3576. The skin anthocyanin content was higher in A3751 (296 mg kg⁻¹) than in A3576 (41 mg kg⁻¹). Maximum anthocyanin levels were attained after 108 and 118 days of flowering in A3751 and A3576, respectively, in conjunction with loss of firmness and red colour acquisition on the un-blushed side of the fruit. At the end of ripening, the β-carotene flesh concentration reached 5 mg kg⁻¹ in A3576 and 15 mg kg⁻¹ in A3751. A significant effect of environment was observed on the anthocyanin content in the two cultivars.     

Lipid oxidation inhibitory effects and phenolic composition of aqueous extracts from medicinal plants of colombian amazonia

Diverse plants of ethnobotanic interest in Amazonia are commonly used in traditional medicine. We determined the antioxidant potential against lipid peroxidation, the antimicrobial activity, and the polyphenol composition of several Amazonian plants (Brownea rosademonte, Piper glandulosissimum, Piper krukoffii, Piper putumayoense, Solanum grandiflorum, and Vismia baccifera). Extracts from the plant leaf, bark, and stem were prepared as aqueous infusions, as used in folk medicine, and added to rat liver microsomes exposed to iron. The polyphenolic composition was detected by reverse-phase HPLC coupled to diode-array detector and MS/MS analysis. The antimicrobial activity was tested by the spot-on-a-lawn method against several indicator microorganisms. All the extracts inhibited lipid oxidation, except the P. glandulosissimum stem. The plant extracts exhibiting high antioxidant potential (V. baccifera and B. rosademonte) contained high levels of flavanols (particularly, catechin and epicatechin). By contrast, S. grandiflorum leaf, which exhibited very low antioxidant activity, was rich in hydroxycinnamic acids. None of the extracts showed antimicrobial activity. This study demonstrates for the first time the presence of bioactive polyphenolic compounds in several Amazonian plants, and highlights the importance of flavanols as major phenolic contributors to antioxidant activity.     

Novel Data on the Polyphenol Composition of Italian Ancient Apple Cultivars

The pulp polyphenol composition of some Italian ancient apple cultivars, Dominici, Giachetta, Grigia di Torriana, Pom d'Aram, Ronzè, and Ros Borsetta, was studied in comparison with a Golden Delicious commercial variety, over a three-year period. Polyphenols were analyzed by liquid chromatography coupled with diode array and mass spectrometer detectors. The results showed that ancient varieties, such as Grigia di Torriana, Ros Borsetta, and Giachetta, constitute good sources of polyphenols, even without the peel. It was demonstrated that some representative apple phenolics, such as chlorogenic acid and phloridzin, were clearly affected by the harvesting year, whereas others, such as catechins and procyanidins, did not.     

Identification of polyphenolic compounds in red and white grape varieties grown in R. Macedonia and changes of their content during ripening

The composition of polyphenols in the skin, seed and pulp extracts of the grapes of Vranec and Smederevka varieties, and Merlot and Chardonnay as well, was analyzed by liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS) and MS/MS techniques. Thirty-one phenolic compounds, including anthocyanins, flavonols and flavan-3-ols, as well as phenolic acids derivatives, have been identified in the extracts prepared from the grapes at physiological maturity, by mass spectrometry applying electrospray ionization operated in alternating ion mode and by performing tandem MS experiments in the ion trap mass analyzer. Grapes were analyzed at three different phases: (i) veraison, (ii) physiological ripeness and (iii) late harvest, in order to follow the evolution of polyphenolic content during berry development, applying spectrophotometric methods. Vranec had a higher polyphenolic content compared to Merlot due to the higher levels of total phenolics and flavonoids in the skins and seeds as well as a higher content of flavan-3-ols and anthocyanins in the skins, allowing discriminating the varieties. HPLC-DAD-MS analysis presented significantly higher relative amounts of anthocyanin monoglucosides and p-coumaroylglucosides in Vranec grapes. Smederevka seeds had a higher amount of flavan-3-ols than Chardonnay, while a higher content of total phenolics and flavonoids was found in the skins of the Chardonnay variety. Anthocyanin content in both red varieties increased during the berry ripening, while flavan-3-ols in seeds were mainly accumulated in the veraison phase followed by decrease of the content with ripening.     

Rapid HPLC/DAD/MS method to determine phenolic acids,glycoalkaloids and anthocyanins in pigmented potatoes (Solanum tuberosum L.) and correlations with variety and geographical origin

In the present study a single procedure to simultaneously determine phenolic acids, anthocyanins and glycoalkaloids was applied in 13 cultivars all with pigmented peel. A single exhaustive extraction for the three classes of compounds and a single analytical HPLC method were proposed. From a quantitative point of view, the RSD values from intra and inter-day assays were <5.7% for the three classes of metabolites. Concerning the influence of different growing areas, the highest anthocyanin concentrations and the lower glycolkaloid content in the pulp were found in tubers from the geographical area at 1000 m a.s.l in southern Italy. Principal Component Analysis (PCA) did not allow the discrimination of different clusters when applied to phenolic acids, while the scatterplot obtained with regard to the anthocyanin profiles clustered the cultivars into five distinct groups. These pigments can be proposed as “fingerprints” of the cultivar.     

Improved loquat (Eriobotrya japonica Lindl.) cultivars: Variation of phenolics and antioxidative potential

Leaves and fruits (peel and flesh) of six improved cultivars (‘Mizuho’, ‘Néctar de Cristal’, ‘Mizauto’, ‘Mizumo’, ‘Centenária’ and ‘NE-3’) of loquat (Eriobotrya japonica Lindl.) were studied for their phenolic composition and antioxidant capacity. The analysis by HPLC-DAD-ESI-MS/MS allowed the identification of 18 compounds (8 hydroxycinnamic acid derivatives and 10 flavonoid glycosides). The quantification of the identified compounds revealed distinct profiles amongst the three analysed materials. Loquat leaves exhibited the lowest amounts of phenolics. 3- And 5-caffeoylquinic, and 5-feruloylquinic acids were the major compounds. Generally, ‘Mizauto’ cultivar presented the highest phenolic content. All loquat materials exhibited DDPH scavenging capacity, in a concentration-dependent manner, the leaves being the most active one. This effect seems to be related to the flavonoid content.