Seasonal Trends of Specific Phenols in 'Hass' Avocado Tissues (original) (raw)
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Changes in phenolic composition of avocado cultivars during harvesting time
Chemistry of Natural Compounds, 2010
Avocado, a tropical fruit native to Central America, is cultivated in tropical climates throughout the world. Avocado is also grown in Turkey, and plantations have rapidly expanded during the past decade. There are numerous cultivated varieties of avocados in the world [1].
Bioactive Polyphenols: Their Role in Quality and Storability of Fruit and Vegetables l
Journal of Applied Botany and Food Quality, 2003
Phenolic compounds are plant secondary metabolites that are naturally present in essentially all plant material, including food products of plant origin. They are particularly prominent in fruit and vegetables where they are important in determining colour, appearance, flavour and taste. These compounds form one of the main classes of secondary metabolites, with a large range of structures: monomeric, dimeric and polymeric phenolics have been identified. Given a free choice the consumer selects foods with a low content of lignin (toughness) andlor tannin (astringency), but sometimes with a relatively high anthocyanin content (appearance andlor ripeness indicator). During the postharvest life of fruit and vegetables and the different technological treatments to which these plant tissues are submitted in order to extend their shelf life, some changes in secondary metabolism occur. These metabolic changes of phenolic compounds, often coupled with the activity of polyphenol oxidase, are responsible for some phenomena affecting the quality of stored plant commodities. In this connection two important aspects, related to the presence of phenolics, receiving increasing attention from biochemists, plant physiologists and food technologists, are the role of phenolics in browning reactions and the resistance mechanism against storage fungi. This paper emphasizes some aspects related to low temperature metabolism of endogenous phenolics in plant tissue under chill stress with reference to shelf life of cold stored fresh fruit and vegetables.
Developmental variation of phenolic compounds in fruit tissue of two apple cultivars
Acta scientiarum polonorum. Technologia alimentaria
Qualitative and quantitative analyses of 'Zonouz' and 'Gala' apples phenolic compounds were accomplished by HPLC. Samples for phenolics study were taken at three different growing stages [1 - fruit early growing stage 2 - mid-stage of fruit development (80 days after full bloom) 3 - during commercial harvest time]. The results showed qualitative differences between two apple cultivars regarding phenolic compounds. The highest amounts of total phenols, flavonoids, flavonols and phenolic acids content in both cultivars were recorded during the fruit early growing stage. The high phenolic acids content was due to increasing in chlorogenic acid content in fruits during early growing stage. The highest amount for flavanol content was recorded in 'Zonouz' peel at the harvest time. Descending pattern was recorded for phloridzin dihydrate content during the season. 'Gala' peel had the greatest amounts for cyanidin-3-galactoside at harvest time. Increasing in ...
Antioxidants
Apples (Malus domestica Borkh) are of particular interest for their high content of healthy phytochemicals. This study investigated the antioxidant activity and polyphenolic compounds of extracts from the fruits from Ozark Gold, Starkinson and Kosztela cultivars and additionally leaves from Ozark Gold cv. Phenolic compounds were identified and quantified by liquid chromatography- mass spectrometer (LC–MS) and high pressure liquid chromatography (HPLC). The samples were collected during fruit development at 60, 80, 130 and 145 days after full bloom. The concentration of apple phenolics was highest early in the season and decreased during fruit development. The leaf phenolics had a more steady level during all the period of collection than the fruits. Among the five groups of analyzed polyphenols, the procyanidins predominated in apple fruits and dihydrochalcones in leaves. The concentration of polyphenols decreased from 39.15, 5.97 and 33.39 g/kg dw (collected at 60 days after full b...
Advanced Analytical Methods for Phenolics in Fruits
Journal of Food Quality, 2018
Phenolic compounds are a group of secondary plant metabolites, many with health-promoting properties that are present in all parts of plants. They have an aromatic structure, including either one or more hydroxyl groups giving them the ability to stabilize free radicals and protect biological tissues against damage related to reactive oxygen species. Phenolic compounds are concentrated in the fruit of plants, and therefore, the fruit can be an important dietary source of these phytochemicals, which exist as monomers, or bound to one another. Polyphenolic compounds are classified into different subclasses based upon the number of phenol ring systems that they contain, saturation, and length of the carbon chain that bind the rings to one another. The phenolic acids present in fruit tissues protect the plant against disease, infections, UV radiation, and insect damage. For this reason, the beneficiary effects of phenolic compounds are continually being investigated for their health-pro...
Food and Bioprocess …, 2012
Polyphenol oxidase activities of lulo, mangosteen, Castilla blackberry, mango, apple guava, tree tomato, papaya, soursop, banana passionfruit, giant granadilla, sweet granadilla, and passion fruit were determined and related to their physicochemical properties. Mangosteen and lulo showed the highest activities (0.1435 and 0.1298 U mL−1, respectively), while passion fruit and banana passionfruit had the lowest ones (0.0101 and 0.0093 U mL−1). The two fruits with highest PPO activity were also the ones in which highest color differences (ΔE) during the first 90 min after fruit crushing were achieved. The Principal Component Analysis revealed a high correlation between PPO activity and total phenolic content for the compounds that are susceptible to act as enzyme substrate. These two variables were also highly correlated with the decrease produced in brightness (measured with the CIELab parameter L*).
Total phenol and antioxidant activity of some fruits and their under-utilized parts
international food research journal, 2013
Some fruits and their under utilized parts were evaluated for total phenolic contents (TPC), antioxidant (AOA) and free radical scavenging activities (FRSA). The leaves (73.8 mg/g) and fruits of Phoenix sylvestris, fruits of Ziziphus jujuba, Syzygium cumini and Zanthoxyllum acanthopodium and leaves of Protium serratum were found to have high amounts of TPC (69.4 mg/g to 128.6 mg/g GAE). The inflorescence and leaves of Phoenix sylvestris, fruits of Protium serratum, Syzygium cumini and Psidium guajava were found with reasonably good AOA (60.7% to 84.9%). Plants with promising AOA were further investigated for FRSA using DPPH free radical assay in terms of inhibitory concentration (IC 50), efficiency concentration (EC 50), anti radical power (ARP) and reducing power (RP). Promising fruit samples were further subjected to concentration-dependent FRSA using different methods and expressed in terms of IC50 values. Fruit extracts (20 μg/ml) of Phoenix sylvestris, Protium serratum and leaves of Zanthoxyllum acanthopodium effectively prevented DNA nicking studied on pBR322 DNA. The fruits of Passiflora edulis were found to be good source of caffeic acid, fruits of Phoenix sylvestris of chlorogenic acid, Phoenix sylvestris, Protium serratum and leaves of Zanthoxyllum acanthopodium were rich in gallic acid. The identification of specific polyphenols was further substantiated by MS/MS analysis.
Rootstock genotype determines phenol content in apple fruits
The effect of weather conditions and eleven apple rootstocks was studied on the phenol content in fruits. Superdwarf rootstocks P 61 and P 22 determined the highest content of all phenolic compounds tested. Dwarf rootstocks M.9, P 62 and semi-dwarf M.26 determined lower content of all phenolic compounds tested. The content of (+)-catechin, procyanidin B1 and total procyanidins content in apple fruits depended on rootstock genotype and high variation coefficient of these compounds between rootstocks was established. Rootstocks had a lesser effect on the content of quercitrin, (-)-epicatechin, total catechins, phloridzin and chlorogenic acid. No clear differences were found between super-dwarf, dwarf and semi-dwarf rootstock groups. Conditions during the growing season, yield and fruit weight impacted on the content of bioactive compounds. Less than 10% difference in total phenols between the growing seasons was recorded for M.26 and P 22. The greatest differences were recorded in the fruits from trees grown on M.9, Pure 1 and P 66 rootstocks. Rootstock B.396 determined the most stable content of all compounds analysed, except for procyanidin B1 and B2.
Molecules
The byproducts (seeds and peels) of an avocado cultivated in the south of Colombia were extracted with aqueous acetone and their antioxidant properties were measured with ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays, and total polyphenol content was determined by Folin–Ciocalteu method. A bioguided fractionation was performed, first by SPE (solid phase extraction) on Amberlite XAD-7, and then by size exclusion chromatography on Sephadex LH-20. The polyphenolic-rich extracts and their fractions were analyzed by ultra-performance liquid chromatography–electrospray ionization–mass spectrometry (UPLC-ESI-MS/MS), finding the presence of organic acids, hydroxycinnamic acids, catechins, free and glycosylated flavonoids, and dimeric and trimeric procyanidins. Catechin, epicatechin, six quercetin derivatives, four dimeric procyanidins (three type B and one type A), and three trimeric procyanidins (two type B and one type A) wer...