Polyphenolic content

Paganga, G. et al.. The polyphenolic content of fruit and vegetables and their antioxidant activities what does a serving constitute Free Radical Res., 30, 153, 1999. Maatta, K.R. et al.. High-performance liquid chromatography (HPLC) analysis of phenolic compounds in berries with diode array and electrospray ionization mass spectrometric (MS) detection Rihes species, J. Agric. Food Chem., 51, 6736, 2003. 

Instant tea produced as described above will dissolve completely in hot water but not in cold water, as the caffeine-polyphenol complexes are insoluble under those conditions. Since virtually all instant tea manufacture in the U.S. is for iced tea preparation, process modification is required. This initial extract may be cooled to 5 to 10°C and the cold water insoluble material or cream be allowed to precipitate. Under these conditions, 20 to 35% of the extract solids may be separated by centrifugation. The supernatant solids will reconstitute in cold water after concentration and drying.105 It is also possible to process the cream to make a portion of it compatible with the product and thereby retain the caffeine and some polyphenolic components that are present in this fraction.106 Commercial use of the enzyme Tannase, which removes gallic acid from gallated tea polyphenols107 and reduces cream formation108 can be used to reduce cream losses and manufacture instant teas retaining more of the natural polyphenol content. 

Ren H, Endo H and Hayashi T (2001a), Antioxidative and antimutagenic activities and polyphenol content of pesticide-free and organically cultivated green vegetables using water-soluble chitosan as a soil modifier and leaf surface spray , JSci FoodAgric, 81, 1426-1432. 

Fig. 16.4 Multiple linear model containing phosphorus, calcium and iron contents of the leaves correlated significantly with the polyphenol contents of fruit. Organic (filled symbols) and conventional fruits (open symbols) did not differ significantly in their average polyphenol contents however, trees with a low leaf nutrient status showed a lower polyphenol contents in fruit (R2 = 0.64). Circles = cultivar Glockenapfel , squares = cultivar Idared area between the curves = space where 95% of the modelled values can be expected.

In the few studies that have been carried out to compare polyphenol content in organic and conventional crops, many, but not all, show cases... 

Alonso AM, Guillen DA, Barroso CG, Puertas B and Gracia A. 2002. Determination of antioxidant activity of wine byproducts and its correlation with polyphenolic content. J Agric Food Chem 50 5832-5836. Al-Saikhan MS, Howard LR and Miller JC Jr. 1995. Antioxidant activity and total phenolics in different genotypes of potato (Solarium tuberosum L). J Food Sci 60 341-343, 7. 

Oszmianski J, Wojdylo A and Kolniak J. 2009. Effect of 1-ascorbic acid, sugar, pectin and freeze-thaw treatment on polyphenol content of frozen strawberries. LWT-Food Sci Technol.42(2) 581-586. 

Heimler D, Isolani L, Vignolini P, Tombelli S and Romani A. 2007. Polyphenol content and antioxidative activity in some species of freshly consumed salads. J Agric Food Chem 55(5) 1724—1729. 

Paganga G, Miller N and Rice-Evans CA. 1999. The polyphenolic content of fruit and vegetables and their antioxidant activities. What does a serving constitute Free Radic Res 30(2) 153-162. 

Thu NN, Sakurai C, Uto H, Van Chuyen N, Lien DTK, Yamamoto S, Ohmori R and Kondo K. 2004. The polyphenol content and antioxidant activities of the main edible vegetables in northern Vietnam. J Nutr Sci Vitaminol 50(3) 203-210. 

Tea exerts a relatively strong inhibitory potency for N-nitroso compound formation both in vitro and in humans. The active constituents may be related to their polyphenols content, especially the tea catechin derivatives [25]. 

Arnold TM, Tanner CE, Hatch WI (1995) Phenotypic variation in polyphenolic content of the tropical brown algae Lobophora variegata as a function of nitrogen availability. Mar Ecol Prog Ser 123 177-183... 

Removing Interfering Polyphenols. The most troublesome problem encountered was high polyphenol content. If not removed, this dark-colored wood extractive decreased resolution during chromatographic separations, quickly render expensive chromatographic media (e.g., HPLC columns) nearly useless, and often precipitated enzymes during subsequent purification steps (14,15), We found it best to remove the bulk of this material prior to the first concentration step. 

Romani, A., Polyphenolic content in five Tuscany cultivars of Olea europaea L., J. Agric. Food Chem., 47, 964, 1999. 

Karabourniotis, G. and Fasseas, C., The dense indumentum with its polyphenol content may replace the protective role of the epidermis in some young xeromorphic leaves, Can. J. Bot., 74, 347, 1996. 

The current understanding of wine oxidation processes centers around pol)q5henols as the main initial substrate of wine oxidation, with crucial roles for catalytic metals in facilitating the reactions (Danilewicz, 2003). The amoimt of oxygen that can be taken up by a particular wine has been found to be proportional to the polyphenol content, an uptake that proceeds more rapidly at a higher pH where the phenolate anion forms of the polyphenols are more abundant (Singleton, 1987). 

Further effects on the polyphenol content of the wines were seen in this trial (Tao et al., 2007), including greater losses of catechin and mal-vidin-3-glucoside imder low SO2 conditions by contrast, more quercetin was lost in the MOX wines under a higher SO2 content, which can be potentially related to the limited ability of SO2 to reduce quercetin qui-nones (Makhotkina and Kilmartin, 2009), along with further reaction products arising from the interaction of quercetin with SO2. By contrast, hydroxycinnamic acids such as caftaric acid and caffeic acid were largely unaffected by MOX while adequate concentrations of free SO2 were maintained in the wines. 

Hamouz, K., Laehman, J., Cepl, J., Dvorak, P, Pivec, V., Prasilova, M. (2007). Site conditions and genotype influence polyphenol content in potatoes. HORTSCI, 34, 132-137. 

Dr. Joe Vinson of the University of Scranton believes that there is something to the chocolate effect, and he came to Belmont to tell us about his intriguing research. Vinson has determined the total polyphenol content of various chocolates and has also found a way of measuring how effective these mixtures are in preventing the oxidation of human ldl in a test tube. In other words, he has calculated a phenol antioxidant index, which takes into account both the quantity and the quality of these desirable substances. At the symposium Vinson reported that cocoa powder and dark chocolate are the best, followed by milk chocolate. Instant cocoa mixes trail the field. Then Vinson delivered the kicker chocolate has more, and better, polyphenols than fruits or vegetables and more than red wine. A forty-gram bar of dark chocolate has as many polyphenols as a cup of that widely promoted antioxidant cocktail we call tea. But there is still the matter of chocolate s fat content. Researchers tell us, though, that at least half of it is stearic acid, which does not raise blood cholesterol. 

In a recent paper, 17 amino acids commonly present in Sauvignon wine from the Coastal region of Croatia were determined by complete assignment of their resonances by the use of aH and 13C NMR spectroscopy (Kosir and Kidric, 2001). In 2003, the metabolite content of the skin and pulp of mature berry extracts for four wines from the Bordeaux area were analyzed (Pereira et ah, 2005). Differences readily observed were due to an absence of polyphenol content in pulp extracts (Fig. 4.20). PCA highlighted that sugars were mainly responsible for cluster separation among samples in both types of extracts. 

For phenol 1-37 pM For H2O2 30-130 pM For lecithin 2.0-48.7 mg L"1 Superoxide radical 0.02-2.0 mM <5% Working media ft-hexane for tyrosinase electrode chloroform for catalase electrode chloroform/hexane (50% v/v) containing 1% by volume of methanol for lecithin electrode. Antioxidant capacity of wines was evaluated in terms of polyphenol content, sulfite and ascorbic acid, and compared to superoxide radical scavenging... 

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