Search Results

You are looking at 101 - 110 of 775 items for :

  • "anthocyanin" x
Clear All
Free access

Zhiguo Ju, Chenglian Liu, Yongbing Yuan, Yongzhang Wang and Gongshi Liu

Crosses between red cultivars produced high frequency of less-colored progeny, while hybridization between non-red cultivars yielded some red-fruited F1 trees. When harvest was delayed and light intensity increased, both green and yellow cultivars accumulated some anthocyanin with higher UDPGal:flavonoid-3-o-glycosyltransferase (UFGalT) activity in colored areas. Overall, anthocyanin accumulation and UFGalT activity were highly correlated (r = 0.8921, P = 0.0001) in fruit from both parental trees and their F1 progeny, but UFGalT activity always was relatively high in fruit peel, whether anthocyanin accumulated or not. There were no significant differences in phenylalanine ammonia-lyase or chalcone synthase activities among the cultivars, and they did not change much after hybridization.

Free access

W. Kalt, J.E. McDonald and S. MacKinnon

Fruit and vegetable components that possess antioxidant capacity are being actively investigated because of the purported impact of dietary antioxidants on human health. Phenolic components, including anthocyanins, are believed to be major contributors to the antioxidant capacity of many small fruit species. Various horticultural factors have been examined with respect to anthocyanin and phenolic content, and antioxidant capacity of small fruit, especially Vaccinium species. Vaccinium species, and certain other fruits, had a high antioxidant capacity compared to strawberries and raspberries. However, genotypic variation in these characteristics was substantial among wild blueberry clones. Fruit maturity did not influence antioxidant capacity, although phenolic profiles changed dramatically during ripening. Fresh storage of certain ripe fruit at 20 °C led to increased anthocyanin content and increased antioxidant capacity. Certain food processing factors, such as heat and oxygen, decreased the antioxidant capacity of blueberry products.

Free access

C.R. Brown, D. Culley, C.-P. Yang, R. Durst and R. Wrolstad

A breeding effort designed to increase the antioxidant level of potato (Solanum tuberosum L.) by means of high concentrations of anthocyanins and/or carotenoids provided selected materials for analysis. Extraction methods suitable for isolating both hydrophilic and lipophilic compounds were used and measurements of total anthocyanin and total carotenoid were made. Two methods of measurement of oxygen radical absorbance capacity (ORAC) adapted to hydrophilic and lipophilic compounds were applied. Total anthocyanin values varied between 9.5 and 38 mg per 100 g fresh weight (FW). The hydrophilic fraction ORAC measurements among anthocyanin-rich clones varied between 250 and 1420 μmol Trolox equivalents per 100 g FW. These two variables were significantly correlated, r = 0.73, and with significant positive slope in linear regression. Measurement of total carotenoids revealed differing degrees of yellowness covered a range of total carotenoid extending from 35 to 795 μg per 100 g FW. Dark yellow cultivars had roughly 10 times more total carotenoid than white-flesh cultivars. The lipophilic fraction ORAC values ranged from 4.6 to 15.3 nmoles α-tocopherol equivalents per 100 g FW. Total carotenoid was correlated with the lipophilic ORAC values, r = 0.77, and also had a statistically significant positive regression coefficient. Clones with red and yellow pigments visible in the flesh had anthocyanins and carotenoids in elevated levels and ORAC contributions from both fractions. The introgression of high levels of carotenoid from germplasm directly extracted from the Papa Amarilla (yellow potato) category of cultivars of South America into long-day adapted North American materials is presented here. Although anthocyanins and carotenoids are major contributors to antioxidant activity, other constituents of potato flesh likely play significant roles in total antioxidant values.

Full access

Eric T. Stafne, Amir Rezazadeh, Melinda Miller-Butler and Barbara J. Smith

; Clark, 2008 , 2013 ; Fernandez, 2012 ; Ruhl, 2010 ). It is a problem that does not appear to have a simple, single cause. Anthocyanin synthesis has been known to be affected by environmental conditions such as growth temperature. Steyn et al. (2004

Full access

Brett Suhayda, Carolyn J. DeMoranville, Hilary A. Sandler, Wesley R. Autio and Justine E. Vanden Heuvel

fungal diseases ( Oudemans et al., 1998 ). As with flower bud formation, fruit anthocyanin production depends on adequate light penetration ( Strik and Poole, 1991 ; Toledo et al., 1993 ). The cranberry fruit must exceed a minimum anthocyanin content to

Free access

Jeff L. Sibley, John M. Ruter and D. Joseph Eakes

The objective of this study was to determine differences in the bulk anthocyanin content of bark tissue of container-grown red maple (Acer rubrum L. and Acer ×freemanii E. Murray) at two Georgia locations with different environmental conditions. Rooted cuttings and tissue-cultured plantlets of eight cultivars were grown in either Blairsville or Tifton, Ga. [U.S. Dept. of Agriculture (USDA) Hardiness Zones 6b and 8a; American Horticultural Society (AHS) Heat Zones 5 and 8, respectively], from June 1995 until Dec. 1996. Bark tissue from twigs of trees grown in Blairsville was visually redder and contained more total anthocyanin than did that of trees grown in Tifton. Levels of total anthocyanins were higher (P = 0.0007) at Blairsville (0.087 mg·g-1, N = 48) than at Tifton (0.068 mg·g-1, N = 47). At both locations the levels were highest in `Landsburg' (`Firedance'™), followed by `Franksred' (`Red Sunset'™) and `October Glory'. This is the first report to quantify anthocyanin differences in bark tissue of container-grown trees. Cooler nights in Blairsville might have contributed to increased coloration by reducing respiratory losses, thus leaving more carbohydrates available for pigment production.

Free access

M.A.L. Smith

The bright red pigmentation in edible, anthocyanin-rich fruits and vegetables is a definite bonus in terms of market appeal. As a result, breeders have worked consistently to intensify anthocyanin levels or alter composition in crops. The positive links between consumption of crops and food products containing natural anthocyanin pigments, and reduced incidence of cardiovascular and other chronic diseases, have been established anecdotally and more recently validated in research trials including those from our laboratory group. The protective events, most attributed to the potent antioxidant properties of anthocyanin pigments and associated phytochemicals, place anthocyanin-rich crops in the category of “Functional Foods,” yielding health protection unrelated to nutritional value. In vitro bioactivity assays have identified components from these crops capable of blocking the initiation stages of carcinogenesis, while a completely separate class of phytochemicals and sets of assays establish efficacy against the promotion stages of tumorigenesis. Animal models for carcinogen-induced damage to mammary gland and skin DNA subsequently demonstrate the in vivo potency of the same target compounds. Similarly, to establish cardioprotective properties, demonstrations of ability to inhibit platelet aggregation, relax vascular muscle tissue, and reduce total serum cholesterol are demonstrated in a series of in vitro assays, and via animal models and human studies. While activity-directed fractionations seek to identify specific responsible compounds, it is increasingly evident that bioactivity is drastically attenuated once specific compounds are isolated, and the synergistic interaction of associated phytochemicals in horticultural crops is prerequisite to realizing health benefits. These complications have slowed the establishment of effective minimum “dosages,” but all the more strongly promote consumption of the crops.

Free access

Zhiguo Ju, Chenglian Liu, Yongbing Yuan and Yongzhan Wang

“Colormotor” is a new product formulated mainly from seaweed extracts for promoting anthocyanin synthesis and improving fruit coloration in apples. The product was applied (150 ppm) 3 weeks before harvest in 2 years of experiments with `Delicious' apples. Colormotor treatment promoted anthocyanin accumulation by 2.5-fold and increased color index of fruit by 50% over controls. Only 23.5% of control fruit had full red color when harvested 140 DAFB, whereas 80% of the fruit sprayed with Colormotor had full red color. UDPG-o-3-glucosyltransferaw activity also was significantly greater in treated fruit. Treatment did not affect ethylene synthesis, fruit firmness, soluble solids, total sugars, or titratable acid incidence either at harvest or during prolonged storage. However, scald incidence after 20 weeks at 0C was significantly decreased by Colormotor treatment. The scald scores were 1.59 in control fruit and 0.67 in treated fruit, respectively, on a scale of 1 to 4.

Free access

Neal Courtney-Gutterson

The biosynthetic pathway for anthocyanins has been studied using genetic, biochemical and molecular biological tools. In the past decade, the core pathway genes have been cloned; a number of genes which act to modify anthocyanin structure have been cloned more recently. The first results in color modification have been reduced flower color intensity using gene suppression methods. In particular, we have utilized chalcone synthase (CHS) and dihydroflavonol reductase (DFR) genes and sense suppression in our experimental system, Petunia hybrida, and in the commercial crops, chrysan-themum (Dendranthema morifolium) and rose (Rosa hybrida). In petunia a range of new phenotypes was obtained; genetic stability of suppressed pheno-types will be described. In chrysanthemum a white-flowering derivative of a pink-flowering variety will be described. In rose uniform, partial reduction in pigment intensity throughout the flower was observed in over a dozen trans-genie derivatives of a red-flowering variety.

Free access

Bernadine C. Strik and Arthur Poole

Timing and severity of pruning in a 30-year-old commercial `McFarlin' cranberry (Vaccinium macrocarpon Ait.) bed were studied. Treatments in 1989 and 1990 consisted of early or late pruning and heavy, moderate, light, or no pruning. Yield component data were collected in Fall 1989 and 1990, just before harvest. Time of pruning did not affect yield components. In 1989, the unpruned and lightly pruned vines had a higher total plant fresh weight, fewer berries, higher berry yield, longer and more fruiting uprights, and fewer nonfruiting uprights (U,) compared with moderately or heavily pruned vines. Average length of UN and anthocyanin content of berries in 1989 were not influenced by pruning. In 1990, the effects of pruning severity were similar to 1989. In 1990, unpruned vines had a lower percent fruit set and berries contained less anthocyanin than pruned vines. Annual pruning with conventional systems in use decreases yield.