Flavonoid Content Of Fruits Research Articles

Evaluation of Metaxenia Effects of Canary Island Palm Pollen on Commercial Date Palm Cultivars: Changes in Antioxidant Capacity and Phenolic and Flavonoid Contents of Fruits

Evaluation of Metaxenia Effects of Canary Island Palm Pollen on Commercial Date Palm Cultivars: Changes in Antioxidant Capacity and Phenolic and Flavonoid Contents of Fruits

The Foraging Activity and Pollination Services of Three Stingless Bee Species to Enhance Fruit Quality and Quantity of Okra (Abelmoschus Esculentus L.)

Insect pollination has been reported to have a better yield quality and quantity than artificial pollination. Wild bees, including stingless bees contribute to effective and efficient pollination on okra (Abelmoschus esculentus L.: Malvaceae). However, previously no report about okra pollination by native Indonesian stingless bees, which can be potential as pollinators. Therefore, this research aims to compare foraging activities of three species of stingless bees (Heterotrigona itama, Tetragonula laeviceps, and T. clypearis) on okra plants and fruits quality and quantity parameters among four pollination treatments (three stingless bee species and without pollinator). Four cages with 50 okra plants were used for pollination treatments. The foraging observation of different stingless bee species on okra was conducted in the cages, and the okra yield from each treatment was compared. Our results showed the foraging activities of three stingless bee species were higher in the morning than those in the afternoon. In the morning, the number of visits of T. clypearis and T. laeviceps were negatively correlated with visit duration. The current study also showed that size and weight of pod, the number of seeds, and the percentage of fruit set of okra were enhanced by pollination of three stingless bee species. Unfortunately, the pollination of stingless bee species did not affect the seed germination and flavonoid content of fruits. The native of Indonesian stingless bees are good pollinators to improve pod quality and quantity.

Effect of different irrigation levels on quality parameters of 'Honeycrisp' apples.

Water shortage is the main factor affecting agricultural production in the vast arid and semi-arid areas of northern China. Using proper irrigation methods can optimize the efficiency of water use and improve the quality of agricultural products. This study investigated the effect of different irrigation levels on the quality of 'Honeycrisp' apples grown in the Loess Plateau of northern China. Different irrigation levels were applied to the 'Honeycrisp' apple trees via root irrigation using ceramic emitters that provide saturation levels of 75-90%θf (S1, where θf is the field capacity), 60-75%θf (S2), 45-50%θf (S3) and no irrigation treatment (CK). Compared to the apples from the CK group, the water content, transverse diameter, individual fruit weight and titratable acid content of S1 and S2 group apples increased significantly. However, their hardness, soluble solids and total sugar content decreased significantly. The phenolic acid content of apples also changed with the irrigation levels. The chlorogenic acid content of apples increased with increased irrigation volume, while the hyperoside, protocatechuic acid and caffeic acid content decreased. Total phenolic and flavonoid contents of fruits were the highest in S2 group apples. They also had the strongest ABTS and DPPH free radical scavenging capacities. The volume of irrigation applied through ceramic emitters significantly impacted the quality of 'Honeycrisp' apples grown in loess areas. Considering water conservation and improving fruit quality, the most suitable ceramic root irrigation level was observed to be 60-75%θf (S2). © 2021 Society of Chemical Industry.

Antioxidant Compounds, Nutritional Quality and Colour of Two Strawberry Genotypes from Fragaria × Ananassa

In this study, average weight, colour, soluble solids content and titratable acidity were determined as quality parameters of strawberry fruits while ascorbic acid, total anthocyanins, total phenolics, total flavonoids, minerals and trace elements content as nutritional parameters. All these attributes along with the DPPH radical scavenging activity were screened in two strawberry genotypes grown on the same site at the ripe stage. Also, the phenolic profiles of the strawberry fruits were obtained by HPLC. Except colour, results showed no significant differences between cultivars in quality parameters. Ascorbic acid found for ‘Premial’ cv. (81.62 mg/100 g) was twice the amount found in ‘Magic’ cv. (42.15 mg/100 g), total phenolics varied from 207.95 (cv. ‘Premial’) to 249.98 (cv. ‘Magic’) mg GAE/100 g while total flavonoid content in fruits of ‘Magic’ cultivar (79.56 mg/100 g) was 2‑fold higher than the one of the ‘Premial’ cv. The quercetin content ranged from 2.72 to 4.66 mg/100 g, whereas free ellagic acid ranged from 6.79 to 9.03 mg/100 g. The pale shiny fruits of ‘Premial’ cv. (higher L*, ho and chroma index) had a lower total anthocyanin content (19.07 mg CG/100 g) than the bluish fruits of the ‘Magic’ cv. (23.96 mg CG/100 g). An inverse relationship between the levels of ascorbic acid and anthocyanin contents was also noticed in strawberry samples. Significant differences were found also in minerals and trace elements content of the two strawberry cultivars. The results revealed the importance of genetic background for the content of antioxidant compounds in strawberry fruits.

Polyphenol content and antioxidant capacity of fruit and vegetable beverages processed by different technology methods

The purpose of the natural drinks production is the preservation of biologically active compounds in maximal amount in prepared drinks. The issue is the loss of these substances due to conventional conservation methods, such as pasteurization. Pascalization, a conservation method using high pressure, performs a new trend in conservation. According to available research, it causes only a minimal loss of bioactive compounds. Influence of conservation technology of fruit and vegetable beverages on the content of bioactive substances - polyphenols, flavonoids and on their antioxidative activity has been investigated. Their content has been compared in fresh juice samples, in samples conserved by pasteurization and after the appliance of high pressure treatment - pascalization (HPP). HPP has a positive effect on total antioxidative capacity of juices - broccoli with apple (increase of the amount from 189.12 mg.100 mL-1 to 217.12 mg.100 mL-1) and beetroot and on total polyphenol content within all samples of beverages except from carrot juice. Decrease of the amounts of flavonoids has been observed within all beverages. For drinks after pasteurization treatment there is evident the decrease of total polyphenols content and total antioxidant activity, besides carrot juice, where the antioxidant capacity value had increased from 37.24 to 43.14 mg.100 mL-1. The flavonoid content of fruit and vegetable juices after heat treatment had increased only in the juice prepared from broccoli with apple (from 40.71 mg.100 mL-1 to 45.14 mg.100 mL-1), the content in other juices had decreased. However, the decrease of the flavonoid content is lower after heat treatment in comparison to HPP, except the samples of cabbage juice with apple. With the exception of flavonoids, HPP has been proved as a gentle conservation technology enabling preserving higher amounts of bioactive substances with antioxidative properties if compared with the heat treatment. For the samples treated by HPP there was observed statistically significant difference in comparison with fresh juice in all factors mentioned above (p <0.05).

Propagation Methods Affect Fruit Morphology and Antioxidant Properties but Maintain Clonal Fidelity in Lowbush Blueberry

The berry morphology (size and weight), phytochemical content (polyphenols, flavonoids, anthocyanins, and proanthocyanidins), and antioxidant activity of lowbush blueberry (Vaccinium angustifolium Ait.) wild clone QB 9C and cultivar Fundy, propagated by tissue culture (TC) and softwood cutting (SC), were studied over two growing seasons to evaluate the effect of propagation methods on fruit yield and the content of antioxidant metabolites. Number of flower clusters, number of berries and berry weight per plant, diameter and weight of individual berry were higher in SC plants than those of TC plants. Significant interaction between genotypes and propagation methods were observed for total phenolic and flavonoid content of fruits. Berries from TC plants contained more polyphenols and flavonoids than those of SC plants. Twenty microsatellite markers were used to assess the clonal fidelity of TC regenerants and SC plants. The identical monomorphic amplification profiles within the TC plants of each genotype confirmed the clonal fidelity of micropropagated blueberry plants. These results indicate that propagation methods affected the morphology and antioxidant metabolites but maintained trueness-to-type genetic makeup in blueberry.

Impact of the quantity and flavonoid content of fruits and vegetables on markers of intake in adults with an increased risk of cardiovascular disease: the FLAVURS trial

Limited robust randomised controlled trials investigating fruit and vegetable (F&V) intake in people at risk of cardiovascular disease (CVD) exist. We aimed to design and validate a dietary strategy of increasing flavonoid-rich versus flavonoid-poor F&V consumption on nutrient biomarker profile. A parallel, randomised, controlled, dose-response dietary intervention study. Participants with a CVD relative risk of 1.5 assessed by risk scores were randomly assigned to one of the 3 groups: habitual (control, CT), high-flavonoid (HF) or low-flavonoid (LF) diets. While the CT group (n = 57) consumed their habitual diet throughout, the HF (n = 58) and LF (n = 59) groups sequentially increased their daily F&V intake by an additional 2, 4 and 6 portions for 6-week periods during the 18-week study. Compliance to target numbers and types of F&V was broadly met and verified by dietary records, and plasma and urinary biomarkers. Mean (± SEM) number of F&V portions/day consumed by the HF and LF groups at baseline (3.8 ± 0.3 and 3.4 ± 0.3), 6 weeks (6.3 ± 0.4 and 5.8 ± 0.3), 12 weeks (7.0 ± 0.3 and 6.8 ± 0.3) and 18 weeks (7.6 ± 0.4 and 8.1 ± 0.4), respectively, was similar at baseline yet higher than the CT group (3.9 ± 0.3, 4.3 ± 0.3, 4.6 ± 0.4, 4.5 ± 0.3) (P = 0.015). There was a dose-dependent increase in dietary and urinary flavonoids in the HF group, with no change in other groups (P = 0.0001). Significantly higher dietary intakes of folate (P = 0.035), non-starch polysaccharides (P = 0.001), vitamin C (P = 0.0001) and carotenoids (P = 0.0001) were observed in both intervention groups compared with CT, which were broadly supported by nutrient biomarker analysis. The success of improving nutrient profile by active encouragement of F&V intake in an intervention study implies the need for a more hands-on public health approach.

Variations in antioxidant capacity of nectarine fruits (Prunus persica cv. red-gold) affected by harvest date

The influence of harvesting date on some physicochemical properties of nectarine (Prunus persica var. Red gold) fruit including fruit weight, pigment content, total carbohydrate, total phenol and antioxidant activity were studied. Fruits were harvested in four different stages; a) two weeks after fruit set, b) pit hardening, c) three weeks after pit hardening and 6 weeks after pit hardening. Results showed that the heaviest fruit either wet or dry was observed in the last harvesting date. The reduction in sucrose at the final harvest might be due to conversion to monosaccharides like fructose or glucose. On the other hand, although the content of total phenolic and flavonoid content of fruits were significantly reduced in the last harvest, no significant reduction was observed in their antioxidant activity. Generally, it can be concluded that compounds like anthocyanin, carotenoids and vitamin C play important role in antioxidant activity in ripened nectarine fruit and their content differ in different harvest times.

Organ-specific distribution of phenolic compounds in bilberry (Vaccinium myrtillus) and ‘northblue’ blueberry (Vaccinium corymbosum x V. angustifolium)

Blueberries and bilberries are recognized as some of the best sources of flavonoids, especially anthocyanins. The contents of flavonoids (anthocyanins, proanthocyanidins, flavonols) and hydroxycinnamic acids in the flower, fruit skin and pulp, leaf and rhizome of bilberry and the blueberry cultivar ‘Northblue’ were analyzed using high-performance liquid chromatography combined with diode-array detection. The most striking difference in the fruits was the predominance of hydroxycinnamic acids in blueberry, whereas in bilberry the anthocyanin content was much higher, particularly in the pulp. Differences in flavonoid contents of fruits were already apparent at the flower stage. Bilberry and blueberry leaves both contained high amounts of proanthocyanidins, flavonols and hydroxycinnamic acids. Blueberry rhizomes accumulated high amounts of hydroxycinnamic acids. All plant parts of bilberry and blueberry are potential sources of phenolic compounds for use either as dietary botanicals or by the pharmaceutical industry.

Introduction of sense constructs of cinnamate 4-hydroxylase (CYP73A24) in transgenic tomato plants shows opposite effects on flux into stem lignin and fruit flavonoids

Understanding regulation of phenolic metabolism underpins attempts to engineer plants for diverse properties such as increased levels of antioxidant flavonoids for dietary improvements or reduction of lignin for improvements to fibre resources for industrial use. Previous attempts to alter phenolic metabolism at the level of the second enzyme of the pathway, cinnamate 4-hydroxylase have employed antisense expression of heterologous sequences in tobacco. The present study describes the consequences of homologous sense expression of tomato CYP73A24 on the lignin content of stems and the flavonoid content of fruits. An extensive number of lines were produced and displayed four developmental variants besides a normal phenotype. These aberrant phenotypes were classified as dwarf plants, plants with distorted (curly) leaves, plants with long internodes and plants with thickened waxy leaves. Nevertheless, some of the lines showed the desired increase in the level of rutin and naringenin in fruit in a normal phenotype background. However this could not be correlated directly to increased levels of PAL and C4H expression as other lines showed less accumulation, although all lines tested showed increases in leaf chlorogenic acid which is typical of Solanaceous plants when engineered in the phenylpropanoid pathway. Almost all transgenic lines analysed showed a considerable reduction in stem lignin and in the lines that were specifically examined, this was correlated with partial sense suppression of C4H. Although not the primary purpose of the study, these reductions in lignin were amongst the greatest seen in plants modified for lignin by manipulation of structural genes. The lignin showed higher syringyl to coniferyl monomeric content contrary to that previously seen in tobacco engineered for downregulation of cinnamate 4-hydroxylase. These outcomes are consistent with placing CYP73A24 more in the lignin pathway and having a role in flux control, while more complex regulatory processes are likely to be involved in flavonoid and chlorogenic acid accumulation.