Antioxidant capacity and phytochemical properties of cornelian cherry (Cornus mas L.) genotypes in Iran

Cornelian cherry (Cornus mas L.) is a naturally growing dogwood species in Arasbaran (East Azerbaijan, Iran). Antioxidant capacity, total anthocyanins, total phenols, ascorbic acid and total flavnoids of a number of selected cornelian cherry genotypes were investigated. The total phenolic and antioxidant activity of methanol extract of cornelian cherry fruits were determined according to Folin–Ciocalteu and DPPH method, respectively. The range of ascorbic acid content of genotypes was 183.25–299.5 mg/100 g fresh weight (FW). Genotype C24 had the highest total antioxidant capacity (82.37) and total phenolic (2695.75 mg galic acid per 100 g FW basis). The highest total anthocyanin was observed in C27 genotype (442.11 mg cyanidin-3-glucoside equivalents/100 g FW). This genotype also had the highest total flavonoid (669 mg catechin per 100 g FW basis). There are linear relationships between the antioxidant capacities with total phenols, total flavonoid and ascorbic acid. But, No statistically significant correlation was observed between antioxidant activity and total anthocyanins. According to Path analysis, the highest direct effect on antioxidant was observed in total flavonoid (0.38). The present study demonstrates the potential of certain cornelian cherry genotypes, notably C24 and C27, for improvement of nutritional value through germplasm enhancement programs.     

Phytochemical and antioxidant properties of selected fig (Ficus carica L.) accessions from the eastern Mediterranean region of Turkey

Fig has been a typical fruit component of the health-promoting Mediterranean diet for a very long time. Phytochemical characters and antioxidant capacity of green-, yellow-, brown-, purple-, and black-fruited fig (Ficus carica L.) accessions were investigated. In this study, total phenolics (TP), total anthocyanins (TA), fructose (FRUC), glucose (GLUC), sucrose (SUC), and variables (such as L*, a*, C*, and hue°) describing fruit skin colors were examined. Also, the antioxidant capacity (TAC) of fig fruits was determined by the ferric reducing antioxidant power (FRAP) assay. Antioxidant capacity was significantly correlated with the polyphenol and anthocyanin (r = 0.74 and 0.63, respectively) contents of fruits. Black fig accessions had the highest TAC (range of 7.9–16.1, mean 12.4 Fe²⁺ mmol/kg FW), TA (range of 32.3–356.0, mean 128.4 μg cy-3-rutinoside/g FW), and TP content (range of 69.1–220.0, mean 118.9 mg GAE/100 g FW). These black-fruited accessions had 2-fold greater TAC, 15-fold greater TA, and 2.5-fold greater TP than green and yellow fig accessions. However, the FRUC, GLUC, and SUC content of brown and purple fig accessions were higher than those of other color groups. The predominant sugars present were fructose (∼56%) and glucose (∼43%), as determined by HPLC.     

Effects of cultivar and rootstock on the antioxidant content and physical characters of clingstone peaches

A study was conducted to investigate the variability in the fruit antioxidant content and physical characters of six clingstone cultivars and three breeding selections of peach grafted on three rootstocks. The parameters measured were fruit weight, fruit and stone dimensions, flesh color using CIELAB color variables, total antioxidant activity using the radical DPPH, total phenolics, ascorbic acid, soluble solids and total acid content. Fruit from cultivar PI-E45 had the highest total antioxidant activity (10.7 mg g⁻¹ DW) and total phenolic (6.9 mg g⁻¹ DW) content, which were up to 6.3- and 5.3-fold greater, respectively, compared with the rest studied cultivars. The highest ascorbic acid content was found in Fortuna (7.3 mg 100 g⁻¹ FW) and was up to 1.4-fold greater compared with the rest studied cultivars. A high correlation between AEAC and the phenolic content was found, but not between AEAC and the ascorbic acid content. The largest fruit was harvested in cultivar Andross followed with a descending order by PI-E45, PI-IB42, PI-A37 (seedlings of Andross), Fortuna and Loadel ? Everts and Catherina ? Romea. Changes in the fruit weight were usually according to changes in stone width. The fruit and stone shape differed among the cultivars but not among the rootstocks studied. Effects of rootstock on the fruit antioxidant contents were not pronounced. Nevertheless rootstocks altered the fruit weight since in all cultivars, apart from Romea and Catherina, when grafted on GF 677 produced the largest fruit (mean 186 g) followed by PR204 (mean 176 g) and even smaller by KID1 (mean 161 g). Results from correlation analyses showed that flesh brightness (measured in frozen fruit) may suggest for more nutritional flesh and small sized fruit may contain a redder and less bright colored flesh.     

Effects of cultivar,orchard elevation,and storage on fruit quality characters of sweet cherry (Prunus avium L.)

Fruit quality characters were analysed in the sweet cherry cultivars, Burlat, Van, Tragana and Mpakirtzeika, harvested from low (39–59 m), medium (216 m) or high (490–546 m) elevation sites. The effects of storage for 2 or 4 days at 2 °C and 1 day at 20 °C on the fruit antioxidant contents were also evaluated. Tragana and Mpakirtzeika had greater fruit fresh weight (FW) and total soluble solid content compared to Van and Burlat, the latter being the most red colored. Tragana and Burlat had greater total phenolic content and total antioxidant capacity, measured by DPPH extinction, compared to Mpakirtzeika and Van (mean values 204.4 mg vs. 103.7 mg gallic acid equivalent 100 g⁻¹ FW, and 176.1 mg vs. 79.3 mg ascorbic acid equivalent 100 g⁻¹ FW, respectively). The geographic elevation had a marked influence on the cherry antioxidant content in all studied cultivars, apart from Van, with high elevation orchards producing cherries with greater contents of antioxidant compounds compared to lower elevation orchards. Changes in the antioxidant contents during storage were depended on the cultivar and some times on the orchard elevation. Total antioxidant capacity was significantly correlated with total phenolic content in Tragana, Burlat and Mpakirtzeika, but not in Van; nevertheless this was not the case during storage.     

The genotypic effects on the chemical composition and antioxidant activity of sea buckthorn (Hippophae rhamnoides L.) berries grown in Turkey

In this study, chemical composition of berries of 10 sea buckthorn (Hippophae rhamnoides L.) genotypes in Turkey was investigated. The total phenolic content of the berries ranged from 21.31 mg gallic acid equivalents (GAE) per g dry weight basis to 55.38 mg GAE per g. The highest antioxidant activity was 93.54% (similar to the standard BHT at 200 mg/L) and the lowest was 80.38%. There was no correlation (R = 0.688) between the total phenolic content and the antioxidant activity. The major fatty acids in berries were palmitoleic acid (35.48%), followed by palmitic acid (28.13%), oleic acid (22.89%) and linoleic acid (3.96%). Total soluble solid content of sea buckthorn genotypes varied from 10.15 to 14.80%, titratable acidity varied from 2.64 to 4.54%, the pH varied from 2.63 to 2.98 and Vitamin C varied from 19 to 121 mg/100 mL. The average content of minerals in the sea buckthorn berries of different genotypes was 20,800 ppm N, 7100 ppm P, 7260 ppm K, 1960 ppm Ca, 1465 ppm Mg, 32 ppm Zn, 24 ppm Cu, 22 ppm Mn and 7 ppm Fe.     

Some physico-chemical characteristics of black mulberry (Morus nigra L.) genotypes from Northeast Anatolia region of Turkey

In this study, some selected physico-chemical properties (antioxidant activity, ascorbic acid, fatty acids, fruit colour, fruit juice yield, fruit weight, organic acids, pH, total phenolic and total soluble solid contents) of five black mulberry (Morus nigra L.) genotypes grown in the Northeast Anatolia region of Turkey was investigated. The total phenolic and antioxidant activity of methanol extract of black mulberry fruits were determined according to Folin-Ciocalteu and β-carotene bleaching method assays, respectively. Fatty acids of mulberry fruits were determined by using gas chromatography. Total phenolic content was observed in black mulberry fruits between 1943 and 2237 mg gallic acid equivalents/100 g fresh mass. The vitamin C content of genotypes varied between 14.9 and 18.7 mg/100 ml. The major fatty acids in all mulberry fruits were linoleic acid (53.57–64.41%) and palmitic acid (11.36–16.41%). Antioxidant activity of black mulberry genotypes was found between 63% and 76%, which lower than standard BHA and BHT. Regarding organic acid content, malic acid was the most predominant with a range of 123–218 mg/g followed by citric acid (21–41 mg/g). The results of the study are helpful for attempting crop improvement in black mulberry for bringing to cultivation.     

李果实中多酚含量及其抗氧化能力研究

为分析不同李品种果实中多酚含量及其抗氧化能力,以14个李品种为试材,测定果皮和果肉中的多酚含量,采用超氧自由基(O_2~-)清除法、羟自由基(OH·)清除法、DPPH法、FRAP法和TBARS法测定抗氧化能力,比较多酚含量、抗氧化能力的差异,分析多酚含量与抗氧化能力的相关性,比较抗氧化能力测定方法间的相关性。结果表明:(1)李果实中富含多酚并且品种间存在差异,不同品种果皮中含量为1.40~3.37 mg·g~(-1) FW,果肉中含量为0.50~0.97 mg·g~(-1) FW,果皮中含量远大于果肉中含量;果皮中多酚含量较高的李品种为皇后李、猪肝李,其次为黑宝石李、红玫瑰李;果肉中多酚含量最高的为秋姬李,其次为威克逊李。(2)李果皮、果肉多酚提取物均具有较强的抗氧化能力,果皮提取物综合抗氧化能力较强的为皇后李、黑宝石李和猪肝李,果肉的为红美丽李、红玫瑰李和秋姬李。(3)果皮中多酚含量与清除O_2~-、OH·能力及DPPH、FRAP、TBARS均呈极显著正相关,果肉中多酚含量与抗氧化能力呈显著正相关。(4)对5种方法的相关性分析表明,各方法从不同的角度评价李果多酚抗氧化能力,方法间均具有很好的相关性,DPPH法与FRAP法综合评价最佳,可作为主要选择。     

The genetic variability,inheritance and inter-relationships of ascorbic acid, β-carotene,phenol and anthocyanin content in strawberry (Fragaria × ananassa Duch.)

Strawberry (Fragaria × ananassa Duch.) is rich source of dietary antioxidants, minerals and nutrients. Dietary antioxidants have been known as beneficial for enhancing the fitness, preventing certain diseases and even mitigating the effects of ageing. The objectives of the present study were to determine variability and inheritance of antioxidants, to identify antioxidant rich and productive genotypes, and to suggest suitable breeding approaches. The genotypes, namely Ofra, Chandler, Festival and Camarosa showed higher concentrations of dietary antioxidants and therefore could be useful in future breeding. Results indicate that the effect of the genotypes on antioxidant contents is stronger than that of the environment. The high heritability (>80%) and low genetic advance as percentage of mean (<40%) for ascorbic acid and β-carotene contents could be improved by heterosis breeding. However, selection and hybridization would be effective tools to enhance the phenols and anthocyanin content, and yield potential as these traits showed high heritability (>80%) and high genetic advance as percentage of mean (>40%). Positive direct effect on fruit yield was highest for phenol content (0.609) which is also fairly close to its correlation coefficient (0.765) indicating that a direct selection based on phenol content would be most effective and that the phenol content could be used as a reliable biochemical marker to identify the productive genotypes having higher amounts of dietary antioxidants. The information could also be used for developing antioxidant rich cultivars, i.e. ‘Breeding Strawberry for High Antioxidants’.     

Antioxidant phytochemicals and gingerol content in diploid and tetraploid clones of ginger (Zingiber officinale Roscoe)

Fresh rhizomes of 18 diploid and tetraploid genotypes of Indian ginger, including commercial cultivars and experimental genotypes, were assayed for gingerol content and antioxidant activity. The tetraploid ginger type was derived from the respective diploid ginger by shoot tip culture. [6]-Gingerol was identified as the major pungent phenolic compound in all samples (mean 1354.78 ± 470 μg/g), while [8]- (mean 180.94 ± 45 μg/g) and [10]-gingerol (mean 234 ± 79 μg/g) occurred in lower concentrations. The total gingerol content of the tetraploid type was much higher than that of the respective diploid type and especially the [10]-gingerol. Both diploid and tetraploid types of the cv. Meghalaya Local contained the highest level of gingerol. At both ploidy levels, the genotypes showed significant differences in phenols and antioxidant activities. Correlation of total phenolics with different antioxidant assay at both diploid and tetraploid level was linear and strong to moderate. For genotypes at both ploidy levels, antioxidant activity (BCO) was determined especially by [6]-gingerol while [8]- and [10]-gingerol did not affect BCO. These results demonstrated that in the tetraploid types of ginger, the gingerol content and antioxidant activity were higher than in the diploid ones.     

Growth and ripening season effects on antioxidant capacity of strawberry cultivar Selva

There is wide awareness on the importance of antioxidants in cell protection against free radicals constantly produced by the cell metabolism. In this work, carried out with strawberry cultivar “Selva”, the antioxidant capacity and content of the main accepted antioxidants – ascorbic acid, dehydroascorbic acid, total phenols and anthocyanins – were determined along 10 growth stages of the fruit. Strawberries were harvested in winter and summer. Minimum/maximum temperatures in the two seasons were 6.3 °C/14.9 °C and 14.5 °C/27.8 °C, respectively. Antioxidant capacity in the small green stage was 27 mmol DPPH/100 g fresh tissue, keeping noticeably high values in the large-green one. Towards the white stage, antioxidant capacity reduced, to remain mostly constant. The antioxidant capacity was higher in those stages where cell division was more important and this parameter correlated mostly with the contents of total phenols and ascorbic acid.     

The influence of flesh colour and growing locality on polyphenolic content and antioxidant activity in potatoes

Compounds contained in potato tubers that may act as antioxidants have been attracting increased attention. The main antioxidants in potatoes are polyphenolic compounds. The total polyphenolic (TP) content and antioxidant activity (AA) in potato tubers of four yellow-fleshed cultivars and two purple-fleshed cultivars from the 2004 harvest were tested. The total polyphenolic content was determined using the Folin-Ciocalteau reagent (FC) and the antioxidant activity, with the DPPH method using stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH·). Significant differences were found in total polyphenolic content between the yellow-fleshed cultivars Karin, Impala, Ditta, and Saturna. Significant differences between yellow and purple-fleshed potatoes were found: the yellow-fleshed cultivars had an average of 2.96 g gallic acid equivalents (GAE) per kg DM, the purple-fleshed cultivars 4.68 g GAE per kg DM. Significant differences in AA between the yellow and purple-fleshed cultivars were determined (yellow-fleshed in an average of 139.3 mg equivalents of ascorbic acid [EAA] per kg DM, purple-fleshed 332.3 mg EAA per kg DM) as well as between the purple-fleshed cultivars Valfi (298 mg EAA per kg DM) and Violette (366 mg EAA per kg DM). The major antioxidants in purple-fleshed cultivars were anthocyanidins petunidin (Valfi 92%_rel) and malvidin (Violette 85%_rel). Cv. Violette contained three times higher content of anthocyanidins than cv. Valfi. Among four experimental localities, the higher situated potato-growing region of Stachy (locality with the lowest average annual and daily minimum temperatures and the highest sum of precipitation in the vegetative period) differed significantly from other localities by a higher TP content, AA and yield in the analyzed cultivars. A high positive correlation between antioxidant activity and total polyphenolic content with R = 0.8648, R² = 0.7478 (P = 0.0001) was found.     

Morpho-pomological and chemical characterization of pomegranate (Punica granatum L.) genotypes in Apulia region,Southeastern Italy

A recent increasing demand in Western countries for pomegranate products by consumers is especially supported for the nutritional and medicinal characteristics, due to the antioxidant properties of this fruit. Some studies have been published on the morphological and biochemical characteristics of pomegranate fruits in some Mediterranean countries, but little information is available about the genotypes present in Italy and in particular in Apulia (Southeastern region of Italy). This study (2008–2009) evaluated morpho-pomological and chemical parameters of eight pomegranate genotypes localized in private small orchards. Significant differences were observed among the pomegranate genotypes for many of the parameters investigated. In particular, fruit weight ranged from 168.9 g (SouMol) to 574.9 g (SouOst), °Brix from 14.7 (ComTri) to 18.0 (SouMol), titratable acidity from 5.4 (ComMol) to 25.0 (SouTri) g/L. SouMol showed the highest polyphenols (97.1 mg/L) and vitamin C (236.3 mg/L) contents. Oil content of the seeds was between 5.90% and 10.30%, no differences have been observed for the fatty acid composition with conjugated linoleic acid (CLA) isomers as the most abundant fraction (81.23%). Considering all the evaluated parameters, and especially those referring to the organoleptic characteristics and antioxidants content, it must be stated that the best genotypes worthy to be considered from agricultural and industrial points of view were AdeSgi for fresh market and SouOst for the juice industry.     

Effect of scale color on the antioxidant capacity of onions

The bulb onion (Allium cepa L.) has been cultivated for thousands of years and used as an important component of human diet. Recent studies suggest that onions can be used to cure, reduce, or prevent some of the health problems such as cancer, cardiovascular diseases, antidiabetic, asthma, antibiosis, and prebiotic effects due to its high antioxidant effect. In this study, we determined the antioxidant capacities of a wide range of onion cultivars; nine commercial cultivars and five advance selections differing in color. The variables tested include bulb size, scale color, total phenolic (TP), total antioxidant activity determined by both “Ferric reducing ability of plasma” (FRAP) and “Trolox equivalent antioxidant capacity” (TEAC). We found that yellow onion had the greatest TP content (3.7 mg GAE/g dw); and, the red group had higher TP mean than the white group (2.2 mg GAE/g dw vs. 1.1 mg GAE/g dw). For the antioxidant capacity measurements, the red group had the greatest means by both methods (15.4 μmol TE/g dw and 9.3 μmol TE/g dw for TEAC and FRAP). Yellow onions had higher TEAC (14.7 μmol TE/g dw vs. 8.7 μmol TE/g dw) and FRAP values (9.8 μmol TE/g dw vs. 5.6 μmol TE/g dw) than white onions. Among the cultivars tested great differences of TP, TEAC and FRAP was observed. The TP content of Me-Tan 88 (8.3 mg GAE/g dw) was two times higher than the yellow group. Yellow color Dayton had the greatest TEAC (20.5 μmol TE/g dw) and FRAP (12.3 μmol TE/g dw) means followed by yellow color Me-Tan 88 (19.4 and 11.4 μmol TE/g dw). The two antioxidant measurements were found to be highly correlated (0.99) where absolute values of FRAP were about 40% less than those of TEAC. The values of TEAC and FRAP were significantly correlated by TP with similar rs (0.74 and 0.73, respectively). TP, TEAC and FRAP were significantly and positively correlated to soluble solids (0.41, 0.43, and 0.40, respectively). Our results suggested that the red onions had higher antioxidant activities than yellow and white onions although yellow onions had the richest phenolic contents.     

Quantification of phenolic acids and antioxidant activity in sweetpotato genotypes

Phenolic acid composition and antioxidant activity in roots of 14 commercially important sweetpotato genotypes were evaluated. Significant differences in total phenolics, individual phenolic acids, and antioxidant activity were found among the different sweetpotato genotypes. Total phenolic content, expressed in terms of chlorogenic acid equivalent, in different genotypes ranged from 1.4 to 4.7 mg g⁻¹ dry weight (DW). Antioxidant activity was evaluated as Trolox equivalent, ranging from 1.3 to 4.6 mg g⁻¹ DW. The highest total phenolic content and antioxidant activity were observed in a purple-fleshed genotype. Chlorogenic acid and 3,5-dicaffeoylquinic acid were the predominant phenolic acids, while caffeic acid was the least abundant in most genotypes. The highest content of chlorogenic acid (422.4 μg g⁻¹ DW) was present in a white-fleshed cultivar ‘Quarter Million’ imported from Jamaica. However, a purple-fleshed genotype had the highest amounts of 3,5-dicaffeoylquinic (485.6 μg g⁻¹ DW), 3,4-dicaffeoylquinic (125.6 μg g⁻¹ DW), 4,5-dicaffeoylquinic (284.4 μg g⁻¹ DW), and caffeic (20.5 μg g⁻¹ DW) acids.     

Phytochemicals and antioxidant capacity of orange (Citrus sinensis (l.) Osbeck cv. Salustiana) juice produced under organic and integrated farming system in Greece

Organically and integrated produced orange (Citrus sinensis (l.) Osbeck cv. Salustiana) fruits were assayed in terms of fruit characteristics and juice phytochemicals over a period of two years. Fruit size and juice volume were higher under organic farming system. There were not any significant differences concerning either the carbohydrates’ or organic acids’ concentrations of the juice. Similar results were obtained concerning the total phenol, the total o-diphenol and the total flavonoid concentration of the juice, while neither hesperidin nor narirutin differentiated significantly. However, β-carotene concentration was detected in higher concentration in organically produced fruit (0.43 mg L⁻¹). Juice extracted from both integrated and organically produced fruits exhibited similar antioxidant capacity values (based on 2,2-diphenyl-1-picryl hydrazyl and ferric reducing/antioxidant power assays), while correlation analysis revealed the significant contribution of phenolic compounds to antioxidant capacity (r = 0.75–0.86). Most of the amino acids determined were quantified in similar concentration in the juice of both organic and integrated produced fruits (approximately 1600 mg L⁻¹). The present results indicate that integrated oranges cv Salustiana, under the cultivation management implemented in this experiment, present similar antioxidant and nutritional values to the organically produced ones.     

Investigation of Antioxidant Content and Capacity in Yellow European Plums

ABSTRACT

Phenolic content and antioxidant capacity of five Yellow European plums (Prunus domestica) were studied using heat reflux extraction. Fresh plums were extracted at 50°C and 70°C, while freeze dried plums were extracted at 50°C, 60°C, and 70°C. Quantification of phenolic compounds such as ascorbic acid, neochlorogenic acid, and chlorogenic acid, was performed using high performance liquid chromatography. Antioxidant activity was determined by evaluating the scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric (Fe³⁺) free radicals. Total phenolic content and ferric reducing antioxidant potential were highest for freeze dried samples extracted at 60°C whereas extraction at 70°C resulted in the lowest yield. Neochlorogenic acid was the predominant phenolic compound in each plum genotype followed by ascorbic acid and chlorogenic acid. This study demonstrates that there is an adequate amount of health promoting phytochemicals within European plums, hence extraction of these compounds have potential for use towards functional food, nutraceutical, and pharmaceutical industries.     

Application of and correlation among antioxidant and antiradical assays for characterizing antioxidant capacity of berries

Various antioxidant assays are used to characterize fruits consumed fresh or processed although an easy, reliable and cheap assay is not available to follow the changes in antioxidant power. This study tested the applicability of a recently developed antioxidant measuring system, Water-soluble (ACW) and Lipid-soluble (ACL) Antioxidant Capacity, using the PHOTOCHEM^® instrument. Initially, 13 cultivars of 4 berry species were assayed with Photochem and compared with widely used methods based on single electron transfer reactions like ferric reducing ability of plasma, total polyphenolic content (TPC) and 2,2′-diphenyl-1-picrylhydrazyl radical-scavenging capacity. Assays based on hydrogen atom transfer reactions were also carried out including total radical-scavenger capacity (TRSC). The correlations among the results were all significant at P ≤ 0.05, except the one between TPC and ACW. The overall antioxidant capacity ranked on the order of strawberry < red currant < raspberry < black currant. However, significant differences could have been detected among genotypes and antioxidants assays used for the analysis. The Photochem instrument is not suitable for easy, cheap and high-throughput routine analysis of berry antioxidant capacity and hence is not preferable to other assays.     

Phenotypic and Bioactive Diversity on Medlar Fruits (Mespilus germanica L.)

Mespilus germanica, known as the medlar, is a large shrub or small tree. The fruit has been cultivated since Roman times, and is unusual in being available in winter, and in being eaten when bletted.  In this study twelve medlar (Mespilus germanica L.) genotypes were harvested at commercial maturity stage (skin brownish, pulp white, fruit hard) from Rize provinces located eastern black sea region and were analyzed for their some important fruit phenotypic (fruit mass, shape index, fruit firmness, ostiole diameter and fruit flesh ratio) and bioactive characteristics (total phenolic content, total antioxidant capacity, vitamin C and phenolic compounds). A wide variation among genotypes on most of the searched parameters was found. Fruit mass and flesh ratio varied from 12.3 g (KRD-1) to 23.6 g (KRD-8) and 83.6?% (KRD-2) to 93.0?% (KRD-4) indicating high variability among genotypes. The total phenolic contents of twelve medlar genotypes varied from 157 to 227 mg gallic acid equivalent in 100 g fresh weight basis. Chlorogenic acid, rutin and p-coumaric acid were dominant in medlar fruits.     

Apricot (Prunus armeniaca L.) fruit quality attributes and phytochemicals under different crop load

Three apricot (Prunus armeniaca L.) cultivars were subjected to different degrees of fruit thinning during pit hardening. At harvest fruit quality characteristics were assessed, along with phytochemicals’ concentration, such as carbohydrates, phenolic compounds and organic acids. Antioxidant capacity of the pulp was estimated by diphenyl picryl hydrazyl and ferric reducing antioxidant power assays. Thinning improved fruit weight in two of the three cultivars with a subsequent decrease in fruit firmness, without significant effect on total soluble solid content and titratable acidity. The skin color was not influenced by thinning, but carbohydrate concentration and sweetness index increased. Total phenol concentration increased with thinning, without any similar increase of the major individual phenolic compounds detected (neo-chlorogenic acid, chlorogenic acid, rutin, catechin, epicatechin, ferulic acid, p-coumaric acid and caffeic acid). The antioxidant capacity of the pulp was not influenced by thinning. In overall, thinning enhanced the pomological traits of apricot fruits as well as their phytochemical content.