Sugars and Organic Acids in 25 Strawberry Cultivars: Qualitative and Quantitative Evaluation.

(1) The nutritional quality of strawberry (Fragaria × ananassa Duch) fruits, among others, is largely maintained by the presence of soluble sugars and organic acids. As the primary products of photosynthesis, they are energy depots in plants, necessary for the construction of cell constituents, but also serve as precursors of aromatic compounds and signaling molecules. (2) In this study, fruits of 25 strawberry cultivars were qualitatively and quantitatively characterized concerning individual sugars and organic acids by HPLC, FT-ICR-MS, and MS imaging analysis. In addition, the total quality index (TQI), as a novel mathematical model, was used to compare all individual parameters evaluated to obtain a quantitative single score, as an indicator of overall fruit quality. (3) Regardless of a large number of cultivars and monitored parameters that were studded, several cultivars stood out in terms of selected primary metabolites, such as 'Rumba', 'Jeny', and 'Sandra', while the latter had the best TQI score. (4) Intercultivar variations in sugars and organic acids profiles, along with other bioactive compounds, should be considered for selection of promising cultivars with improved naturally occurring nutraceutical traits. Besides the search for a pleasant taste, increased awareness of healthy nutrition resulted in heightening consumer demand for high-quality fruit.

Authenticity assessment of cultivated berries via phenolic profiles of seeds.

Considering the health-benefits of berry fruits consumption and increased market demands for food authenticity as one of the most important quality assurances, phenolic profiling by high-performance thin layer chromatography and ultra-high-performance liquid chromatography hyphenated with mass spectrometry was combined with multivariate analysis for phytochemical characterization and intercultivar discrimination of cultivated berry seeds. The phenolic profiles of 45 berry seeds from nine genuine Serbian cultivated fruit species (strawberry, raspberry, blackberry, black currant, blueberry, gooseberry, cape gooseberry, chokeberry, and goji berry) revealed a good differentiation according to botanical origin. In order to determine biomarkers responsible for the classification, a total of 103 phenolic compounds were identified, including 53 phenolic acids and their derivatives, 26 flavonoids and 24 glycosides. Biomarkers derived from the phenolic profile of berry seeds proved to be a powerful tool in the authentication of botanical origin, and may be useful in detection of frauds in berry-based seed-containing product.

Rich in Phenolics-Strong Antioxidant Fruit? Comparative Study of 25 Strawberry Cultivars.

Phenolic compounds of 25 newly introduced strawberry cultivars were profiled using spectrophotometry, electron paramagnetic resonance (EPR) spectroscopy, and high-performance liquid chromatography-mass spectrometry. Total phenolic and anthocyanin content (TPC and TACY, respectively), as well as vitamin C, and concentrations of individual phenolic compounds in fruits were evaluated to identify the most promising cultivars according to their phenolic profile. The highest values of TPC, TACY, and vitamin C were recorded in 'Premy' (1.53 mg eq GA g-1 FW), 'Sandra' (30.60 mg eq Pg-3-g 100 g-1 FW), and 'Laetitia' (56.32 mg 100 g-1 FW), respectively. The DPPH and •OH radicals scavenging activity of fruit methanolic extracts was estimated using EPR spectroscopy. All cultivars are almost uniformly effective in the scavenging of •OH radical, while 'Tea', 'Premy', and 'Joly' were marked as highly potent cultivars (over 70%) in terms of DPPH-antiradical activity. Specific peroxidase activities were the highest in 'Garda', 'Federica', and 'Rumba' (0.11, 0.08, and 0.06 U mg-1 prot, respectively). 'Laetitia', 'Joly', 'Arianna', 'Tea', and 'Mila' cultivars were distinguished from others as the richest concerning almost all flavonoids and phenolic acids, including some other parameters of bioactivity. These cultivars could be recommended to consumers as functional fruit foods.

Phenolic Profiling of 12 Strawberry Cultivars Using Different Spectroscopic Methods.

Phenolic compounds of 12 strawberry cultivars were profiled using spectrophotometry, spectrofluorometry, and high-performance liquid chromatography-mass spectrometry, coupled with multivariate regression analysis. Total phenolic content, total anthocyanin content, and total antioxidant capacity (TPC, TACY, and TAC, respectively) and concentrations of individual phenolics were evaluated, and the multivariate statistic was employed to identify the most promising cultivars based on their phenolic content. According to the principal component analysis, TAC was strongly correlated with the TPC (0.81), pointing out its importance in overall antioxidant activity. 'Joly', 'Laetitia', and 'Asia' cultivars were distinguished from others as the richest in concerning identified anthocyanins, almost all flavonoids and phenolic acids. Multivariate curve resolution with alternating least squares indicated the presence of two main types of fluorophores assigned to anthocyanins and phenolics, in which emission spectral ratios also showed the highest values in the referred cultivars. These cultivars could be recommended to consumers in terms of the health functionality of fruit.

Chemometric Characterization of Strawberries and Blueberries according to Their Phenolic Profile: Combined Effect of Cultivar and Cultivation System.

Chemical characterizations of leaves and fruits that were obtained from organically and integrally produced strawberries ('Favette', 'Alba', and 'Clery') and blueberries ('Bluecrop', 'Duke', and 'Nui') from western Serbia were undertaken in this study. Phenolic analysis was done while using ultra-high performance liquid chromatography coupled to a linear ion trap-Orbitrap hybrid mass analyzer, while total phenolic content (TPC), total anthocyanin content (TAC), and radical-scavenging activity (RSA) by spectrophotometry. In general, leaves and fruits from blueberry showed higher levels of TPC and TAC as compared to strawberry. These chemical traits were larger in organic grown fruits and larger in leaves than fruits. The most abundant phenolics in leaves and fruits of blueberry was 5-O-caffeoylquinic acid, followed by quercetin 3-O-galactoside, while catechin, quercetin, and kaempferol 3-O-glucosid were dominant in the leaves and fruits of strawberry. cis, trans-Abscisic acid was detected in all fruit samples, but not in leaves. Blueberries (both fruits and leaves) were separated from strawberries, but only organic blueberry fruits were distinguished from integrated fruits, according to principal component analysis. Quercetin, kaempferol, 5-O-caffeoylquinic acid, ferulic acid, caffeic acid, catechin, p-coumaric acid, and p-hydroxybenzoic acid were the most influential phenolic compounds for the separation. Much higher contents of TPC, RSA, TAC, quercetin 3-O-galactoside, and quercetin were found in fruits and TPC, RSA, catechin, p-hydroxybenzoicacid, p-coumaricacid, and ferulic acid in leaves in all three blueberry cultivars and the strawberry cultivar 'Clery'. These phenolic compounds are good sources of antioxidant compounds with potentially high beneficial effects on human health.

Comparison of Sugar Profile between Leaves and Fruits of Blueberry and Strawberry Cultivars Grown in Organic and Integrated Production System.

The objective of this study was to determine and compare the sugar profile, distribution in fruits and leaves and sink-source relationship in three strawberry ('Favette', 'Alba' and 'Clery') and three blueberry cultivars ('Bluecrop', 'Duke' and 'Nui') grown in organic (OP) and integrated production systems (IP). Sugar analysis was done using high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). The results showed that monosaccharide glucose and fructose and disaccharide sucrose were the most important sugars in strawberry, while monosaccharide glucose, fructose, and galactose were the most important in blueberry. Source-sink relationship was different in strawberry compared to blueberry, having a much higher quantity of sugars in its fruits in relation to leaves. According to principal component analysis (PCA), galactose, arabinose, and melibiose were the most important sugars in separating the fruits of strawberries from blueberries, while panose, ribose, stachyose, galactose, maltose, rhamnose, and raffinose were the most important sugar component in leaves recognition. Galactitol, melibiose, and gentiobiose were the key sugars that split out strawberry fruits and leaves, while galactose, maltotriose, raffinose, fructose, and glucose divided blueberry fruits and leaves in two groups. PCA was difficult to distinguish between OP and IP, because the stress-specific responses of the studied plants were highly variable due to the different sensitivity levels and defense strategies of each cultivar, which directly affected the sugar distribution. Due to its high content of sugars, especially fructose, the strawberry cultivar 'Clery' and the blueberry cultivars 'Bluecrop' and 'Nui' could be singled out in this study as being the most suitable cultivars for OP.

Enzymatic Profile of 'Willamette' Raspberry Leaf and Fruit Affected by Prohexadione-Ca and Young Canes Removal Treatments.

The influence of growth regulator prohexadione-Ca (ProCa) concurrently with young canes removal on the modification of photosynthetic pigments content and antioxidant enzymes (peroxidase, POD; catalase, CAT; polyphenol oxidase, PPO; superoxide dismutase, SOD) activities in leaves and fruits of raspberry (Rubus idaeus L.) cultivar 'Willamette' was studied. ProCa increased while canes removal decreased chlorophylls and carotenoids content compared to control. POD, CAT, and PPO activities in leaves after removal of young canes were higher compared to control (2-4 times) which was visually confirmed for POD by isoelectrofocusing. Removal of young canes slithly increased, while ProCa significantly enhanced SOD activity in leaves compared to control (475.10 and 218.38 nkat mg-1 prot, respectively). Pattern of SOD activity in fruit was similar as in leaf with substantial increase compared to control (about 15 times). Combination of implemented measures increased activity of all enzymes in the leaves and fruits. Our study could provide a better knowledge of the ProCa and canes removal influences on the action of enzymes in order to regulate their activities in fruit products.

Variation in nutritional quality and chemical composition of fresh strawberry fruit: combined effect of cultivar and storage.

Bioclimatic air ionisation system (BI) works by neutralising air pollutants and microorganisms by means of oxidation with "activated oxygen". We investigated the effects of storage on changes in weight loss, chemical and sensory fruit properties in eight cultivars of strawberries (Fragaria x ananassa Duch.). All cultivars were evaluated for their standard parameters of quality (soluble solids content, total acidity, vitamin C content, total antioxidant activity - TAC, total phenolic and anthocyanins content) at different store conditions: fresh fruits-control, cold stored (at 4 °C) fruits without controlled atmospheres and cold stored (at 4 °C) fruits in BI. The present study outlines that anthocyanins of the strawberries stored in BI were subjected to significant degradation. These strawberries have prolonged shelf-life accompanied by weight loss reduction, TAC increment, and sensory properties improvement in tested cultivars, retaining other nutritional fruit qualities.

The influence of early yield on the accumulation of major taste and health-related compounds in black and red currant cultivars (Ribes spp.).

The focus of our study was to investigate the effect of crop load on the accumulation and composition of primary metabolites (sugars and organic acids), selected groups of flavonoids (anthocyanins and flavonols), and total phenolics in two subsequent years in four black currant cultivars ('Titania', 'Triton', 'Tsema', and 'Cacanska crna') and three red currant cultivars ('Junifer', 'Rolan', and 'Stanza'). For the determination and quantification of compounds, high-performance liquid chromatography-photodiode array with a mass spectrometer was used. Significant differences among cultivars were detected in all analyzed compounds. Anthocyanins were the predominant phenolic group and were more abundant in black currant cultivars as compared to red ones. Similar amounts of sugars and organic acids were measured in both Ribes species; however, vitamin C was 3-fold higher in black currants. A larger crop load in the second year had a negative effect on the sugar content of berries and promoted a higher degree of acids, with the exception of vitamin C, which was higher in the year with a lower crop load. On the other hand, the content of anthocyanins and flavonols was higher in the year with a larger crop load, while there were no differences in total phenolic content.