Changing the content of phenolic compounds as the response of blackcurrant (Ribes nigrum L.) leaves after blackcurrant leaf midge (Dasineura tetensi Rübs.) infestation

Lignocellulosic Waste Compounds for Pancreatic Lipase Inhibition: Preliminary Extraction by Freon, Obtaining of Proanthocyanidins and Testing on Lipase Activity

The twigs of sea buckthorn, blackcurrant, gooseberries, quince, and grapes were evaluated as a promising source of biologically active compounds-proanthocyanidins (PACs). Sea buckthorn twigs had the highest content of PACs (9.2% on dry biomass). Preliminary pretreatment of biomass with freon R134a did not allow an increase in PACs content in the composition of hydrophilic extract but confirmed the value of freon extract as an antibacterial agent against P. aeruginosa and B. cereus. The content of PACs was used as an indicator for assessment of the influence of hydrophilic extracts on pancreatic lipase activity. Under normal physiological conditions, in the presence of bile, the extract, which contained 42.4% of PACs was more effective compared to the extract which contained 17.5% of PACs. At all concentrations (0.2-40 mg of sample/g of pancreatic lipase), it inhibited lipase activity by 33%. Purified PACs were the most effective in inhibiting lipase activity (by 36%). However, in pathological physiological conditions (without bile), the opposite effect on lipase activity was observed. Thus, PACs and extracts can be used as inhibitors of pancreatic lipase only under normal physiological conditions.

Assessment of Infestation of Selected Blackcurrant (Ribes nigrum L.) Genotypes by the Blackcurrant Leaf Midge (Dasineura tetensi Rübs.) in Poland

Simple Summary

Dasineura tetensi is a widespread blackcurrant pest. The susceptibility of blackcurrant genotypes to leaf midge colonization was assessed to select the genotypes least susceptible to be used as parents in the breeding. Experiments were conducted between 2012–2014 in Poland. Percentage shoot damage, and number of eggs and larvae were assessed for each genotype. Among tested blackcurrant genotypes, none were found to be completely resistant to this pest. However, some genotypes (Big Ben, Nr 8/72, Ben Connan, Ben Alder, Ben Hope, Foxendown, Ben Nevis, Fariegh, Ojebyn, and Ben Tirran) were colonized by the pest below the threshold level (10%); proving tolerance to the pest. The fewest pest eggs were recorded on the genotypes Big Ben, Ben Connan, Ben Alder, and Ben Nevis, and out of these Big Ben, Nr 8/72, Ben Connan, and Foxendown had the least larvae recorded.

Abstract

Blackcurrant leaf midge (Dasineura tetensi) is a widespread pest of blackcurrant. Attacks by this pest can cause up to 60% reduction in the growth of shoots resulting in yield decreases. Our study, conducted (2012–2014) in Poland, aimed to assess the susceptibility of blackcurrant genotypes to D. tetensi, in order to select genotypes as parental lines for breeding new blackcurrant genotypes. Among tested blackcurrant genotypes, none were found to be completely resistant to this pest. The pest colonized genotypes Big Ben, Nr 8/72, Ben Connan, Ben Alder, Ben Hope, Foxendown, Ben Nevis, Fariegh, Ojebyn, and Ben Tirran below the threshold level (10%). In contrast, genotypes Nr 7/15, Ben Lomond, Ben Finlay, Tisel, Polares, Polonus, Tiben, PC-110, Polben, Gofert, Ruben, and Ores suffered pest levels above the threshold. With regard to egg numbers, the fewest were recorded on genotypes Big Ben, Ben Connan, Ben Alder, and Ben Nevis, and the most on Gofert and Ores. Fewer larvae were recorded on genotypes Big Ben, Nr 8/72, Ben Connan, and Foxendown compared to Ben Lomond, PC-110, Gofert, Tiben, Polben, and Ores. Developing blackcurrant genotype resistance to leaf midge strongly supports the IPM strategy.

Phenolic composition, antioxidant capacity and physical characterization of ten blackcurrant (Ribes nigrum) cultivars, their juices, and the inhibition of type 2 diabetes and inflammation biochemical markers

The objective was to analyze the phenolic composition, antioxidant capacity, and physical characteristics of 10 blackcurrant cultivars, their juices, and the enzymatic inhibition of dipeptidyl peptidase-IV, α-amylase, α-glucosidase, nitric oxide synthase, and cyclooxygenase-2. Fruit masses ranged from 0.47 to 1.22 g and diameters from 7.42 to 14.42 mm. For the juices, pH ranged from 2.80 to 2.96, soluble solids from 11.33% to 17.5%, total acidity from 3.17 to 4.26 g/100 mL, and viscosity from 1.28 to 273.83 mPa·s. Total anthocyanins (TA) ranged from 1.81 to 5.48 mg eq cyanidin 3-O-glucoside/100 g, total polyphenols (TP) from 7.67 to 39.70 mg eq gallic acid/100 g, total condensed tannins from 3.24 to 7.76 g eq catechin/100 g, and antioxidant capacity from 219.24 to 499.26 μmol eq Trolox/100 g. Juices of the cultivars Coronet and Consort contained the highest levels of TA, TP, and antioxidants. Whistler cultivar contained high concentrations of major anthocyanins. Juices from all cultivars favorably inhibited the activities of enzymes used as surrogate biochemical markers for T2 diabetes and inflammation.

Detection and comparison of phenolic compounds in different extracts of black currant leaves by liquid chromatography coupled with high-resolution ESI-LTQ-Orbitrap MS and high-sensitivity ESI-Qtrap MS

Liquid preparations such as tinctures and infusion derived from Ribes nigrum L. (black currant) leaves are widely used in Europe. Despite the various uses reported for the infusion and hydroalcoholic extracts of the leaves of this species, their chemical profile has not yet been defined. In the present study, the infusion, hydroalcholic and methanolic extracts prepared from R. nigrum leaves were analyzed. LC-MS analyses of these extracts allowed the characterization of 31 phenolic compounds mainly belonging to organic acids, flavonoids, catechins and its oligomers. Quantitative results proved that these preparations are a rich source of polyphenols and flavonoids and among them the infusion presented the highest polyphenol levels. A metabolomics approach was also used for the comparison and evaluation of the chemical composition of the different extracts obtained from R. nigrum leaves.