Total polyphenols, total anthocyanins, and reduced ascorbic acid were evaluated in berries belonging to the genera Rubus, Ribes, and Aronia by means of spectrophotometric and high-performance liquid chromatography (HPLC) techniques. The 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical scavenging activity of the fruit extracts was tested. Total polyphenols ranged from 140.6 to 888.5 mg/100 g fresh weight (FW ), total anthocyanins ranged from 22.0 to 460.5 mg/100 g FW, and reduced ascorbic acid ranged from 12.4 to 153.8 mg/ 100 g FW. The average EC 50 values for Aronia melanocarpa, Ribes nigrum, Ribes rubrum, Rubus fruticosus, and Rubus idaeus were 1.8, 2.8, 5.3, 6.4, and 8.2 mg FW, respectively. The results indicate that the fruits tested are good sources of natural antioxidants.
Propolis is one of the most fascinating honey bee (Apis mellifera L.) products. It is a plant derived product that bees\ud
produce from resins that they collect from different plant organs and with which they mix beeswax. Propolis is a building\ud
material and a protective agent in the bee hive. It also plays an important role in honey bee social immunity, and is\ud
widely used by humans as an ingredient of nutraceuticals, over-the-counter preparations and cosmetics. Its chemical\ud
composition varies by geographic location, climatic zone and local flora. The understanding of the chemical diversity of\ud
propolis is very important in propolis research. In this manuscript, we give an overview of the available methods for\ud
studying propolis in different aspects: propolis in the bee colony; chemical composition and plant sources of propolis;\ud
biological activity of propolis with respect to bees and humans; and approaches for standardization and quality control\ud
for the purposes of industrial application
Cannabis sativa L. is a dioecious plant belonging to the Cannabaceae family. The main phytochemicals that are found in this plant are represented by cannabinoids, flavones, and terpenes. Some biological activities of cannabinoids are known to be enhanced by the presence of terpenes and flavonoids in the extracts, due to a synergistic action. In the light of all the above, the present study was aimed at the multi-component analysis of the bioactive compounds present in fibre-type C. sativa (hemp) inflorescences of different varieties by means of innovative HPLC and GC methods. In particular, the profiling of non-psychoactive cannabinoids was carried out by means of HPLC-UV/DAD, ESI-MS, and MS2. The content of prenylated flavones in hemp extracts, including cannflavins A and B, was also evaluated by HPLC. The study on Cannabis volatile compounds was performed by developing a new method based on headspace solid-phase microextraction (HS-SPME) coupled with GC-MS and GC-FID. Cannabidiolic acid (CBDA) and cannabidiol (CBD) were found to be the most abundant cannabinoids in the hemp samples analysed, while β-myrcene and β-caryophyllene were the major terpenes. As regards flavonoids, cannflavin A was observed to be the main compound in almost all the samples. The methods developed in this work are suitable for the comprehensive chemical analysis of both hemp plant material and related pharmaceutical or nutraceutical products in order to ensure their quality, efficacy, and safety.
The composition and antioxidant activity of Italian poplar
propolis
obtained using three harvesting methods and extracted with different
solvents were evaluated. Waxes, balsams, and resins contents were
determined. Flavones and flavonols, flavanones and dihydroflavonols,
and total phenolics were also analyzed. To characterize the phenolic
composition, the presence of 15 compounds was verified through HPLC-MS/MS.
The antioxidant activity was evaluated through 1,1-diphenyl-2-picrylhydrazyl
radical and reducing power assays. The ability of propolis to inhibit
lipid oxidation was monitored by analyzing hydroperoxide and TBARS
formation in lipids incorporated into an oil-in-water (O/W) emulsion.
Acetone shows the highest extraction capacity. Wedge propolis has
the highest concentration of active phenolic compounds (TP = 359.1
± 16.3 GAEs/g; TFF = 5.83 ± 0.42%; TFD = 7.34 ± 1.8%)
and seems to be the most promising for obtaining high-value propolis
more suitable to prepare high-quality dietary supplements (TBARS =
0.012 ± 0.009 mmol std/g; RP = 0.77 ± 0.07 TEs/g).
The importance of honey adulteration detection has recently increased owing to the limited production levels in recent years and the relative high price of honey; therefore, this illegal practice has become more and more attractive to producers. Hence, the need has arisen for more effective analytical methods aiming at detecting honey adulteration. The present research presents an effective method to detect adulteration in honey falsified by intentional addition of different concentrations of commercial sugar syrups, using one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) coupled with multivariate statistical analysis. Sixty-three authentic and 63 adulterated honey samples were analyzed. To prepare adulterated honeys, seven different sugar syrups normally used for nutrition of bees were used. The best discriminant model was obtained by 1D spectra, and leave-one-out cross-validation showed a predictive capacity of 95.2%. 2D NMR also furnished acceptable results (cross-validation correct classification 90.5%), although the (1)H NMR sequence is preferable because it is the simplest and fastest NMR technique.
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