Effect of harvest time on some in vitro functional properties of hop polyphenols

Health benefits of hop polyphenols are well studied. In the present investigation, we examined the antioxidant activity, anti-nitric oxide (NO) production, and anti-adipocyte differentiation of polyphenols extracted from hops (HPP), harvested at different times for over 4years. Saaz hop variety from the Czech Republic was used in the in vitro assays. Twenty-three polyphenols were quantitatively analyzed using Orbitrap liquid chromatography-mass spectrometry (LC-MS), and their health promoting effects were assayed individually. Strong effects of low concentrations of HPP were observed in the above three assays. A significant increase in anti-adipocyte differentiation activity per unit weight of HPP was obtained in the early harvested samples. A significant difference in anti-NO production activity per unit weight of HPP was observed among the different harvest years. HPP significantly increased in early harvested samples. Our results suggest that some in vitro functional properties of hops vary with harvest time and year and are dependent on different polyphenols.

Optimizing geographical traceability models of Chinese Lycium barbarum: Investigating effects of region, cultivar, and harvest year on nutrients, bioactives, elements and stable isotope composition

Lycium barbarum is a type of "medicine-food homology" whose geographical origin has attracted strong interest from consumers due to different regional quality characteristics. A sophisticated OPLS-DA model to verify Lycium barbarum origin was developed using 266 samples gathered from five cultivars in two regions between 2020 and 2022, which was based on 67 indices, including nutrients, bioactives, elements and stable isotopes. Twelve variables (fructose, δ2H, glucose, tartaric acid, Mo, Na, Sr, His, Phe, Mn, Lys and Rb) were selected to refine models that could distinguish Lycium barbarum origin without being impacted by cultivar or year. The model of training set and testing set samples had discrimination rates of 100 % and 94.71 % to 98.28 %, suggesting an optimized multi-variate analysis strategy using OPLS-DA model could correctly predict the origin of blind Lycium barbarum samples. This study provides new evidence for constructing a reliable traceability model for the geographical origins of Lycium barbarum.

Verification of the age of 10- and 20-year-old Tawny Port wines using Radiocarbon

Port is a famous sort of fortified wine, exclusively produced in the Douro region of Portugal. Among the various types of Port wines, the Tawny types with stated maturation ages of 10 or 20 years are among the higher quality and more expensive ones. Fraudulently producing those with a shorter maturation time than claimed, along with additions or treatments to mask this, would make production of those wines cheaper. Here, we present a method, based on Radiocarbon (14C) age determination of the ethanol and the sugar residue, to verify the maturation time of such Port wines. We successfully verified the method using single harvest year "Vintage" Port wines. We then analyzed a total of twenty 10- and 20-year-old Tawny Port wines, bought at various retail stores in the Netherlands. We found that seven of those had a significantly shorter maturation age than claimed on the label.