Hazelnut shells represent a waste material (about 42% of the total biomass) deriving from hazelnut harvest. These are mainly used as a heating source; however, they represent an interesting source of polyphenols useful in health field. The impact on phenolic profile and concentrations of hazelnut shell extracts obtained by three extraction methods (maceration, ultrasonic bath, and high-power ultrasonic), as well as temperature, extraction time, and preventive maceration, was studied. The prepared extracts were characterized in terms of chemical composition, antioxidant and antimicrobial activities. Eighteen different phenolic compounds were identified and quantified by chemical analysis and gallic acid was the most abundant in all the extracts analyzed. Other relevant compounds were chlorogenic acid, protocatechuic acid and catechin. Preventive maceration had a positive effect on the extraction of different types of compounds regardless of the method performed. Application of the high-power ultrasonic method had different effects, either positive or negative, depending on the type of compound and extraction time. All the prepared extracts showed antioxidant activity especially those prepared by maceration, and many of them were able to inhibit the growth of both B. subtilis and B. cereus.

Polyphenols (PCs) are a numerous class of bioactive molecules and are known for their antioxidant activity. In this work, the potential of the quadrupole/linear ion trap hybrid mass spectrometer (LIT-QqQ) was exploited to develop a semi-untargeted method for the identification of polyphenols in different food matrices: green coffee, Crocus sativus L. (saffron) and Humulus lupulus L. (hop). Several conjugate forms of flavonoids and hydroxycinnamic acid were detected using neutral loss (NL) as a survey scan coupled with dependent scans with enhanced product ion (EPI) based on information-dependent acquisition (IDA) criteria. The presented approach is focused on a specific class of molecules and provides comprehensive information on the different conjugation models that are related to specific base molecules, thus allowing a quick and effective identification of all possible combinations, such as mono-, di-, or tri-glycosylation or another type of conjugation such as quinic acid esters.

The aim of the present work was to evaluate if the use of grape pomace (GP) in the feeding of dairy ewes can improve the content of phenolic compounds (PCs) in the milk and affect the anti-inflammatory and antioxidative status of the milk. For this purpose, 46 ewes were randomly assigned to two groups of 23 animals each: a control group (Ctrl) that received a standard diet and an experimental group (GP+), whose diet was been formulated with 10% GP on a dry matter (DM) basis. At the end of the 60 days of the trial, from 10 ewes selected randomly from each group, individual milk samples were collected and analyzed for the identification and the quantification of phenolic compounds through an ultra-high-performance liquid chromatography system, and milk anti-inflammatory and antioxidative status were evaluated by enzyme-linked immunosorbent assay, determining the activity of GPx and CAT and the levels of IL-1 and TNFα. In addition, gelatinolytic activity of Type IV collagenases (MMP-2/MMP-9) was evaluated by the fluorometric method and zymographic approach. The results obtained showed that the diet with GP affects the phenolic profile of milk, inducing milk enrichment of phenolic compounds without, however, having a significant impact on milk antioxidant and inflammatory status. However, a lower activity of MMP-9 was found in GP+ milk. The use of the molecular docking approach showed the ability of luteolin to approach the catalytic pocket of the enzyme, interfering with the recruitment of the substrate, and therefore, slowing down their hydrolytic activity.

This work was aimed at investigating the effects of rate and timing of nitrogen fertilization applied to a maternal wheat crop on phytochemical content and antioxidant activity of edible sprouts and wheatgrass obtained from offspring grains. We hypothesized that imbalance in N nutrition experienced by the mother plants translates into transgenerational responses on seedlings obtained from the offspring seeds. To this purpose, we sprouted grains of two bread wheat cultivars (Bologna and Bora) grown in the field under four N fertilization schedules: constantly well N fed with a total of 300 kg N ha⁻¹; N fed only very early, i.e., one month after sowing, with 60 kg N ha⁻¹; N fed only late, i.e., at initial shoot elongation, with 120 kg N ha⁻¹; and unfertilized control. We measured percent germination, seedling growth, vegetation indices (by reflectance spectroscopy), the phytochemical content (total phenols, phenolic acids, carotenoids, chlorophylls), and the antioxidant activity (by gold nanoparticles photometric assay) of extracts in sprout and wheatgrass obtained from the harvested seeds. Our main finding is that grains obtained from crops subjected to late N deficiency produced wheatgrass with much higher phenolic content (as compared to the other N treatments), and this was observed in both cultivars. Thus, we conclude that late N deficiency is a stressing condition which elicits the production of phenols. This may help counterbalance the loss of income related to lower grain yield in crops subjected to such an imbalance in N nutrition.

Polyphenols are phytochemicals naturally present in wines that arouse much interest in the scientific community due to their healthy properties. In addition, their role as descriptors of various wine qualities, such as the geographical origin or the grape variety, cannot be underestimated. Here, Pinot Noir and Xarel·lo monovarietal samples belonging to the sparkling wine production process have been studied, corresponding to base wines from a first alcoholic fermentation (plus malolactic in some cases), base wines resulting from tartaric stabilization, and sparkling wines from a second alcoholic fermentation aged for 3 and 7 months. One of the objectives of this paper is to obtain valuable chemical and oenological information by processing a huge amount of data with suitable chemometric methods. High-performance liquid chromatography coupled with ultraviolet spectroscopy and tandem mass spectrometry (HPLC-UV-MS/MS) has been used for the determination of polyphenols in wines and related samples. The method relies on reversed-phase mode and further detection by multiple reaction monitoring. Concentrations of relevant phenolic compounds have been determined, and the resulting compositional data have been used for characterization purposes. Exploratory studies by principal component analysis have shown that samples can be discriminated according to varietal and quality issues. Further classification models have been established to assign unknown samples to their corresponding classes. For this purpose, a sequential classification tree has been designed involving both variety and quality classes, and an excellent classification rate has been achieved.

This study investigated the phytochemical content of melon sprouts obtained from by-product seeds of fruit processing and the elicitation effect obtained by the application of salinity to the growing substrate. Seeds from two melon Cultivars (Thales and SV9424ML) were sprouted at 0, 12.5, 25, and 50 mM NaCl concentrations (Salt). Due to intra-lot seed variability in germination speed, sprouts were harvested at 1 and 2 weeks after sowing (WAS), included as an experimental factor (Harvest), collecting, at each harvest, only those that had reached the ready-to-eat stage. Seed germination, shoot and root lengths, fresh and dry weights, and their content in phenolic compounds were determined. Cultivar, Harvest, and Cultivar × Harvest interaction affected sprout phenolic compound content more than Salt. In general, Thales exhibited a significantly greater phenolic compound content (+67.9%, on average). Harvest influenced phytochemicals, with sprouts at 2WAS exhibiting lower flavonoid and hydroxybenzoic acid levels (−31.3% and −73.0%, respectively), yet higher hydroxycinnamic acid content (+298.6%). This was a consequence of variations in p-coumaric and ferulic acids at 2WAS and in flavonoids at 1WAS. Moreover, Salt had an appreciable effect only on Thales, at moderate levels (25 mM NaCl). Our results suggest that the sprouting of by-product seeds of vegetables should be finely modulated based on the seed intra-lot variability in germination speed and on cultivar responsiveness to salinity for phytochemical elicitation.