In hop cultivation, one-third of the crop is a valuable product (hop cones), and two-thirds is unexploited biomass, consisting mainly of leaves and stems, which, in a circular economy approach, can ...be recovered and, once stabilized, supplied to industrial sectors, such as cosmetics, pharmaceuticals and phytotherapy, with high added value. In this regard, this study aimed to investigate the effects of two different drying methods: oven drying (OD) at 45 °C and freeze-drying (FD), on the overall nutraceutical profile (i.e., total phenols, total flavans and total thiols), pigment content (i.e., carotenoids and chlorophylls) and the antioxidant potential of leaves from five different
varieties grown in central Italy. Moreover, attenuated total reflectance infrared (ATR-FTIR) spectroscopy was applied to dried leaf powders to study the influence of both the variety and treatment on their molecular fingerprints. The spectral data were then analyzed by principal component analysis (PCA), which was able to group the samples mainly based on the applied treatment. Considering the overall phytochemical profile, FD appeared to be the most suitable drying method, while OD provided higher carotenoid retention, depending on the genotype considered. Finally, unsupervised chemometric tools (i.e., PCA and hierarchical clustering) revealed that the two main clusters contained subclusters based on the drying treatment applied; these subgroups were related to the susceptibility of the variety to the drying conditions studied.
This study investigated the use of conventional and innovative extraction methods to produce food-grade hop extracts with high antioxidant capacity and content in bioactive compounds. Conventional ...extractions (CONV) were performed under dynamic maceration at 25 and 60 °C; innovative extractions were performed using two ultrasound systems, a laboratory bath (US) and a high-power ultrasound bath (HPUS), and a high-pressure industrial process. For CONV, US, and HPUS extractions the effect of the extraction time was also tested. Experimental results showed that extraction method, temperature, and time affect to a different extent the phenolic profile and have a significant effect (
< 0.05) on the total phenolic content, total flavonoid content, antiradical capacity (ABTS), chlorophyll
, and total carotenoids content. Overall, US and CONV 60 °C extractions showed the highest extraction efficiency for almost all the investigated compounds, however, the extraction method and time to be used strongly depends on the target compounds to extract.
Nowadays, there is a growing interest in botanicals for human nutrition and care.
wild berries are edible and medicinal fruits that contain many healthy bioactive components, which can be considered ...a valuable resource for the food ingredient market and for nutraceutical and cosmetic sectors. In the present study, the polyphenols and in vitro antiradical and hypoglycemic activities of five wild Italian accessions of
were investigated, and their chemical profiles were treated by means of unsupervised chemometric techniques like the hierarchical and principal component analysis. Moreover, Fourier-transformed mid-infrared spectroscopy was used to provide a rapid assessment of the phytochemical composition of different accessions. Samples differed mainly in their anthocyanin content and overall nutraceutical potential. Anthocyanins were present mainly as glycosides of cyanidin and delphinidin, with delphinidin-3-O-glucoside being the most abundant one, ranging from 49 ± 1 to 111 ± 3 mg g
(for P1 and P2, respectively;
< 0.05). Extracts were screened for their in vitro biological activities by using the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS
), 2,2-diphenyl-1-picrylhydrazyl (DPPH
) antiradical tests, while their hypoglycemic activity was investigated by the α-glucosidase inhibition test. In both in vitro antiradical tests, the highest capacity was recorded for P2 (EC
: 1.17 and 0.064 mg mL
, for DPPH
and ABTS
, respectively), with values higher than those reported in the literature for
fruit extracts. P2 also showed the highest inhibition power towards α-glucosidase (about 70%). Moreover, the nonparametric correlation analysis pointed out a very high significant correlation between the percentage of α-glucosidase inhibition and cyanidin-3-O-rutinoside (r: 0.973;
< 0.01). Finally, the application of hierarchical analysis to samples analyzed provided three different clusters based on the average phytochemical content coded as low, medium and high. Moreover, principal component analysis made it possible to establish similarities among the accessions depending on their overall nutraceutical characteristics and on the relative anthocyanin content.
In this work, an innovative coating strategy that is able to prolong the shelf-life of fresh-cut kiwifruit was proposed, and the effectiveness of the procedure was evaluated for a period of ten days ...under cold storage (4 °C). Alginate (2%
/
) functionalized with green extracts from hop (
L.) cones (HE; 0.5 and 1%,
/
) was used as a coating material in order to assess the best performing strategy, leading to the most stable product. At the concentrations used to formulate the edible coatings, no contribution related to hop bitterness on the final product was recorded. The results were compared to control samples (without edible coating and coated only with alginate at 2%
/
). The plant extract was characterized by its main chemical traits and by
H NMR profiling, revealing the presence of antioxidant and antimicrobial bioactive compounds (i.e., alpha and beta hop acids, xanthohumol). Furthermore, the characteristics of the samples during cold storage were evaluated by physico-chemical (i.e., weight loss, soluble solid content, titratable acidity, pH, color attributes) and nutraceutical (i.e., total polyphenol, ascorbic acid content, total carotenoids, chlorophylls) traits. The results showed that the incorporation of hop extracts into the edible coatings tested was able to preserve the quality and nutraceutical traits of fresh-cut kiwifruit during cold storage, thus prolonging their shelf life and marketability.
The present study aimed to chemically and sensorially characterize hop samples, cv Cascade, grown in two different Italian regions (Latium and Tuscany) as well as their derived beers by a multi ...analytical approach. Significant differences in bitter acid, oil and polyphenol content were observed for hop samples according to their origin. Gas chromatography-olfactometry analysis pointed out floral notes for Tuscany samples, where hops from Latium were characterized by spicy and resinous notes, correlated to the presence of sesquiterpenes. Differences in the molecular fingerprinting were also highlighted by Fourier–Transform Infrared Spectroscopy. The differences found in the hops were reflected in the beers, which were clearly recognized as distinct by a sensory panel. Both beer samples were mainly characterized by six aroma compounds (linalool, geraniol and β-damascenone, citronellol, 2-phenylethyl acetate, and 2-phenylethanol), three of which were potentially responsible for the geographic origin of the hops given their significantly different concentrations.
•Lactic acid-based eutectic mixtures were studied for hop’s active compounds recovery.•Structural analysis was performed by FTIR and Raman spectroscopic techniques.•Eutectic mixtures improved the ...extraction efficiency of hop’s bioactive compounds.•The highest antimicrobial activity was recorded against P. aeruginosa.
In the present study, natural deep eutectic solvents were used to increase the extraction efficiency (EE) of bioactive compounds from hop (Humulus lupulus L) cones under ultrasounds irradiation. Three lactic acid-based deep eutectic solvents (namely LaDES) were developed, physicochemical characterized and their EE values compared with those of a control extract, obtained using aqueous methanol (80%) acidified with HCl (0.1%). The supramolecular organization of LaDES and their extracts were analysed using FTIR spectroscopy and Raman spectroscopy to clarify the interactions among LaDES components and between LaDES and the bioactive components of the plant matrix. The phytochemical profiles of green extracts were evaluated using both spectrophotometric assays and HPLC-DAD analysis and the results were compared with those from the control samples. Among the different combinations of LaDES tested, lactic acid: sucrose showed the highest EE against hop bitter acids (α-acids: 8.9 ± 0.1% w/w; β-acids: 3.2 ± 0.3% w/w), while lactic acid: urea extracted more non-phenolic pigments (total chlorophyll: 8.79 ± 0.09 mg g−1 d.b.; total carotenoids: 2.22 ± 0.02 mg g−1 d.b.) than the other two LaDES combinations and control. Polyphenols were better extracted by lactic acid: glycine than the other solvents tested (71.2 ± 0.1 mg gallic acid equivalents g−1 d.b.), also showing the highest antiradical potential against both ABTS+ and DPPH (EC50_ABTS: 0.63 ± 0.01 μg; EC50_DPPH: 69 ± 2 μg). Finally, all LaDES inhibited both Gram- positive and negative bacteria, while non activity was recorded against tested yeasts.
•Green methods to obtain hop extracts rich in bioactive compounds were proposed.•Efficiency of ultrasound- and microwave-assisted extraction of hops were compared.•Microwave-assisted extraction with ...ethanol produced 2.5 times more xanthohumol than ultrasounds.•1H-NMR fingerprinting of hop green extracts was carried out.•Trigonelline was identified in the hop aqueous extracts.
Currently, there is a continuous growth in demand for medicinal and aromatic plant derived molecules obtained in a sustainable and eco-friendly way. Among the medicinal plants that have a plethora of health-related properties, there is definitely hops. In the present study, microwaves (MW) and ultrasounds (US) were used to increase the extraction efficiency of bioactive compounds from hop cones using water, ethanol and their mixture as food-grade solvents. A multidisciplinary approach was used for the in-depth characterization of green extracts. The bioactive components were determined by chemical methods, using both spectrophotometric assays as well as high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis of individual phenols, bitter acids and xanthohumol, and results were compared with those from a control extract, obtained using aqueous methanol (80 %) acidified with HCl (0.1 %). Moreover, we applied proton nuclear magnetic resonance (1H-NMR) spectroscopy to reveal insights on the different composition in terms of primary and secondary metabolites of the green extracts analyzed. Generally, microwave-assisted extraction (MAE) of hop cones with ethanol showed the strongest extraction power for almost all the bioactive compounds investigated, as well as the shortest extraction time (1 min) and the highest antiradical capacity. 1H-NMR analyses showed an overall greater influence of solvent polarity, rather than extraction technique, on the average composition of the final extract. 1H-NMR fingerprinting of hop aqueous extracts highlighted as main components sugars and amino acids, as well as other metabolites including trigonelline, an alkaloid with interesting biological properties. However, the two extraction techniques significantly affected the contribution of signals in the terpene or aromatic regions when ethanol and ethanol:water were used as solvents, proving a better extraction efficiency for these compounds of MW than US. Regardless the extraction technique and solvent used, the most abundant polyphenol compound in the green extracts analyzed was catechin, ranging from 2989 ± 10 to 14009 ± 248 μg g−1 (for UAEETOH and MAEETOH, respectively), followed by rutin and chlorogenic acid. 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-Azinobis 3-ethylbenzothiazoline-6-sulfonic acid-diammonium salt (ABTS) radical scavenging methods were used to evaluate the biological properties of green hop extracts, showing a superior free-radical scavenging capacity in MW irradiated ethanol samples compared to other samples tested. The inter-relationships between the parameters analyzed and the different extraction conditions, as well as the relationships among variables, were investigated by principal component analysis.
Hop extracts represent a natural alternative to synthetic food additives because of their high content of bitter acids and volatile organic compounds (VOCs) with bittering, flavoring, and ...antimicrobial properties. However, broader uses of hop extracts as natural techno‐functional ingredients rely on the identification of sustainable and affordable extraction technologies allowing to diversify the processes and produce extracts characterized by different compositions and, consequently, qualitative properties.
Thus, this study is aimed to evaluate and compare the effect of innovative and conventional extraction methods on the bitter acids content and VOCs pattern of food‐grade ethanolic hop extracts for food applications.
Innovative extractions were carried out by using two ultrasound systems (a laboratory bath US and a high‐power ultrasound bath HPUS), and a high‐pressure industrial process (high hydrostatic pressure HHP). Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60°C; for ultrasound and conventional methods, the effect of the extraction time was also investigated.
Among the extracts, the highest and lowest content of bitter acids was found in CONV 60°C extracts, and HHP and CONV 25°C extracts, respectively. Of the 34 VOCs identified in dry hops, ∼24 compounds were found in US, HPUS and CONV extracts, while only 18 were found in HHP. CONV extractions showed higher selectivity for sesquiterpenes, while US and HPUS showed higher selectivity for esters and monoterpenes. Hierarchical cluster analysis (HCA) and partial least squares‐discriminant analysis (PLS‐DA) allowed classifying hop extracts based on the extraction methods and also allowed highlighting the technological conditions to produce hop extracts with specific techno‐functional and flavoring properties.
Practical Application
The study showed that different extraction methods can lead to hop products with varying sensory and functional properties. By selecting the right extraction method, companies can produce hop extracts with specific compositions that meet their needs for clean label and sustainable food products, as well as new edible packaging or coatings.
A sustainable approach for the green synthesis of silver nanoparticles (AgNPs) using an aqueous extract of hyperpigmented tomato (Solanum lycopersicum L) skins (HTS) was described. AgNPs ...characterization and catalytic activity in the degradation of methylene blue were reported. The influence of some experimental parameters on synthesis, such as green extract concentration, pH, microwave irradiation time, as well as stabilization time, was investigated. HTS extract was initially characterized regarding its reducing potential, Fourier Transform Infrared (FTIR) molecular fingerprinting and 1H NMR metabolite profiling and then used as a reducing-stabilizing agent for the green synthesis of AgNPs. Furthermore, a comparative study, with chemically synthetized AgNPs, was carried out and the catalytic activity of synthesized nanoparticles in the reduction of methylene blue was studied by UV–visible spectrophotometer. Obtained AgNPs were analyzed by ultraviolet–visible spectroscopy, FTIR, scanning electron microscopy and electrochemical analyses (cyclic and anodic stripping voltammetry). In general, obtained AgNPs were spherical in shape, with a diameter ranging from 21 to 93 nm, and very stable over time. Interestingly, a red shift of the surface plasmon resonance of green nanoparticles was observed as the volume of the HTS extract increased. Lastly, an improved catalytic activity in the reduction of methylene blue was detected in the case of green synthesized nanoparticles, with respect to those conventionally produced.
•Hyperpigmented tomato skins were used for silver nanoparticles production.•Hyperpigmented tomato skin extracts were analyzed by spectroscopic and chromatographic analyses.•Reducing sugars are the major reducing components in the extracts.•Obtained silver nanoparticles were fully characterized.•Green nanoparticles showed better catalytic properties than chemically synthetized counterparts.
To investigate human babesiosis in the Bolivian Chaco, in 2013 we tested blood samples from 271 healthy persons living in 2 rural communities in this region. Microscopy and PCR indicated that 3.3% of ...persons were positive for Babesia microti parasites (US lineage); seroprevalence was 45.7%. Appropriate screening should mitigate the risk for transfusion-associated babesiosis.
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