Productivity and nutritional and nutraceutical value of strawberry fruits (Fragaria x ananassa Duch.) cultivated under irrigation with treated wastewaters

Electrochemical sensors based on sewage sludge-derived biochar for the analysis of anthocyanins in berry fruits

The reutilization of waste and the reduction of the general environmental impact of every production are fundamental goals that must be achieved in the framework of a circular economy. Recycled carbon-rich materials may represent a promising alternative to other less-sustainable carbonaceous materials used in the production of electrochemical sensing platforms. Herein, we propose an innovative carbon paste electrode (CPE) composed of biochar derived from biological sludge obtained from municipal and industrial wastewater treatment plants. The physicochemical properties of the biochar after a chemical treatment with an acidic solution obtained from industrial by-products were investigated. The electrode surface characterization was carried out by analyzing common redox probes and multiple phenols bearing varying numbers of –OH and –OCH₃ groups in their structure. Furthermore, the CPE was also tested on the evaluation of the phenolic fingerprints of Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Fragaria × ananassa. Standard anthocyanin mixtures and extracts of the aforementioned fruits were analyzed to provide a phenolic characterization of real samples. The obtained results show that the sewage sludge–derived biochar can be a promising material for the development of electroanalytical sensors.

Optimization and Validation of a Method Based on QuEChERS Extraction and Gas Chromatographic-Mass Spectrometric Analysis for the Determination of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls in Olive Fruits Irrigated with Treated Wastewaters

The wastewater reuse is an important measure to face water shortage, thus improving the resilience of agricultural production chains. However, treated wastewater can contain residual organic micropollutants residues that may result in crop contamination. Among edible crops, olive is the most important agricultural product in the Mediterranean region. Methods to assess the contamination of organic micropollutants such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in olives are poorly investigated. Given the complexity of olives, this study focused on the development and validation of a method for the simultaneous extraction of PAHs and PCBs from olives, and subsequent analysis by gas chromatography coupled with mass spectrometry detection. Extraction was optimized through a QuEChERS protocol, studying the effect of the extraction solvent (CH2Cl2, cyclohexane, CH3CN) and of the dispersive-solid phase extraction (d-SPE) sorbent (octadecyl silica, Florisil, primary secondary amine, Z-Sep) on the recovery of micropollutants. The best recoveries (94–122%, relative standard deviations below 5%) were obtained using CH3CN/H2O and a double purification step with Z-Sep and Florisil. The method developed for PAHs and PCBs, which showed good intra-day (<2.7%) and inter-day (<2.9%) precision and low matrix effect (|ME| < 14%), was applied to the analysis of olives grown by irrigation with reclaimed wastewaters.

Colorimetric selective quantification of anthocyanins with catechol/pyrogallol moiety in edible plants upon zinc complexation

Here is examined the colour development from common anthocyanins (i.e., cyanidin, delphinidin, malvidin, and pelargonidin glycosides) and from anthocyanins-rich extracts (i.e., bilberries, strawberries, and raspberries), using zinc-anthocyanin complexes as molecular probe. We have observed the absorbance increase in the blue region in presence of large excess of zinc ion at acidic pH for cyanidin and delphinidin derivatives, likely due to quinoidal base stabilization from catechol and pyrogallol moiety. The assay condition were studied and applied to natural extracts containing these compounds. The same behaviour was observed for bilberry and, to a minor extent, for raspberry extracts, due to the larger cyanidin/delphinidin contents in the former than in the latter. Anthocyanin standard UV-Vis analysis in buffer has shown a very good linear correlation for cyanidin and delphinidin (R² = 0.995 and 0.997, respectively), good precision (CV% = 7.4% and 5.3% respectively), high sensitivity (Cyε_600nm = 8300 M^-1 cm^-1, LOD = 0.264 ± 0.005 mg L^-1, LOQ = 0.478 ± 0.007 mg L^-1, and Dpε_600nm = 15,900 M^-1 cm^-1, LOD = 0.143 ± 0.002 mg L^-1, LOQ = 0.478 ± 0.007 mg L^-1). The effectiveness of this colorimetric method for the selective quantification of catechol/pyrogallol-based anthocyanins has been demonstrated in the aforementioned complex real matrices and compared to LC-MS/MS analysis and pH-differential method, offering a valuable tool to characterize plant and food extracts particularly rich in zinc-coordinating anthocyanins.

Agronomic performance and food safety of strawberry cultivated on a remediated sediment

A marine sediment phytoremediated and homogenized by landfarming was tested for its potential recycle as growing media in horticulture. Two strawberry cultivars, Camarosa and Monterey, were grown on remediated sediment alone (TS100), commercial peat/pumice based growing medium (TS0) and a mixture 1:1 in volume of sediment and peat (TS50). Chemical fertility and strawberry production and safety of produced food were monitored for three consecutive productive seasons on the same growing media. During the first year of cultivation, plants grown on sediment-based media showed a significantly lower biomass production and fruit yield compared with peat, mainly due to the sediment low fertility. In the subsequent two years, the plant re-cultivation improved the sediment structure and N mineralization, and on the third cultivation year both strawberry cultivars showed higher fruit productivity and no accumulation of potentially toxic trace metals. The produced fruits did non accumulate high concentrations of trace metals, and risk assessment showed no risks for human health related to the consumption of strawberry produced on sediment-based growing media. We concluded that a phytoremediated sediment could be recycled as an ingredient of soilless growing media for reducing the environmental impact of plant nursery production and posing no risks for human health. These results show that reclaimed sediments could be reconsidered as a component material category in the new EU regulation on fertilizers.

Circular Economy for a Sustainable Agri-Food Supply Chain: A Review for Current Trends and Future Pathways

The current agri-food supply chain is affected by different problems such as food loss and waste generation along the supply chain, and the circular economy offers a possibility to enhance and optimize the production and consumption to seek to a sustainable paradigm. The circular economy can be a winning approach to intervene and moderate the impacts generated in the agri-food sector, proposing actions and solutions to readmit wastes and by-products in the productive chain. The aim of this work was to perform a literature review coupled with a bibliometric analysis, using VOSviewer software, on the circular economy model in the agri-food sector, with particular relevance to the reuse and valorisation of wastes and by-products. Results showed that the topic is of particular relevance in the scientific community, and the concept is continuously evolving. Europe plays a leading role in the research, thanks to the involvement of the Member States, policy makers and stakeholders. Nevertheless, some aspects such as the development of a new economic circular model and some limitations of the current policies deserve further investigation.

Liquid Chromatographic Quadrupole Time-of-Flight Mass Spectrometric Untargeted Profiling of (Poly)phenolic Compounds in Rubus idaeus L. and Rubus occidentalis L. Fruits and Their Comparative Evaluation

This study provided a detailed profiling of the antioxidant and bioactive compounds occurring in three varieties of Rubus idaeus L. fruits (“Fall Gold”, “Glen Ample” and “Tulameen”) compared to Rubus occidentalis L. black raspberry (“Jewel” cultivar), adopting a comprehensive untargeted metabolomics approach developed with UHPLC analysis coupled with quadrupole/time-of-flight high resolution mass spectrometry, using the SWATH^® acquisition protocol. The feature selection and annotation workflow, applied to the analysis of raspberry extracts in both polarities, allowed identifying 68 bioactive compounds mainly belonging to the classes of (poly)phenolic compounds. Interestingly, some of these identifications (e.g., ferulic acid glycosides and the ellagitannin-like nobotanin/malabathrin) represent the first report in raspberry fruits. Principal component analysis made possible highlighting the features more related to the expression of a genotype effect within the R. idaeus species or between the two raspberry species herein investigated. Overall, flavanols were the most discriminating features for the Fall Gold variety, whereas ellagitannins and flavonol glycosides represent more distinctive metabolic traits in Glen Ample and Tulameen fruits. Moreover, R. occidentalis Jewel variety was strongly characterized by the occurrence of anthocyanins, such as cyanidin, pelargonidin and delphinidin glycosides.