Design and preliminary test of a fluidised bed photoreactor for ethylene oxidation on mesoporous mixed SiO2/TiO2 nanocomposites under UV-A illumination

Ethylene (C2H4) is a plant hormone that has numerous effects on many horticultural and ornamental crops. It accelerates senescence, stimulates chlorophyll loss, enhances excessive softening, promotes discoloration and browning during storage of fresh produce. Among the techniques used to remove or inhibit ethylene action during postharvest handling of fresh products (potassium-based system, high temperature catalytic oxidation, inhibition of ethylene receptors), the use of titanium oxide (TiO2)-based materials with photocatalytic activity under ultraviolet (UV) light is one of the most promising. A fluidised-bed photoreactor (FBP) was designed to decompose ethylene in the storage room atmosphere, and the relative prototype was manufactured. Since TiO2 powder alone is not suitable for use within a fluidised bed, preliminary tests to select the best support were performed. Alumina microspheres showed a good fluidisation behavior; its functionality was tested with different kind of support material and actual photocatalytic activity was tested using SiO2/TiO2-coated alumina microspheres. A reduction of approximately 72% of ethylene concentration in the tested 40 ppm ethylene gas mixture was observed after 4.5 h of 36W UV light exposure. FBP resulted to be suitable to avoid the detrimental presence of C2H4 in the atmosphere surrounding fresh products within cold storage rooms

Feasibility study for the surface prediction and mapping of phytonutrients in minimally processed rocket leaves (Diplotaxis tenuifolia) during storage by hyperspectral imaging

A comprehensive study of the feasibility of hyperspectral imaging in visible (400–1000 nm) and near infrared (900–1700 nm) regions was investigated for prediction and concentration mapping of Vitamin C, ascorbic acid (AA), dehydroascorbic acid (DHAA) and phenols in wild rocket (Diplotaxis tenuifolia) over a storage span of 12 days at 5 °C. Partial least squares regression (PLSR) with different data pretreatments and wavelength selection resulted in satisfactory predictions for all parameters in the NIR range except DHAA. Prediction models were used for concentration mapping to follow changes over time. The prediction maps will be comprehensively study to assess the pixel to pixel variation within the rocket leaves. The PLSR models for Vitamin C, AA and phenols yielded an R2 of 0.76, 0.73 and 0.78, respectively in external prediction with root mean square errors approximately equivalent to those of reference analysis. Conclusively, hyperspectral imaging, with the correct mapping approach, can be a useful tool for the prediction and mapping of phytonutrients in wild rocket (Diplotaxis tenuifolia) over time

Comparison performance of visible-nir and near-infrared hyperspectral imaging for prediction of nutritional quality of goji berry (Lycium barbarum l.)

The potential of hyperspectral imaging for the prediction of the internal composition of goji berries was investigated. The prediction performances of models obtained in the Visible-Near Infrared (VIS-NIR) (400–1000 nm) and in the Near Infrared (NIR) (900–1700 nm) regions were compared. Analyzed constituents included Vitamin C, total antioxidant, phenols, anthocyanin, soluble solids content (SSC), and total acidity (TA). For vitamin C and AA, partial least square regression (PLSR) combined with different data pretreatments and wavelength selection resulted in a satisfactory prediction in the NIR region obtaining the R2pred value of 0.91. As for phenols, SSC, and TA, a better performance was obtained in the VIS-NIR region yielding the R2pred values of 0.62, 0.94, and 0.84, respectively. However, the prediction of total antioxidant and anthocyanin content did not give satisfactory results. Conclusively, hyperspectral imaging can be a useful tool for the prediction of the main constituents of the goji berry (Lycium barbarum L.)

Using chemometrics to characterise and unravel the near infra-red spectral changes induced in aubergine fruit by chilling injury as influenced by storage time and temperature

The early non-destructive detection of chilling injury (CI) in aubergine fruit was investigated using spectroscopy. CI is a physiological disorder that occurs when the fruit is subjected to temperatures lower than 12 °C. Reference measurements of CI were acquired by visual appearance analysis, measuring electrolyte leakage (EL), mass loss and firmness evaluations which demonstrated that even before three days of storage at 2 °C, the CI process was initiated. An ANOVA-simultaneous component analysis (ASCA) was used to investigate the effect of temperature and storage time on the Fourier transform – near infra-red (FT-NIR) spectral fingerprints. The ASCA model demonstrated that temperature, duration of storage, and their interaction had a significant effect on the spectra. In addition, it was possible to highlight the main variations in the experimental results with reference to the effects of the main factors, and with respect to storage time, to discover any major monotonic trends with time. Partial least squares-discriminant analysis (PLS-DA) was used as a supervised classification method to discriminate between fruit based on chilling and safe temperatures. In this case, only significant spectral wavebands which were significantly influenced by the effect of temperature based on ASCA were utilised. PLS-DA prediction accuracy was 87.4 ± 2.7% as estimated by a repeated double-cross-validation procedure (50 runs) and the significance of the observed discrimination was verified by means of permutation tests. The outcomes of this study indicate a promising potential for near infra-red spectroscopy (NIRS) to provide non-invasive, rapid and reliable detection of CI in aubergine fruit

E-fuels, technical and economic analysis of the production of synthetic kerosene precursor as sustainable aviation fuel

In the context of European and national energy policies to pursue the energy transition process, the issue of alternative-renewable liquid fuels is clearly addressed, whose purpose is to support the growth of sustainable mobility towards the goal of net zero emissions. On the base of the goals to be achieved in the medium and long term in relation to the theme of decarbonization and the development of new sustainable technologies, the present work deals with the e-fuels, which are produced by hydrogen from water electrolysis driven by renewable energy and CO2 captured from air or industrial sources. In particular, the attention is focused on the production of synthetic kerosene with the purpose to decarbonize the aviation sector, which is one of the most difficult electrifiable sectors due to logistical problems. The main objective of this work is the techno-economic analysis of the production of synthetic kerosene starting from green H2 and CO2 from direct air capture. The study of two main process schemes is carried out for the production of a synthetic crude oil, also called syncrude, rich in the kerosene fraction of interest. In the first scheme, called two-stage or indirect process, the incoming carbon dioxide and hydrogen are transformed through the Reverse-Water-Gas-Shift (RWGS) reaction in a syngas which allows to produce, by means of the Fischer-Tropsch (FT) reaction, the product of interest. The second scheme, referred to as single-stage or direct process, involves the direct formation of syncrude (direct FT-CO2) starting from carbon dioxide and hydrogen. In both cases, kinetic models representative of the considered reactions are selected in order to carry out an accurate process analysis. Through sensitivity analysis and process evaluations, some process optimizations like material recycle and heat integration are performed in order to increasing the efficiency and carry out a cost comparison to evaluate economic feasibility. Regarding the indirect and direct processes, 66.18 bbl/d and 38.46 bbl/d are produced respectively. Considering all the results and scenarios with and without optimizations, the range of the product cost is from 460 to 1435 €/bbl for the indirect process and from 752 to 2364 €/bbl for the direct process. These values strongly depend on the considered prices of power energy and hydrogen used for the present work

3rd International Symposium on Postharvest Pathology: Using Science to Increase Food Availability

Controlling microbial contamination is a critical aspect of reducing losses of harvested apple fruit during storage. The use of synthetic pesticides is still an essential tool; however, the future use of these compounds is increasingly limited due to the onset of pathogen resistance and to growing consumer demand for fruits free of pesticide residues. In this work, we evaluated two different strategies for the storage 'of 'Cripps Pink' apples. In the first one, the apples were sprayed with electrolyzed water (EW) at 400 mg L-1of free available chlorine (FAC) in the field before harvest, and were then stored at 1°C under controlled atmosphere for 4 months. At the end of the storage period, the percentage of rotted apples, especially with regard to Gloesporium spp. rotting, was evaluated and compared to the percentage of conventionally treated (pyraclostrobin+boscalid) apples. In the second storage strategy, apples were not treated with EW in the field, but moved directly to the storage facility after harvest, where they were stored for 2 months at 1°C in controlled atmosphere, and then either washed with working line water, or washed by dipping in EW at 50 mg L-1or washed by spraying with EW at 400 mg L-1FAC. After washing, the apples were stored at 25°C and checked every seven days. The bacterial contamination of washing water and the presence of pesticide residues on apples were also analyzed. The results evidenced that the percentage of rotted apples was significantly lower if the apples were treated with EW at 400 mg L-1of FAC before harvest. EW can be considered as an effective means of controlling microbial contamination and rotting. EW also can reduce the pesticide residues in 'Cripps Pink' apples