93 research outputs found

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

    Get PDF
    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.)

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

    Get PDF
    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

    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

    Get PDF
    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

    Camptothecin-psammaplin A hybrids as topoisomerase I and HDAC dual-action inhibitors

    Get PDF
    Recent studies have demonstrated enhanced anticancer effects of combination therapy consisting of camptothecin derivatives and HDAC inhibitors. To exploit this synergy in a single active compound, we designed new dual-acting multivalent molecules simultaneously targeting topoisomerase I and HDAC. In particular, a selected compound containing a camptothecin and the psammaplin A scaffold showed a broad spectrum of antiproliferative activity, with IC50values in the nanomolar range. Preliminary in vivo results indicated a strong antitumor activity on human mesothelioma primary cell line MM473 orthotopically xenografted in CD-1 nude mice and very high tolerability

    Detection and enumeration of Listeria monocytogenes in fresh cut vegetables using MPN-Real-Time PCR

    Get PDF
    Listeria monocytogenes is a gram positive, rod shaped, pathogenic bacterium, causative agent of a severe infection generally known as listeriosis. Packaging and storage conditions of fresh cut vegetables may favour the growth of this psychrotrophic pathogen leading to potential health threat. Detection and enumeration of L. monocytogenes in concentrations up to 103 CFU/g, usually implies use of the most-probable-number technique (MPN) which may take up to seven days for verified identification of the pathogen. We developed a fast and reliable protocol combining MPN with a Real-Time quantitative PCR (qPCR) approach. Samples of fresh cut salads (25 g) purchased at local shops were spiked with 1 to 105 CFU/g of L. monocytogenes. Samples were homogenized, and triplicate series of tubes containing 10-5 to 10 g of food were incubated in Fraser broth at 30\ub0C for 48 h for standard MPN analysis. After incubation, broth samples were taken from each tube and DNA was extracted. DNA from enrichment tubes was used as template in a qPCR assay targeting a 64 bp hlyA gene sequence of L. monocytogenes. Results of this assay were than compared with those of standard MPN analysis and a complete accordance was observed. Furthermore, we tested an enrichment free approach using the same qPCR assay. Samples were prepared as described for MPN-qPCR while DNA extraction was performed prior to enrichment of inoculated salads. This approach allowed us to identify L. monocytogenes in samples spiked with 10-105 CFU/g. The whole process, including DNA extraction, required less than four hours, thus providing a fast and reliable tool for detection of L. monocytogenes in fresh cut vegetables

    Antioxidant capacity, phenolic and vitamin C contents of quinoa (Chenopodium quinoa Willd.) as affected by sprouting and storage conditions

    Get PDF
    Antioxidant capacity (AC) of quinoa (Chenopodium quinoa Willd. cv. Real) seeds and sprouts obtained after 4 days of seed germination at 20°C and 70% humidity was evaluated using trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays, able to highlight reducing activity and peroxyl radical scavenging capacity, respectively; phenolic content (PC) was also measured. Both TEAC and ORAC assays revealed a significantly higher (about 2- and 2.8-fold, respectively) AC of 4-day-old sprouts compared to seeds; consistently, also PC values of sprouts resulted about 2.6 times higher than seeds. In order to investigate the influence of storage on AC and PC, as well as on vitamin C content (VCC), 4-day-old sprouts were subjected for 7 days at 5°C to three different conditions of controlled atmosphere storage (CAS) compared with air. Interestingly, whatever the CAS conditions, storage of quinoa sprouts up to 7 days induced an increase of AC evaluated in terms of reducing activity by TEAC assay. Consistently, an increase of PC and VCC was measured during storage, positively correlated to TEAC values. Moreover, a decrease of peroxyl radical scavenging activity, measured by ORAC, was observed after 7 days of storage, in accordance with a shift of AC towards the reducing activity component. Overall, these findings indicate that sprouting approach using quinoa may provide highly antioxidant-enriched seedlings that may improve nutritional quality of diet or of functional foods. Interestingly, antioxidant properties of quinoa sprouts may be deeply influenced by storage, able to increase reducing activity by increasing phenols and vitamin C

    Hybrid topoisomerase i and HDAC inhibitors as dual action anticancer agents

    Get PDF
    Recent studies have shown that HDAC inhibitors act synergistically with camptothecin derivatives in combination therapies. To exploit this synergy, new hybrid molecules targeting simultaneously topoisomerase I and HDAC were designed. In particular, a selected multivalent agent containing a camptothecin and a SAHA-like template showed a broad spectrum of antiproliferative activity, with IC50 values in the nanomolar range. Preliminary in vivo results indicated a strong antitumor activity on human mesothelioma primary cell line MM473 orthotopically xenografted in CD-1 nude mice and very high tolerability
    • …
    corecore