Assessment of “Sugranineteen” Table Grape Maturation Using Destructive and Auto-Fluorescence Methods

The optimal harvesting of table grapes is commonly determined based on technological and phenolic indices analyzed over the course of its maturity. The classical techniques used for these analyses are destructive, time-consuming, and work for a limited number of samples that may not represent the heterogeneity of the vineyard. This study aimed to follow the ripening season of table grapes using non-destructive tools as a rapid and accurate alternative for destructive techniques. Grape samples were collected from a Sugranineteen vineyard during the ripening season to measure the basic maturity indices via wet chemistry, and total polyphenols, anthocyanins, and flavonoids were evaluated by spectrophotometry. Fluorescent readings were collected from intact clusters with a portable optical sensor (Multiplex® 3, Force-A, France) that generates indices correlated to different maturity parameters. Results revealed strong relationships between the Multiplex® indices ANTH_RG and FERARI and the skin anthocyanin content, with R2 values equal to 0.9613 and 0.8713, respectively. The NBI_R index was also related to total anthocyanins (R2 = 0.8032), while the SFR_R index was linked to the titratable acidity (R2 = 0.6186), the sugar content (R2 = 0.7954), and to the color index of red grapes (CIRG) (R2 = 0.7835). Results demonstrated that Multiplex® 3 can be applied on intact clusters as an effective non-destructive tool for a rapid estimation of table grapes’ anthocyanin content

Rachis browning and water loss description during postharvest storage of ‘Krissy’ and ‘Thompson Seedless’ table grapes

Rachis browning is a serious symptom of water loss affecting the quality of table grapes (Vitis vinifera L.) during storage. It has been evaluated subjectively based on a color scale or by image analysis, while water loss, which is considered as the main factor behind this problem, is mostly measured on basis of whole-cluster weight loss, with only few studies focusing on the rachis exclusively. Our main objective was to compare the sensitivity to water loss and rachis browning of ‘Krissy’ and ‘Thompson Seedless’ cultivars under different storage conditions and using different methods of evaluation (NIR spectrometry, image analysis, colorimeter, weight loss from initial weight and relative water content). The rachises were evaluated during 3 d subjected to a combination of temperatures (0 °C or 20 °C), relative humidity (Saturated or reduced RH), and previous storage at 0 °C for 0 (HT, Harvest Time) and 30 days (ST, Storage Time). NIR spectra (896−2500 nm) were collected, and Partial Least Squares regression (PLS) models were calculated to test the correlation between the spectra and the measurements from other evaluation techniques. Results showed that ‘Krissy’ is more sensitive to dehydration symptoms than ‘Thompson Seedless’. Saturated RH combined with low temperature (0 °C) are the most suitable to reduce rachis browning and water loss during the 3 d of storage at both HT and ST. The decrease in RWC (Relative Water Content) coincided with an increase in rachis browning throughout storage. Additionally, results provided six NIRS-based prediction models for browning severity (R2 = 0.82 and 0.84), hue color (R2 = 0.68 and 0.72) and water loss (R2 = 0.63 and 0.90) in rachises of ‘Krissy’ and ‘Thompson Seedless’, respectively. These results demonstrate that the NIRS can be a suitable non-destructive method to quantify a range of rachis browning severity produced under different storage conditions

Structural, optical, and magnetic properties of the ferromagnetic semiconductor hematite-ilmenite Fe2−xTixO3−δ thin films on SrTiO3(001) prepared by pulsed laser deposition

International audienc

Investigation of high quality magnetite thin films grown on SrTiO3(001) substrates by pulsed laser deposition

International audienc

Attempts to induce tolerance to Trichostrongylus colubriformis

Background and objectives: The possibility of manipulating the immune response in lambs to the gastrointestinal nematode Trichostrongylus colubriformis to reduce production losses associated with infection was investigated. In a series of four experiments, attempts to immunize sheep via the mucosal route to modify the immune response and induce mucosal tolerance are outlined. Initially, a proof of concept study was conducted with lambs being injected with multiple doses of a somatic T colubriformis antigen without an adjuvant in the rectal submucosa and subsequently challenged with T colubriformis L3 larvae. This was followed by a dose‐response study comparing different antigen doses to identify the optimum dose of the nematode antigen for successful induction of mucosal tolerance. The final two studies were conducted to determine the larval stage specificity of the parasite antigen and the most suitable site of delivery required to stimulate mucosal tolerance. Methods: In the proof of concept study, lambs either received repeated injections in the rectal submucosa at 3 × weekly intervals with 15 µg of L3, 11 µg of L4 and 21 µg of immature adult (L5) somatic T colubriformis antigens (ANT) or not (INF) prior to infection with T colubriformis . In the dose‐rate study, antigen dose rates of 100%, 50%, 10%, 1% or 0% of the antigen concentration used in the proof of concept study were compared while the larval stage study compared antigen from either L3, L4, L5 stages or combination of all (COMB) and the route of administration study compared antigen delivery into either the rectal submucosa (RE) or sub‐cutaneous injection (SC). Results: During infection, lamb growth was improved by antigen treatment between days 21 and 42 in the proof of concept study (P = .009), for groups 10%, 50% and 100% in the dose‐rate study (P .05 for all). Parasite‐specific IgA and IgE showed a dose‐response (the dose‐rate study), were not affected by larval stage (the larval stage study) and were greater in RE than SC (the route of administration study). IL‐4 production following lymphocyte stimulation was greatest in COMB (the larval stage study) and RE (the route of administration study). Conclusions: Although antigen treatment improved performance, this was inconsistent and appeared to stimulate immunity rather than induce tolerance. Combined larval stages were more efficient than individual stages, and intra‐rectal administration was more effective than sub‐cutaneous

Human intestine luminal ACE2 and amino acid transporter expression increased by ACE-inhibitors

Sodium-dependent neutral amino acid transporter B(0)AT1 (SLC6A19) and imino acid (proline) transporter SIT1 (SLC6A20) are expressed at the luminal membrane of small intestine enterocytes and proximal tubule kidney cells where they exert key functions for amino acid (re)absorption as documented by their role in Hartnup disorder and iminoglycinuria, respectively. Expression of B(0)AT1 was shown in rodent intestine to depend on the presence of the carboxypeptidase angiotensin-converting enzyme 2 (ACE2). This enzyme belongs to the renin-angiotensin system and its expression is induced by treatment with ACE-inhibitors (ACEIs) or angiotensin II AT1 receptor blockers (ARBs) in many rodent tissues. We show here in the Xenopus laevis oocyte expression system that human ACE2 also functionally interacts with SIT1. To investigate in human intestine the potential effect of ACEIs or ARBs on ACE2, we analysed intestinal biopsies taken during routine gastroduodenoscopy and ileocolonoscopy from 46 patients of which 9 were under ACEI and 13 ARB treatment. Analysis of transcript expression by real-time PCR and of proteins by immunofluorescence showed a co-localization of SIT1 and B(0)AT1 with ACE2 in the brush-border membrane of human small intestine enterocytes and a distinct axial expression pattern of the tested gene products along the intestine. Patients treated with ACEIs displayed in comparison with untreated controls increased intestinal mRNA levels of ACE2, peptide transporter PEPT1 (SLC15A1) and AA transporters B(0)AT1 and PAT1 (SLC36A1). This study unravels in human intestine the localization and distribution of intestinal transporters involved in amino acid absorption and suggests that ACEIs impact on their expression