Design,Synthesis, Biological Activity,and Structural Analysis of Lactam‐Constrained PTPRJ Agonist Peptides

PTPRJ is a receptor‐like protein tyrosine phosphatase mainly known for its antiproliferative and tumor‐suppressive functions. PTPRJ dephosphorylates several growth factors and their receptors, negatively regulating cell proliferation and migration. We recently identified a disulfide‐bridged nonapeptide, named PTPRJ‐19 (H‐[Cys‐His‐His‐Asn‐Leu‐Thr‐His‐Ala‐Cys]‐OH), which activates PTPRJ, thereby causing cell growth inhibition and apoptosis of both cancer and endothelial cells. With the aim of replacing the disulfide bridge by a chemically more stable moiety, we have synthesized and tested a series of lactam analogues of PTPRJ‐19 . This replacement led to analogues with higher activity and greater stability than the parent peptide.     

Edible Insects in a Food Safety and Nutritional Perspective: A Critical Review

Increasing world population worsens the serious problem of food security in developing countries. On the other hand in industrialized countries, where the problem of food security is of minor concern, health problems related to food refer to 2 main factors: food safety and environmental sustainability of food production. For these reasons, new ways must be found to increase yields while preserving food quality, natural habitats, and biodiversity. Insects could be of great interest as a possible solution due to their capability to satisfy 2 different requirements: (i) they are an important source of protein and other nutrients; (ii) their use as food has ecological advantages over conventional meat and, in the long run, economic benefits. However, little is known on the food safety side and this can be of critical importance to meet society's approval, especially if people are not accustomed to eating insects. This paper aims to collect information in order to evaluate how insects could be safely used as food and to discuss nutritional data to justify why insect food sources can no longer be neglected. Legislative issues will also be discussed.     

Application of near infrared reflectance spectroscopy to protein analysis of grassland herbage samples

Near infrared reflectance spectroscopy (NIRS) was evaluated for the prediction of the protein content in samples of grassland herbage taken at different stages of maturity (flowering to fruiting stage) in ‘Dehesa’ zones of Central-Western Spain. A Technicon Infra Alyzer model 500 scanning monochromator interfaced with a Hewlett-Packard 1000 minicomputer was used for the study. Protein content was predicted with NIRS data treated as log I/R using six or seven wavelengths. Calibrations were evaluated by comparing Kjeldahl analyses with those predicted by NIRS. The prediction of protein was found to be acceptable, the standard error carying between 0.56 and 0.68% in a range of protein content from 6.76 to 13.98%.     

Physical properties of enzyme-supplemented doughs and relationship with bread quality parameters

 The textural properties of wheat doughs made with different commercial amylases, xylanases/pentosanases, lipases and glucose-oxidase, singly and in mixed combinations, were investigated. Parameters from the texture profile analysis (TPA) and measurement of stickiness (Chen and Hoseney test) were determined after mixing the dough and after it had rested for 3.5 h. Resting of doughs led to softer and less cohesive doughs, with higher adhesive properties. Enzymes acted quickly and induced significant changes in the textural properties of doughs immediately after mixing. The influence of enzymes continued during resting. Xylanases/pentosanases substantially reduced dough consistency and increased stickiness, while addition of glucose-oxidase and specific lipases overcame these effects. Strong correlations could be established between different TPA parameters and stickiness and bread quality characteristics (i.e. volume, density and texture). Bread quality could be described by a single or multiple linear combination of textural variables. Received: 21 May 1997 / Revised version: 10 July 1997     

Co-occurrence and distribution of deoxynivalenol,nivalenol and zearalenone in wheat from Brazil

Fusarium mycotoxins deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) were investigated in wheat from the 2009 and 2010 crop years. Samples (n = 745) from commercial fields were collected in four wheat producing regions (WPR) which differed in weather conditions. Analyses were performed using HPLC-DAD. Contamination with ZEN, DON and NIV occurred in 56, 86 and 50%, respectively. Also, mean concentrations were different: DON = 1046 µg kg^?1, NIV < 100 µg kg^?1 and ZEN = 82 µg kg^?1. Co-occurrence of ZEN, DON and NIV was observed in 74% of the samples from 2009 and in 12% from 2010. Wet/cold region WPR I had the highest mycotoxin concentration. Wet/moderately hot region WPR II had the lowest mycotoxin levels. Furthermore, the mean concentration of each mycotoxin was higher in samples from 2009 as compared with those from 2010. Precipitation during flowering or harvest periods may explain these results.     

Gamma Irradiation of in-Shell and Blanched Peanuts Protects against Mycotoxic Fungi and Retains Their Nutraceutical Components during Long-Term Storage

Peanut samples were irradiated (0.0, 5.2, 7.2 or 10.0 kGy), stored for a year (room temperature) and examined every three months. Mycotoxic fungi (MF) were detected in non-irradiated blanched peanuts. A dose of 5.2 kGy was found suitable to prevent MF growth in blanched samples. No MF was detected in in-shell peanuts, with or without irradiation. The colors of the control in-shell and blanched samples were, respectively, 44.72 and 60.21 (L *); 25.20 and 20.38 (Chroma); 53.05 and 86.46 (°Hue). The water activities (Aw) were 0.673 and 0.425. The corresponding fatty acids were 13.33% and 12.14% (C16:0), 44.94% and 44.92% (C18:1, ω9) and 37.10% and 37.63% (C18:2, ω6). The total phenolics (TP) were 4.62 and 2.52 mg GAE/g, with antioxidant activities (AA) of 16.97 and 10.36 μmol TEAC/g. Storage time negatively correlated with Aw (in-shell peanuts) or L *, linoleic acid, TP and AA (in-shell and blanched peanuts) but positively correlated with Aw (blanched peanuts), and with oleic acid (in-shell and blanched peanuts). Irradiation positively correlated with antioxidant activity (blanched peanuts). No correlation was found between irradiation and AA (in-shell samples) or fatty acids and TP (in-shell and blanched peanuts). Irradiation protected against MF and retained both the polyunsaturated fatty acids and polyphenols in the samples.     

Antioxidant activity and dietary fibre of Prensal Blanc white grape (Vitis vinifera) by‐products

Stem and pomace of a white grape (Vitis vinifera) variety, Prensal Blanc, were studied for the first time: general composition and dietary fibre components together with the total soluble polyphenol content and antioxidant activity. Both by‐products present high contents of total dietary fibre (TDF), 790 g kg^?1 d.m. (stem) and 716 g kg^?1 d.m. (pomace). Values of the soluble dietary fibres in relation to TDF differed: 5% (stem) and 14.4% (pomace). Similar values of Klason lignin were found: 229 g kg^?1 (stem) and 278 g kg^?1 (pomace), however, the pomace exhibited more than twice the content of the condensed tannins (168 g kg^?1) with regard to the stem (79 g kg^?1). Notable were the high resistant protein contents of both by‐products. Stem and pomace showed appreciable amounts of total soluble polyphenols (87 g kg^?1 against 35 g kg^?1 respectively). The free radical scavenging capacity of the former by‐products was determined using the 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH) method, obtaining EC₅₀ values of 0.79 g d.m. g^?1 DPPH (stem) and 1.32 g d.m. g^?1 DPPH (pomace). These data shows that both vinification by‐products from the Prensal Blanc variety are a good source of dietary fibre and have antioxidant properties.     

Efficient light-scattering calculations for aggregates of large spheres

Calculation of the scattering pattern from aggregates of spheres through the T-matrix approach yields high-precision results but at a high-computational cost, especially when the aggregate concerned is large or is composed of large-size spheres. With reference to a specific but representative aggregate, we discuss how and to what extent the computational effort can be reduced but still preserve the qualitative features of the signature of the aggregate concerned.     

Uptake of Escherichia coli, Vibrio cholerae non-O1 and Enterococcus durans by, and depuration of mussels (Mytilus galloprovincialis)

The uptakes of Escherichia coli, Vibrio cholerae non-O1 and Enterococcus durans by mussels (Mytilus galloprovincialis) and the times for depuration were investigated in order to determine the most useful indicator of vibrio contamination. The mussels were maintained in tanks of static seawater contaminated with bacteria at 5 log10 CFU/ml for bioaccumulation. Depuration was carried out by circulating fresh seawater through the tanks. Each organism was presented alone and with others to mussels, at temperatures of 14 and 21 degrees C. In water contaminated with either single or mixed organisms, the bacteria accumulated rapidly in the mussels reaching high concentrations after 1 h. With both single and mixed organisms, the maximum numbers of E. coli in mussels were 6.6 log10 CFU/g at 14 degrees C and 5.4 log10 CFU/g at 21 degrees C. Both V. cholerae non-O1 and E. durans alone or with other organisms reached a number ranging from 6.5 to 7 log10 CFU/g at both temperatures. During depuration the numbers of all the organisms slowly decreased, with E. coli alone, numbers ranged from 2.8 to 2 log10 CFU/g after 72 h at both 14 and 21 degrees C, and the organisms were undetectable after 144 h. With mixed organisms at 14 degrees C E. coli became undetectable after 168 h but at 21 degrees C no E. coli were recovered after 72 h. At 14 degrees C V. cholerae non-O1 alone also was undetectable after 168 h, but at 21 degrees C and with mixed organisms at both temperatures. V. cholerae was recovered after 168 h at numbers about 1 log10 CFU/g. After 168 h numbers of E. durans alone ranged from 2.6 log10 CFU/g at 14 degrees C to 1.5 log10 CFU/g at 21 degrees C, and with mixed organisms the numbers ranged from 2.3 to 2.0 log10 CFU/g at both temperatures. Of the three bacteria of faecal origin, E. durans is quickly acquired by mussels and released more slowly than the others, while E. coli quickly becomes undetectable. The results suggest that, for this kind of seafood, enterococci may be a more appropriate indicator than E. coli of risks to consumers from vibrios.