Thermal properties of polynorbornene (cis- and trans-) and hydrogenated polynorbornene

Summary The thermal properties of trans-polynorbornene, cis-polynorbornene and hydrogenated polynorbornene were examined and its reversibility tested. Trans-polynorbornene samples, formed in various solvents, exhibit a softening range, from ambient temperature until 375 °C. However, syndiotactic cis-polynorbornene samples show a narrower melting range (between 150 and 375 °C). The fusion enthalpies of cis-polynorbornene samples are around 300-400 J/g. The temperature of decomposition is ca. 456 °C (minimum peak DSC) for trans-polynorbornene and ca. 466 °C, 10 °C higher, for cis-polynorbornene. The solvent used for the polymerization of norbornene has a negligible influence in the melting temperature range or in the decomposition temperature. The treatment with 2,6-di-tert-butyl-4-methyl-phenol during the isolation of polynorbornene leads to materials with different thermal properties. Trans-polynorbornene isolated without 2,6-di-tert-butyl-4-methyl-phenol exhibited an exothermic peak accompanied by an slight increase in weight (1-2%), while samples treated with 2,6-di-tert-butyl-4-methyl-phenol do not show these features.     

Germinated Cajanus cajan seeds as ingredients in pasta products: Chemical,biological and sensory evaluation

Pigeon peas (Cajanus cajan) seeds were germinated for 4 days at 20 °C in darkness in order to improve the nutritional quality of seeds. Germination brought about a sharp reduction of α-galactosides, phytic acid and trypsin inhibitor activity (83%, 61% and 36%, respectively) and an increment of vitamin B₂ (145%), vitamin C (from negligible amounts to 14 mg/100 g d.m.), vitamin E (108%) and total antioxidant capacity (28%). These flours were used as ingredients to produce pasta products in a proportion of 5%, 8% and 10%. The supplemented pasta products had shorter cooking time and higher water absorption, cooking and protein losses in water than had control pasta (100% semolina). From sensory evaluation, fortified pasta generally had acceptability similar to control pasta. Cooked pasta with the highest level of substitution (semolina:germinated pigeon pea flour at 10%) was chemically and biologically evaluated and results showed that protein, fat, dietary fibre and mineral contents were improved. Fortified pasta provided more vitamin B₁, B₂, E and antioxidant capacity than did control pasta. Biological assessment of fortified, cooked pasta indicated that true TD and PER value increased by 12% and 64%, respectively, in comparison with control. The germinated pigeon pea flour can be an excellent ingredient to increase the nutritional value of semolina pasta without affecting the sensory properties.     

Quality of the diet of women with severe and morbid obesity undergoing gastric bypass and sleeve gastrectomy

The objective of this study was to evaluate the changes of dietary intake and quality of the diet in patients undergoing gastric bypass and sleeve surgery. In 36 women with severe and morbid obesity it was assessed their nutrient intakes and dietary quality before and 6 months after bariatric surgery through three-day food records. Vitamin and mineral intakes from supplements were strictly controlled. Energy and nutrient intakes were significantly decreased 6 months after surgery bypass compared to the pre-surgery period with the exceptions of calcium and vitamin C. No differences were observed between groups. The Dietary quality index was also similar in both groups. Dietary intakes of calcium, iron, zinc, copper, folic acid, vitamin C, and vitamin E were below 100% of adequacy from at the 6th month after the surgery. Nevertheless, by considering both diet and supplements supply, nutrient adequacy of all but calcium and folic acid was above 100% in both groups. Gastric bypass patients presented greater values. In conclusion, these patients present an important reduction of their energy and nutrient intakes, with no major impact of the type of surgery. Supplement characteristics are crucial to cover nutritional needs.     

Chemical,biological and sensory evaluation of pasta products supplemented with α‐galactoside‐free lupin flours

α‐Galactoside‐free lupin flour has been used to supplement durum wheat semolina flour in order to increase the nutritive value of pasta products. Supplemented pasta products had a shorter cooking time, higher cooking water absorption, cooking loss and protein loss in water than control pasta prepared with only semolina. Sensory evaluation of cooked pastas showed that products supplemented with 80 g kg^?1 of α‐galactoside‐free Lupinus angustifolius var. Emir flour or with 100 g kg^?1 of α‐galactoside‐free Lupinus angustifolius var. Troll flour showed the same acceptability by panellists as the semolina pasta. These levels of supplementation were selected for further studies. The cooked α‐galactoside‐free lupin/semolina pastas showed higher amounts of protein, dietary fibre, calcium, phosphorus, magnesium, zinc and antioxidant capacity than control pasta and a reasonable level of vitamin B₁, vitamin B₂ and vitamin E. Biological assessment of cooked pastas indicated that the true protein digestibility did not change after the fortification of semolina but protein efficiency ratio increased sharply in the pasta supplemented with α‐galactoside‐free lupin flours (2.07 and 1.92 for Emir and Troll lupin varieties, respectively) in comparison with the control pasta (1.11). It is concluded that the α‐galactoside‐free lupin flours are an adequate ingredient to improve the nutritional quality of pasta products without adding flatulent oligosaccharides. Copyright © 2006 Society of Chemical Industry     

Characterization of polyphenol oxidase and peroxidase from peach mesocarp (Prunus persica L. cv. Babygold)

The two enzymes involved in enzymatic browning reactions—polyphenol oxidase (PPO) and peroxidase (POD)—were extracted from peach fruit mesocarp. PPO was mainly located in the membrane fraction and was in its latent state. However, POD activity was found in the soluble fraction. The kinetic characterization of PPO and POD was carried out with a natural substrate (chlorogenic acid) and with a non‐physiological substrate. Under native isoelectric focusing (IEF), several PPO isoenzymes were present in the pH range 5.4–5.8. A partially denaturing sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE) showed the presence of two active bands with apparent molecular masses of 49 and 50 kDa. A totally denaturing SDS‐PAGE indicated the presence of a single polypeptide with a molecular mass of 60 kDa, as revealed by western blot. POD was also analyzed by IEF, showing the presence of two strongly basic isoenzymes, which were resolved by cationic native PAGE into two different bands. Copyright © 2007 Society of Chemical Industry     

Persimmon (Diospyros kaki Thunb.) coproducts as a new ingredient in pork liver pâté: influence on quality properties

Persimmon (Diospyros kaki Thunb.) coproducts are rich in fibre, sugar, minerals and bioactive compounds, make it a good candidate for use in the meat industry. The aim was to evaluate the effect of adding (3% and 6%) two different types of persimmon flour (from cultivars ‘Rojo Brillante’ and ‘Triumph’) on the chemical composition (proximate composition, haeme iron and nitrite residual level), physicochemical properties (pH, water activity and colour), lipid oxidation, emulsion stability, texture and sensory acceptance of pork liver pâté. The addition of persimmon flours decreased residual nitrite levels in pâté to an extent that depended on the concentration and type of flour. Lipid oxidation in pâtés was also reduced by persimmon flour addition, an effect made evident by the increase in pâté redness, which could allow its application as natural antioxidant. In a sensory analysis, all the pâtés with persimmon flour added were better accepted than the control.     

Synthesis and functionalization of superparamagnetic poly-?-caprolactone microparticles for the selective isolation of subpopulations of human adipose-derived stem cells

There has been a growing interest in using biofunctionalized magnetic particles for cell isolation. This paper describes the synthesis and characterization of magnetite-polymer (Fe₃O₄-poly-ɛ-caprolactone, magnetite-PCL) microparticles surface functionalized with amino and epoxy groups allowing easy covalent attachment of specific antibodies and subsequent ability to bind target cells. Particles with different sizes (4–135 µm), spherical shape and superparamagnetic behaviour (magnetite content of about 13 wt%) were obtained. The functionalized microparticles presented high protein-binding capacity (coupling efficiency of 47% for epoxy- and 71% for amino-functionalized particles) with a low level of non-specific binding. We have further investigated the influence of initial protein concentration, pH, ionic strength, temperature and incubation time on the capacity of amino-functionalized particles to bind protein molecules. The results showed that maximum protein coupling is rapidly achieved (≤5 h) at pH 5.5 and low ionic strength (0.05 M NaCl). Furthermore, when cultured in direct contact with osteoblast-like cells (Saos-2) or human-derived adipose stem cells (ASCs), the amino-functionalized particles did not affect the proliferation and morphology of the cells. As a proof of principle for the application of magnetic microparticles for cell isolation, CD105 (endoglin) antibody was coupled to the magnetic particle surface to bind subpopulations of human ASCs expressing the CD105 antigen. The isolation of CD105+ ASCs from a heterogeneous cell population was confirmed by flow cytometry analysis. Given the demonstrated potential of functionalized magnetite-PCL microparticles for selective cell isolation, we expect that these particles may be further applied in immuno-magnetic cell separation owing to their versatility and ease of surface modification.     

Effects of diet enriched with restructured meats,containing Himanthalia elongata, on hypercholesterolaemic induction,CYP7A1 expression and antioxidant enzyme activity and expression in growing rats

Meat and pork consumptions are very high in Spain. Seaweeds are rich in fibre, minerals, and bioactive substances. Due to the growing demand for healthier meats, this work studied the effect of diets containing restructured pork (RP) enriched with Himanthalia elongata (Sea Spaghetti) on: (1) cholesterolaemia; (2) liver cytochrome P450 7A1 (CYP7A1) expression; (3) liver antioxidant enzyme activities and gene expression; (4) the liver antioxidant substrate concentrations. Four groups of 10 Wistar rats each were fed a mix of 85% AIN-93 M rodent diet and 15% freeze-dried RM for 35 days. The control group (C) consumed control RP; the Sea Spaghetti (SS) group, RP with 5% Sea Spaghetti. Animals on added cholesterol diets (CholC and CholSS) consumed their basal C and SS diets enriched with cholesterol and cholic acid as hypercholesterolaemic agent. Food intake was significantly affected by the alga × cholesterol interaction and by dietary cholesterol (both p < 0.001). Plasma cholesterol was significantly affected by the cholesterol × alga interaction (p < 0.05). CholC rats showed significantly higher plasma cholesterol (p < 0.001) than did their C counterparts, whilst serum cholesterol of CholSS was significantly lower (p < 0.05) than that of CholC. The glutathione peroxide (GSSG) concentrations and all mRNA expressions were significantly affected by the cholesterol × alga interaction (at least p < 0.05). SS vs C group showed significant (at least p < 0.05) increases in superoxide dismutase (Mn-SOD and Cu,Zn-SOD), glutathione peroxidase (GPx) and decrease of glutathione reductase (GR) expressions, and increased GR activity, GSSG and the redox index. CholSS vs CholC showed significant (at least p < 0.05) increases of CYP7A1, GR and Cu,Zn-SOD expression but decreases in catalase, Mn-SOD and GPx expression, and increase of GR activity. In conclusion, Sea Spaghetti could be widely used in RP design. Its addition to non-cholesterol enriched RP diet reduced oxidation mechanisms. SS-RP partially blocked the effect of the hypercholesterolaemic agent, giving rise to a new balance of the antioxidant enzyme expression.     

Influence of Fermentation Conditions on Glucosinolates, Ascorbigen, and Ascorbic Acid Content in White Cabbage (Brassica oleracea var. capitata cv. Taler) Cultivated in Different Seasons

ABSTRACT:  The content of glucosinolates (GLS), ascorbigen, and ascorbic acid in white cabbage ( Brassica oleracea var. capitata cv. Taler) cultivated in different seasons (summer and winter) was determined, before and after spontaneous and starter-induced fermentation. Different salt concentrations (0.5% NaCl or 1.5% NaCl) were used for sauerkraut production. Glucoiberin, sinigrin, and glucobrassicin were dominating in raw white cabbage cultivated either in winter or summer seasons. Ascorbigen precursor, glucobrassicin, was found higher in cabbage cultivated in winter (2.54 μmol/g dw) than those grown in summer (1.83 μmol/g dw). Cabbage fermented for 7 d was found to contain only traces of some GLS irrespective of the fermentation conditions used. Ascorbigen synthesis occurred during white cabbage fermentation. Brining cabbage at low salt concentration (0.5% NaCl) improved ascorbigen content in sauerkraut after 7 d of fermentation at 25 °C. The highest ascorbigen concentration was observed in low-sodium (0.5% NaCl) sauerkraut produced from cabbage cultivated in winter submitted to either natural (109.0 μmol/100 g dw) or starter-induced fermentation (108.3 and 104.6 μmol/100 g dw in cabbages fermented by L. plantarum and L. mesenteroides , respectively). Ascorbic acid content was found higher in cabbage cultivated in summer and fermentation process led to significant reductions. Therefore, the selection of cabbages with high glucobrassicin content and the production of low-sodium sauerkrauts may provide enhanced health benefits towards prevention of chronic diseases.