Isolation and Partial Characterization of Okenia (Okenia hypogaea) Starch

Okenia hypogaea (Schlech. & Cham.) belongs to the family of the Nyctaginacea, which produces a seed that is composed mainly of starch, the probable origin of Okenia hypogaea is Mexico. The aim of this work was to isolate the starch from Okenia hypogaea and to evaluate its chemical composition, along with some physicochemical and functional properties. Okenia gave a starch yield of 36 %; this starch had an amylose content of 26.1 %, with a fat content similar to corn starch, but with a higher ash fraction. Okenia starch possessed a small granule size (1—3 μm), the same as amaranth starch, with similar characteristics of stability and clarity of pastes as corn starch. At 60 °C the water retention capacity of okenia starch was higher than that of corn starch, but at higher temperatures an inverse pattern was found. When the temperature in the experiments increased, solubility and swelling values increased; okenia starch had higher swelling values than corn starch over the range of temperatures assayed. Okenia starch also presented a lower freeze‐thaw stability than corn starch on the first two cycles. Overall, it was concluded that due to its physicochemical and functional properties, it is worthwhile to test the use of okenia starch in the cosmetic and food industry.     

Monitoring of headspace volatiles in milk‐cereal‐based liquid infant foods during storage

The effect of storage (time and temperature) on the evolution of pentanal, hexanal, heptanal and pentane as volatile lipid oxidation products in two liquid ready‐to‐eat milk‐cereal‐based infant foods was studied. An SPME‐GC method was used to this effect. Samples were stored for 9 months at 25, 30 and 37 °C and tested eight times during this period. Freshly produced infant foods contained pentanal, hexanal and heptanal (mean values: 10.71, 71.5 and 1.2 µg/kg, respectively), which decreased during the first 3 months of storage, although from the fourth month onwards no significant differences among storage times were found. Aldehyde content was inversely proportional to storage temperature. Pentane content was directly proportional to storage temperature and increased (19.9 µg/kg at zero time) over all months of storage up to 43.1 µg/kg.     

High conjugated linoleic acid (CLA) content in milk and dairy products using a dietary supplementation of sunflower seed in cows. Thrombogenic/atherogenic risk issues

This study was undertaken to determine the effect of dietary supplementation of sunflower seed in cows on the chemical composition of milk and dairy products. Cream, butter and butter oil were prepared from milk produced by cows fed a control diet (control products) or diet supplemented with 11.2% sunflour seed (CLA-rich products). Milk samples collected were determined for lactose. A sample of CLA-rich or control product was determined for fatty acid profile as well as fat, protein and ash contents. The index of atherogenicity (IA) and the index of thrombogenicity (IT) were also calculated. Results revealed that there was no effect of the inclusion of sunflower seed in the diet on the lactose content in milk and total fat, protein and ash contents in the dairy products. Average contents of conjugated linoleic acid (CLA) and transvaccenic acid (TVA), expressed as g/100g total fatty acid were 0.54 and 1.6, respectively in the control products, and 2 and 6.4, respectively in the CLA-rich products. The content of either CLA or TVA was approximately four fold higher in the latter products. Moreover, CLA-rich products showed considerably low IA and IT, which were, respectively, 38.4 and 25.0% less than those from control products. Fatty acid profiles were unaffected during processing, which demonstrates that CLA is a stable component in the dairy products analyzed. It was concluded that dietary supplementation of sunflower seed in cows increases the CLA and TVA contents in milk, which may contribute to the reduction of the risk of cardiovascular diseases in humans.     

A tentative characterization of white dry-cured hams from Teruel (Spain) by SPME-GC

Forty-six volatile compounds were identified and quantified in four parts (subcutaneous fat, and biceps femoris, semitendinosus and semimembranosus muscles) of 41 samples from Spain, France and Italy. The Univariate Brown–Forsythe test was used to determine the volatile compounds from each part of the ham that can distinguish the hams of Teruel from Iberian and white hams. Stepwise linear discriminant analysis was used in-tandem to refine the most discriminating volatile compounds. Six compounds (2-propanone, butanol, 3-methylbutanol, 3-methylbutanal, hexanal and limonene) were able to distinguish the dry-cured hams from Teruel, Iberian hams, and French and Spanish white hams simultaneously. MDS was also applied to the volatiles selected by SLDA. Information on the series of volatiles and individual compounds is also displayed.     

Integral utilisation of barley husk for the production of food additives

A new and effective chemical–biotechnological process for the global utilisation of barley husk (obtained from the spent grains in the brewing process) is reported. With the proposed process the three main components of the lignocellulosic residue (cellulose, hemicellulose and lignin) are utilised. A first treatment with sulfuric acid (pre‐hydrolysis) allowed the solubilisation of hemicelluloses to give xylose and glucose‐containing liquors (suitable to make fermentation media for the continuous lactic acid (LA) production with L. pentosus) and a solid phase containing cellulose and lignin. In this set of experiments, a maximum volumetric productivity (Q_P) = 2.077 g L^?1 h^?1 and product yield (Y_P/S) = 0.62 g g^?1 were obtained for a dilution rate of 0.01 h^?1. The solid residues from pre‐hydrolysis were treated with NaOH in order to increase their cellulase digestibility, and dissolve the lignin content. The cellulose residue was used as substrates for lactic acid production by simultaneous saccharification and fermentation (SSF) in media containing Trichoderma reesei cellulases and Lactobacillus rhamnosus cells using the complete MRS broth or a cheaper medium. In both cases similar LA concentrations and volumetric productivities were achieved (P = 73.4–71.0 g L^?1 and Q_P = 1.28–1.25 g L^?1 h^?1, respectively), where P is LA concentration. The lignin solution obtained after the alkaline treatment was extracted with ethyl acetate in order to obtain the phenolic components. The extract obtained at pH 3 showed three times more antioxidant activity than the one extracted at pH 12.8, with an EC₅₀ of 1.396 g L^?1 for pH 3 and 4.604 g L^?1 for pH 12.8. The best extracts showed twice antioxidant activity than BHT. Copyright © 2007 Society of Chemical Industry     

Comparative Kinetic Study and Microwaves Non-Thermal Effects on the Formation of Poly(amic acid) 4,4'-(Hexafluoroisopropylidene)diphthalic Anhydride (6FDA) and 4,4'-(Hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline (BAPHF). Reaction Activated by Microwave, Ultrasound and Conventional Heating

Green chemistry is the design of chemical processes that reduce or eliminate negative environmental impacts. The use and production of chemicals involve the reduction of waste products, non-toxic components, and improved efficiency. Green chemistry applies innovative scientific solutions in the use of new reagents, catalysts and non-classical modes of activation such as ultrasounds or microwaves. Kinetic behavior and non-thermal effect of poly(amic acid) synthesized from (6FDA) dianhydride and (BAPHF) diamine in a low microwave absorbing p-dioxane solvent at low temperature of 30, 50, 70 °C were studied, under conventional heating (CH), microwave (MW) and ultrasound irradiation (US). Results show that the polycondensation rate decreases (MW > US > CH) and that the increased rates observed with US and MW are due to decreased activation energies of the Arrhenius equation. Rate constant for a chemical process activated by conventional heating declines proportionally as the induction time increases, however, this behavior is not observed under microwave and ultrasound activation. We can say that in addition to the thermal microwave effect, a non-thermal microwave effect is present in the system.     

Nanomaterials and the environment: a review for the biennium 2008-2010

Applications of nanotechnology are touching almost every aspect of modern life. The increased use of engineered nanomaterials (ENMs) in consumer products, chemical and medical equipment, information technology, and energy, among others, has increased the number of publications (informative and scientific) on ENMs. By the 1950s, very few papers were committed to nanomaterials (NMs), but in 2009, more than 80,000 journal articles included the concept nanotechnology. The objective of this review is to compile and analyze publications on NMs in the biennium 2008-2010. This review includes the most recent publications in risk assessment/toxicity, characterization and stability, toxicity, fate and transport of NMs in terrestrial ecosystems, and new ENMs. Carbon nanotubes, metallic, metal oxides and hydroxides nanoparticles, quantum dots, and polystyrene NPs are included.     

Comparison of Antimutagenic Activity of Phenolic Compounds in Newly Harvested and Stored Common Beans Phaseolus vulgaris against Aflatoxin B1

ABSTRACT: Phenolic compounds were extracted from recently harvested or stored black Jamapa beans ( Phaseolus vulgaris ) that were subjected or not to thermal treatment. The beans studied were cropped in the same area and were from the same lot. The highest amount of condensed tannins (CT) was found in the seed coat of recently harvested beans [222.41 ± 16mg of (+)-catechin equivalents per gram of seed coat]. After 2 yof storage, the amount of CT dropped significantly [35.8 ± 3.4 mg of (+) -catechin equivalents per gram of seed coat]. Thermal treatment significantly reduced the amount of CT in whole beans by approximately 70%. The raw seeds contained 13.76 ±1.2 mg of (+)-cat-echin equivalents per gram of seeds and a portion of CT appeared in the broth [9.4 ± 0.1 mg of (+) -catechin equivalents per gram of lyophilized broth]. The antimutagenic activity of these extracted phenolic compounds was tested against aflatoxin B₁ (AFB₁) in the Kado microsuspension assay. Newly harvested beans showed higher antimutagenic activity against AFB₁ mutagenicity than stored beans. The results suggest that to take the maximum advantage of components with biological activity present in beans, they must be used fresh.     

Frozen Foods Treated by Pressure Shift Freezing: Proteins and Enzymes

ABSTRACT: This work was focused on the changes that potatoes undergo after pressure shift freezing (PSF) treatment on protein content, peroxidase (POD), and polyphenoloxidase (PPO) enzymes. The samples were subjected to different conditions of P/T (210 MPa at −20°C; 180 MPa at −16°C; 150 MPa at −12°C; and 120 MPa at −8°C). Results showed that none of these conditions were enough to inactivate the POD and PPO enzymes. The POD was more resistant than PPO. Three isoenzymes of POD (61, 51, and 46 kDa) were detected. The protein content decreased about 50% after the PSF treatment at 210 MPa, −20°C; however, sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed 2 bands of about 21 kDa quite resistant to the treatment. On the contrary, mass spectrometry revealed among the resistant proteins, 2 fragments of pH 8.5 and about 20 kDa were more sensitive to 150 MPa, −12°C. The 2 fragments matched to a Solanum tuberosum proteinase inhibitor II protein