Solidification of a PEG 1500-epoxy nanocomposite around a horizontal pipe

A PCM-epoxy phase change material composite (polyethylene glycol 1500-epoxy) was developed as heat storage building element for houses with low energy consumption. The PCM component, polyethylene glycol 1500, was integrated in an epoxy matrix, and presents a phase change interval of 34-42 °C and an enthalpy of solidification of 103.411 kJ/kg. Experiments on solidification were conducted using a Plexiglas test cell filled with the PEG 1500-epoxy nanocomposite material (P15-E) for further implementation of this material in buildings. The forwarded solidification model assumes negligible convection in the liquid region and predicts the time for radial formation of two regions: a mushy-zone and a solid, annular one around the pipe during solidification. The heat transfer during solidification can be also characterized by the time evolution of both liquid and solid radial fronts. The model was analytically solved using Megerlin approximation concerning “solidification with mushy zone”, with the third order condition at the external frontier. The experimental values are in agreement with the calculated theoretical curves.     

The Nutritional Value of Protein-hydrolyzed Formulae

Allergy to cow's milk proteins is a challenging condition in early infancy. Allergic infants may be predisposed to impairments of growth from either the disease itself or the nutritional constraints of the exclusion diet they should follow. Formulae based on extensively hydrolyzed cow's milk proteins are widely used, representing therapy, and constituting 100% nutrient source in the first four to six months of life and half the daily nutrient intake in the second semester of life. In some cases, these products are used also for preventive purposes. Some impairments in growth have been reported for infants using these products, even if mostly limited to the first year of life, with no apparent consequences in either the medium or long term. The macronutrient content of infant formulae based on protein hydrolysates, whichever the source, should carefully be tested not only as far as the optimal utilization of nitrogenous sources but also on the nature and metabolic fate of non-nitrogen caloric sources, represented by carbohydrates and fats, and micronutrients, particularly iron. It is recommended that studies aimed at the allergologic effects of these products also include an appropriate nutritional evaluation to determine their efficiency.     

Retention of ochratoxin A and fumonisin B1 and B2 from beer on solid surfaces: comparison of efficiency of adsorbents with different origin

Fifteen solid materials with variable origin and various adsorption properties for retention of mycotoxins were tested—mineral materials, organic polymers and chemical modified silica gels that are used in widespread separation techniques. Some filtration materials currently utilized in brewing technology for beer clarifying and filtration were also examined. Adsorbents have been investigated in model and real samples (beer) and evaluated on the basis of adsorption capacity for ochratoxin A and fumonisin B1 and B2. Mentioned mycotoxins are commonly present in beers and may increase the risk on human health in high beer-consuming countries. The ability of adsorbent to retain mycotoxins on its surface was evaluated as micrograms of mycotoxin per one gram of adsorbent or as percentage of mycotoxin adsorbed. The experiments were accomplished in dynamic mode, which is mostly applied in beer production. The quality profile of beer after treatment with adsorbents in connection with high efficiency of mycotoxins’ removal was also considered. The main beer qualitative attributes such as pH value, color, iso-alpha acids were defined. As perspective adsorbents has shown to be carbon and modified silica gels. The retention of ochratoxin A on carbon was 90–96% in range of carbon dosages 2.5–6.5 g/l, and its retention on modified silica gels alters in scope of 64–94%. The retentive effect of fumonisin B1 and B2 on modified silica gels reached 74–100% in dependence on adsorbent dosage. Most changes underwent iso-alpha acids likely in consequence of retention on adsorbents together with mycotoxins. To achieve the scheduled goals the sensitive HPLC methods with fluorescence detection were used.     

Structure and Functionality of Whey Protein Concentrate-Based Products with Different Water Contents

Properties of different heated mixtures of whey protein concentrate, starch, gelatin, and sucrose with different water contents were studied. The water activity of samples was determined. The structural properties were analyzed by confocal laser scanning microscopy, solubility assays in different extraction solutions, polyacrylamide gel electrophoresis, and differential scanning calorimetry. Color, texture, and water-holding capacity of samples were also determined. Results show that a certain water content it is needed to form a structure with solid characteristics in these mixtures. The temperature for starch gelatinization is lower than the temperature for whey proteins denaturation, but when sucrose is present, whey proteins are denatured, before the gelatinization of starch. Sucrose is major contributor to the adhesiveness of the samples and to the decrease of their water activity. Also, sucrose decreases the firmness and cohesiveness of the samples. The main component that contributes to the browning of the samples during the heat treatment is whey protein concentrate, whereas starch is the main component responsible for the water-holding capacity in these samples. Gelatin does not modify appreciably the properties of the mixtures in the proportion used in these assays.     

Antioxidant activity of seed polyphenols in fifteen wild Lathyrus species from South Spain

Antioxidant activity of seed phenolics was studied in the following Lathyrus species: Lathyrus hirsutus, Lathyrus filiformis, Lathyrus sativus, Lathyrus cicera, Lathyrus angulatus, Lathyrus sphaericus, Lathyrus annuus, Lathyrus clymenum, Lathyrus pratensis, Lathyrus ochrus, Lathyrus aphaca, Lathyrus latifolius, Lathyrus setifolius, Lathyrus tingitanus and Lathyrus amphicarpos. Phenolic contents ranged from 3.8 mg/g meal in L. setifolius to 29.2 mg/g meal in L. sphaericus. In general, non-cultivated Lathyrus species contained higher phenolic contents than cultivated ones. A negative correlation between seed size and phenolic contents was observed and was related to the higher proportion of hulls in the smaller seeds. L. annuus possessed phenolics with highest specific antioxidant activity. These phenolics were more than two times more antioxidant than equivalent amounts of phenolics extracted from commercial chickpea, lupin or soy. On the other hand, L. aphaca possessed the highest antioxidant activity per mg of flour extract. This antioxidant activity was twice that observed in same amounts of extracted flours from commercial chickpea, lupin or soy. Results show that studied Lathyrus species are rich in phenolic compounds with higher antioxidant activity than phenolics of widely consumed legumes such as soy, chickpea or lupin. In conclusion, Lathyrus may represent an interesting source of phenolic compounds with high antioxidant activity that may be useful as natural antioxidants and contribute to revalorize the cultivation of these legumes.     

Microwave heating of different commercial categories of olive oil: Part I. Effect on chemical oxidative stability indices and phenolic compounds

The effect of microwave heating of extra virgin olive oil (EVOo), olive oil (Oo) and pomace olive oil (Po) in domestic appliances, was investigated in terms of chemical oxidative indices (peroxide, p-anisidine and Totox values), free acidity, water content, total phenol content and different classes of phenolic compounds.