Rapid Assessment of Frying Performance Using Small Size Samples of Oils/Fats

A rapid, effective test mimicking actual frying was developed to assess the frying performance of oils and fats using small size samples. To a small volume of the oil to be tested, a formulated food consisting of gelatinized potato starch, glucose and silica gel (4:1:1 w/w) were added and content heated at 185 ± 5 °C with mixing for 2 h. Thermo-oxidative degradation of the oil was assessed by the measurement of the total amount of polar components and their composition, including degradation of tocopherols. The developed fast test accurately mimics actual frying done using an institutional fryer as assessed by the accumulation and composition of total polar components and the amount of residual tocopherols. The validity of the test was assessed using the following oils: regular canola, high oleic– low linolenic canola, and high oleic sunflower. Comparison of data between the fast frying test and institutional frying revealed a lack of significant differences. The developed frying test provides reliable quantitative and qualitative data describing the performance of the frying oil/fat. The rapid frying procedure allows assessment of the frying performance of oils at the early stages of development where usually only small amounts of the sample are available and when a large number of samples have to be tested assessing effects of oil additives.     

Electrochemical studies of carbon-rich polymer-derived SiCN ceramics as anode materials for lithium-ion batteries

The electrochemical behavior of poly(phenylvinylsilylcarbodiimide)-derived SiCN ceramics as anode material for lithium-ion batteries is reported here for the first time. The novel carbon-rich silicon carbonitride (SiCN) ceramics have been synthesized by the thermal treatment of poly(phenylvinylsilylcarbodiimide) under argon atmosphere at five temperatures, namely 1100, 1300, 1500, 1700 and 2000 °C. The SiCN electrodes were prepared without any conducting additives and were tested in electrochemical two electrodes cell using cyclic voltammetry and galvanostatic techniques. The capacity of the carbon-rich SiCN samples was found to be stable upon galvanostatic cycling and reaches almost 300 mAh/g for the sample prepared at 1300 °C with oxygen as the impurity. The dependence of the microstructure, especially of the crystallinity of the segregated carbon phase and of the oxygen impurities on the electrochemical behavior of the SiCN material, was analysed. At all temperatures of thermolysis, the free carbon phase has been identified as “soft carbon”.     

Nutrient redistribution by grazing cattle drives patterns of topsoil N and P stocks in a low-input pasture ecosystem

Nutrient cycles in grassland often involve net transfers from some areas to others. Here, we analyse patterns of N and P transfers by cattle in two grazing periods, and their relationships to soil P and N stocks in an unfertilised old pasture with a history of >50 years grazing. Net transfers were assessed from spatial patterns of nutrient ingestion and excretion. Total soil N and P were determined at 0–5, 5–10, 10–30 and 30–60 cm. All analyses were performed with a spatial resolution of 10 × 10 m² or higher. Data were geostatistically interpolated. Nutrients accumulated in the flat crest zone and were depleted in the steeper areas. Nutrient ingestion was less and excretion higher in the accumulation zone (and vice versa in the depletion zone) revealing that both components of grazer-driven net transfers of nutrients promoted the development of accumulation/depletion zones. Topsoil stocks of N and P were closely correlated with excreta density and net transfers of N (P < 0.001), whereas N and P at 30–60 cm displayed only weak or no correlation. Redistribution involved a small fraction of the soil stocks: nutrients grazed in two periods were equivalent to 0.8% of N and 0.2% of P of the whole pasture (0–60 cm). These factors suggest that topsoil nutrient distribution was modified by long-term stable patterns of net transfers of nutrients. The excess of N in the accumulation zone (N in accumulation zone minus N in depletion zone, in 0–60 cm) was 11 times larger than that of annual (i.e. short-term) net transfers; but for P, it was 30 times larger. This contrast likely derived from leaching/volatilization losses of N in the accumulation zone and only small inputs of biologically fixed N in the depletion zone. The nitrogen status of vegetation (Nitrogen Nutrition Index) had a strong effect on herbage production throughout the pasture, while the Phosphorus Nutrition Index indicated no limitation, except in urine patches.     

Consensus design of repeat proteins

Consensus design is a valuable protein-engineering method that is based on statistical information derived from sequence alignments of homologous proteins. Recently, consensus design was adapted to repeat proteins. We discuss the potential of this novel repeat-based approach for the design of consensus repeat proteins and repeat protein libraries and summarize recent results from such experiments.