Selenium content of breast milk

Selenium levels in human milk in the winter period ranged from 5.3 μg/l to 23.8 μg/l, the mean value being 11.0 μg/l. The nursing women were divided into several groups according to the results of a questionnaire, i.e. according to their social status (refugees or otherwise), number of deliveries, post partum days, the weight they had gained during pregnancy, their age and smoking habits. The mean levels of selenium for each group are presented. Selenium was determined by hydride generation atomic absorption spectrometry.     

TUDIES ON THE FATTY ACID COMPOSITION OF HOP EXTRACT

Studies on fatty acids composition of hop extract obtained from Vurtenberg hop by extraction with a threecomponent mixture was carried out. It has been established that the content of fatty acids in hop extract is 0.3% ±5%. Fatty acids composition was determined by Gas-chromatographic analysis. The presence of the following unsaturated fatty acids has been proven: C_16:1; C_18:1; C_18:2; C_18:3; C_20:1 which represent about 40% of the general content of fatty acids in the extract.     

基于数字图像的非均质岩土工程材料的数值分析方法

提出了一种基于数字图像的非均质岩土工程结构的二维数值分析方法。以花岗岩为例,先将岩石的表面图像导入计算机中;然后采用基于彩色空间的数字图像技术将组成花岗岩的几种主要材料:长石、石英和黑云母一一分辨出来并再现岩石的细观结构;再通过一个简单的线性转换,将图像细观结构转换为矢量细观结构;最后,岩石的矢量细观结构可以与数值计算方法--有限元法或有限差分法结合,从而实现非均质岩石材料的力学分析。采用有限差分法FLAC程序来分析岩石的破坏过程。传统室内试验数值模拟表明材料的细观结构对应力分布和破坏模式有着明显的影响,基于数字图像的数值分析方法可以真实地实现岩土工程材料的非均质分析。     

IMPLEMENTATION of an AUTOMATED REAL-TIME STATISTICAL PROCESS CONTROLLER

Through a simple application, this research demonstrates the potential and procedure of applying computer vision and control techniques in developing automated real-time statistical process controllers (SPC). A computer vision system was developed to sample and measure quality variables (area, length, and width) of an extruded food product. Shewhart control charts were used to monitor the state of statistical control. Corrective actions were determined by using a PI control algorithm to minimize the product size variation caused by material inconsistency in moisture content. the system was implemented and tested. Considerable improvement was achieved in product size uniformity.     

Lipid oxidation in chicken as affected by cooking and frozen storage

Oxidative rancidity in fresh, frozen and cooked chicken breast and leg meat was evaluated by measuring malondialdehyde (MDA) in fat from meat with an improved 2-thiobarbituric acid (TBA) assay with antioxidant protection, and by measuring the relative fluorescent products of organic and aqueous layers from Folch extracted meat. Fresh samples were frozen for 3 and 6 months at ?18 °C and cooked in convection and microwave ovens. Frozen storage for 3 and 6 months either before cooking or after convection and microwave cooking substantially increased MDA concentrations in fat from meat, whereas cooking was more effective in generating fluorescent products. There were no significant differences in free MDA concentrations or TBA numbers in chicken meat between convection and microwave cooking methods. The certain secondary fluorescent products were significantly higher in meat cooked by convection oven. The initial levels of either MDA or fluorescent products in meat are of primary importance in determining the final MDA and fluorescence levels after processing.     

Chilled storage of golden gray mullet (Liza aurata)

This study determined quality changes of whole ungutted golden gray mullet (Liza aurata) while stored in ice or in a refrigerator (without ice). Changes in microbiological quality (total viable and psychrophilic counts, lactic acid bacteria and Enterobacteriaceae), chemical quality (pH, total volatile basic nitrogen, trimethylamine, peroxide value, thiobarbituric acid, and free fatty acids), and raw fish sensory attributes were evaluated during 16 days of storage. The sensory attributes of golden gray mullet correlated well with the microbiological analyses (r = 0.92). Based on the overall raw acceptability sensory scores and the microbiological tests, the shelf life of the raw golden gray mullet was 10 days in ice and about 14 days in a refrigerator.     

Essential and trace elements content of commercial infant foods in the UK

There is a paucity of data in respect of the nutritional quality of complementary foods for infants and young children aged between 6 and 12 months. The primary objective of this study was to examine nutritive values of such complementary infant food on the UK market in order to ascertain their suitability relative to dietary guidelines for the 6–9 months age group. Quantitative analyses were conducted on eight different products representing four popular brands (meat and vegetable based) currently on sale in the UK. Eight major mineral and trace elements, namely: calcium, copper, magnesium, iron, zinc, potassium, sodium and selenium were measured by ICP–OES and ICP–MS. The results of these studies were referenced to the Recommended Nutrient Intake (RNI) values for 6–9 months old children, and a menu of entire daily intake of minerals and trace elements was composed taking into consideration the nutrient and energy intake from milk consumption. Based on these comparisons, all the food samples studied in this work contained less essential minerals than expected from the RNI values except for potassium in meat and vegetable based recipes. These results suggest that commercial complementary infant foods on the UK market may not contain the minimum levels of minerals required for the labelling declaration of micronutrient content (Commission Directive 2006/125/EC). This provides opportunities and scope for product optimisation to improve their nutritive value.     

Effects of deamidation on aggregation and emulsifying properties of barley glutelin

The structure, solubility and emulsifying properties of the deamidated barley glutelin were investigated. The SDS–PAGE, size exclusion chromatography combined with a laser photometer (SEC-LP) and Fourier transform infrared spectroscopy (FTIR) results revealed that glutelin underwent a rapid hydrolysis and unfolding even at the initial stage of deamidation, leading to remarkably improved glutelin solubility at both acidic and neutral pHs. The deamidated glutelin demonstrated a strong tendency to form soluble aggregates of very large molecular weight (10⁶–10⁷ g/mol) probably due to disulphide-crosslinking and hydrophobic interactions. These aggregates played a major role in stabilising the emulsions at a broad range of deamidation levels (2.2–5.6% to 43%). In this way, undesirable property changes which result from excessive deamidation can be avoided, leading to wider applications of deamidated barley glutelin as an emulsifying ingredient in food and non-food applications.     

Effect of solvent type on the extractability of bioactive compounds,antioxidant capacity and colour properties of natural annatto extracts

This study was conducted to obtain annatto extracts with both high antioxidant capacity and colour potential using solvents of different polarities (water, ethanol/water, ethanol, ethanol/ethyl acetate and ethyl acetate). The highest levels of total phenolic compounds were found in the water, ethanol/water and ethanol extracts (0.5 mg GAE mL^?1), and the highest level of bixin was found in the ethanol/ethyl acetate extract (5.2 mg mL^?1), which was characterised as the reddest and the most vivid one (a* = 40.5, h° = 46.1, C* = 58.4). The ethanol/ethyl acetate extract also showed the highest antioxidant activity (4.7 μm TEAC mL^?1) and the highest percentage of tryptophan protection against singlet oxygen (63.6%). On the other hand, ethyl acetate and ethanol/water were the least effective solvents for the extraction of phenolic compounds and bixin, respectively. According to the multivariate statistical analysis, ethanol/ethyl acetate and ethyl acetate were the most promising solvents to obtain annatto extracts with both antioxidant and colour properties.