The impact of magnetic field-assisted freeze-thaw treatment on the quality of foxtail millet sourdough and steamed bread.

Foxtail millet and sourdough are used to make foxtail millet sourdough steamed bread to improve the flavor and taste. Compared with the conventional freeze-thaw treatment (CFT), the effect of magnetic field-assisted freeze-thaw treatment (MFT) on the storage quality of foxtail millet sourdough and steamed bread is explored. The results showed that compared with CFT, MFT shortened the phase transition time of dough; decreased the water loss rate, the water mobility, and the freezable water content; increased the fermentation volume; stabilized the rheological properties; and minimized the damage of freezing and thawing to the secondary structure and microstructure of the gluten. In addition, an analysis of the specific volume, texture, surface color, and texture structure showed that MFT was beneficial to slowing the deterioration of the steamed bread texture. Finally, MFT effectively inhibited the growth and recrystallization of ice crystals during freezing and thawing, improving the quality of millet dough and steamed bread.

Novel Eu-dipeptide assemblies for a fluorescence sensing strategy to ultrasensitive determine trace sulfamethazine.

Self-assembled Eu-dipeptide (tryptophan-phenylalanine) microparticles with multi-emission fluorescence was prepared and modified with a single-stranded DNA corresponding to the sulfamethazine (SMZ) adapter (Eu-PMPs@cDNA). Aptamer-functionalized magnetic Fe3O4 (MNPs@aptamer) was used to specifically bind the target SMZ. Using Eu-PMPs@cDNA as fluorescent signal probe and MNPs@aptamer as catcher, a noncompetitive fluorescence sensing strategy was developed for determination of SMZ with good sensitivity, accuracy, selectivity, and stability. Under the optimized conditions, fluorescence increases linearly in the 0-20 ng/mL SMZ concentration range, and the detection limit is 0.014 ng/mL. The fluorescence sensing method was applied to analysis of water and fish muscle samples, and recoveries ranged from 81.78 to 119.46 % with relative standard deviations below 4.2 %. This study offered a reliable and sensitive fluorescence sensing strategy for SMZ determination in food samples, which owns great potential for wide-ranging application in harmful compounds assay by simply changing the type of aptamer and its complementary single-stranded DNA.

The effect of heat moisture treatment times on physicochemical and digestibility properties of adzuki bean, pea, and white kidney bean flours and starches.

The effects of heat moisture treatment (HMT) times on the physicochemical properties of three bean flours and their starch were analyzed. The colors of L*, b* and ΔE values increased significantly with time. The adzuki bean and pea flours showed better WAI and SP, and better gelation of starch at 2 h. The rheological properties of mixed HMT dough (3:7) exhibited the typical solid-like weak gel behavior. HMT had a significantly decreased on the pasting viscosity of bean flour starch with treated time. HMT caused the starch granules damage, but did not radically change the crystal type. FTIR results showed more proteins attached to the surface of starch granules, and the short-range molecular order decreased the DO at 2 h. In vitro digestibility inferred that RDS converted into SDS and RS. These results indicated that HMT significantly affected the digestibility and physicochemical properties of bean flours.

[Analysis for the blood mineral content of children aged 3 to 12 years in 7 cities and 2 towns in China].

OBJECTIVE: To investigate the status of blood mineral content of children aged 3 to 12 years in Chinese cities and countryside and explore the possible related influencing factors. METHODS: The multistage stratified cluster random sampling was used to select one kindergarten and one primary school in seven cities (Beijing and Guangzhou and so on) and two towns randomly. Firstly, we selected one bottom class, middle class, top class in one kindergarten and one second grade and fifth grade in one primary school randomly. Then all of the healthful students of these classes were investigated and the blood mineral content of calcium, magnesium, lead, iron, copper, and zinc were detected. RESULTS: In the research, 1 842 students were investigated. The means of calcium, magnesium, lead, iron, copper, and zinc were in the standard range. The blood lead content of the boys was higher than that of the girls. The blood mineral content of different ages had statistical significance. The blood calcium and blood copper contents of the preschool children were higher than those of the school children. However, the school children had significantly higher blood lead, iron, and zinc contents in comparison with those of the preschool children. The incidences of iron deficiency and zinc deficiency were 35.5% and 39.6%, respectively. The incidence of iron deficiency and zinc deficiency of different ages had statistical significance, and with the age increasing, the incidence showed a decreasing trend. The incidences of iron deficiency and zinc deficiency of children whose age was more than or equal to 3 years and less than 4 years were up to 47.1% and 64.6%, respectively. The incidence of iron deficiency of the children in the countryside area was significantly higher than those in the first-tier cities. However, the incidence of zinc deficiency of the children in the countryside area was significantly lower than those in the first-tier cities and second-tier cities. CONCLUSION: The status of iron deficiency and zinc deficiency of children aged 3 to 12 years in Chinese cities and countryside were still serious. We should pay more attention to the nutrition interventional research on iron and zinc.

[Analysis on the iron deficiency and the rate of anemia of 3-11 year old children in 7 cities and 2 countryside in China].

OBJECTIVE: To investigate the status of iron deficiency and the rate of anemia of 3 - 11 year-old children in Chinese cities and countryside and explore the possible related influencing factors. METHODS: The multistage stratified cluster random sampling was used to select one kindergarten and one primary school in seven cities (Beijing, Shenyang, Suzhou, Zhengzhou, Chengdu, Lenzhou and Guangzhou) and two countryside randomly in Hebei Province one bottom class, middle class, top class in one kindergarten and one second grade and fifth grade in one primary school were selected randomly. All of the healthful students of these classes were investigated and the element iron and the parameters of red blood cell were detected. RESULTS: 1863 students in 7 cities and 2 countryside were investigated in the research. The incidence of iron deficiency of different ages had statistical significance and with the age increasing, the incidence showed a decreasing trend. The incidences of iron deficiency were 47.1% and 38.2% in 3 -4 year-old children and 4 - 5 year-old children, respectively. The incidence of anemia of different ages had statistical significance. The incidences of anemia of 3 - 4 year-old children and 4 -5 year-old children were significantly higher than those of 5 - 6 year-old children. The incidences of anemia were 4.0% and 7.1% in 3 - 4 year-old children and 4 -5 year-old children, respectively. No statistical significance for different sex of the same age was found for iron deficiency and anemia incidence. The incidence (12%) of anemia of the children in countryside area was significantly higher than those in first-tier cities and second-tier cities. CONCLUSION: The status of iron deficiency and the rate of anemia of 3 - 11 year-old children in Chinese cities and countryside were improved recently, but still serious. It should be paid more attention to the children with lower serum iron content and the children in rural areas.

[Effects of soybean isoflavone on reproductive development in SD rats].

OBJECTIVE: To assess the effects of soybean isoflavone on reproductive development in SD rats. METHODS: Forty 4 week-old SD rats (20 males and 20 females) were randomly divided into a control group and a soy isoflavone (SI) group according to their body mass, and were fed with normal diet or normal diet added with soy isoflavone (100 mg/kg BW), respectively. The body weight, daily food intake, estrous cycle, fertility index, pregnant index, gestation length, number of pups, blood hormone level, the weight of reproduction organ and the quality of sperm of the parental generation and the sex ratio, anogenital distance, vagina opening time, prepuce separation time of F1 generation were recorded. The data were analyzed by two independent t test, and the data of pups in each litter were analyzed as a unit. RESULTS: Compared with the control group, the body weight and food utilization of male and female rats in SI group were lower before copulation (P < 0.05). The total number of sperm of parental males was higher (P < 0.05). Serum luteinizing hormone (LH) level of parental male was lower (P < 0.05), serum luteinizing hormone (LH), prolactin (PRL) and progesterone (P) of parental female were lower in SI group (P < 0.05). There were no significant differences of other indices such as estrous cycle, mating index, fertility index between two groups. CONCLUSION: SI has certain effect on the bodyweight of parental males, food utilization of females, and the total number of sperm and the level of some hormones.

Complete genome sequence of Streptococcus thermophilus strain MN-ZLW-002.

Streptococcus thermophilus MN-ZLW-002 was originally isolated from traditionally fermented Chinese dairy products. One of the strain-dependent characteristics of this bacterium is its ability to produce exopolysaccharides (EPSs). This study determined and analyzed the genome sequence of MN-ZLW-002. Its complete genome comprised 2,046 genes and 1,848,520 nucleotides with an average GC content of 39%. The EPS cluster of MN-ZLW-002 includes 25 open reading frames (ORFs), and some results indicate a horizontal gene transfer between MN-ZLW-002 and other lactic acid bacteria (LAB).

The chemical composition of human milk from Inner Mongolia of China.

In Inner Mongolia, China, the chemical composition of 66 breast milk samples at three lactation stages was analysed. Except for total nitrogen content, the contents of total solid, fat, NPN, lactose and ash were not significantly different between colostral, transitional and mature milk. Fatty acids did not vary over the three lactation stages, while unsaturated fatty acids accounted for 59.95-63.22% of the total fatty acids. Relatively low contents of vitamins were in the milk because the volunteer mothers did not take any vitamin supplementation over the entire lactation period. Besides sodium and phosphate, the concentrations of most minerals in the breast milk remained fairly constant across the three lactation stages.

[Application of solid sampling graphite furnace atomic absorption spectrophotometry to mensuration of brain iron content in rats].

In the present study, the authors performed the solid sampling and detected the iron levels in cortex, hippocampus and striatum of rat brain by GFAAS. The authors' results showed that there are no remarkable difference between the data obtained by solid sampling graphite furnace atomic absorption and liquid sampling graphite furnace atomic absorption. Compared to liquid sampling graphite furnace atomic absorption, the sample pre-treatment stage was obviously simplified, the cost was reduced significantly, and the time was shortened significantly in the solid sampling GFAAS. This study will be beneficial to the mensuration of iron content in micro-tissue of animal by solid sampling GFASS.

Purification and characterization of an immunomodulatory Peptide from bovine placenta water-soluble extract.

An immunomodulatory peptide was isolated from bovine placenta water-soluble extract and purified by consecutive chromatography on DEAE Sepharose CL-6B, Sephadex G-25, and Sephasil C18 column using lymphocyte proliferation assay to identify the active fractions. The immunomodulatory peptide showed a dose-dependent stimulating effect on lymphocyte proliferation. The isoelectric point of the immunodulatory peptide was determined to be 3.82 by capillary isoelectric focusing electrophoresis. The molecular mass of the immunomodulatory peptide was determined to be 2133.52 Da by mass spectrometry. The first 10 amino acid sequence of the immunomodulatory peptide was Tyr-X-Phe-Leu-Gly-Leu-Pro-Gly-X-Thr. This immunomodulatory peptide showed no significant homology with other immunomodulatory peptides. Additionally, it was thermostable, retaining about 60% of immune activity after incubating at 80 degrees C for 30 min.