华东葡萄和里扎马特的离体保存研究初报

对华东葡萄和里扎马特在添加不同浓度多效唑(0,1.0,2.0,3.0,4.0,5.0 mg/L)的GS培养基上培养7个月,结果表明,里扎马特在多效唑浓度为4.0mg/L的GS培养基上,生长抑制率达80%以上,适于离体保存。华东葡萄在多效唑浓度为4.0mg/L的GS培养基上,也达到80%以上的抑制率,但保存5个月后,叶片由绿变白,干枯。此外,多效唑可促进华东葡萄和里扎马特生根。     

正交试验法优化香柏(变种)中总黄酮提取工艺

研究提取香柏总黄酮的最佳工艺条件。以总黄酮的得率为考察指标,溶剂回流作为提取手段,利用单因素和正交试验,考察提取温度、提取时间、乙醇溶液体积分数、液固比以及提取次数对总黄酮得率的影响。最优工艺条件为:在80℃水浴条件下,提取时间90 min、乙醇溶液体积分数60%、液固比50∶1(mL/g)、提取次数3次。在最优工艺条件下总黄酮的提取率可达7.68 g/100 g。该方法操作方便、准确可靠,可以用于工业化生产。     

Novel anti-obesity peptide (RLLPH) derived from hazelnut (Corylus heterophylla Fisch) protein hydrolysates inhibits adipogenesis in 3T3-L1 adipocytes by regulating adipogenic transcription factors and adenosine monophosphate-activated protein kinase (AMPK) activation

1. Download : Download high-res image (202KB)
2. Download : Download full-size image

     

The quality of protein-enriched products from sunflower seeds. 1. The effect of various production processes on the nutritive value of meals and protein isolates

Globulin isolates from native sunflower seed and industrial extraction meal obtained by extraction with different electrolyte solutions and subsequent isoelectric precipitation are relatively poor in the essential amino acids lysine, threonine, and methionine as compared to defatted seed meals. On the other hand, albumins separated by means of polyanionic complexing agents (sodium alginate and aluminium potassium sulphate) are relatively rich in these amino acids, and albumin-globulin-co-precipitates have a correspondingly balanced amino-acid composition, being also reflected by nutrition physiological values as BW, NPU, and EAA-index. As compared to seed meals protein isolates are characterized furthermore by a better protein digestibility.     

Effect of succinylation on the functional and physicochemical properties of α‐globulin,the major protein fraction from Sesamum indicum L.

α‐Globulin the major protein fraction fromSesamum indicum was succinylated to different levels and the effect of the chemical modification was evaluated both on the functional and physicochemical properties. The results suggest that the pH of minimum solubility shifted to the more acidic side (pH ˜ 4.5–5.5) for the succinylated α‐globulin whereas for control α‐globulin the pH of minimum solubility was 6.5. Succinylation also increased emulsion activity and emulsion stability of the protein. The emulsion stability increased from a control value of 53 ± 3 s to a value of 122 ± 5 s. Bulk density, water absorption capacity, oil absorption capacity, foam capacity and foam stability were evaluated in phosphate buffer (pH 7.0) containing 0.5 M sodium chloride and all these properties showed increased values as a result of succinylation. Ultracentrifugation studies showed that the % composition of 7S component increases with concomitant decrease in that of 11S fraction with the increase in percentage of succinylation. Further increase in succinylation resulted in only 2S component which is a dissociated form of 11S and/or 7S protein fractions. The fluorescence emission studies showed a decrease in the fluorescence emission intensity of α‐globulin as a result of succinylation. The thermal stability of the protein molecule decreased due to progressive succinylation as indicated by decrease in the apparent thermal denaturation temperature from a control value of 84 to 62°C at a succinylation level of 40%. These results suggest that succinylation improves the functional characteristics of α‐globulin. Such changes in the functional properties have been attributed partly to the dissociation of the protein molecule at higher levels of succinylation and the increase in the net negative charge on the protein.     

Production,characterization and application of protein isolates from shark Part 1. Influence of pH,ionic strength,solid/liquid relationship and extraction time on to the extractability and precipitability of shark flesh proteins

In oppossiton to the extraction time, the pH, the sodium chloride content and the solid/liquid relationship show a clear influence onto the extractability of shark flesh proteins; that is also valied for the protein precipitability as a function of the pH. The relative low extractability of the shark flesh proteins by pH 5 or pH 4 with 0.25% NaCl offers interesting possibilities for a production of protein isolates from shark flesh through a flesh cleaning-extraction process.     

II. Yeast sequencing reports. The sequence of 12·5 kb from the right arm of chromosome II predicts a new N-terminal sequence for the IRA1 protein and reveals two new genes,one of which is a DEAD-box helicase

We have determined the complete nucleotide sequence of a 12·5 kb segment from the right arm of chromosome II carried by the cosmid α20. The sequence encodes the 5′ end of the IRA1 gene. Two complete new open reading frames and the 3′ non-coding region of the SUP1 (SUP45) gene. A comparison of our sequence with the data bank reveals a 154 amino acid extension at the N-terminus of Ira1p compared to the previously predicted sequence. According to the 11th edition of the Saccharomyces cerevisiae genetic map, our sequence should encode the MAK5 gene, which is necessary for the maintenance of dsRNA killer plasmids. One of the two new open reading frames, YBR1119, is predicted to encode an RNA helicase, thus YBR1119 may correspond to the MAK5 gene. The sequence has been deposited in the EMBL data library under Accession Number X78937.