Advanced Materials Research Vols. 941-944

Abstract: The effects of brine salting on sturgeon muscle proteins were studied during the processing of salting at different levels of NaCl . The aim was to observe conformational stability and possible degradation or denaturation of sturgeon protein by determining the biochemical characteristics of protein using Fourier-transform-infrared spectroscopy( FTIR), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), fluorescence and other means. The salting process significantly decreased the actomyosin content, Ca²⁺-ATPase activity,total and reactive sulfhydryls (SHs) and increased surface hydrophobicity of actomyosin. The results showed that the processing of salting salting induced the degradation or denaturation of actomyosin. From SDS–PAGE, actin was affected by salt to a lesser extent by the process than myosin heavy chain (MHC). From the FTIR, the secondary structure of protein changed significantly ,especiallyα-helix, at different levels of NaCl .

Abstract: The purpose of this experiment is to evaluate the nutritional value of amino acids and its commercial value in the fish processing sector in Antarctic krill with cross-referenced in the white shrimp. For determination of the composition of 17 amino acids in the two shrimp muscle, free amino acids were measured using sulfosalicylic acid method, hydrolysed amino acid using hydrochloric acid hydrolysis.17 kinds of hydrolysed amino acids are measured in the muscle of Antarctic krill and White shrimp, which total content is 513.59±18.56mg/g and 537.61±16.8mg/g respectively.16 kinds of free amino acids are measured, which total content is 616.88±44.61mg/100g and 1276±75.67mg/100g respectively, while cysteine is not found. According to amino acid score (AAS), chemical score (CS), the limiting amino acid of Antarctic krill and White shrimp is valine and methionine + cysteine. The umani amino acids accounted for 27.76% of free amino acids and 35.69% of hydrolysed amino acids in Antarctic krill, while White shrimp is 41.08% and 31.52% respectively. The amino acids in Antarctic krill, TAV of which is greater than 1, include glutamic acid, alanine, lysine and arginine.

Abstract: The purpose of this study was to extract Sambucus williamsii (SW) seed oil by supercritical carbon dioxide. Volatile components in SW seed oil were analyzed by GC/MS and 17 volatile components were identified. Physical and chemical indexes of the oil were determined by GB code methods and the results showed that these indexes were in accordance with the Chinese national standards. The antioxidant activity of the oil was evaluated by reducing power assay. A significant and linear correlation coefficient between the reducing power activity and the concentration of SW seed oil was found (R=0.9957). The experimental result suggested that SW seed oil had potential antioxidant activity.

Abstract: In order to control pesticide pollution, the degradation of dicamba in aqueous solution was investigated in a bubble reactor in laboratory using separate UV, separate O₃, O₃/UV systems. The experimental results show that UV has a synergistic effect on ozonation. The synergy factor of O₃/UV system is calculated to be 1.96. The degradation of dicamba follows pseudo-first-order kinetics. Considering that the composition of actual water is complex, chloride, nitrate, carbonate and bicarbonate ions, common ions appeared in actual water, were selected to add to reaction solution in O₃/UV system. Chloride and nitrite ions have inhibiting effect. Carbonate and bicarbonate ions have promoting effect. In O₃/UV system, different impurity ions have different influence on dicamba degradation with small amount addition.

Abstract: Tilapia skin gelatins were extracted with optimal acetic or citric acid concentrations which provide similar optimum protein yield (22g/100 wet weight), and rheological properties of gelatin solutions with various concentrations were measured and characterized. Commercial valued properties including bloom strength, gelling and melting point, viscosity were measured to compare the samples of the two gelatins. Liner viscoelastic range (LVR) of gelatin preparations with increasing concentration and decreasing temperature were determined. Temperature sweep was conducted for comparison and characterization the relationships between concentration and gelling/melting point of gelatin extracted by citric acid or acetic acid. The results showed that the melting and gelling point varying with concentration followed exponential curve (R2 as high as 0.99), and there were rarely molecular fractions in extracted gelatins. Elastic modulus (G′) of gelatin gels was mainly a function of cold temperature and time, while the discrepancy between the melting behaviors of gelatin extracted by two acids may stem from the composition and molecular weight of gelatin chains. In conclusion, the tilapia skin gelatin extracted in our study is of high qualities and rheological analysis is a critical tool for material of gelatin differentiation from varied molecular properties.

Abstract: The present study was to investigate the film forming properties of tilapia skin gelatin as affected by the addition of 2%, 5% Arabic gum or pectin (g/g gelatin), as well as 1%, 2% glutaraldehyde (GTA) (g/g gelatin) in an attempt to improve gelatin film properties. Tensile strength (TS) and transparency of gelatin film were improved 36.6% and 30.3% by the addition of Arabic gum, respectively, while the water vapor permeability (WVP) was not affected. The addition of pectin had less effect on the film tensile strength and transparency, but led to 41.7% of increase in WVP. Tensile strength and WVP of gelatin-arabic gum composite film cross-linked with 2% GTA were better than those of 1% GTA cross-linked composite film, though the extensibility and transparency were slightly weak. The FTIR spectra of gelatin films showed that both Arabic gum and pectin formed cross-linkages with gelatin protein molecules, while GTA facilitated the formation of intermolecular bonds, resulting in more stable films.

Abstract: MicroRNAs (miRNAs) are endogenous small RNAs transcribed from non-coding DNA, which have the capacity to base pair with the target mRNAs (messenger RNAs) to repress their translation or resulted in cleavage. We have paid much attention on the DNA and its coded proteins, the discovery of miRNAs as gene negatively regulators has led to a fundamental change in understanding of post-transcriptional gene regulation in plants. Fungal pathogens infection is the main cause of most economic crops diseases. Unlike humans, plants don’t evolved to have a adaptive immune system, they protect themselves with a mechanism consists of activation and response. Recently, high throughput sequencing validated that miRNA play a crucial role in plant-fungus interaction. A better understanding of miRNA-mediated disease mechanism in fungi should clarify the strategy of crop disease control. MiRNA-based manipulations as gene suppressors, such as artificial miRNAs, may emerge as a new alternative approach for the improvement of crops and control of crop disease.

Abstract: The aim of this work was to find out the effects of exogenous enzymes on the fermentation period of fermented sausages. The results showed that the FFAs and NPN contents of the sausages added exogenous enzymes were 2.83 and 3.34 times than that of the samples without exogenous enzymes (CK) at fermenting 12 h, respectively. Thus, compared with the CK, the fermentation period could be reduced about 60% by adding 0.10% lipase, 0.01%% acidic protease and 0.015% flavor protease, and the quality of products were as good as CK.

Abstract: Decreasing effects of fluoride contents in Antarctic krill (Euphausia superba) as affected by chemical treatments with and without heating were investigated. The used chemicals were Na₂SO₃, citric acid, acetic acid, HCl, betaine, sodium chloride. Fluoride contents per dry weight were 1138±1 mg/kg in the whole body of krill (WBK) and 333±2 mg/kg in the peeled krill meat (PKM) respectively. When WBK was treated with chemicals with and without heating, Decreasing effects of fluoride contents is not significant. The effect of defluorination by chemical treatments with heating is more significant than without heating. Particularly, the treatment of betaine without heating showed the best reduction effect of 48±9mg/kg and the highest defluorination efficiency of 85.59%, followed by citric acid (52±11mg/kg,84.38%), acetic acid (55±6mg/kg,83.48%) and hydrochloric acid (62±5mg/kg,81.38%).

Abstract: fasciated and lc loci controlled locule number of tomato fruit. The candidate gene of fasciated loci had been cloned the lc loci was also been fine mapping and two single-nucleotide polymorphisms (SNPs) located near WUSCHEL were found to be responsible for locule number. But whether WUSCHEL was the candidate gene of lc loci had not been known. In this study, we analyzed the expression of WUSCHEL in tomato with different locule number and under high and low temperature. The result showed that WUSCHEL expressed higher in FL1 which fruit with 2-4 locules than in MLK1 with 15 locules. We identified the WUSCHEL might be candidate gene of lc loci.