关键词：
Gelling;Low salt fish products;PH-shifting process;Silver carp;Surimi
摘要：
The pH-shifting processes (include acid and alkali process) and conventional water-wash process was applied to recover protein from bony silver carp muscle. And the new process was evaluated to obtain proteins for low salt (0% and 1% NaCl, w/w) fish products. The alkali isolated protein (AK) exhibited the best solubility at all salt concentrations. Furthermore, the AK had the highest gel strength and water binding capacity at low salt concentrations (0% and 1%). Low salt products of AK containing 1% salt showed similar mechanical properties to the water wash surimi (WM) obtained with 2% salt. The results obtained showed that the alkali process is a good method to recover functional proteins from boney silver carp muscle for low salt fish products.
摘要：
The physical and chemical properties of the flours, starches, and modified starches of indica rice and japonica rice were investigated in this paper. Results showed that the swelling powers of flour, starch, and phosphate starch [substitution degree (DS)=0.065] of japonica rice were significantly higher than those (DS=0.065) of indica rice. The transmittance of modified starches was highest; and that of flours was lowest. The pasting property investigated with rapid visco analyzer (RVA) indicated that the peak viscosity and breakdown value of paste with high swelling power were high. Furthermore, the effect of protein and amylose content on pasting property were investigated. The results of rheological properties determined using rheological rheometer showed that at the same temperature, the storage modulus (G') of flour, starch, and modified starch of indica rice was higher than that of japonica rice. For each variety, the G' of flour was the highest, while the G' of modified starch was the lowest.
期刊：
Journal of Medicinal Plants Research,2011年5(17):4298-4303 ISSN：1996-0875
通讯作者：
Lin, Qinlu
作者机构：
[Xiao, Huaxi; Wu, Yue; Wu, Wei; Fu, Xiangjin; Liu, Gao-Qiang; Lin, Qinlu] Cent S Univ Forestry & Technol, Natl Engn Lab Rice & By Prod Further Proc, Changsha 410004, Hunan, Peoples R China.;[Xiao, Huaxi; Fu, Xiangjin; Liu, Gao-Qiang; Lin, Qinlu] Cent S Univ Forestry & Technol, Coll Life Sci & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha 410004, Hunan, Peoples R China.;[Tian, Wei] Hunan Agr Univ, Dept Food Sci & Technol, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Lin, Qinlu] C;Cent S Univ Forestry & Technol, Natl Engn Lab Rice & By Prod Further Proc, Changsha 410004, Hunan, Peoples R China.
关键词：
Green tea polyphenols;rice starch;gelatinization;retrogradation;differential scanning calorimetry;X-ray diffraction
摘要：
The effect of green tea polyphenols (GTP) on the property of rice starch was investigated. 0, 5, 10 and 15% of GTP (based on rice starch weight) was added to rice starches with high (HAC), intermediate (IAC) and low (LAC) amylose contents, respectively. The gelatinization and retrogradation properties of rice starches with different amylose content containing different levels of GTP were analyzed by differential scanning calorimetry (DSC). The results exhibited that GTP could retard retrogradation of the three rice starches, which was further proved by X-ray diffraction investigation. In the DSC analysis, the temperature and enthalpy of starches gelatinization decreased with the concentration of GTP increasing. After storage at 4 degrees C for 20 days, retrogradation enthalpy (Delta H-ret) for all rice starches with different levels GTP began to appear, and the Delta H-ret and degree of retrogradation (DR%) of the three rice starches significantly decreased with the increased level of GTP. The X-ray diffractogram indicate that all the three gelatinized rice starch gels showed B-type X-ray diffraction patterns, and the B-type X-ray diffraction patterns gradually disappeared with the concentration of GTP increasing.
摘要：
The pH-shifting treatment (including acid treatment and alkali treatment) caused partly denaturation and degrading of myofibril. The pH-shifting treatment increased the surface hydrophobicity, surface -SH content and total -SH content, reduced the Ca-ATPase activity. Acid treated myofibril (ACM) did not show any endothermic transition peak in differential scanning calorimetry (DSC); while alkali treated myofibril (AKM) showed reduced T max value for myosin and actin. The SDS-PAGE indicated that acid treatment caused severe degrading of myosin heavy chain. High turbidity of ACM indicated more myofibril aggregated during acid treatment. The final G’ was in the decline order of M (550 Pa), AKM (135 Pa), and ACM (25 Pa). In conclusion, the alkali treatment was milder than the acid treatment.
