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排序方式: 共有1415条查询结果,搜索用时 15 毫秒
1.
Yinjuan Cao Shunzhong He Qunli Yu Ling Han Wei Zhang Xiaohong Zou 《International Journal of Food Science & Technology》2022,57(5):3001-3011
This study investigated the effect of 5 freeze–thaw cycles (freezing at −18°C for 12 h and then thawing at 4°C for approximately 12 h) on the meat quality, proximate composition, water distribution and microstructure of bovine rumen smooth muscle (BSM). As the number of freeze–thaw cycles increased, BSM pH, shear force, water content and protein content decreased by 3.06%, 35.50%, 14.49% and 21.11%, respectively, whereas BSM thawing loss, cooking loss, pressing loss, total aerobic count (TAC), ash content and fat content increased by 108.12%, 47.75%, 78.33%, 90.99%, 105% and 35.20%, respectively. The freeze–thaw cycles resulted in greater protein and lipid oxidation, as evidenced by a 36.46% reduction in the sulfhydryl content and a 209.06% and 338.46% increase in the carbonyl and malondialdehyde contents, respectively. Ice crystal formation disrupted the structural integrity of the muscle tissue. Low-field nuclear magnetic resonance results showed that the freeze–thaw cycles prolonged the relaxation times (T2b, T21 and T22), indicating that immobile water shifted to free water, and consequently, free water mobility increased. After 3 freeze–thaw cycles, the decline in shear force slowed, the increase in thawing loss became accelerated, and the TAC approached the domain value (6 log colony-forming units/g). Therefore, the number of freeze–thaw cycles of smooth muscle during transport, storage and distribution should be controlled to 3 or fewer. The current results provide a theoretical basis and data support for the further utilisation and culinary processing of smooth muscle. 相似文献
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Riham Gharib Jouda Mediouni Ben Jema Catherine Charcosset Sophie Fourmentin Hlne Greige‐Gerges 《European Journal of Lipid Science and Technology》2020,122(5)
Eucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention. Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release. 相似文献
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某公司加氢裂化装置生产的喷气燃料在冰点试验时发现了悬浮物,并且悬浮物在回温过程中消失。虽然通过调整原料中催化裂化柴油(简称催化柴油)、外购原料、常三线柴油的掺炼情况,减少原料中芳烃及正构烷烃的含量,但是在冰点试验时依然发现了悬浮物;其次,通过调整反应深度和分馏塔分离效果(喷气燃料馏程),以及对影响喷气燃料质量的其他因素进行排查,仍然未找到出现悬浮物的原因;最后通过化验分析方法排查发现,在干燥环境(没有湿空气的影响)下进行喷气燃料冰点试验时,可以避免产生絮状物,说明空气中的水是喷气燃料冰点试验中产生絮状物的直接原因。因此,在进行喷气燃料冰点试验时要采取措施隔绝水分。 相似文献
6.
Jiang-Yang Mei Ting Huang Cong-Hao Bai Zhen Fu 《International Journal of Food Science & Technology》2021,56(2):692-699
This study aims to investigate chitosan (CS) with five different molecular weight (Mw) on freeze–thaw stability of Arenga pinnata starch (APS) gel subjected to five freeze–thaw cycles (FTC). The syneresis of APS gels was reduced by adding CS and the APS gel with high Mw CS had lower syneresis duo to a higher water holding capacity (P < 0.05). The addition of CS significantly decreased the hardness and molecular ordered structure of APS gel. In addition, CS could improve the microstructural stability. The results suggested that CS could effectively improve the freeze–thaw stability of APS gel, and CS with higher Mw might have more practical utility to improve stability of APS gel. 相似文献
7.
Zhongpei Du Dongxu Yao Yongfeng Xia Kaihui Zuo Jinwei Yin Hanqin Liang Yu-Ping Zeng 《Journal of the American Ceramic Society》2020,103(10):5990-5998
Highly porous silica ceramics with unidirectional pores were prepared using the freeze casting method. By adjusting the solid content and freezing temperature, the porosity of the ceramics was tailored in the range of 78.20%-84.59% and pore size in the range of 8.4-71.4 μm, respectively. Sound absorption properties of porous silica ceramics was studied and the effect of structural factors was systematically investigated. The results showed that higher porosity and smaller pores of the porous ceramics favored the sound absorption in the entire sound wave frequency. By backing the sample with small pore size porous ceramics, the sound absorption property was enhanced, particularly in the low and medium frequency range, thus the sound absorption peak shifted towards lower frequency. The presence of air gap in the back would also favor sound absorption in low and medium frequency range. The as-fabricated porous silica ceramics owed excellent sound absorption properties due to their unidirectional pores and low flow resistances. 相似文献
8.
The Tunable Porous Structure of Gelatin–Bioglass Nanocomposite Scaffolds for Bone Tissue Engineering Applications: Physicochemical,Mechanical, and In Vitro Properties 下载免费PDF全文
Unidirectional freeze‐casting method is used to fabricate gelatin–bioglass nanoparticles (BGNPs) scaffolds. Transmission electron microscopy (TEM) images show that sol–gel prepared BGNPs are distributed throughout the scaffold with diameters of less than 10 nm. Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetric are used to evaluate the physicochemical properties of BGNPs. Scanning electron microscopy (SEM) micrographs present an oriented porous structure and a homogeneous distribution of BGNPs in the gelatin matrix. The lamellar‐type structure indicates an improvement of mechanical strength and absorption capacity of the scaffolds. Increasing the concentration of BGNPs from 0 to 50 wt% have no noticeable effect on pore orientation, but decreases porosity and pore size distribution. Increase in BGNPs content improves the compressive strength. The absorption and biodegradation rate reduces with augmentation in BGNPs concentration. Bioactivity is evaluated through apatite formation after immersion of the nanocomposites in simulated body fluid and is verified by SEM–energy‐dispersive X‐ray spectroscopy (EDS), an element map analysis, X‐ray powder diffractometer, and FTIR spectrum. SEM images and methyl thiazolyl tetrazolium assay confirm the biocompatibility of scaffolds and the supportive behavior of nanocomposites in cellular spreading. The results show that gelatin–(30 wt%)bioglass nanocomposites have incipient physicochemical and biological properties. 相似文献
9.
V. N. Beloborodov T. G. Glotova A. L. Isakov A. K. Tkachuk 《Journal of Mining Science》2002,38(5):518-522
The prototype of portable device is developed and approved for probing the concrete piles located in soil. The procedure for determining the pile length is proposed. 相似文献
10.
作者根据自己多年来的科研实践,系统的总结了示踪技术在我国煤矿通风安全方面的应用;指出示踪技术是一种安全、可靠、简便、先进的通风安全检测手段;对促进我国煤矿安全、提高煤矿通风安全技术水平有重要意义。 相似文献