LIPID AND CHOLESTEROL OXIDATION,COLOR CHANGES,AND VOLATILE PRODUCTION IN IRRADIATED RAW PORK BATTERS WITH DIFFERENT FAT CONTENT1

An emulsion-type product was prepared to determine the effect of irradiation on lipid and cholesterol oxidation, color change, and volatile production in raw pork with different fat contents. Lipid oxidation increased with an increase in fat content or irradiation dose. Irradiated batters had higher cholesterol oxides than nonirradiated, and the major cholesterol oxides formed in irradiated pork batters were 7α- and 7β-hydroxycholesterol. Hunter color a- and b-values of raw pork batters were decreased by irradiation regardless of fat content. Irradiation increased the amount ofvolatiles significantly. Although lipid oxidation of high fat products (10 and 15% fat) was higher than that of low fat products (4%), high fat products did not always produce greater amount of volatiles. In summary, irradiation increased lipid and cholesterol oxidation, volatiles production and had detrimental effects on the color of raw pork batters under aerobic condition.     

SYNERGISTIC EFFECT OF VITAMIN B1 ON SANITIZER AND DISINFECTANT TREATMENTS FOR REDUCTION OF BACILLUS CEREUS IN RICE

The synergistic bactericidal effects of vitamin B₁ (thiamine dilauryl sulfate) and the efficacy of commercial sanitizers for minimization of Bacillus cereus contamination in cooked rice were investigated. Sanitizer-treated rice exhibited a greater reduction than water-treated rice, while sanitizer-treated rice with Vitamin B₁ produced an even greater reduction. The treatments for B. cereus in rice included (1) 100 ppm hydrogen peroxide with 500 ppm vitamin B₁; (2) 200 ppm hydrogen peroxide with 100 ppm vitamin B₁; (3) 400 ppm hydrogen peroxide; (4) 50 ppm chlorine with 500 ppm vitamin B₁; (5) 60 ppm chlorine with 300 ppm vitamin B₁; (6) 70 ppm chlorine with 100 ppm vitamin B₁; (7) 80 ppm chlorine; and (8) 100,000 ppm ethanol with 500 vitamin B_1. All treatments completely eliminated B. cereus in rice. The sensory properties of all sanitizer-treated cooked rice did not differ significantly from the same properties for water-treated cooked rice.

PRACTICAL APPLICATIONS

The prevalence of Bacillus cereus in rice and rice products has been documented and control of the growth of B. cereus in rice is an important consideration. The results obtained from this study can be of use to rice producers in the manufacture of safe products. Although chemical disinfectants can be used to reduce the amount of B. cereus in rice, vitamin B₁ can also be used as an effective additive that reduces the amount of disinfectant use via a synergistic antimicrobial effect. The increasing use of chemical disinfectants for safety in the food industry can be reversed using our method.     

Comparison of the Thermostability of Red Hake and Alaska Pollock Surimi during Processing

Thermostability of red hake (Vrophycis chuss) mince and its temperature-dependent gel-forming properties were determined while using Alaska pollock (Theragra chalcogrumma) for comparison. Fish mince and surimi were subjected to various washwater, chopping and setting/ cooking temperatures, cooking times at varying salt concentrations and moisture levels. The optimal temperatures for washing and chopping were 15°C and 12°C for red hake and 10°C and 4°C for pollock, respectively. All treatments significantly affected gel properties. For red hake gels, 77% moisture, 2.0% salt, and a 40°C preheat-setting temperature produced the most cohesive gel. Gels of both red hake and pollock gradually became less cohesive with extended cooking time. The results suggest that red hake is more thermally stable than pollock.     

肝转移癌射频消融治疗方案制定——超声造影的应用价值

【摘要】 目的 探讨超声造影（CEUS）在肝转移癌经皮射频消融（RFA）治疗前的应用价值。方法 2001年7月—2012年12月期间经皮RFA治疗的肝转移癌共267例485灶为本研究对象。其中180例251灶RFA治疗前行CEUS检查并确定RFA治疗方案（CEUS组）,另87例234灶为RFA治疗前未行CEUS检查（对照组）。两组病例的各项临床资料差异均无统计学意义（P < 0.05）。治疗后采用增强CT或（和）MRI、CEUS及肿瘤标志物检查定期随访判断疗效。结果 CEUS组中,25.1%（63/251灶）的CEUS测值较常规超声增大3 mm以上;8.8%（22/251灶）CEUS后显示清晰;造影后发现新病灶41灶。RFA治疗后,肿瘤早期灭活率CEUS组与对照组分别为95.2%（239/251灶）、92.7%（217/234灶）,差异无统计学意义（P > 0.05）。局部复发率CEUS组低于对照组,分别为12.4%（31/251）、19.7%（46/234）（P < 0.05）。局部复发时间CEUS组与对照组差异无统计学意义（P > 0.05）。结论 肝转移癌经皮RFA治疗前行CEUS检查有助于准确判断病灶大小及数目,制订有效治疗方案,从而提高肿瘤早期灭活率、降低复发新生率。     

残留复发性肝肿瘤射频消融治疗——超声造影的应用价值

【摘要】 目的 探讨对比增强超声（CEUS）在肝脏残留复发性恶性肿瘤进行射频消融（RFA）治疗的临床应用。方法 517例原发性肝癌（HCC）、肝转移癌患者经各种治疗后残留或局部复发拟行RFA治疗,共619个病灶为研究对象。复发HCC 281例290灶,病灶大小平均（3.4 ± 1.5）cm,其中CEUS引导治疗组150例154灶,常规超声引导组131例136灶。另复发肝转移癌236 例329 灶,病灶大小平均（3.1 ± 1.3）cm,其中CEUS引导治疗组152例198 灶,常规超声引导组84例131灶。结果 复发HCC CEUS组与常规组治疗结果比较:1个月肿瘤灭活率分别为96.1%和89.7%（P = 0.032）;肿瘤局部复发率各为9.7%和17.6%（P = 0.049）;两组间差异均有统计学意义。复发肝转移癌CEUS组与常规组治疗结果比较:1个月肿瘤灭活率88.4%和87.0%（P = 0.712）;肿瘤局部复发率16.7%和23.7%（P = 0.117）,两组间差异均无统计学意义。结论 CEUS 指导RFA治疗复发HCC,可有效提高早期灭活率,降低局部复发。     

Effects of Post-Harvest Handling and Processing on Vitamin Contents of Peas

Vitamin contents of peas were measured at various stages of raw product handling, during 1976–1979 seasons, on different cultivars, on different sizes of peas, at various stages of processing, and at different processing plants. Some cultivar differences were shown in ascorbic acid, carotene, and folic acid, and different sizes of peas contained significantly different amounts of ascorbic acid, carotene, and thiamin contents. Profound effects were observed during blanching and thermal processing of peas. Ascorbic acid, thiamin, vitamin B₆, and niacin contents of canned peas were significantly (95% level) lower than those of fresh peas. Also some significant differences in vitamin contents of canned peas among different processing plants were observed.     

空气自然对流式质子交换膜燃料电池的三维建模和实验分析

在空气自然对流式燃料电池内部,速度、温度、组分浓度及电流分布特性有着极强的耦合作用.氧气质量传输限制引起的浓度过电位是这种燃料电池的主要性能损失.从自然对流、传热传质的角度,建立了三维数学模型.利用三维流体动力学软件和用户建立的子程序,对自然对流下Navier-Stokes 方程,能量方程,电化学动力学方程以及组分、水的传输方程进行了数值求解.通过分析数值计算的结果,结合自然对流的特性,设计了实验系统.对温度分布和电池性能进行了测试.对空气湿度对电池性能的影响进行了分析.数值计算结果与实验结果很好地吻合.模型的建立,对于认识空气自然对流式质子交换膜燃料电池内部的耦合传输现象有极大的意义,可以作为质子交换膜燃料电池的计算机辅助优化设计工具.     

不同形态白炭黑对胎面胶性能的影响

通过选用不同形态的白炭黑,来研究其在同一个胎面胶中的硫化特性和物理机械性能。研究表明,其对胶料的性能影响不大,只是粉末状样品由于颗粒较小,比重较轻,较易产生粉尘较易飞扬,在密炼过程中容易对环境造成污染以及给工人身心健康带来负面影响。故在生产过程中,即使在成本小量增加的前提下也应该选用颗粒状等较不易产生粉尘的白炭黑来使用,以免对员工健康造成危害。     

回转窑轮带在受接触力时的非线性有限元仿真

用有限元非线性分析方法，建立回转窑轮带和托轮接触有限元分析模型；并通过编程计算出轮带和托轮的最佳接触刚度；通过仿真，可绘出整个轮带的应力分布图和变形图。与理论算法比较，此方法所得结果更直接，观察结果更方便，且与理论结果很相近。