铸轧机熔炼炉、静置炉仪表及电气控制系统的改造

介绍铝板材铸轧机熔炼炉、静置炉温度控制系统的原理,分析原设计控制系统出现的控制仪表烧毁及电气故障、仪表故障与电气故障难以判别、致使故障处理时间较大等原因,并对其控制系统实施了改造,取得了较好的效果。     

20kt/a竹浆制浆料片输送堵塞问题的分析及处理

针对200kt/a竹浆连续蒸煮装置在建成投料试运行中频繁出现料片在缓冲仓及分料螺旋中堵塞现象进行分析,在查出堵塞原因后对设备进行改造,解决了料片输送堵塞问题。     

竹浆厂除硅工艺技术的探索

为解决竹材在硫酸盐法蒸煮过程中硅与氢氧化钠反应生成硅酸钠而进入蒸煮黑液,导致碱回收系统一系列的“硅干扰”问题,通过在硫酸蒸煮过程中添加偏铝酸钠、氧化钙、硫酸铝留硅剂和在预苛化过程中添加铝盐除硅剂可降低或解决“硅干扰”对竹浆制浆的影响。     

不同加热条件下牛肉嫩度和保水性的变化及机理

为探究不同加热条件下牛肉嫩度及保水性的变化机理,测定了牛肉在不同加热温度和时间条件下的蒸煮损失率、剪切力、肌原纤维小片化指数和肌节长度,并进行了差示扫描量热和低场核磁共振测定。结果表明,随加热温度的升高,蒸煮损失率显著增大(P0.05);剪切力整体趋于上升,但在45~55℃和75℃以上温度时均出现下降趋势,肌原纤维小片化指数在55~65℃显著增加(P0.05),可能由肌动球蛋白解离造成,这也是55℃时剪切力下降的主要原因;差示扫描量热测定中变性焓值和低场核磁共振T2弛豫谱测定中的T_(21)与A21逐渐降低,肌节长度呈缩短趋势,这与蒸煮损失率的变化一致。这些结果表明55~65℃是牛肉加热过程中的一个关键控制温度范围,可以为进一步形成牛肉类菜肴低温加热技术提供理论依据。     

酱卤肉制品关键加工技术研究进展

酱卤肉制品是深受我国居民喜爱的一种传统肉制品，在从作坊式生产到工业化生产的转变过程中，通过持续的技术改进，产品品质得到不断提高。本文围绕酱卤肉制品3 个主要的加工环节：腌制、卤制和杀菌，对酱卤肉制品的加工技术进行总结。目前，腌制技术主要有滚揉腌制、注射腌制、高压腌制、超声波辅助腌制等；卤制技术主要有老汤卤制技术和定量卤制技术；杀菌技术主要有热力杀菌、微波杀菌、超高压杀菌、高压电场杀菌、超声波杀菌、辐照杀菌等。这些技术，特别是新技术在改善肉制品等食品品质方面具有良好的效果，使用这些技术将有助于提高酱卤肉制品质量，更好适应消费市场的需求。     

Thermal processing implications on the digestibility of meat,fish and seafood proteins

Thermal processing is an inevitable part of the processing and preparation of meat and meat products for human consumption. However, thermal processing techniques, both commercial and domestic, induce modifications in muscle proteins which can have implications for their digestibility. The nutritive value of muscle proteins is closely related to their digestibility in the gastrointestinal tract and is determined by the end products that it presents in the assimilable form (amino acids and small peptides) for the absorption. The present review examines how different thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect the digestibility of muscle proteins in the gastrointestinal tract. By altering the functional and structural properties of muscle proteins, thermal processing has the potential to influence the digestibility negatively or positively, depending on the processing conditions. Thermal processes such as sous-vide can induce favourable changes, such as partial unfolding or exposure of cleavage sites, in muscle proteins and improve their digestibility whereas processes such as stewing and roasting can induce unfavourable changes, such as protein aggregation, severe oxidation, cross linking or increased disulfide (S-S) content and decrease the susceptibility of proteins during gastrointestinal digestion. The review examines how the underlying mechanisms of different processing conditions can be translated into higher or lower protein digestibility in detail. This review expands the current understanding of muscle protein digestion and generates knowledge that will be indispensable for optimizing the digestibility of thermally processed muscle foods for maximum nutritional benefits and optimal meal planning.     

Physicochemical and fatty acid characteristics of stewed pork as affected by cooking method and time

This study was designed to investigate the effects of cooking on physicochemical and fatty acid characteristics of stewed pork. Pre‐fried or raw pork belly cubes were stewed for 60, 90, 120, 150 or 180 min. After cooking, proximate chemical composition, texture, sensory evaluation, lipid oxidation, fatty acid profiles and cholesterol content were determined. Prolonged cooking time resulted in higher percentages of dry matter, fat and fat loss in stewed cubes (P < 0.01), and pre‐frying also increased fat loss. Tenderness and elasticity values of texture profile analysis and sensory scores were the highest for the cubes stewed for 180 min or by pre‐frying combined with stewing for 150 min. Pre‐frying and extended cooking time significantly increased lipid oxidation (P < 0.01). Cooking modified fatty acid profiles which altered the derived cardiovascular indices, and reduced cholesterol content. Prolonged stewing improved eating quality and most nutritional values of pork belly.     

液晶灌注工艺研究

液晶灌注在整个液晶显示器(LCD)的制造过程中有着举足轻重的作用,优化灌注制程对提高生产良率、缩短工艺所耗时间具有极其重要的意义。本文从生产实践出发对液晶灌注工艺进行了详细的研究,探讨了影响液晶灌注的几个重要因素,通过实验对液晶灌注参数进行了优化,并提出了改善措施,在一定程度上提高了液晶的灌注质量。     

Changes of volatiles in soy sauce‐stewed pork during cold storage and reheating

Pork, soy sauce, and pork in soy sauce were cooked separately for 4 h; their volatiles were isolated, analysed and compared. Many of the volatiles reported to be present in pork or soy sauce were lost, and some volatiles identified in this research were generated from precursors in pork and soy sauce during cooking. Water‐boiled pork and soy sauce‐stewed pork were prepared and stored at 4 °C; they were reheated daily and stored again at 4 °C for 10 days. During storage the amount of compounds containing sulphur, such as dimethyl trisulphide and thialdine, was higher in the water‐boiled pork than in the soy sauce‐stewed pork. 3,5‐Dimethyl‐trans‐1,2,4‐trithiolane was found only in the soy sauce‐stewed pork. Significantly more aldehydes produced from lipid oxidation, such as hexanal, 2,4‐decadienal and 2‐undecenal, were present in the water‐boiled pork than in the soy sauce‐stewed pork during storage. These aldehydes reached a maximum quantity at day 6 of storage. In contrast, the soy sauce‐stewed pork contained more hexadecanal, octadecanal and 9‐octadecenal than the water‐boiled pork. © 2001 Society of Chemical Industry