A combination of near-infrared hyperspectral imaging with two-dimensional correlation analysis for monitoring the content of biogenic amines in mutton

The study investigated the feasibility of using a combination of near-infrared hyperspectral imaging (NIR-HSI) with two-dimensional correlation (2DCOS) analysis for rapid and non-destructive determination of the content of biogenic amines in mutton during refrigerated storage. Total contents of biogenic amines (TBA) were used as the perturbation. By analysing the synchronous and asynchronous two-dimensional correlation spectra, sensitive variables that were closely related to TBA contents were obtained. The results showed that the wavelengths in the spectra range of 1002–1335 nm were the research area for the detection of TBA contents in mutton. The least-squares support vector machines (LSSVM) model based on effective wavelengths selected by competitive adaptive reweighted sampling (CARS) from 2DCOS analysis showed excellent results, with correlation coefficient in prediction (Rp) of 0.91, root mean square error in prediction (RMSEP) of 1.67 mg kg⁻¹ and the ratio of performance deviation (RPD) of 2.76. The research demonstrated that the combination of NIR-HSI and 2DCOS could be used as an effective method for monitoring the content of biogenic amines in mutton.     

羊肉的产地溯源和鉴别技术研究进展

随着羊肉消费量不断增加和相关食品安全问题频现,对羊肉溯源和掺假鉴别技术的需求已经成为当前社会的关注热点之一。目前,对于羊肉的溯源和鉴别已有相应研究,稳定同位素技术、矿物质元素指纹图谱、近红外光谱、DNA分子标记溯源技术、基于脂肪酸的溯源和鉴别技术、基于风味化合物的产地溯源和鉴别技术等在溯源和鉴别研究中得到了大量应用。但在这些技术不断发展的同时,也暴露出了一些亟待解决的问题。本文基于当前羊肉溯源和鉴别技术的相关研究资料和文献,对相应技术的优缺点进行总结和讨论,分析目前技术研究中存在的问题,并提出相应的建议和解决方法,以期为羊肉溯源和鉴别的进一步研究提供理论支持。     

新鲜猪肉气调保鲜包装技术与设备

本文介绍鲜猪肉气调保鲜包装混合气体的组成、保持鲜肉色泽与防腐保鲜效果和GM型气体比例混合器的结构与性能。通过鲜猪肉的气调包装和真空包装保鲜效果试验得出：在0～6℃温度贮藏14天后，两种包装的保鲜和保持色泽的效果相比较，气调包装鲜猪肉的细菌总数低于真空包装，血色素的指标是真空包装的三倍。研制的GM型气体比例混合器，可使二种气体（O2与CO2或CO2与N2）或三种气体（O2、CO2、N2）任意体积比例混合，气体比例混合的精度（±1％，其标准流量在0．1MPa压力下为2．4m3／h）GM型气体比例混合器的供气量可满足热成型真空充气包装机或其他机型的气调包装操作要求。     

一次泵变流量系统设计要点

一次泵变流量系统是一种优化的空调水系统的设计方案,可降低空调系统的整体能耗,属于节能环保的空调系统,但是其系统的构成、运行特点和控制理念都与传统的二次泵系统不同.本文着重讨论一次泵变流量系统的设计方法,主要包括采用一次泵变流量系统设计时经常会碰到的问题,如:对冷水机组流量变化范围及流量变化率的限制的要求,冷冻水泵流量变化的控制方法,以及冷冻水系统的控制原理.介绍在一次泵变流量系统中遇到冷水机组大小机搭配时冷冻水系统的设计方法,并就一次泵变流量系统加载、减载冷水机组的逻辑等问题进行阐述.     

鸡肉冰点调节剂的筛选及其贮藏期间品质变化

以新鲜鸡胸肉为原料,冰点为指标,采用响应面法对冰点调节剂的配比进行优化,并对冰鲜鸡肉贮藏期间品质变化进行研究。结果表明,筛选出冰点调节剂的最佳配方为:NaCl 5.48%、海藻糖3.12%、VC2.06%、山梨醇2.06%,在此条件下,预测鸡肉冰点为-2.4℃;在贮藏温度-2.4℃条件下,随着贮藏时间的延长,添加冰点调节剂的处理组在硬度、弹性、黏附性、咀嚼性和恢复性方面显著优于未添加冰点调节剂的对照组(P<0.05),且处理组有较高L*和a*、较低b*,保持了较好肉的色泽;贮藏期间处理组的挥发性盐基氮(total volatile basic nitrogen,TVB-N)上升值均低于对照组,其货架期可延长至24 d;扫描电镜(scanning electron micrograph,SEM)分析贮藏24 d鸡肉的微观结构表明,处理组的肉组织结构优于对照组,其肌原纤维结构未出现断裂、排列整齐且紧密。     

以茶多酚为主体的抗氧化剂联用对冷却肉保鲜作用的研究

研究了茶多酚及其分别与维生素E(VE)、维生素C(VC)、(VE VC)联用对冷却肉的保鲜作用,探讨了各组抗氧化剂的保鲜机理.结果表明:茶多酚对冷却肉具有显著的保鲜效果,它与Vε、VC、(VE VC)联合使用时有增效作用.保鲜效果顺序为:茶多酚 VC VE＞茶多酚 VE＞茶多酚 VC＞茶多酚＞对照组.     

空调冷水系统设计常见问题及对策

为了使中央空调能有效地达到节能降耗，就空调冷水系统设计、调试、运行管理过程中可能出现的问题进行了分析和总结，并提出了所需要采取的技术措施。     

Surimi-Like Products From Mutton

Surimi-like mutton products were produced using hand boned meat (HBM) and mechanically separated meat (MSM). Washing increased moisture and decreased fat and protein in surimi-like products. Collagen solubility and water holding capacity were higher for surimi-like products from MSM when compared to those from HBM. Washing reduced bone content of MSM. Percentage of 14:0, 16:0, 18:0 and 18:1 fatty acids tended to decrease and percentage of polyunsat-urated fatty acids tended to increase with washing. Acceptable restructured beef steaks with reduced salt content were produced when washed HBM or washed MSM were included.