基于包装功能的时间–温度指示器与食品新鲜度指示器研究进展

目的 从包装功能实现的角度分析研究时间–温度指示器和食品新鲜度指示器的原理、类型与发展趋势，指出开发设计时间–温度指示器和食品新鲜度指示器应完成的包装功能，为有效实现包装交流功能提供研究思路和技术支持。方法 列出现有食品包装功能在物理环境、周围环境和人类环境下的实现矩阵，通过研究时间–温度指示器和食品新鲜度指示器的实现原理和所满足的包装交流功能，探讨这2种技术提高矩阵中分值较低元素的可行性。结果 时间–温度指示器监测食品所经历的时间、温度的完整历程，有助于提高实现矩阵中ComA元素的分值;食品新鲜度指示器提供生理变化或微生物生长引起的食品质量变化的定性或半定量信息，有助于提高实现矩阵中ComH元素的分值。结论 时间–温度指示器和食品新鲜度指示器能够有效提升食品包装的交流功能，保证消费者安全，减少资源浪费，具有广阔的发展前景。     

4种常见果蔬保鲜运输超声波加湿的生命周期模拟研究

通过生命周期评估显示:与传统供应链相比,超声波加湿可将部分水果和蔬菜的环境影响(包括气候变化影响)降低23%,当加湿器应用于果蔬供应链,且总固有损失>24%时,加湿器的加入能使损失减少20%以上,说明超声波加湿技术能使果蔬供应链管理更具可持续性。     

列车贮藏方式对生猪肉原料新鲜度的影响研究

探究夏季高温期某铁路局集团公司旅客列车贮藏条件下生猪肉原料的品质变化,为改善餐车生猪肉保存及取用方式、保障旅客列车食品安全提供可靠依据。在实验室条件下模拟该列车餐车实际条件下生猪肉贮藏及取用方式:将生猪肉分别在4℃(冷藏)和-10℃(冷冻)两种条件下贮藏,再解冻,使用,再贮藏。通过猪肉的色泽、气味、组织状态感官指标以及挥发性盐基氮(TVB-N)、硫化氢、球蛋白沉淀理化指标的变化为依据,来评价猪肉的新鲜度。结果表明:夏季高温期间,该铁路局集团公司列车生猪肉原料,在4℃冷藏贮存条件下,有2d保质期,在-10℃冷冻贮藏条件下,10d内猪肉品质能够保持新鲜,满足铁路运输的时限要求。该铁路公司列车贮藏和使用生猪肉符合规范,用肉时限在保质期范围内,能够保证全年时段肉质新鲜安全。为保障铁路旅客的食品安全,生猪肉原料应贮存在制冷效果良好的冷冻冰箱内,取用肉类置于冷藏保存的,应在2d内使用完毕。     

Non-targeted high-resolution mass spectrometry study for evaluation of milk freshness

Milk freshness is an important parameter for both consumers' health and quality of milk-based products. Up to now there have been neither analytical methods nor specific parameters to uniquely define milk freshness from a complete and univocal chemical perspective. In this study, 8 molecules were selected and identified as responsible for milk aging, using a liquid chromatography–high-resolution mass spectrometry approach followed by chemometric data elaboration. For model setup and marker selection, 30 high-quality pasteurized fresh milk samples were collected directly from the production site and analyzed immediately and after storage at 2 to 8°C for 7 d. The markers were then validated by challenging the model with a set of 10 milk samples, not previously analyzed. Our results demonstrated that the markers identified within this study can be successfully used for the correct classification of non-fresh milk samples, complementing and successfully enhancing parallel evaluations obtainable through sensory measures.     

Model of vegetable freshness perception using luminance cues

Freshness perception is a quality discrimination process that influences our consumer choice and eating behavior, especially of highly perishable products such as vegetables. Previous research used photographic stimuli to investigate the relationship between luminance distribution and freshness perception for a cabbage leaf (C. Arce-Lopera, Masuda, Kimura, et al., 2013) and a strawberry (Carlos Arce-Lopera, Masuda, Kimura, Wada, & Okajima, 2012). In this study, the luminance and chromatic information of the freshness degradation process of four different vegetables (cabbage, strawberry, carrot and spinach) was recorded in a temperature, humidity and light controlled environment. However, instead of a camera, a 2D luminance and chromaticity analyzer (TOPCON UA1000) was chosen as the measurement equipment. Then, using a color management system to guarantee the exact reproduction of the recorded luminance and chromatic data of the real objects, a color and a grayscale version of the stimuli was created. Subsequently, those pictures were randomly presented to subjects who had to rate their perceived freshness using a visual analog scale. The achromatic results did not differ from the chromatic ones suggesting that luminance information is sufficient to enable an accurate estimation of vegetable freshness. Additionally, the original images were digitally manipulated only by modifying their luminance distribution and keeping their color information intact. When the resulting images were presented, using the same psychophysical experimental setting, the results showed that the perceived freshness also changed concordantly with the changes on the asymmetry of the luminance distribution. Finally, a model for vegetable freshness perception that utilizes only luminance cues is presented.     

基于圆锥形仿生气体室的鸡肉新鲜度电子鼻检测技术

为了快捷、无损检测鸡肉新鲜度,建立了基于圆锥形仿生气体采集室的电子鼻系统。根据鸡肉产生的气味,合理选用了气敏传感器阵列。借鉴嗅觉灵敏的犬类鼻道结构,优化设计了仿生气体采集室。采用RBF神经网络作为模式识别方法。经理化试验结果表明,系统检测鸡肉新鲜度准确率高达98.75%,因此所设计的仿生电子鼻检测鸡肉新鲜度是可行的。