Prediction of fish quality level with machine learning

In this study, sea bream, sea bass, anchovy and trout were captured and recorded using a digital camera during refrigerated storage for 7 days. In addition, their total viable counts (TVC) were determined on a daily basis. Based on the TVC, each fish was classified as ‘fresh’ when it was <5 log cfu per g, and as ‘not fresh’ when it was >7 log cfu per g. They were uploaded on a web-based machine learning software called Teachable Machine (TM), which was trained about the pupils and heads of the fish. In addition, images of each species from different angles were uploaded to the software in order to ensure the recognition of fish species by TM. The data of the study indicated that the TM was able to distinguish fish species with high accuracy rates and achieved over 86% success in estimating the freshness of the fish species tested.     

Effects of non-thermal plasma treating wheat kernel on the physicochemical properties of wheat flour and the quality of fresh wet noodles

The effects of non-thermal plasma (NTP) on the physicochemical properties of wheat flour and the quality of fresh wet noodles ( FWN) were investigated. The results showed that NTP effectively decreased the total plate count (TPC), yeast and mould count (YMC) and Bacillus spp. in wheat flour. Wet gluten contents and the stability time reached the maximum when treated for 20 s. The viscosity of starch increased significantly after treatment due to the increased of damaged starch. The contents of secondary structure were altered to some extent, which was because that the ordered network structure of gluten protein broken. Furthermore, compared with the control, texture properties of FWN were enhanced significantly at 20 s, and the darkening rate of FWN was greatly inhibited due to the low polyphenol oxidase (PPO) activity. Consequently, the most suitable treatment was 500 W for 20 s, providing a basis for the application of NTP in flour products.     

不同品种小麦粉对马铃薯面条食用品质的影响

为筛选出适宜加工马铃薯面条的小麦粉品种,本研究比较分析了双福02-1、永良4、奎冬5、济南17、山农15和新冬18六种不同品种小麦粉对马铃薯面条蒸煮损失、拉伸特性、TPA质构特性的影响,并利用扫描电子显微镜对其内部结构进行观察。结果表明:在马铃薯全粉添加量20%,小麦粉添加量80%,面团含水量35%的条件下,济南17和山农15两种小麦粉制得马铃薯面条的蒸煮损失、拉伸特性、质构特性等品质指标均显著优于其他4种小麦粉。扫描电镜结果表明,济南17和山农15马铃薯干面内部结构更加致密,空隙率更小。由双福02-1、永良4小麦粉制得马铃薯面条感官品质整体较差。综合以上结果,六种小麦粉中济南17和山农15较适合制作马铃薯面条,而双福02-1和永良4制作的马铃薯面条加工适应性较差。     

小草坝新鲜天麻中多种金属元素评价分析

目的 分析评价云南小草坝新鲜天麻中9种金属元素含量水平。方法 采用电感耦合等离子体质谱法检测云南小草坝新鲜天麻中铁Fe、铜Cu、钴Co、锰Mn、镍Ni、硒Se、砷As、铅Pb、汞Hg的含量, 并使用食品安全指数IFS法进行重金属污染评价。结果 云南小草坝新鲜天麻中各元素均检出, 参照《现行药用植物及制剂进出口绿色行业标准》及《中国药典》2015年版中重金属限量值判定, 54份天麻中Cu、Pb、As、Hg的含量均没有样品超过限量指标。按照GB 2762-2012食品标准进行判定, Pb有40.7%的超标率, As、Hg均未出现超标样品。小草坝产区新鲜天麻中As、Pb、Hg的IFS值均小于1。结论 云南小草坝新鲜天麻中微量元素丰富, 食品安全风险整体上在可接受范围, 但仍需关注可能存在的铅污染水平。     

硅量子点荧光传感器快速检测鲜奶中的四环素

建立以硅量子点(silicon quantum dot,SiQDs)为荧光传感器快速检测四环素的新方法,以N-(β-氨乙基)-γ-氨丙基甲基二甲氧基硅烷为硅源,柠檬酸为还原剂,采用水热法合成SiQDs;通过透射电镜(transmission electron microscope,TEM)和光谱分析法研究其形貌结构和光学特性;利用四环素能有效地猝灭SiQDs荧光,构建荧光传感器用于四环素检测。结果显示,所制备的SiQDs呈球形、稳定性高,水溶性好。在优化的实验条件下,方法的线性范围为0.05~90μmol/L,检出限为18 nmol/L,用于生鲜牛奶样品测定,加标回收率为92.36%~104.07%。该方法简便、快速、灵敏,适于鲜奶中四环素的准确测定。     

小麦粉特性对Biangbiang面品质的影响

为促进陕西传统特色面食Biangbiang面的产业化,研究小麦粉品质特性与Biangbiang面品质的关系。以市售12种小麦粉为原材料,测定其理化指标和流变学指标,并对由这些小麦粉制成的Biangbiang面进行感官评价和质构测定。相关分析表明:小麦粉的蛋白质质量分数、沉淀值、吸水率、形成时间、稳定时间、弱化度、粉质质量指数、最大拉伸阻力、拉伸比例与面的感官品质存在显著或极显著相关;蛋白质质量分数、沉淀值、形成时间、稳定时间、粉质质量指数、拉伸面积和最大拉伸阻力与质构指标的硬度、咀嚼性、弹性存在显著或极显著正相关。通过主成分分析和聚类分析得出适合制作Biangbiang面的小麦粉品质指标范围:蛋白质质量分数11. 02%～12. 66%、沉淀值26. 06～36. 26 m L、吸水率61. 27%～65. 83%、形成时间4. 36～5. 74 min、稳定时间5. 40～7. 86 min、弱化度55. 17～89. 83 FU、粉质质量指数73. 38～104. 12、拉伸面积82. 88～113. 12 cm2、最大拉伸阻力416. 68～564. 82 BU、拉伸比例1. 63～3. 27。     

脉冲喷动床微波冻干方便面品质与能耗研究

以湿面条为实验原料,进行脉冲喷动床微波冻干(PSBMFD)面饼品质与能耗研究,并与传统电加热冻干(CFD)方式进行对比分析。研究表明:PSBMFD面饼的复水时间、复水比及复水前后硬度值分别为150 s、3.07、4 692.36 g、520.45 g,水分、色差及收缩率的均匀度分别为94.51%、94.31%、92.23%,感观评价总分为8.2,干燥时间为3.5 h,干燥产品总耗能为8.05 kWh/kg。PSBMFD技术不仅提高冻干面饼的干燥均匀度,改善冻干面饼的品质,而且与CFD相比,能够明显地缩短冻干时间(58.83%),降低冻干能耗(66.63%)。     

基于多维约束的食品包装设计

通过分析与研究,提出食品包装的多维约束设计模型,阐明其区别于传统包装设计的优势。并从需求约束、目标约束、资源约束3个维度构建食品包装多维约束设计模型。通过研究用户需求、市场需求、甲方要求、资源限制等,得到相关约束条件下对应的不同设计映射域。从而明确食品包装设计中色彩、图形、规格、风格、文化等要素,最终完成设计。通过乾州挂面包装设计的实际案例验证了方法和模型的可行性。