基于卷积神经网络的食品图像识别

目的 探究一种基于Inception_V3-CNN模型的食品图像识别和分类方法。方法 选取包含20类食品和19609张的食品图像建立数据集Food-101, 通过卷积神经网络(convolutional neural networks, CNN)提取图像候选区域的视觉特征, 并自动进行分类, 使其具有较高的识别率; 此外, 采集来自kaggle库中已标注的食品图像集做预测对比实验, 以保证Inception_V3-CNN模型检测的准确度。结果 该方法能够去除背景噪音, 且仅需部分提取视觉特征, 可以有效解决网络食品图像的分类问题, 与多视图支持向量机(support vector machine, SVM)+方向梯度直方图(histogram of oriented gradients, HOG)和传统CNN方法相比, 在测试时间相近、设备计算能力相同的条件下, 该方法识别率更高, 迭代次数为15000次时, Loss值降至4.92, 准确率可达93.89%。结论 此方法可以快速识别食品图像, 在实际网络图片中能有较好的可移植性。将算法移植到移动设备中实现APP的模块化操作也将成为后续工作探索的重点方向。     

山东省2018年餐饮食品质量安全状况及对策探讨

目的 对2018年山东省餐饮食品质量安全状况进行汇总分析。方法 依据2018年山东省级监管部门公布的山东省食品安全监督抽检信息通告, 对餐饮食品的监督抽检情况进行分析, 讨论不合格原因, 探讨改善餐饮食品安全状况的对策。结果 餐饮具的问题最为突出, 合格率比总体平均合格率低21.64%, 自消毒餐饮具合格率比集中消毒餐饮具合格率低21.49%; 其次是鲜奶吧自制巴氏杀菌乳、发酵乳的微生物污染问题较为严重; 第三是微生物和污染物的项目合格率分别比项目平均合格率低3.26%和2.30%。大肠菌群和阴离子合成洗涤剂超标是主要问题。结论 针对餐饮环节存在的安全风险, 可通过落实餐饮经营者食品安全的第一责任制度, 完善餐饮食品相关标准, 加强餐饮服务行业监管, 建立危害分析关键控制点系统(HACCP)等措施提高产品的质量安全水平。     

公众对餐饮服务食品安全知识、态度、行为的调查分析

目的 掌握公众餐饮服务食品安全知识、态度、行为情况, 发现公众对餐饮服务食品安全的关注点。方法 通过现场问卷调查与网络问卷调查2种方式, 随机对500名韩城市公众进行了问卷调查。结果 公众对餐饮服务食品安全的关注水平和满意水平均较高; 关心餐饮单位是否具备相关许可证件的公众比例达到了53.35%; 投诉举报电话的知晓率达到了79.29%; 遇到食品安全问题时的维权方式主要是与经营者交涉; 大部分公众对推广“阳光厨房”工作持积极认可态度; 公众对餐饮服务食品安全态度主要受微信、微博朋友圈的影响; 餐饮服务食品安全问题主要由餐饮店不讲诚信造成的; 产生餐饮服务食品安全问题的主要因素是由加工过程卫生不达标造成; 监管部门应重点整治的对象是无证照餐饮店; 最担心发生食品安全问题的食品种类是油炸类食品。结论 通过此次调查分析, 可以从公众视角全面了解韩城市当前餐饮服务食品安全情况, 发现监管部门应该加强的监管环节、对象及种类, 有针对性的提出对策与建议, 为提高餐饮服务食品安全公众满意水平, 进一步加强餐饮服务食品安全监管工作提供理论和数据参考。     

食品包装用复合膜材质分析方法研究

目的 研究食品包装用复合膜材质的分析方法。方法 样品截面经包埋抛光后, 采用扫描电镜-能谱仪(scanning electron microscope-energy dispersive spectrometer, SEM-EDS)对样品层数及各层元素信息进行表征。样品经甲酸浸泡分层后, 采用傅里叶变换红外光谱仪(fourier transforminfrared spectroscopy, FT-IR)、差式扫描量热仪(differential scanning calorimetry, DSC)、SEM-EDS对分层后各层薄膜的红外特征吸收峰、熔点、元素信息进行表征。结果 确认该复合膜具有4层结构, 从外表面到内表面材质依次为PET层(厚度约13 μm)、PA层(厚度约16 μm)、铝层(厚度约10 μm)、PP/PE共混层(厚度约67 μm)。结论 通过溶剂剥离分层, SEM-EDS、FT-IR、DSC连用表征分析, 可以确认食品包装用复合膜的多层膜整体结构及每层薄膜材质。     

红外光谱技术在食品检测中的应用

红外光谱在食品检测研究中的应用较为广泛, 具有样品前处理简单、操作方便、易于推广, 且对气体、液体和固体样品均可准确检测等优点, 表现出良好的发展前景。本文概述红外光谱技术的检测基本原理和化学计量学在红外光谱技术中的应用, 在简要对比常用检测分析方法的优缺点基础上, 对红外光谱技术在食品鉴伪、品质研究、有害物检测和成分分析等领域的研究进展进行了综述, 详细介绍该技术与化学计量学结合评价食品品质的应用实例, 同时提出目前研究存在的局限性, 并陈述改进建议, 且对该技术在食品检测研究的未来发展方向作出展望, 以期为该技术的深入研究提供参考。     

初榨椰子油在烘焙食品中的应用

初榨椰子油富含中碳链脂肪酸,具有抗氧化、抗菌、易消化吸收、不在体内堆积脂肪等优势,在烘焙领域中具有良好的应用前景。对初榨椰子油作为烘焙用油的比较优势、初榨椰子油与其他物质混合在烘焙食品中的使用、初榨椰子油在烘焙相关领域中的应用进行分析,为其在烘焙领域中的应用与发展提供参考。     

Meta‐Analysis for Correlating Structure of Bioactive Peptides in Foods of Animal Origin with Regard to Effect and Stability

Amino acid (AA) sequences of 807 bioactive peptides from foods of animal origin were examined in order to correlate peptide structure with activity (antihypertensive, antioxidative, immunomodulatory, antimicrobial, hypolipidemic, antithrombotic, and opioid) and stability in vivo. Food sources, such as milk, meat, eggs, and marine products, show different frequencies of bioactive peptides exhibiting specific effects. There is a correlation of peptide structure and effect, depending on type and position of AA. Opioid peptides contain a high percentage of aromatic AA residues, while antimicrobial peptides show an excess of positively charged AAs. AA residue position is significant, with those in the first and penultimate positions having the biggest effects on peptide activity. Peptides that have activity in vivo contain a high percentage (67%) of proline residues, but the positions of proline in the sequence depend on the length of the peptide. We also discuss the influence of processing on activity of these peptides, as well as methods for predicting release from the source protein and activity of peptides.     

Brazilian Artisanal Cheeses: An Overview of their Characteristics,Main Types and Regulatory Aspects

A large variety of cheeses exist in Brazil, reflecting historical and cultural aspects. Brazilian artisanal cheeses present differences in the processing, ripening time (when applied), type of milk used, texture, size, shape, color, moisture content, flavor, the use or not of starter cultures, among others. This review describes the main artisanal cheeses produced in Brazil, focusing on general and particular characteristics associated with their making process and geographical identity. Overall, the high variability of the physicochemical data and deficiency of information on sensorial properties of Brazilian artisanal cheeses were noticed. On the other hand, culture‐dependent methods were mostly used to expand the knowledge into the microbiology of these cheeses, whereas their microbial diversity has been recently discovered through the use of 16S rRNA gene sequencing‐based methods. The certification of a geographical indication for Brazilian artisanal cheeses may encompass an essential milestone for adding value to these products. Regardless of their significance in the diet, culture, and economy of producing regions, taken together, the reviewed literature discloses the need of insightful studies to generate scientific data to support the expansion of the market, while ensuring the protection of historic aspects related to the production of Brazilian artisanal cheeses.     

Recent Advances in Microalgal Bioactives for Food,Feed, and Healthcare Products: Commercial Potential,Market Space,and Sustainability

To combat food scarcity as well as to ensure nutritional food supply for sustainable living of increasing population, microalgae are considered as innovative sources for adequate nutrition. Currently, the dried biomass, various carotenoids, phycocyanin, phycoerythrin, omega fatty acids, and enzymes are being used as food additives, food coloring agents, and food supplements. Apart from nutritional importance, microalgae are finding the place in the market as “functional foods.” When compared to the total market size of food and feed products derived from all the possible sources, the market portfolio of microalgae‐based products is still smaller, but increasing steadily. On the other hand, the genetic modification of microalgae for enhanced production of commercially important metabolites holds a great potential. However, the success of commercial application of genetically modified (GM) algae will be defined by their safety to human health and environment. In view of this, the present study attempts to highlight the industrially important microalgal metabolites, their production, and application in food, feed, nutraceuticals, pharmaceuticals, and cosmeceuticals. The current and future market trends for microalgal products have been thoroughly discussed. Importantly, the safety pertaining to microalgae cultivation and consumption, and regulatory issues for GM microalgae have also been covered.     

GutSelf: Interindividual Variability in the Processing of Dietary Compounds by the Human Gastrointestinal Tract

Nutritional research is currently entering the field of personalized nutrition, to a large extent driven by major technological breakthroughs in analytical sciences and biocomputing. An efficient launching of the personalized approach depends on the ability of researchers to comprehensively monitor and characterize interindividual variability in the activity of the human gastrointestinal tract. This information is currently not available in such a form. This review therefore aims at identifying and discussing published data, providing evidence on interindividual variability in the processing of the major nutrients, i.e., protein, fat, carbohydrates, vitamins, and minerals, along the gastrointestinal tract, including oral processing, intestinal digestion, and absorption. Although interindividual variability is not a primary endpoint of most studies identified, a significant number of publications provides a wealth of information on this topic for each category of nutrients. This knowledge remains fragmented, however, and understanding the clinical relevance of most of the interindividual responses to food ingestion described in this review remains unclear. In that regard, this review has identified a gap and sets the base for future research addressing the issue of the interindividual variability in the response of the human organism to the ingestion of foods.