超声技术在食品工业中的应用研究进展

超声波是频率超过20 k Hz的声波,其声场具有独特的空化现象,可同时产生热效应和机械效应,在食品加工领域应用具有处理效率高、可控性好、成本低等优点,近年来在食品加工领域被广泛关注。本文从超声技术作用机制出发,综述了国内外有关超声技术在食品加工业中的应用和研究新进展,主要包括利用高频和低频超声对不同食品原料进行超声提取、超声降解、超声辅助酶解、超声干燥、超声灭菌、超声乳化和超声嫩化等方面,并对其可能的作用机制进行了分析归纳。超声技术除具有传统破碎、断裂原料细胞作用之外,超声辅助酶解等生物物理结合加工方式也符合"十三五"食品科技创新专项规划中发展现代食品绿色加工与低碳制造技术的要求。本文为食品绿色制造和产业转型升级提供了理论依据。     

食品水分的在线微波测定技术

介绍了水分微波测定技术在食品加工过程中的应用,分析了微波水分检测系统的检测原理、应用特性及其基本的水分检测模型,给出了一种食品干燥过程在线自动水分测控系统的应用实例.     

Uncertainty analysis of hygrometer-obtained water activity measurements of saturated salt slurries and food materials

Water activity is a critical food stability parameter. Thus, assessment of the uncertainty associated with the instruments and measurement procedures used to obtain a_w data is critical and can be accomplished using uncertainty analysis. Uncertainty analysis was applied to a_w data obtained for two saturated salt slurries (potassium acetate and potassium chloride) and two food materials (corn flakes and grape jam) at 25 °C using a commercially available dew point hygrometer, the AquaLab 3TE. Sources of uncertainty investigated included sample and dew point temperatures, sample lot, cup volume, and sample preparation (“as is” or ground), and day to day changes. Uncertainty analysis revealed that the magnitude of the different sources of uncertainty depended on material type, but that the dew point hygrometer instrument uncertainty was always significantly smaller than each of the other sources of uncertainty investigated, except for jam cup volume, which was exceeding small. Uncertainty analysis also revealed that dew point hygrometer accuracy was better than the ±0.003 a_w value reported by the manufacturer. Measurement procedures were identified that could be implemented to reduce a_w measurement uncertainty for corn flake and jam food materials. The uncertainty analysis used herein can also be applied to investigate other food materials and/or instruments.     

食品工业中的超声提取技术

应用超声强化提取过程可有效地提高提取效率，缩短提取时间，节约成本，甚至还可以提高产品的质量和产量。本文论述了超声波与媒质的基本作用及其产生的效应，超声提取技术在食品工业中的应用，并阐述了超声强化提取的机理，指出了该技术所存在的问题和研究方向。     

食品工业中超声技术现状与发展趋势

介绍了功率超声技术在天然功能成分辅助提取、破壁渗透、均质乳化、食品保鲜、强化酶促反应、切割、解冻、雾化喷涂、有机物的聚合与降解以及探测超声在食品品质评估和含量测定等领域的研究现状。尤其着重探讨了超声强化辅助提取的最新研究进展,并指出目前超声波研究存在的问题和今后工业化研究的重点。还需要完善超声波作用机理相关理论,确定更合适的频率和组合,为进一步研究超声波技术在食品工业上的利用提供参考。     

生物基活性食品包装材料的研究进展

传统的塑料食品包装材料大多来自于不可再生的石化资源,难以降解,不仅造成白色污染,且包装中的某些成分迁移至食品中也给食品安全带来负面影响。随着对“双碳目标”的认知和食品安全关注度的提升,绿色、安全、可降解同时可延长食品的保质期的生物基活性包装材料成为研究热点。本文从活性剂的类型和活性包装的功能角度介绍了生物基活性基材的类型和特点,综述了基于淀粉、纤维素、壳聚糖、蛋白质、聚乳酸等生物基材的活性食品包装材料的研究现状,对比分析不同类型生物基活性包装的优势和弊端,探讨各生物基食品活性包装材料存在的问题及解决的对策,最后对未来生物基活性包装的应用和研究趋势进行展望,以期为开发和选用绿色环保、性能优良、使用安全的生物基活性食品包装提供参考。     

Quality control materials in food composition databanks

Reference materials (RMs) have emerged with the aim of improving analytical methods performance, in what regards to their validation, calibration, uncertainty, training and internal quality control, and of increasing the comparability of measurements between laboratories. Due to their unquestionable importance, but still low availability and high cost, the present work has determined the suitability of infant formula, powdered garlic, tea and infusion as quality control materials for phosphorus analysis. Phosphorous was determined using a spectrometric method. Homogeneity and stability were determined within and between samples according with ISO guidelines. The results show that quality control materials prepared under rigorous procedures are valuable tools in the food composition analysis.     

Solid fat content determination using ultrasonic velocity measurements

The ultrasonic group velocity has been measured through 0–20% mass fraction samples of tristearin, tripalmitin, trilaurin and 1-oleodipalmitin suspended in paraffin oil at 25°C and 1 MHz. For tristearin, tripalmitin and trilaurin there is an increase of about 3.1 m/sec per 1% increase in insoluble triglyceride in suspension. For trilaurin and 1-oleodipalmitin there is a slight decrease in velocity with increasing soluble triglyceride. The technique may, therefore, prove useful for determination of solubilities of triglycerides in suspension, as well as for determining solid fat contents. For the tristearin/paraffin oil suspensions there is a good correlation between the solid content added and that predicted by a theoretical formula available in the literature (correlation = 0.998 for twenty samples). The reproducibility of the solid fat content determination is 0.2%, the accuracy is about 0.6%. The technique is easily automated, cheap, accurate, rapid and non-intrusive and should, therefore, prove useful both as an in-line quality control monitoring device and as a new instrumental technique for research applications.     

食品及食品包装材料中塑化剂的检测研究进展

食品和食品包装材料中塑化剂对人体的危害不可小觑。本文主要介绍了食品及食品包装材料中塑化剂国内外检测标准、样品前处理方法及主要的检测方法。欧盟法规(EU)No 10/2011相对于以往的2002/72/EC对于迁移测试的要求整体趋于严格,生产企业有必要改进生产工艺以应对更新的测试规则。国家现有的标准中对于食品和食品包装材料中塑化剂有一定的要求,目前最常见的研究大部分为食品和食品包装材料中邻苯二甲酸酯类化合物,但对于其他类型的塑化剂检测结果相对较少,这也将是今后食品和食品包装材料中塑化剂检测研究的一个主要方向。