On the heat stability of whey protein: Effect of sodium hexametaphosphate

Despite a growing demand for whey protein‐based drinks, their instability and lack of solubility during thermal processing is a major challenge for food product formulators. In the present study, the effects of different hydrocolloids and sodium hexametaphosphate (SHMP) on the heat stability, rheological properties, microstructure and sensory characteristics of whey protein concentrate (WPC) dispersions were evaluated. The results indicated that at pH 4, xanthan, k‐carrageenan, low methoxyl pectin (LMP) and guar stabilised WPC dispersion without heat treatment, all maintained stability during pasteurisation but not sterilisation. For pH 7, for the same set of hydrocolloids, a similar trend was also observed, albeit at different concentrations. However, by adding optimum ratios of SHMP protein denaturation was retarded, particularly in the case of LMP and i‐carrageenan. The highest and lowest apparent viscosities were exhibited by samples containing 0.01% and 0.15% w/w SHMP, respectively. This study highlights the potential capability of SHMP in the prevention of protein denaturation. An exact plausible stability mechanism still needs further more detailed investigation.     

Unsupervised data processing for classifier-based speech translator

Concept classification has been used as a translation method and has shown notable benefits within the suite of speech-to-speech translation applications. However, the main bottleneck in achieving an acceptable performance with such classifiers is the cumbersome task of annotating large amounts of training data. Any attempt to develop a method to assist in, or to completely automate, data annotation needs a distance measure to compare sentences based on the concept they convey. Here, we introduce a new method of sentence comparison that is motivated from the translation point of view. In this method the imperfect translations produced by a phrase-based statistical machine translation system are used to compare the concepts of the source sentences. Three clustering methods are adapted to support the concept-base distance. These methods are applied to prepare groups of paraphrases and use them as training sets in concept classification tasks. The statistical machine translation is also used to enhance the training data for the classifier which is crucial when such data are sparse. Experiments show the effectiveness of the proposed methods.     

Filament stretchability of biopolymer fluids and controlling factors

Filament stretchability of biopolymer fluids composed of casein and waxy maize starch has been investigated as a function of fluid properties (viscosity and viscoelasticity) and stretching speed. The stretching of a filament was conducted at a controlled speed using a Texture Analyzer and was monitored using a high speed camera. The maximum stretchable length, L_max, was used to quantify the stretchability of a filament. Influences of various contributing factors were analyzed using dimensionless numbers (Ohnesorge number Oh, Weber number We, and capillary number Ca). It was found that, for fluids that are dominantly viscous, the capillary number could be the dominant factor determining filament stretching, demonstrated by the master curve of the maximum stretchable length against the capillary number. However, for increasingly viscoelastic fluids, the stretching behaviour showed significant deviation from the master curve, suggesting that viscoelasticity could be another pronounced factor influencing the stretching of such biopolymer fluids.     

溶菌酶的修饰、功能特性及其在食品保鲜中的应用研究进展

溶菌酶是一种自然界中广泛存在的天然防腐剂,能选择性溶解目标微生物的细胞壁而使其失去生理活性,已被广泛应用于食品工业。天然溶菌酶主要抑制革兰氏阳性菌的生长,而对革兰氏阴性菌几乎不起作用或作用较弱;因此,对溶菌酶实施分子结构调整,扩展其抑菌谱具有十分重要的意义。本文重点将近年来国内外已报道的各类溶菌酶增效技术（物理、化学与生物改性技术等,特别是辅以纳米制备技术）、改性后溶菌酶对有害微生物的抑制效果及作用机制和改性后溶菌酶的其他功能特性变化（活性、稳定性、乳化性等）等做了详细综述;同时介绍了改性溶菌酶在食品贮藏与保鲜等领域中的应用情况,并对溶菌酶的分子改性策略、溶菌酶与纳米及材料科学结合应用的潜力进行了展望。     

仿生素肉糜制品加工中原辅料的应用研究进展

仿生素肉糜制品以素仿荤,不仅能在不产生杀戮和减少环境污染的情况下提供接近真实肉类的味道和营养价值,还可有效规避食用动物肉的潜在健康风险,为转变传统肉类消费模式提供了一个理想的选择,已成为素食加工领域的研发热点。本文归纳总结了国内外仿生素肉糜制品加工中原辅料的组成和配方,阐述各原辅料组分对产品质构、风味、色泽、营养等方面的影响,综述该类产品国内外生产研发现状,进而探讨我国仿生素肉糜制品加工中存在的理论和技术问题以及未来发展趋势。