Structural changes in batter coating systems during deep-fat frying

大多数食物在油炸前都涂上一层面糊。面糊涂层为设计具有独特感官和质地属性的油炸产品提供了机会。它们显著地改变了油炸过程中的传热和传质特性。对油炸食品质量的日益重视继续提出了新的挑战，需要基础科学和工程知识来充分解决。过去几年的进展表明，面糊配方（面粉，配料等），其转化（蛋白质变性、糊化等）以及其结构（密度、孔隙率、孔径分布、微观结构等）可能是理解面糊涂层功能的关键要素。拟议的研究计划的目标包括调查面粉类型和成分对油炸面糊系统的脂肪吸收和质构的影响;并研究油炸面糊和面糊涂层产品中淀粉颗粒糊化、蛋白质网络形成和多孔结构的发展。将使用通用Instron试验机和分形分析测量纹理特征。共聚焦扫描激光显微镜（CSLM）技术结合图像分析将用于检查油炸产品中的脂肪分布以及水，淀粉和蛋白质的变化。将从三个方面研究面糊产品的结构，即孔隙率测定法，CSLM和X射线显微计算机断层扫描（MCT）方法。协议获得定量数据的孔隙和孔径分布，以前在我们的实验室开发，将延长击球手。将为CSLM和X射线断层扫描研究制定适当的方案，并结合图像分析。X射线MCT是一种特别新颖的方法，用于重建油炸产品中孔隙的3-D可视化。将这3种技术结合起来，以获得油炸产品中多孔结构发展的综合分析。将开发一个三维孔隙网络模型，并用于解释质地和脂肪吸收特性。该项目将积极吸引研究生和一名研究助理。这将为培养食品工程人才提供极好的机会。

Most foods are coated with batter before frying. Batter coatings provide opportunities to design fried products with unique sensory and textural attributes. They significantly modify heat and mass transfer characteristics during frying. The increasing emphasis on quality of fried foods have continued to present new challenges that will require fundamental science and engineering knowledge to address adequately. Progress in the past years indicate that batter formulation (flour, ingredients, etc.), its transformation (protein denaturation, gelatinization, etc.) as well as its structure (density, porosity, pore size distribution, microstructure, etc) may be among the key elements in understanding batter coating functionalities. The objectives of the proposed research program include investigating the influence of flour types and ingredients on fat absorption and texture of fried batter systems; and studying the development of starch granule gelatinization, protein network formation and porous structure in fried batters and batter coated products. Textural characteristics will be measured using the Universal Instron Testing Machine and fractal analysis. The Confocal Scanning Laser Microscopy (CSLM) technique coupled with image analysis will be used to examine fat distributions as well as water, starch and protein changes in the fried products. Structure of battered products will be studied from 3 fronts namely porosimetry, CSLM and x-ray micro-computed tomographic (MCT) methods. Protocol for obtaining quantitative data on pores and pore size distributions, previously developed in our laboratory, will be extended for batters. Appropriate protocols will be developed for the CSLM and x-ray tomography studies with combined image analysis. The x-ray MCT is a particularly novel method for reconstructing 3-D visualization of pores in the fried products. The 3 techniques will be combined to obtain a comprehensive analysis of porous structure development in the fried products. A 3-D pore network model will be developed and used to interpret texture and fat absorption characteristics. The project will actively engage graduate students and a research associate. It will provide excellent opportunities for training food engineering personnel.