Structural changes in batter coating systems during deep-fat frying

大多数食物在油炸前都涂上面糊。面糊涂层提供了设计具有独特感官和质地属性的油炸产品的机会。它们显著改变了油炸过程中的热量和传质特性。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应对。过去几年的进展表明，面糊配方(面粉、配料等)及其转化(蛋白质变性、糊化等)。以及它的结构(密度、孔隙率、孔径分布、微结构等)可能是理解电池涂层功能的关键因素之一。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脂肪吸收和质地的影响，以及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。质地特性将使用万能Instron试验机和分形分析进行测量。共聚焦扫描激光显微镜(CSLM)技术与图像分析相结合，将用于检测油炸产品中的脂肪分布以及水分、淀粉和蛋白质的变化。打碎产物的结构将从三个方面进行研究，即孔隙度测量、CSLM和X射线显微计算机断层扫描(MCT)方法。我们实验室以前开发的用于获得关于孔和孔大小分布的定量数据的协议将扩展到面糊。将为结合图像分析的CSLM和x射线断层扫描研究制定适当的方案。X射线MCT是一种特别新颖的方法，可以重建油炸产品中毛孔的三维可视化。将这三种技术结合起来，对油炸产品中的多孔结构发展进行全面的分析。将开发一个三维孔洞网络模型，并用于解释纹理和脂肪吸收特性。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绝佳的机会。

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.