Dept. of Food Science and Technology, Univ. of California, Davis, CA 95616, USA.
J Food Sci. 2009 Aug;74(6):E291-7. doi: 10.1111/j.1750-3841.2009.01205.x.
The Bostwick consistometer remains an integral part of assessing the consistency of tomato products in the factory. This work addresses the blending of tomato pastes, packed at different Bostwick readings, for use in tomato ketchup production. The objective of this study was to correlate in-line viscosity measurements of 12 degrees Bx tomato concentrates to final product quality. Five blends of tomato concentrate were prepared by blending 2 pastes and diluting the mixture to a soluble solids level of 12 degrees Bx. In-line viscometry measurements at process temperature were made using magnetic resonance viscometry. The resulting Herschel-Bulkley parameters were used to evaluate an apparent viscosity at a characteristic shear rate. The apparent viscosity and Bostwick measurement for the blends were correlated based on a gravity current flow analysis, yielding a coefficient of determination of over 0.99. Ketchup was made from the tomato concentrate blends at 3 levels of natural tomato soluble solids (NTSS). The ketchup Bostwick measurement was then correlated to the ratio of (eta/rho)(-1/5) of the 12 degrees Bx tomato concentrate yielding coefficients of determination of 0.97, 0.97, and 0.91 for NTSS levels of 6%, 7%, and 7.8%, respectively. This study demonstrates that final product quality can be predicted from in-line viscosity measurements of an intermediate product.
博斯特威克稠度计仍然是评估工厂中番茄酱产品一致性的重要组成部分。这项工作涉及到不同博斯特威克读数包装的番茄酱糊的混合，用于生产番茄酱。本研究的目的是将 12 度 Bx 番茄浓缩物的在线粘度测量与最终产品质量相关联。通过混合 2 种糊剂并将混合物稀释至可溶性固形物水平为 12 度 Bx，制备了 5 种番茄浓缩物的混合物。在工艺温度下使用磁共振粘度计进行在线粘度测量。使用赫谢尔-布尔克参数来评估在特征剪切速率下的表观粘度。基于重力流分析，对混合物的表观粘度和博斯特威克测量值进行了相关性分析，相关系数超过 0.99。从番茄浓缩物混合物中制备了 3 种天然番茄可溶性固形物（NTSS）水平的番茄酱。然后将番茄酱的博斯特威克测量值与 12 度 Bx 番茄浓缩物的（eta/rho）^-1/5 比值相关联，对于 NTSS 水平分别为 6%、7%和 7.8%，得到的决定系数分别为 0.97、0.97 和 0.91。本研究表明，可以通过中间产品的在线粘度测量来预测最终产品质量。
