用凝乳和培养凝乳制作纤维状高剪切烹饪挤压马苏里拉奶酪

热点

在较低的比机械能（23–27 kJ·kg）下可产生长而细的纤维−1).

比机械能反映了所有可控挤压参数的影响。

挤出凝乳的含水量受模具冷却温度的影响最大。

凝乳特性与出口温度（22–54°C）表现出更多的线性相关性。

加热和冷却温度对于形成纤维状凝块结构非常重要。

摘要

为了了解高剪切挤出过程中奶酪凝块的剪切，双螺杆挤出机的可控制参数与表征挤出过程对产品性能影响的测量和计算参数相关。凝乳特性与比机械能SME（23–390 kJ·kg）相关−1） Texit（22-54℃）和停留时间RT（36-507s）；研究的广泛实验范围为奶酪凝乳的挤压提供了新的见解。在较低的SME（23–27 kJ·kg）下，纤维更长、更细−1）高特氏温度（50-54℃）和短RT（55-60秒）。而挤压凝乳在高SME（166–390 kJ·kg）下生产−1）低特氏温度（22–23°C）和长RT（371–396 s）倾向于形成纤维形成较少的紧凑结构。研究发现，加热段的温度Th和冷却模的温度Tc决定了挤出过程中从粘弹性固体到粘弹性液体的临界凝乳相变，反之亦然，这对纤维状干酪凝乳结构的形成非常重要。Tc是影响SME的最重要因素，表明冷却过程在增加剪切力方面有相当大的贡献。Th和Tc对凝乳成分和质构特性有显著影响，表明较高的Th会增强凝乳弹性并降低熔体强度，而较高的Tc会降低水分含量并提高熔体强度。我们得出结论，通过控制挤出参数，可以生产出各种具有定制性能的结构化mozzarella产品。

High shear cooking extrusion to create fibrous mozzarella cheese from renneted and cultured curd 

Highlights 

Long and fine fibers were produced at low specific mechanical energy (23–27 kJ·kg−1).

Specific mechanical energy reflects effect of all controllable extrusion parameters.

Water content of the extruded curds was most affected by die cooling temperature.

Curd properties exhibited more linear correlations with exit temperature (22–54 °C).

Heating and cooling temperatures are important for creating fibrous curd structures.

Abstract

To understand shearing on cheese curds during high shear extrusion, the controlable parameters of a twin-screw extruder were related with measured and calculated parameters that characterise the extrusion process effects on product properties. Curd properties were correlated with specific mechanical energy SME (23–390 kJ·kg−1), Texit (22–54 °C) and residence time RT (36–507 s); the wide experimental range studied provided new insights regarding extrusion of cheese curds. Longer and finer fibers were produced at low SME (23–27 kJ·kg−1), high Texit (50–54 °C) and short RT (55–60 s). Whereas extruded curds produced at high SME (166–390 kJ·kg−1), low Texit (22–23 °C) and long RT (371–396 s) tend to form a compact structure with less fiber formation. Temperature in the heating section, Th, and temperature of the cooling die, Tc, were found to determine critical curd phase transitions during extrusion, from viscoelastic solid to viscoelastic liquid and vice versa, that are important for the creation of fibrous cheese curd structures. Tc was the most important factor influencing SME, indicating the considerable contribution of the cooling process in increasing the shear forces. Curd composition and textural properties were significantly influenced by Th and Tc, showing that a higher Th enhances curd elasticity and reduces melt strength while a higher Tc induces lower water content and increases melt strength. We concluded that a variety of structured mozzarella products with customized properties can be produced by controlling the extrusion parameters.