摘要:

ABSTRACTA simplified model of food extruders is proposed. Analysis of this model suggests that extruder output and power consumption can be described by simple relationships of dimensionless groups. Comparison of the theoretical relationships with data obtained by processing a pseudoplastic dough in four different extruders indicates a sound scale‐up technique has been established. A method of extending the analysis to more complicated extrusion problems is suggeste

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00279.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTDuring the various stages of marketing, frozen food products are frequently subjected to changes in temperature which affect their quality.In the present work, a mathematical model is developed to analyze the thermal behaviour of frozen meat subjected, under different insulation conditions, to thermal step functions and periodic fluctuations in temperature varying in amplitude and frequency.The heat transfer equation has been numerically solved, since it is a system with physical properties that vary with the temperature, and fluctuating boundary conditions.At the same time, laboratory experiments were performed to verify that the mathematical model is applicable to one‐dimensional and three‐dimensional heat transfer problems.The obtained results were compared with analytical solutions for the heat transfer equation, with constant coefficients, determining the temperature range for which it is possible to use average values in the physical propert

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00280.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTWith the aim of studying pre‐rinsing and cleaning of a milk storage tank, different representative samples are collected during the process and their components (protein, sugar and lipid) analysed. The main conclusions of this study may be summarized as follows: (1) The mean thickness of milk remaining in the tank ranges around 20 μm. It depends on the dropping time and on the possible presence of milk foam. (2) The different main milk components do not exhibit the same removal rate and sugar seems to be completely removable by rinsing only. (3) Prerinsing may be characterized by four periods of which one depends on a diffusion mechanism. (4) Pre‐rinse is a very rapid process which mainly depends on the pre‐rinse solution volume used per unit of soiled surface. (5) Hard water, osmosed water alone or admixed with a surface active agent or caustic soda (1%) lead to the same r

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00281.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00282.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00278.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY