摘要:

ABSTRACTFick's Law of diffusion was used in the analysis of the air drying behavior of fresh (non‐osmosed) and osmosed pineapple. the drying rates of osmosed pineapples were significantly decreased due to the presence of infused solute. the effective diffusion coefficient decreased with the increasing solid gain during osmosi

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1991.tb00088.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTLiterature surveys have revealed inadequate information on heat transfer characteristics during evaporation in straight‐sided horizontal thin film scraped surface heat exchangers (SSHE). the evaporation of water, concentration of milk and dehydration of cream (30–40% total solids) at different rotor speeds, number of blades, flow rates and temperature differentials were studied in 108 tests with objectives to develop a predictive equation for overall heat transfer coefficient and to study its variation with regard to above parameters in the light of proposed mechanism governing fluid flow, film formation and heat transfer. Data were processed in HCL System‐4 computer to fit in quadratic form by method of least squares. Experiments were conducted at higher temperatures compared to those encountered in milk evaporators. the information would be useful in designing SSHE for processing several Indian dairy pro

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1991.tb00089.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTSpecific heat of dehydrated pulps, which were obtained from 31 different fruits at several moisture contents, was determined by the indirect mixing method. Data are reported for each fruit. They confirm the application of linear functions, especially at moisture contents above 50%. an exponential regression equation for calculation of specific heat in the whole range of moisture content was established using all the values.

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1991.tb00090.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTHeat transfer coefficients, h, (J/cm2°C min) were determined for a pork/soy hull mixture during heating in a convection oven (142°C) with and without control of the dew point. Data were acquired by heat processing 5 stacked layers of product (10 × 10 × 1 cm) so that heat was only conducted into the top surface. One experiment was designed to determine h when the second layer from the top reached one of 6 temperatures: 20, 32, 44, 56, 68 and 77°C, with no control of the dew point. the second experiment determined h for 60 min of heating for 5 dew point levels: 6, 21, 31, 40 and 50°C. Without the control of humidity, values for h ranged from 0.0170–0.0366 J/cm2°C min. the heat transfer coefficient increased with temperature and heat processing time. Product yield and surface area ratios decreased as h increased. When relative humidity was controlled, values for h ranged from 0.0167–0.0270 J/cm2°C min, decreasing for dew points

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1991.tb00091.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTThe rates of changes of texture, cook drip and free fatty acid during frozen storage of scallop meats at −30, −18, −12, −8 and −5°C were studied. Both the physical and chemical changes were found to follow first order kinetics. the activation energies for toughness, cook drip and free fatty acid were 43.6, 69.3 and 37.9 kJ/mol, re

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1991.tb00092.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTElectrical conductivities of three vegetable and two meat samples were determined by subjecting them to a constant voltage power supply in a static ohmic heating device. Conductivities of vegetable samples were increased by soaking them in salt solutions, while soaking in water resulted in reduced conductivity due to leaching of electrolytes. Conductivities under ohmic heating conditions increased linearly with temperature. When field strengths were decreased, the conductivity‐temperature curve gradually became nonlinear, and under conventional heating conditions, a sharp transition was observe

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1991.tb00093.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY