摘要:

ABSTRACTMathematical models are often used for determining commercial thermal process schedules for heterogeneous foods processed in an aseptic processing system. the particle/fluid interface convective heat transfer coefficient is a critical input parameter for these models and must be determined experimentally. Experiments were conducted at 129.4°C in a specially designed apparatus to determine the particle/fluid interface convective heat transfer coefficient for model food particles heated by Newtonian and non‐Newtonian fluids. Values of the heat transfer coefficient ranged between 55.63 and 89.5 W/m10C for particles heated in a non‐Newtonian fluid and between 65.67 and 107.11 W/m20C for particles heated in a Newtonian f

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1990.tb00067.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTA cascade thin film scraped surface heat exchangers, having sterilizer, regenerator and cooler sections was designed and fabricated. It was employed for inactivation of thermostable proteases and lipases in milk. Buffalo milk was sterilized in the temperature range: 143–152°C for holding times of 0.75, 1.0 and 1.25 s. Samples collected aseptically were stored at 37°C to study the proteolytic and lypolytic activities. the study established that activity of enzymes in milk subjected to higher temperature was far less than that of milk processed at lower temperature for same holding time. the effect of longer holding times was simi

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1990.tb00068.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTA simple inexpensive calorimeter was built to measure specific heat of foods at various process temperatures. By using vegetable/mineral oil as the heating medium in place of water, specific heat at temperatures beyond 100°C can also be evaluated. Specific heat of whole wheat dough and Chapati (round disc prepared mostly from whole wheat flour dough) at various stages of cooking and puffing were determined. Based on the experimental data a linear equation (C = 2476.56 + 23.56M − 3.79Te) is proposed from the experimental data for specific heat of wheat flour, dough, cooked and puffed Chapati and for other food materials at moisture levels ranging from 0.1% to 80% and temperature ranges from 303° to 336

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1990.tb00069.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTThe effects of artificial drying on Laird lentil qualities such as breakage susceptibility, cooking quality, and seed germination were determined at three initial moisture levels, 16%, 18%, 20% wet basis and seven levels of drying temperature varying from 40°C to 80°C. Cooking quality was not affected by drying in the range of treatments used in this study. High initial Omoisture content and lengthy drying periods at temperatures above 40°C were associated with increased seed breakage. Seed germination was particularly sensitive to heat treatment at 80°C and extended drying time for high moisture samp

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1990.tb00070.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

ABSTRACTLiquid‐to‐particle convective heat transfer coefficients were measured during continuous flow through tubes, using an experimental technique in which a thermocouple was moved at the same speed as the particle. Water was used as the carrier fluid and transducer particles were made hollow to approximate densities of real food particles. Results from over 250 experimental runs over a fluid Reynolds number range from 7300 to 43600, showed that the convective coefficient was increased significantly with increasing fluid flow rate and particle to tube diameter ratio. Convective coefficient values ranged from 688 to 3005 w/m20C depending on the experimental conditions. Dimensionless correlations obtained between the Nusselt number, particle Reynolds number, particle to tube diameter ratio, and the particle Froude number yielded R2values ranging from 0.82 to 0.92 depending on the complexity of the relat

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1990.tb00071.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY