摘要:

ABSTRACTConduction heating of high moisture rough rice was evaluated as a means of arresting fungal growth using an experimental batch‐type rotary heating unit. the heat treatments significantly reduced fungal activity in rough rice as measured by dilution plating and carbon dioxide production. the effectiveness of heat treatments depended upon the exposure time and heating surface temperature. Exposure times for isothermal heating of rough rice were determined for inactivating the fungi to specified mortality levels based on the heating surface temperature. Subsequently, a general procedure which accounted for the heating lags was developed for estimating the heat dosages based on the time‐temperature history of the bulk grain during conduction heating in any given equipm

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1988.tb00015.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTA computer simulation model was developed to predict the time for temperature equilibration as well as microbial growth within a food product during freezing and the equilibration to frozen storage conditions. Theoretical results indicate that freezing medium temperature, surface heat transfer coefficient and product size influence the equilibration time significantly. Storage conditions influenced the equilibration time during storage and significantly influenced the growth of microorganisms. Microbial growth is a function of the freezing time. Slow freezing of a food product from a high initial temperature and stored at a relatively high temperature can provide conditions for microbial growth as compared to very rapid freezing processes. the model is a useful tool for approximate indications of effects of freezing conditions on microbial growth within a food product.

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1988.tb00016.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTThe flesh color of 5 clingstone peach cultivars was measured (in CIELAB coordinates) by tristimulus colorimeter before and after canning. Before canning, fruit were separated into 3 color classes (1A: green‐yellow, 4A: yellow‐green, 7A: orange) by visual comparison with a trial maturity chart. After canning, flesh color was measured and visually graded. All samples in color class 1A were rated USDA grade C, while classes 4A and 7A were rated grade A. Flesh color was also measured as a function of time before and after harvest. Fresh flesh L* values were approximately constant, a* values increased steadily, and b* values increased then slightly decreased. Final specifications for a new maturity chart were 7 colors of constant luminance (L*= 76.5) and linearly increasing a* and b* values (−5.0 to 13.0 and 70.1 to 76.4, respectively), corresponding to a time step of 3.5 days between c

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1988.tb00017.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

ABSTRACTSorption isotherms and drying mechanisms of Bintje potatoes have been investigated experimentally. the product temperature and the moisture content was determined during the drying experiments.A simulation method to estimate the diffusion coefficient and the moisture content profiles for the potatoes was performed by means of a finite‐difference computer program. Experimentally determined moisture contents were compared with calculated for different estimated values of the diffusion coefficient. If the diffusion coefficient was assumed to be 0.8.10−9m2/s the correlations were acceptable. the simulated moisture content profiles also gave the surface moisture content.The surface mass transfer coefficient has been calculated, the resulting β values were in the range of 0.014–0.0

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1988.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY