Continuous Thermal Processing of Foods – Pasteurization and UHT Sterilization. Article in International Journal of Food Science & Technology 36(6) – International Journal of Food Science & Technology Continuous Thermal Processing of Foods – Pasteurization and UHT Sterilization. Buy Continuous Thermal Processing of Foods: Pasteurization and UHT Sterilization and more from our comprehensive selection of Continuous Thermal .
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Diversity of Bacillus cereus strains in extended proecssing life. The milk is held at the required temperature for the required period of time while it passes through a holding tube.
Heat resistance of Bacillus cereus spores located between sterilizatiion and seal surfaces. This condition applies to the holding tube only and hence, for ESL milk, closely reflects the heat input in a direct heating system but considerably underestimates the heat input of interest in an indirect heating system.
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Optimum Thermal Processing for Extended Shelf-Life (ESL) Milk
Micro-organisms in pasteurised milk after refrigerated storage. The chemical effect of a heat process can be assessed in several ways pasteuriztion the kinetics of various chemical reactions.
Unfortunately, such contamination can be sporadic with isolated batches and even some but not all packages in a batch being contaminated; such contamination should be eliminated by aseptic packaging. Such precautions typically include: The literature is thoroughly covered processin clearly summarised.
Cashback will be credited snd Amazon Pay balance within 10 days. The spore cycle; pp. Strains that fermented lactose produced more enterotoxin than strains that did not. A systematic approach to determine global thermal inactivation parameters for various food pathogens.
Pasteurization, sterilization, and aseptic processing are all discussed, with emphasis on the underlying principles and problems of heat treatment of more viscous fluids, where streamline flow conditions are likely to prevail, and of products containing particles.
Clearly these conditions lie to the left of ESL line 1 and would not be expected to inactivate all psychrotrophic spores. Abstract Extended shelf-life ESL or ultra-pasteurized milk is produced by thermal processing using conditions between those used for traditional high-temperature, short-time HTST pasteurization and those used for ultra-high-temperature UHT sterilization.
Van Netten et al. Pasteurization and heat treatments designed to further procesding the shelf znd of pasteurized products are also discussed, and the pasteurization and sterilization processes are compared to highlight similarities and differences.
Dispatched from the UK in 3 business days When will my order arrive? Precise control of this is achieved by imposing sufficient backpressure on the holding tube to ensure single-phase turbulent flow. Lewis and Neil J.
The relative importance of these for the shelf-life of ESL milk depends on whether the milk is packaged aseptically or under very clean, but not aseptic, conditions. The system also includes specially developed packaging equipment that ensures post-processing contamination PPC is minimal. This situation applies if the milk is packaged aseptically and there is no PPC. The effect of a novel low temperature-short time LTST process to extend the shelf-life of fluid milk. Advanced Dairy Science and Technology.
Home Contact Us Help Free delivery worldwide. Use of naturally-occurring materials. This book contains over illustrations and 50 tables, as well as extensive cross-referencing and a comprehensive reference section.
Apart from the fact that the growth of psychrotrophic spore-formers can limit the shelf-life of ESL milk, some psychrotrophic spore-formers are pathogenic and hence pose a safety issue in ESL milk.
Post-Processing Contamination The above discussion relates to the keeping quality of ESL milk as affected by the bacteria in the raw milk that are not killed by the heat process. Wiley Blackwell; Oxford, UK: Regulatory perspectives to ESL products: Since ESL milk oasteurization usually not packaged under aseptic conditions, the bacteria in such ESL milk include spore-forming bacteria whose spores are not destroyed by the heating process, as well as spore-forming and non-spore-forming bacteria entering the milk after processing.
The key aim for optimizing the heating conditions for ESL processing is to maximize anx sporicidal effect but minimize the chemical effect, which results in cooked flavor production.
Optimum Thermal Processing for Extended Shelf-Life (ESL) Milk
Illustrations note XV, p. A further consideration that can affect ESL milk is the bacteriological quality of the raw milk. Spores of psychrotrophic bacteria are generally more heat-sensitive than those of mesophilic and thermophilic bacteria and hence less severe conditions will be required to destroy the former, although there are exceptions, e.
However, for indirect systems the heat input of interest includes that to which the milk is subjected in the heating and cooling stages as well as the holding tube. The engineering principles in the book are carefully and thoroughly explained and will be valuable to graduate students conducting research in the field as well as processors interested in optimising the safety and quality of their product.
Psychrotrophic Spore-Formers In determining the ideal temperature—time combinations of ESL milk processing to ensure a long shelf-life, a major consideration is choosing combinations that destroy spores of psychrotrophic bacteria.
Packaging should be the same as what is found in a retail store, psateurization the item is handmade or was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag.
Any Condition Any Condition. Rysstad and Kolstad [ 1 cotninuous reported Milk is sprayed under pressurePa according to Myer et al. Published online Nov