Section G. Deposits from whole milk in heat treatment plant—a review and discussion

Abstract

Introduction Methods for experimental investigation Deposit distribution and composition Factors affecting deposit formation Plant operating conditions Air content Acidity Age Season Herd differences Preholding Electrical or magnetic treatment CONTENTS 317 318 318 321 321 321 322 322 323 324 324 325 PAGE Possible mechanisms of deposit formation 326 Mineral salts and the effects of temperature near a heating surface 326 The effect of preholding 327 The involvement of proteins and fat 328 Deposits in directly heated systems 329 Sediment and deposit 329 The effect of deposit-surface interaction 329 Conclusions 330 References 330

Evaluation of Soil Deposition and Removal Processes: An Interpretive Review

“…Burton (20) stated that the sequence of supersaturation of mineral salts, nucleation, and crystal growth leading to deposit formation is also applicable to directly heated (steam injection) systems where a large quantity of precipitable material becomes available immediately after mixing of the milk with steam. Some of this material is carried to the enclosing surfaces by turbulence, and deposition occurs.…”

“…Proteins normally appear to be denatured or even degraded into nonprotein compounds (48,89). Denaturation of soluble proteins during preheating of milk prior to ultra-high temperature (UHT) processing results in marked changes in the structure and composition of the deposit formed on UHT equipment surfaces (20). Lyster (75) analyzed deposits collected from stainless steel plates of an UHT processing plant and found materials other than protein, fat, and minerals were present to the extent of 5 to 10%.…”

“…However, correlation was a strong positive with fat content. He later indicated that it is unlikely that fat is closely involved in deposit formation since the amount of deposit does not vary linearly with fat content, and since it is well known that the deposit problem exists with skim milk as well as with whole milk (20). He postulated that the deposition more likely is influenced by some minor milk constituent (5) which is closely associated and varies with the fat content but is also in skim milk.…”

Modelagem e simulação dinâmica da pasteurização contínua de leite sujeito à incrustação.

“…Embora haja uma quantidade considerável de trabalhos a respeito do fenômeno de incrustação do leite bovino em trocadores de calor, esse problema está somente parcialmente compreendido devido à natureza complexa do leite e dos seus processos fabris (BANSAL, CHEN, 2006;BELMAR-BEINY, FRYER, 1992;BELMAR-BEINY et al, 1993;BELL, SANDERS, 1944;BOXLER et al, 2014;BURTON, 1967BURTON, , 1968CHANGANI et al, 1997;GEORGIADIS, MACCHIETTO, 2000;GOTHAM et al, 1992;JUN, PURI, 2006;LEEDER, 1956;PETIT et al, 2013). Além disso, não foi possível traduzir esse entendimento numa forma efetiva de melhorar os projetos dos PHEs por modelos de incrustação (DE JONG, 2008).…”

“…Na maioria destes casos, opera-se com água e proteínas do soro lácteo. Isso ocorre por alguns motivos: a) alta complexidade de se trabalhar com leite bovino in natura cru (BURTON, 1968;BURTON, 1988);b) também porque são amplamente usados como ingredientes funcionais em iogurtes, bebidas lácteas, formulações alimentares, molhos, etc. (BELMAR-BEINY et al, 1993); c) contém mais de 50 % de β-lactoglobulina, que é a proteína considerada responsável por formação de depósitos (DE JONG, 2008;LALANDE, RENE, 1988).…”