Lactose Crystallization in Whey Permeate

Industrial crystallization of lactose from cheese whey whether deproteinated or not, is a very slow and tedious process because of several unit operations involved (Nickerson, 1970). These unit operations include concentration, crystallization based on gradual cooling of the concentrated liquor, resolubilization, the use of absorbents, filtration and recrystallization (Webb and Whitter, 1970; Modler etc., 1987). We envision that the introduction of the ethanol leaching method for producing high purity lactose will reduce the process steps and minimize the production costs.

Leviton and Leighton (1938) found that lactose could be extracted from whey powder with 73% ethanol, provided the lactose in the whey powder was amorphous. Amorphous lactose dissolves rapidly in this solvent and forms a highly supersaturated solution while the protein remains in the solid state. If the solution is quickly separated from the protein by filtration or centrifugation before lactose crystallization takes place, it is possible to obtain a protein raffinate of low lactose content. The supersaturated lactose solution is unstable and soon deposits crystals of lactose monohydrate (LMH) until the saturation point for lactose (29%) is reached. In a later study, Leviton (1949) found that the purity of lactose obtained by a single crystallization in 62% methanol was comparable to that of the refined milk sugar of commerse.

Many dairy processing plants use ultrafiltration (UF) for processing whey into whey protein concentrate. However, for good economic return, each ultrafiltration plant must have an associated process for utilization of the permeate. In fact, expansion in the use of UF has been hindered by the difficulty of using permeate profitably. The composition of permeate from whey and skim milk is quite similar. According to the data, lactose represents approximately 86% of the total solids present in the permeate. Therefore, it seems that the permeate is an ideal source from which to recover a high purity lactose.

Задание 2. Сопоставьте английские слова с их переводом:

1) industrial crystallization подсырная сыворотка

2) several unit operations постепенное охлаждение

3) resolubilization медленный процесс

4) concentrated liquor отдельный комплекс операций

5) cheese whey повторное растворение

6) associated process вспомогательный завод

7) later study обезжиренное молоко

8) tedious process промышленная кристаллизация

9) gradual cooling концентрированный раствор

10) skim milk последующая работа

Задание 3. Образуйте существительные от глаголов при помощи суффикса

-ation, как показано в примере:

-ation [-ei∫n]

Model: to crystallize – crystallization

to filtrate, to recrystallize, to centrifugate, to saturate, to utilize.

Задание 4. Вставьте нужные слова и предлоги из текста:

1. These unit operations include … based on … cooling … the concentrated …, resolubilization, the use … absorbents, filtration and ….

2. Leviton and Leighton found that … could be extracted … whey powder …

73 % ethanol, provided the lactose … the whey powder was amorphous.

3. Many dairy processing plants use …. for processing whey … whey protein …

4. The composition … permeate … whey and … milk is quite similar.

5. It seems that the permeate is an ideal … … which to recover a high purity …

Вопросы к практическому занятию

1. Является ли промышленная кристаллизация лактозы относительно медленным процессом? Почему?

2. Что включает в себя данный комплекс операций?

3. Что поможет ускорить процесс и снизить затраты на производство?

4. Какие способы словообразование вы знаете?

Практическое занятие 15

МИКРОФИЛЬТРАЦИЯ ДЛЯ ОТДЕЛЕНИЯ БАКТЕРИЙ ИЗ МОЛОКА

И РАССОЛА

MICROFILTRATION FOR THE REDUCTION OF BACTERIA IN MILK

AND BRINE

Теоретическая часть

Данный лексический материал предназначен для того, чтобы студенты запомнили специальные термины, характерные для текстов по указанной тематике, и успешно применяли их в речи.

reduction отделение

brine рассол

Cross Flow Microfiltration микрофильтрация кросс-флоу

Application применение

treatment обработка

innovations in equipment design применение специального оборудования

integration зд. использование

processing переработка

cheese brine сырный рассол

running cost текущая стоимость

MF/HTT МФ/УВТ

removal удаление