ЭлБиб

скристаллизованной лактозы в экспериментальном образце в 1,5 раза больше, чем

в контрольном, и составляет 58,6 %. Эксперименты показали, что предложенный

циклический режим кристаллизации эффективнее традиционного постепенного

охлаждения, реализованного в контрольном образце. Такой способ кристаллиза-

ции лактозы из концентрированной сыворотки не требует сложных технических

средств и может быть легко реализован на практике.

Summary

The object of the research is the crystallization of lactose in concentrated

nanofiltrate(up to 55 % of solids, desalinated to 50 %) of whey. The process of

crystallization is carried out under themode of cyclic temperatures with a gradual lowering

of heating and cooling temperature limits in each cycle. To carry out the experiment the

nanofiltrate was placed in two flasks, one of them contained an experimental sample

and the other one – a control sample. The flask with the experimental sample was

periodically placed to the cold thermostat from the hot one and vice versa. The hot

thermostat temperature was maintained at 70 °C and the cold thermostat temperature

- at 5 °C. Nanofiltrate cooling contributed to lactose crystallization, and heating

resulted in the partial dissolution of mainly small lactose crystals. To implement the

mode of gradual reduction of temperature limits, the heating time was reduced by two

minutes in each subsequent cycle, and the cooling time, was increased by two minutes

respectively, so the complete period of each of the four cycles made up 30 minutes. The

experiment lasted for two hours in total. The maximum heating temperature in cycles

constituted 68, 58, 48, and 45 °C, respectively. The minimum cooling temperature in

cycles was 17, 15.5, 12.6 and 9°C, respectively. The control sample was placed in the

cold thermostat with the temperature of 7 °C and it was kept there throughout the

experiment; its temperature decreased from 22 to 9 °C within 2 hours. The experimental

studies show that the crystallization mode under consideration allows to increase the

average crystal size up to 120 μm, which is 1.8 times more compared to the control

sample. The percentage of the crystallized lactose in the experimental sample is 1.5

times more than in the control one and makes up 58.6 %. The experiments show that

the proposed cyclic mode of crystallization is more effective than the traditional gradual

cooling, implemented in the control sample. This method of crystallization of lactose

from concentrated whey does not require any complex technical facilities and can be

easily put into practice.

Молочнохозяйственный вестник, №2 (22), II кв. 2016

178

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