Yogurt production technology and yoghurt production line

Yogurt is a natural, healthy product, a good dessert, low in calories, and therefore very suitable for diets. Drink yogurt is nothing more than a yogurt with broken coagulum and a lower skim content. Product undergoes a stronger cooling after the coagulum breakage. Juices are preferred as flavouring agents instead of fruits purées or pieces. 

In yogurt production line, packaging is usually made in plastic bottles.

Below are some guidelines on the different ways to increase yogurt consistency in yogurt production line:

YOGURT PRODUCTION LINE - PHASE 1 

CONSISTENCY INCREMENT – RAW MATERIALS PREPARATION

Increase the solid content
By increasing the milk proteins, in our yogurt production line we increase the number of solids, i.e. the consistency of the casein gel. Yoghurt and the percentage of milk powder added to the original milk.

Water content reduction by evaporation
Through the evaporation of water phase we obviously obtain an increase in the milk proteins and in the fat content. Evaporation is however an extra expensive step to be added to the production of yogurt. Its elimination results anyway in a higher yield.

Use of a stabilizer
The use of a stabilizer in yogurt production line gives the possibility to break the balance between the various yogurt components without having to face quality problems in the final product.

This is due to the following reasons:

The fat can be reduced to the desired value without facing problems of whey separation

The milk proteins can be reduced to a percentage which prevents them to give taste problems in the final product

The loss in consistency, due to mechanical stress, it can be reduced to minimum

YOGURT PRODUCTION LINE - PHASE 2

THERMAL MILK TREATMENT AND HOMOGENISATION

The main purposes for the milk heat treatment in yogurt production line are the following:

To kill possible pathogenic micro-organisms

To eliminate most of the other organisms in order to increase the product shelf life

To inactivate occurring enzymes

To give proteins a certain level of denaturation. This improves the yogurt consistency and viscosity, preventing whey separation

An homogeniser is connected to a pasteuriser in-line.

The homogenisation phase is very important especially in a yogurt containing fat, less in skimmed yogurt, even if the homogenisation is also affecting the casein particles increasing the final texture of yogurt.

The advantages given by homogenisation to yogurt production are the following:

Improved the yogurt consistency

Greater stability against whey separation

The yogurt looks whiter, with a creamier and fuller taste than the non-homogenized yogurt 

Better distribution of the stabilizer in the system

The thermal treatment line handles high pasteurising temperatures, longs stoppages and homogenisation.

YOGURT PRODUCTION LINE - PHASE 3

ADDING STARTERS

You can find in the market deep-frozen or freeze-dried culture that can be used directly in the fermentation tank or as mother culture to be added in approx. 2% percentage.

YOGHURT PRODUCTION LINE - PHASE 4

YOGURT RIPENING

The common type of incubation, in yogurt production, is up to 3 – 4 hours at 41 – 45°C.

In certain cases a longer time of incubation is applied, ranging from 7 to 14 hours at 30 –37°C. The low temperature favours a lower acid content yogurt production.

The 3 main types of yogurt are:

Stirred yogurt: the ripening takes place in special ripening tanks with a soft breakage phase

Set yogurt: the ripening takes place in the final container (cup) without breakage

Liquid yogurt: the ripening takes place in special ripening tanks with a special breakage phase