Model Number: JMSY-2 Brand Name: JIMEI Key Specifications/Special Features: Automatic PE bottle yogurt processing line machineDescriptions:Pretreatment of the milk is the same, regardless of whether set or stirred yogurt is to be producedIt includes standardization of the fat and dry matter contents, heat treatment and homogenizationIt is assumed that the milk has been standardized to the required fat content before entering the line and standardization of the dry matter content takes place in an evaporator in the process line

If the dry matter content is adjusted by addition of milk powder, the equipment used is similar to that described under recombined milk

Any additives, such as stabilizers, vitamins, and more, can be metered into the milk before the heat treatment

When the yogurt milk has been pretreated and cooled to inoculation temperature, the procedure for further treatment depends on whether set, stirred, drink, frozen or concentrated yogurt is to be produced

The quality of the yogurt in terms of texture and flavor is essential

Figure 11.14 shows the processing of stirred yogurt

The pretreated milk, cooled to incubation temperature, is pumped to the incubation tanks (7)

Simultaneously a preset volume of bulk starter (6) is dosed into the milk stream

After a tank has been filled, agitation commences and continues for a short time to assure uniform distribution of the starter culture

The incubation tanks are insulated to ensure that the temperature remains constant during the incubation period

The tanks can be fitted with pH meters to check the development of acidity

In typical production of stirred yogurt the incubation period is 2.5 to 3hours at 42 – 43C when the ordinary type of bulk starter (2.5 – 3% inoculums) is utilized

To attain optimum quality, cooling from 42 – 43C to15 – 22C should be accomplished within 30 minutes after the ideal pH-value has been reached to stop further development of bacteria

The coagulum must be subjected to gentle mechanical treatment so that the final product will have the correct consistency

Cooling takes place in a plate heat exchanger (8) with special plate

After cooling to 15 – 22C, the yogurt is ready for packing

Fruit and various flavors can be added (10) to the yogurt when it is transferred from the buffer tanks to the filling machines

This is done continuously with a variable speed metering pump which feeds the ingredients into the yogurt in the fruit blending unit

The blending unit is static and hygienically designed to guarantee that the fruit is thoroughly mixed into the yogurt

The fruit metering pump and the yogurt feed pump operate synchronously