Tea beverage production process----cooling filter blending

Tea beverage production process----cooling filter blending

cool down

The purpose of cooling is to quickly reduce the tea extract to room temperature to prevent oxidative browning of the tea juice caused by standing for a long time. The cooling method is usually a plate heat exchanger, using tap water or chilled water as a medium, and the tea extract is quickly cooled to room temperature (20-30 ° C).

According to the form of the heat exchanger, sufficient space should be left at both ends of the heat exchanger to meet the needs of cleaning and maintenance. In the form of a fixed tube heat exchanger, there should be sufficient space at both ends to allow the tube to be withdrawn and replaced. When the tube is cleaned with a mechanical spray, the tube can be brushed at both ends. The fixed head cover end of the floating head heat exchanger should have sufficient space for the tube bundle to be withdrawn from the housing, and the outer head cover end must also leave more than one meter of space for the outer head cover and the floating head cover to be attached. The fixed head cover of the U-tube heat exchanger should allow sufficient space for the tube bundle to be withdrawn, or leave enough space at the opposite end to disassemble the housing. When chemical cleaning is used, the scaled scale should be analyzed and tested according to the actual situation and the water quality, and the chemicals should be cleaned separately.

Since the difficulty of cleaning is rapidly increased with the increase of the thickness of the scale layer or the deposition, the cleaning interval should not be too long, and should be periodically according to the characteristics of the production equipment, the nature of the heat exchange medium, the corrosion rate and the operating cycle. Inspect, repair and clean.

filter

Tea beverages may precipitate and turbid due to the presence of certain solid particles and water quality, so filtration is required. In order to save the national filtration cost and achieve better filtration effect, the fixed substance in the tea juice is usually removed by multi-stage filtration. In order to obtain a better filtration effect, the tea extract is generally coarsely filtered and then finely filtered.

(1) Coarse filtration: When the tea extract is extracted in the extraction tank, the 40-mesh metal screen is usually installed in the extraction tank outlet, and the tea residue is first filtered out. Before the fine filtration, in order to improve the efficiency of the fine filtration, a 300-mesh stainless steel screen or copper mesh pre-filtration should be used first.

(2) Fine filtration: The coarsely filtered tea extract is finely filtered using a plate and frame filter or a diatomaceous earth filter. The finely filtered tea juice requires clear and transparent, no turbidity or precipitation. Fine filtration can also be carried out using a 10-70 μm pore size precision filter to obtain clear and transparent tea juice.

Provisioning

The main purpose of the blending is to adjust the tea juice after the rate to the appropriate concentration and pH, and add sugar and flavor. In actual production, the tea juice after leaching is a concentrated juice, and the concentration needs to be adjusted. The key step of processing the finished product during the flavor blending of tea beverages is generally the amount of tea polyphenols to calculate the amount of water to be added, to make a small sample, to measure the pH value, and then to evaluate its sensory and quality. To evaluate the quality of tea beverages, mainly depends on the aroma, taste and color of tea beverages. In the process of processing, flavor substances can be added according to different needs, such as adding apple juice and blending into fruit tea such as apple tea beverage.

In actual production, water is added to the filtered tea extract according to the formulation requirements to adjust the concentration of the tea soup. At the same time, L-ascorbic acid which has been dissolved with a small amount of water is added to ensure the quality of the tea soup.