Apple is a kind of fruit that we can see it everywhere. Apple contains a lot of vitamins, regular consumption is good for our skin. However, with the improvement of living standards, fewer people like to eat apples. All kinds of apple juice drinks can be seen in our supermarket, most apple juice drinks are made from concentrated apple juice.
Concentrated apple juice has small volume, the content of soluble solids can be up to 65%-70%. Concentrated apple juice can save the cost of packing and transportation, and it can be preserved for a long time. Now we talk about the production process of concentrated apple juice.
Processing flow of concentrated apple juice
- Choosing raw materials.
- Sorting apples.
- Washing apples.
- Finished products - concentrated apple juice.
Technical points of concentrated apple juice production
The preparation of fruit juice
The fruit juice preparation must choose mature, sound and high quality apple raw materials to produce high quality concentrated apple juice.
Recovery of aromatic substances
The main components of apple aroma substances are hydroxyl compounds, such as vinyl aldehyde and acetaldehyde. In the concentrated juice of 1:150, the content of hydroxyl compounds is 520-1500 mg / L, while the content of ester is only 190-890 mg / L, and the content of free acid is only 70-620 mg / L. The ethanol content of the high quality aromatic substance concentrate is less than or equal to 2.5%.
Clarification is an important pretreatment measure before concentrating, Several commonly used apple juice clarification processes are as follows.
- The enzyme was treated at 50 ℃ for 1~2 hours.
- At room temperature (20-25 ℃), the juice is stored in a large tank for cold enzymatic treatment, and the treatment time is 6~8 hours.
- The aseptic enzymes and clarifying agents are added to the aseptic juice for enzyme treatment, and the pectin in apple juice will completely dissolve after 2-3 days.
The evaporation time of apple juice concentrating equipment is usually a few seconds or a few minutes, the evaporation temperature is usually 55-60 ℃, and the evaporation temperature of some concentrating machines are low to 30 ℃. At such a short time and low evaporation temperature, it will not cause adverse changes in the composition of the product and the quality of the senses.
The main methods of concentrating are vacuum concentration, freeze concentration, and reverse osmosis concentration. The clarified juice is concentrated to 1/5-1/7 by vacuum concentrating equipment, and the sugar degree is 65%-68%. Because the coexistence of pectin, sugar and acid will form a part of the gel, so the concentration limit of the cloudy juice is 1/4.
Filling and storage
The apple juice from the concentrating equipment should be quickly cooled to less than 10 ℃. If the low temperature evaporation concentration equipment is used for concentration, it is necessary to use the plate heat exchanger to heat the concentrated juice to 80 ℃. After heat preservation for dozens of seconds, hot filling and cooling quickly after sealing. Although the concentrated juice has resisted microbial contamination, the concentrated juice after filling should be refrigerated at 0-4 ℃ in order to prevent quality changes.