Strawberry Jam Processing

The strawberry jam production process uses frozen strawberries or fresh strawberries as raw materials, after strawberry washing, crushing, ingredients blending and boiling to make the strawberry jam products.

The end product strawberry jam should be dark red, have smooth, uniform tissues, and the presence of fruit pieces in the final product, with a pH value range of 3.0 to 3.5, and solid brix is 60-65Brix.

The strawberry jam processing machines involve strawberry washing machines(Only for the fresh strawberry as raw material), strawberry milling machines, colloid mills for dissolving powder and pectin materials, strawberry jam blending and cooking tanks, strawberry jam filling machines, RO water treatment system and CIP system.

The main ingredients used for strawberry jam processing are frozen strawberry, water, sugar, fructose syrup, honey, acid, modified starch, strawberry flavor, color agent, and preservatives.

The capacity for strawberry jam processing is from 300kg/h-3,000 kg/h, and the production equipment can be in continuous or batch based on customers’ requirements and capacity.

The end products of the strawberry jam can be filled into glass jars, soft bags, cans, or other consumable containers, and can have a shelf life of around 1 to 2 years when stored unopened in a cool, dark place.

Strawberry jam processing should choose the fully ripened, red color, stems removed, and cleaned frozen strawberries. Some manufacturers also use freshly ripened strawberries as raw materials, if fresh strawberries, they should be thoroughly cleaned by a bubble washing machine and brush washing machines to remove the dirty parts of the strawberry.

Fresh strawberry stems will be removed manually, and then fed into the air bubble washing machines to clean the dirty matter and pesticide residue on the fruit surface through water and cleaning solutions. After that, the strawberries will be lifted to the belt conveyor to sort out the low-quality and rotten fruits.

Frozen strawberries after natural thawing or machine thawing will be fed into tooth crushers. The sieve screen of the crusher is set to be 3mm-5mm, so that the strawberry can be crushed evenly and with small strawberry pulp. If no pieces or fruit chunks are desired in the end products, the strawberries after crushing and milling need to be pumped into the pulping machines with the sieve screen 1.2mm.

The sugar, modified starch and pectin need to be dissolved in a colloid mill or water powder mixer. When dissolving, the sugar and water feed ratio is about 1:5; The modified starch and water ratio is 1:6; The pectin and water ratio is 1:10. When dissolving these powder products with the colloid mill, need to feed cooling water all the time to avoid overheating of the machine and the colloid mill is blocked.

Strawberry jam preparation and boiling is the core process in the strawberry jam processing plant, the whole process is conducted in the vacuum blending and boiling tanks, and the vacuum tanks can be equipped with 2 sets to realize the continuous production. The boiling tank has the following features:

SUS304, jacketed tank with coil jacket and rock wool insulation, atmospheric pressure tank, negative pressure resistance -0.078Mpa, upper and lower oval heads, CIP cleaning ball, pressure-tight manhole, respirator with manual butterfly valve, central coaxial double Stirring, central paddle + wall scraping 60rpm (scraping the wall should be staggered up and down, the wall can be scraped), mechanical seal, frequency conversion gear motor, mirror light, steam heating, top feeding Port, water inlet, drain port, tank top sight glass. The temperature sensor interface at the bottom of the tank, the capacitance low liquid level gauge interface, and the pressure gauge on the top.

There are 3 processes when preparing the fruit jam:

Firstly, feed the crushed strawberry pulp, sugar, potassium sorbate, acid, and water into the vacuum boiling tank, then start the agitator for mixing and increase the temperature to 80-85℃hold for 20 minutes.

Secondly, dissolving pectin and xanthan gum in water and then pumped into the vacuum boiling tanks, mixing and increasing the temperature to 80-85℃hold for 20 minutes.

Thirdly, dissolving modified starch and color agent, then feed into boiling tanks, mixing and increasing temperature to 80-85℃hold for 15 minutes until the end product Brix value reaches 60-65Brix.

Considering the high viscosity of strawberry jam and the presence of fruit pieces, a piston pump or a double screw pump is typically used for product transfer. Both pump types are well-suited for handling high-viscosity, particulate products while maintaining a low shear rate. During the transfer of strawberry jam from the boiling tank to the filling machine, these pumps ensure gentle handling of the product, effectively minimizing damage to fruit pieces and reducing quality loss to the lowest possible level.

To minimize product loss during jam transfer, sterile water or RO purified water is used after production to push the remaining fruit jam out of the pipelines. This flushing process ensures maximum product recovery, reduces material waste, and improves overall production efficiency while maintaining hygienic standards.

Strawberry jam can be filled into soft bags, glass jars, or metal cans, depending on the target market and packaging requirements. Due to its high viscosity and fruit particulate content, the jam is typically transferred by a double screw pump and fed into piston fillers, which are specifically designed for accurate filling of thick, non-homogeneous products.

Hot Filling and Pasteurization Process

Strawberry jam filling is usually carried out using the hot filling process. By filling the product at elevated temperatures, microbial activity is effectively reduced, and the filling temperature itself contributes to bacteria inactivation, ensuring product safety and shelf stability.

To further enhance food safety, some manufacturers apply secondary pasteurization after filling. The filled containers are conveyed through water bath pasteurizers or spray tunnel pasteurizers, followed by controlled cooling to room temperature. After cooling, the products are packed and transferred to the warehouse for storage and distribution.

Aseptic Strawberry Jam Filling for B2B Applications

For customers targeting aseptic strawberry jam production, the jam can be processed and filled aseptically after boiling. In this case, the finished product is filled into 800L–1000L aseptic TOTE (IBC) tanks using an aseptic filling system. This packaging format is widely used in B2B markets, such as supplying strawberry jam or fruit preparations to yogurt and dairy product manufacturers.

Composition of an Aseptic TOTE Tank Filling Station

A complete aseptic TOTE tank filling station for strawberry jam typically includes:

• Aseptic filling valves
• TOTE tank handling and positioning system
• Gravimetric weighing and filling control system
• Nitrogen dosing system for oxygen displacement
• Sterile air system
• SIP (Sterilization-in-Place) system
• CIP (Cleaning-in-Place) system
• TOTE tank conveying system

This aseptic filling solution ensures extended shelf life, minimal contamination risk, and high product quality, making it an ideal choice for industrial-scale strawberry jam processing and B2B ingredient supply.