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How Is Vacuum Packed Sweetcorn Cob Made?


How is vacuum packed sweetcorn cob made?


Sweet corn is an excellent source of vitamin C, fiber, potassium, folate, and magnesium. It also contains antioxidants like lutein and zeaxanthin. Today, we enjoy sweet corn in many different forms, including canned, frozen, and vacuum-packed.

Sweetcorn is a seasonal vegetable. Also known as corn on the cob, sweetcorn is composed of rows of tightly packed golden yellow kernels, growing along with a tough central core. Unfortunately, like most fresh vegetables, corn on the cob can have a short shelf life, the sugars begin to break down, it dries out, and can over mature quickly.

We are showing you the step-by-step process we did to vacuum packed sweetcorn which can be stored at ambient temperature for over 12 months and how shelf-stable sweetcorn cobs are made.

Discover how to select, store and prepare sweetcorn as well as our best ideas for cooking and packing it.


Technical process flow:


Corn receiving- Husking, Peeling-Selection, Sorting-Cutting- Blanching, Cooling-Pouch loading- Vacuum Packing- Retort sterilization process- Pouch cleaning- Inspection-Carton packaging


1.      Corns Reception:

Picking your corn and pluck the ears at the right time. After collecting your harvest, it is necessary to avoid squeezing and bumping in the process of loading unloading and transportation. Handle them lightly to reduce losses and improve the yield of finished products.

After receiving corn cobs from trucks, all cobs are carefully selected and sorted for next process, husking.


2.      Husking, Peeling


Husking machine unit is used to automatically husk (remove) leaves and hairs from corn cobs.

Vibrating feeder to feed corn cobs into the husking unit, husking unit with adjustable angle of husking rollers.


3.      Trimming & Cutting


Sweet corn cutter with manual feeding is intended to trim ears of corn cobs. Cobs are cut into even lengths. Corn cutter is equipped with automatic cutting head that provides excellent cutting performance. Capacity depends on operator’s feed efficiency.


4.      Blanching & Cooling


After cutting, sweet corn are conveyed into the blanching machine. Blanching is carried out in a immersion type blanching machine with water of 85 -95oC, the corns undergo the blanching process for 10-12 mins.

The water in the blancher is heated by means of direct steam injection, which is absorbed completely into the water. The recirculation system requires very little steam to reheat the water.

Blanching is one of the stages of corn kernel technological production processes for consumer purposes. Blanching process significantly affects the quality of the corns. The main purpose of blanching is the inactivation of the tissue enzymes responsible for spoiling the material as well as undesirable changes in its color, taste, and texture.


After blanching, the corns are conveyed to exist the blancher and enter the cooling machine by underwater belt conveyor.

Cooling machine is water canal type with belt conveyor and water spray nozzles on top.

Corns are cooled down to 50oC then go to next step, vacuum packaging.


5.      Vacuum Packaging


There are several types of vacuum packaging machine for sweet corns in the market based on the production capacity, packaging flexibility and automation requirements.

  1. Vacuum chamber packaging machine

  2. Belt type vacuum packaging machine

  3. Rotary pouch-feed vacuum packaging machine

After loading the cobs into the retortable pouches, then the vacuum sealing process carried out in the packaging machine. All systems are designed to work with the pre-made shrink bags/pouches.

Make sure the integrity of the pouches’ hermetic seal is not compromised and the vacuum packaging deliver the high level of performance, speed and excellence for your unique needs.


6.      Retort Sterilization Process


After vacuum packaging, the packed cobs will be loaded into the stainless steel retort trays for retort sterilization process. After commercial sterilization process, you get your shelf-stable products and can introduce them into the consumer-packaged goods markets.

So which kind retort is the best fit for your vacuum packed sweet corns thermal processing?


Well, not all retorts are created equal when it comes to flexible packages processing, standard offerings from many present retort manufacturers include batch steam, water spray, water immersion, steam-air models. Innovaster offers all of the models and most are available as rotary or non-rotary models.

We recommend the water immersion retorts for sweet corns packed in vacuum pouches processing. Water immersion retorts are also the most commonly used in the producers’ plants.

It has larger capacity compared with other models of the same size vessel and allows the shorter come-up time. All sweet corns are deep in hot water during cooking phase that results in good flavor and appearance. Abundant feedback from our customers prove the water immersion retorts are the preferred in vacuum packed sweet corn industry.

Water immersion retorts can be designed in different configurations, dual tank design- top tank is hot water reservoir, bottom retort vessel, or several retort vessels sharing one hot water reservoir depending on the specific capacity. Click to see details.


7.      Pouches Cleaning & Cooling & Drying


Cleaning and cooling are conducted in the cooling water canal with belt conveyor with air pump. This step is optional. After cleaning and cooling, corns are conveyed to the air blower to dry the water on the pouches.


8.      Inspection & Storage


After drying, workers will inspect the pouches to remove the leaked pouches. All sweet corns will be stored in the room at ambient temperature for 7 days, at last, pack the sweet corns in cases and deliver to the markets.


We understand there can be exceptions to any generalization. Our recommendations do not preclude the application of other methods or equipments applied in the vacuum packed sweet corns processing.

We hope this paper is useful in helping you to choose the right equipment for your needs.

For information on our retort machines, please contact our sales consultant at info@innovaster-tech.com or via phone at +8618953652200.

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