Cellulose casing characteristics, common problems and solutions

Casing has a great influence on the setting, taste, color and taste of sausage. Therefore, the performance of casing is very important for sausage processing. Today, we will talk about cellulose casing, matters needing attention in use, common problems and solutions.

01
Structure and characteristics of cellulose casing

1. Material
Cellulose casing is generally regenerated natural plant cellulose, which is generally layered structure after regeneration. A certain strength and elasticity can be obtained by crosslinking multiple layers of regenerated cellulose molecules into a network structure. The primary regenerated cellulose has a high degree of molecular polymerization and high mechanical strength. After processing and drying, the tensile strength can reach 2~3N/mm and the elongation is above 12%.

2. Characteristics
Cellulose casing has excellent processing performance, the strength of the shrink rod of cellulose casing is large, and the strength between folds after shrinking is moderate, which is very suitable for high-speed and automatic filling. Because of its multi-layer network structure, cellulose casing has good air permeability and excellent air permeability and smoke permeability, which is an ideal smoked casing.
Cellulose casing has good thermal stability and less cooking deformation, and can be peeled quickly by peeling machine after cooking. Because the peeling coating is pre-sprayed inside the casing, the meat will not stick, and the sausage has a smooth surface and good appearance.

3. Processing flow and equipment

The process of sausage processing with cellulose casing is basically similar, including meat preparation → filling → hanging → cooking → packaging. The difference is that small-caliber cellulose casings do not need to be soaked before use, and because regenerated cellulose is inedible, cellulose casings are usually peeled after cooking, and a few of them are not peeled, such as cellulose casings that are smoked.

02
Common problems and solutions
From the point of view of sausage processing, combined with the characteristics of cellulose casing products, the problems that are easy to occur in the process of sausage processing with cellulose casing were analyzed and discussed.
1. Continuous automatic feeding is not possible.
Feeding refers to the process that the filling machine automatically loads cellulose casings into the filling tube. One of the characteristics of cellulose casing is to adapt to the rapid filling of automatic equipment, so accurate feeding of casing is the first step of filling processing. The casing rod must have a high strength, so that the rod will not break during the automatic feeding process, because once the rod breaks, the automatic feeding may not be completed, resulting in production stoppage and even damage to machine parts. At the same time, the casing stick needs to be hard and straight, and the opening should be smooth and not deformed, so as to realize the accurate feeding of the filling pipe. Compared with manual feeding of casing, this undoubtedly increases the production difficulty of cellulose casing.
2. The center of casing stick does not match the filling tube.
If the center of the casing stick is too small, the filling tube cannot be inserted, or the casing cannot slide freely on the filling tube because the center hole is too small. If the central hole of the casing stick is too large, the casing can't rotate freely with the filling pipe, and it can't be twisted, which is easy to cause the problem of foaming in the casing gap or wrinkling on the sausage surface. At this time, it is necessary to check the casing specifications or replace the filling pipe. The casing stick, the filling pipe and the twister must be kept in a straight line, and the casing stick should pass through the center of the twister chuck.
3. The rod length is too long or insufficient
Casing sticks should meet the requirements of standard stick length and match the length of filling pipe. Insufficient compression or elastic elongation of the casing rod may lead to the casing rod being too long, which may easily lead to the rod breaking when feeding, or the excessively long part needs to be removed manually. If the compression of casing is too large, the length of casing rod is insufficient, and the casing rod may be broken or the feeding is not smooth due to the excessive pulling force during filling. At this time, the filling pressure can be appropriately increased or the filling speed can be slowed down to adapt to the large pulling force.
4. Quantitative control
For sausage products that require high packaging and appearance, quantitative stability is a very important sausage quality index. On the one hand, quantitative control requires that the size of sausage casing should be uniform and the deviation should be strictly controlled within the standard range. The quantitative problem may be accompanied by the phenomenon of uneven thickness and different length of sausage. In the aspect of filling equipment, the problem of inaccurate quantification may also be caused by the following factors: the filling speed is too high; The vacuum degree is too low; The filling pipe is too thin or too long; Too little material in the hopper; The vacuum pipeline is blocked or the air pressure is unstable.
5. Filling damage
Damage is a common problem in the filling process. The damage of cellulose casing during filling is mostly caused by kink, so the model of filling tube should match the kink device; The damage of cellulose casing may also be caused by burrs or crumbs, and the strength of casing is reduced after wetting, which leads to cracking or casing defects, such as needle holes caused by the abrasion of casing by machines during telescoping, so strict control and inspection should be carried out in production.
6. Sausages have poor appearance
Poor appearance of intestine includes over-filling, pear-shaped end, uneven thickness or different length. Overfilling can easily lead to casing rupture, or subsequent peeling is difficult. In this case, it is necessary to check whether the filling pressure is too high or whether the tying and ligating device is in place. The pear-shaped end of sausage mainly considers whether the meat is too thin, or the filling capacity is insufficient and the filling is not full; When hanging for a long time, the end may swell due to the falling of meat. At this time, it is necessary to adjust the formula of meat and fill it according to the recommended filling caliber. In view of the uneven thickness of sausage, we should investigate whether the filling pressure is stable, whether the meat preparation is uniform, whether the fluidity is qualified and whether the kinking device is smooth. On the basis of these problems, we should investigate whether the elasticity of cellulose casing is stable and whether there is deviation in caliber.
7. Casing cooking rupture or sausage explosion
In this case, it is first necessary to investigate whether there are crumbs on the processing line of the smoking room or whether there are burrs on the smoking rack. We should also investigate whether the sausage is too full. During the cooking process, the meat material expands too much when heated, or it is unevenly heated, and the casing loses too much water and becomes fragile, resulting in too much contraction, which leads to rupture. At this time, we should check whether the knot is too tight to eliminate the risk of bowel loss in advance. The humidity in the smoking room should not be too low, and too low relative humidity has a great influence on the rupture of casing.
8. Smoked color is not good
If the color is too dark or smoked, it will not be colored. Controlling smoking temperature and time is an important link to obtain uniform and stable smoking effect. The control of relative humidity in the smoking room also has a great influence on the smoking effect. The relative humidity in the smoking room is usually controlled at 35%~55%, and it may be higher when producing specific products. The relative humidity should be uniform, and uneven humidity will cause uneven smoking and peeling. In addition, too much or too little peeling liquid sprayed into cellulose casing will also affect the smoking effect, which can be adjusted by adjusting the smoking temperature or duration.
9. Sausage peeling
Before peeling, sausages must be cooled, such as with salt water, otherwise it will be difficult to peel. When peeling, the humidity should not be too low and the temperature should not be too high. It is better to use a steam peeler. Common peeling problems include casing peeling, incomplete peeling, cut marks on sausage, etc. First, make sure that the cutting knife used is appropriate, and check whether the steam pressure is sufficient. If the sausage is under-filled, over-filled, and uneven in shape in the early processing, it is necessary to adjust the peeling device appropriately to ensure the smooth peeling processing.

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