1. Brief Introduction

Beef is low-cholesterol, low-fat, delicious, and rich in many nutrients, which is very popular among consumers. A type of low-temperature meat product represented by beef ham, its heat sterilization temperature is lower than 120℃, and protein denaturation is moderate, which guarantees the nutritional value of meat products and its unique flavor and taste to the greatest extent. Therefore, low-temperature meat products are becoming more and more popular. Consumer’s favorite.

In the processing of low-temperature meat products, marinating is an important process, which can effectively improve the color, flavor, and texture of the product. Traditional pickling methods take a long time, are low efficiency, and are prone to microbial contamination. In order to improve the pickling efficiency and shorten the time, scholars at home and abroad have studied modern pickling technologies represented by tumbling, ultrasonic, ultra-high pressure, etc. However, ultra-high pressure and ultrasonic have not yet achieved large-scale production due to the limitations of technology and equipment production processes. Industrialization and commercialization.

Tumbling has been industrialized in most enterprises and is a commonly used process in the production and processing of meat products. It applies mechanical force to the meat to improve the texture and flavor of meat products and increase their water retention. Tumble marinating can increase the absorption rate of the marinating liquid by the meat, effectively increasing the extraction speed of salt-soluble protein, and accelerating its movement to the surface of the meat block, thereby reducing the amount of marinating liquid and reducing production costs. At present, the most researched technologies mainly include atmospheric pressure tumbling, pulsating vacuum tumbling, and vacuum tumbling.

2. Technological Process:

Raw Meat Processing→Preparation of Pickling Liquid→Injection→Rolling and Kneading→Vacuum Filling→Baking→Cooking→Cooling→Vacuum Packaging→Finished Product

3. Operation Points:

3.1. Raw Meat Processing:

The connective tissue, congestion, broken bones, and fat in the raw meat are removed and divided into meat pieces of 3cm×3cm×6cm.

3.2. Preparation of Pickling Liquid:

Addition of salt 2.5% (based on the quality of raw meat, the same below), 0.2% of white pepper, 0.3% of complex phosphate (mass ratio of sodium pyrophosphate/sodium tripolyphosphate/sodium hexametaphosphate 4:3:3), D -Sodium erythorbate 0.16%, ice water 20% (the mass ratio of ice to water 1:1), sodium nitrite 0.015%, white sugar 2.0%, glucose 0.5%, ginger powder 0.1%, monosodium glutamate 0.2%, carrageenan 0.1% , Dissolve the ingredients in ice water at a temperature of 0~4℃, and stir until they are uniformly dissolved.

3.3. Pickling Liquid Injection:

Inject the prepared marinating solution evenly into the pre-treated raw meat with an injection rate of 120%, and the injection temperature is controlled at 0~4℃.

3.4. Tumbling and Marinating:

The static marinating was used as the sample control group, and the other groups were marinated under normal pressure, vacuum tumbling, and pulsed vacuum tumbling, and marinated in the cold storage at 0-8℃ for 8 hours.

3.5. Vacuum Filling:

The marinated raw meat is put into a vacuum sausage stuffer for filling, and the casing is a collagen casing with a diameter of 5 cm.

3.6. Baking:

Bake in an oven at 65～70℃ for 30min.

3.7. Cooking:

Cook at 85°C water temperature until the core temperature reaches 75°C.

3.8. Vacuum Packaging:

Cool to room temperature, vacuum package, and store at 0~4℃.

4. Different Marinating Methods

4.1. Stand Still Marinating:

As a control group, they were marinated in cold storage at 0~8℃ for 8 hours.

4.2. Normal Pressure Tumbling:

One-way intermittent tumbling is adopted, that is, it is carried out in a continuous cycle of “rolling → standing → rolling → standing”. The total time of tumbling is 8h, tumbling for 20min, and standing for 10min; tumbling temperature is 0~8 ℃.

4.3. Pulsating Vacuum Tumbling:

The vacuum degree is 0.08MPa during tumbling, and the vacuum tumbling is 20min. When standing still, the mixed gas of CO2 and N2 (volume ratio 1:1) is returned to normal pressure and kept for 10min. The tumbling temperature is 0~8℃. To intermittent rolling, that is rolling → standing → rolling → standing, in a continuous cycle, the total rolling time is 8h.

4.4. Vacuum Tumbling：

The vacuum degree is 0.08MPa, and the one-way intermittent tumbling is adopted, that is, tumbling→standstill→rolling→standstill, in a continuous cycle. The temperature of the tumbling is 0~8℃, and the total time of tumbling is 8h. Knead for 20 minutes and let stand for 10 minutes.

5. The effect of Tumbling and Curing on Beef Ham

5.1. Influence on Water Mass Fraction, Water Activity and PH Value:

The water mass fraction of the vacuum tumbled sample is the highest, and the sample marinated at rest is the lowest. Because rolling can reduce the water activity of the product, promote the combination of water and muscle fibers, and improve the water retention capacity of the product. At the same time, it can also increase the pH value of the product. Among them, the pH value of vacuum tumble marinating is the highest, and there are significant differences between different marinating processes. This is because the marinating liquid fully penetrates into the meat pieces during tumbling, and the alkaline buffer substances such as phosphate in the marinating liquid increase the pH value of the meat. Tumble and marinate can also promote partial proteolysis to increase free amino acids, thereby increasing the pH of the meat.

5.2. Effect on Cooking Loss Rate, Pickling Liquid Absorption Rate and Yield Rate:

Rolling and kneading can significantly reduce the cooking loss rate of beef ham, in which vacuum rolling <pulsating vacuum rolling <normal pressure rolling <standing marinating. There is no significant difference in the cooking loss rate between the vacuum tumbling and pulsating vacuum tumbling samples, but they are significantly lower than the normal pressure rolling and standing marinating.

Compared with the control group, rolling and kneading can increase the absorption rate of the pickling liquid by about 10%, and the yield rate of the product is also significantly improved. Among them, the vacuum tumbler group has the highest yield. During the vacuum tumbling process, due to the formation of negative pressure in the drum under the vacuum condition, the meat block expands, the muscle fiber structure becomes loose, the space increases, and the water holding capacity increases. On the surface of the meat block, a film is formed on the surface of the meat block when heated, so as to achieve water retention, reduce the cooking loss of the product, and increase the yield of the product.

5.3. Effect on Color:

Color is a more intuitive indicator that affects consumers when choosing meat products and is affected by many factors, such as water retention and pH. The brightness and redness after tumbling and pickling were significantly different from those of the control group. After kneading and pickling, the brightness value increased, and the vacuum kneading reached the maximum value, the redness was reduced, and the yellowness was less affected. This may be because, during the tumbling process, the marinating liquid can fully penetrate into the meat, and the increase in the concentration of the marinating liquid causes the myoglobin to be diluted, resulting in a decrease in the redness value.

5.4. Impact on Texture:

There are significant differences in the effects of different curing processes on the texture characteristics of beef ham. Compared with the control group and normal pressure pickling, vacuum tumbling and pulsating vacuum tumbling can improve the texture characteristics of the product, and the hardness, elasticity, cohesion and chewiness of the vacuum tumbling product are maximized. During the tumbling process, the meat pieces become loose, the marinating liquid enters to dissolve part of the salt-soluble protein, and then after a long period of tumbling, the salt-soluble protein is evenly distributed on the surface of the meat piece. After heat treatment, the protein denatures and forms a gel. It makes the meat pieces and the meat pieces adhere and connect to each other, stabilize the structure of the product, and improve the texture quality of the product.

5.5. Impact on Microstructure:

The microstructure of meat products is closely related to their quality, such as water retention and tenderness. After magnifying 1000 times under the scanning electron microscope, it can be observed that compared with the control group, the tumbling and curing can cause changes in the muscle fiber structure of the beef ham. The unkneaded beef fiber bundles are arranged neatly and have a uniform thickness, but after the kneading treatment, they all have different degrees of breakage, and the muscle fibers have become thinner. Among them, the degree of pulsating tumbling marinating and vacuum tumbling marinating is more obvious, and the muscle fibers of vacuum tumbling and marinating are finer so that its tenderness and quality are improved.

5.6. Effect on Moisture Distribution:

Under vacuum tumbling conditions, the relative content of non-flowing water is the highest, and the relative content of free water is the lowest. The relative content of bound water increased significantly after tumbling, indicating that free water can migrate in the direction of non-flowing water and bound water during the tumbling process. The water retention of meat products mainly depends on the non-flowing water existing between myofibrils, myofilaments, and membranes. It can dissolve some small molecules and salts, enhance the electrostatic repulsion between protein molecules, and change the structure of muscle fibers. Relaxation, combined with a large amount of non-flowing water, thereby improving the water retention capacity of meat products.

5.7. Effects on Protein Secondary Structure:

Among the various forces that maintain the secondary structure of proteins, hydrogen bonds are the main force that maintains α-helix and β-sheets, and the strength of hydrogen bonds is different for different secondary structures. It plays an important role in maintaining the stability of the gel network structure. After tumbling and pickling, the relative content of α-helix and β-sheet structure increased, and the relative content of β-turn and random coil structure decreased. Among them, the change of vacuum tumble is the most obvious, indicating that tumble can change the secondary structure of the protein and promote the transformation of disordered structures such as random coils to ordered structures such as α-helices. Thereby strengthening the hydrogen bond force inside the protein and improving the stability of its structure.

Conclusion:

After the beef ham was cured by standing, normal pressure tumbling marinating, pulse vacuum tumbling marinating, and vacuum tumbling marinating, it was found that the moisture content and pH value of vacuum tumbling and marinating were higher than normal pressure. Tumble and pulsate vacuum tumble. In addition, the cooking loss rate of vacuum tumbling is the lowest, the absorption rate of the pickling liquid is the highest, and the yield rate is significantly improved. After vacuum tumbling and curing, the brightness value of beef ham was significantly increased, the redness value was reduced, the yellowness value was basically unchanged, the color of the product was improved, and the texture characteristics and sensory scores were better than other groups. Under a scanning electron microscope, magnified 1,000 times, it was found that the muscle fibers of the beef brine ham after vacuum tumble marinating were thinner, and the degree of damage and breakage was more obvious. The secondary structure of the protein was determined, and it was found that the secondary structure of the protein was more stable in the vacuum tumbled and cured state. Therefore, the most suitable tumbling curing technique for beef ham is the vacuum tumbling curing technique.