CN111587906A - A kind of yak slaughtering and processing method with safety and quality improvement - Google Patents

Abstract

The invention discloses a yak slaughtering and processing method with improved safety and quality. This method can effectively reduce the microbial contamination on the surface of the carcass through the high-pressure spraying process of ozone water, especially the neck and other parts where the high-pressure cleaning effect is not good, and can significantly improve the food safety of the yak carcass; Yak meat; the weight of yak eye meat is increased by cutting, which effectively improves the edible quality and economic value of yak meat.

Description

A kind of yak slaughtering and processing method with safety and quality improvement

technical field

The invention belongs to the field of yak slaughtering and processing, and relates to a yak slaughtering and processing method with improved safety and quality.

Background technique

As an important means of production and the main source of animal protein for the people of the Qinghai-Tibet Plateau, yak has a very special historical and cultural status. Compared with beef cattle and yellow cattle, yak has a very special body structure: it is smaller in size and has developed and dense skirt hair (carcass pollution is easily caused during slaughtering); the bone structure is significantly different (ordinary yak has 14 pairs of ribs, more than beef cattle and yellow cattle). A pair of ribs, Jinchuan yak is up to 15 pairs of ribs); affected by the natural environment and breeding methods, the slaughtering age is generally 5-7 years old, or even older. Therefore, the meat is old and tough, and the food quality is relatively poor. Therefore, the existing beef cattle slaughtering process cannot fully meet the needs of yak slaughtering and processing. In addition, the current Tibetan yak breeding scale is small and scattered. Small workshops and slaughter households are the main body of yak slaughtering. There are huge hidden dangers; lack of basic cooling and maturation technology, the quality of yak meat cannot be effectively improved, which greatly affects the comprehensive economic benefits of yak slaughtering and processing, and is not conducive to the development of yak industry in Tibetan areas. .

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a yak slaughtering and processing method with improved safety.

The slaughtering and processing method of yak provided by the present invention comprises successively:

1) The yak to be slaughtered with a transportation distance ≤500km or a transportation time ≤6h should stop eating and rest for 12-24 hours, and stop drinking 3 hours before slaughtering;

The yak to be slaughtered with the transportation distance > 500km or the transportation time > 6h, rest for 60h-72h, stop eating for 12-24h before slaughtering, and stop drinking for 3h;

2) Stunning, slaughtering, stabbing, draining blood, and conducting low-voltage electrical stimulation;

3) Shave the skirt hair from top to bottom at the midline of the yak's abdomen, rinse, cut the front hooves and horns, pre-strip the head, and cut the back hooves;

4) Pre-peeling and tearing the yak carcass;

5) Cut the head of the yak carcass after the skin has been pulled, open the chest and take the internal organs, then split the yak and trim it to obtain a trimmed two-part body;

6) Spray the inside and outside of the entire yak carcass, the saw section, the split section and the knife edge to obtain a clean two-part body;

7) Pre-cooling the cleaned bipartites, then cut them into yak quarters, deboned, divided, frozen, and refrigerated.

The step 1) of the above method is conducive to reducing the stress response of yak long-distance transportation and improving the quality of yak meat;

Described step 2) in draining blood step, draining blood time is 6-8min;

In the low-voltage electrical stimulation step, the electrical stimulation working voltage is 25V-30V, and the action time is 30s-60s. This step can promote yak muscle contraction, accelerate muscle glycolysis, thereby speed up yak meat tenderization, and facilitate further blood discharge;

In the described step 3), the width of the skirt hair shaved is no less than 20cm;

In the rinsing step, the scope of rinsing is around the abdomen, hind legs and anus of the yak; the rinsing mode is high-pressure water rinsing;

In the steps of cutting front hooves and horns, pre-stripping the head and cutting back hooves, the tools used are hydraulic scissors.

In described step 4), the scope of pre-skinning is yak hind legs, chest and abdomen and front legs;

The equipment used for the pre-peeling is a carcass processing conveyor and a peeling knife;

The skin-pulling is mechanical skin-pushing.

In the described step 5), the tool used for splitting the yak is a half saw; the splitting direction is along the yak vertebrae.

Described step 6) in the spraying step, the shower liquid is ozone water or warm water;

The concentration of the ozone water is 6mg/L-12mg/L; specifically, it can be 10mg/L;

The water temperature of the warm water is 30-35°C; specifically, 32°C;

The spray method is top-down high-pressure spray;

The spraying time is not less than 45s; specifically 45s-90s or 60s.

In the step 7) precooling, the precooling temperature is 0°C-4°C;

The relative humidity of the pre-cooling environment is 85%-90%;

The cooling time is not less than 72h; specifically 72-168h;

In the described truncation step of yak tetrad, the truncation method is to cross the 13th to 14th ribs according to the natural arc;

The cutting tool used is a tetrad saw;

In the freezing step, the temperature is below -28°C;

The freezing time is to make the temperature of the product center drop below -15°C.

The invention provides a yak slaughtering and processing method with safety and quality improvement. In the first step of the method, according to the stress intensity of yak transportation, a corresponding resting method is adopted to reduce the stress response of yak transportation, which is beneficial to improve the quality of yak meat. By adding a low-voltage electrical stimulation step after draining the blood in the second step, muscle glycolysis is accelerated so as to accelerate the tenderization speed of yak meat and facilitate further blood discharge. And by maturing for a certain period of time in the cooling room, the yak meat can be further tenderized, and the tenderness of the yak meat can be significantly improved. In view of the particularity that the long skirt hair of yak is easy to cause microbial contamination of the carcass, by adding a skirt hair shaving process in step 3, the degree of microbial contamination on the carcass surface during the yak ripping process can be effectively reduced. At the same time, by adding the ozone water high-pressure spraying process, the microbial contamination on the carcass surface can be effectively reduced, especially for the neck and other parts where the high-pressure cleaning effect is not good. Therefore, the food safety of yak carcass can be significantly improved. Since yak has one more pair of ribs than beef cattle and cattle, step 7 cuts the yak carcass from the 13th to the 14th rib into quarters according to the natural arc. Compared with the beef cattle slaughtering process, this method increases the weight of the yak eye meat. , to improve the efficiency of yak slaughtering and processing.

Description of drawings

Figure 1 shows the changes in the total number of colonies on the surface of the yak carcass in each process.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments. The methods are conventional methods unless otherwise specified. The raw materials can be obtained from open commercial sources unless otherwise specified.

Embodiment 1,

Step 1: The yak to be slaughtered with a transportation distance of 400km is sent to the slaughtering pen to stop eating and rest for 12 hours, and stop drinking 3 hours before slaughtering. To eliminate the stress response of yak long-distance transportation and improve the quality of yak meat;

Step 2: Drive the yak into the turning box to stun, slaughter, fasten the yak's hind legs with iron chains, lift it into the bloodletting track through the elevator, assassinate the bloodletting on the bloodletting track, drain the blood for 8 minutes, and perform 30V low-voltage electrical stimulation. For 60s, it promotes yak muscle contraction, accelerates muscle glycolysis, thus accelerates yak meat tenderization, and facilitates further blood discharge;

Step 3: Use a shaving tool to shave the skirt hair from top to bottom at the midline of the yak's abdomen, with a width of 25cm. Then, rinse the yak's abdomen, hind legs and around the anus with high pressure water. After showering, the front hooves and horns are cut with hydraulic scissors, the head is pre-stripped, and the rear hooves are finally cut;

Step 4: Transfer the yak carcass to the carcass processing conveyor, and use a skinning knife to pre-skin the yak hind legs, breast and abdomen, and front legs;

Step 5: The pre-stripped yak is automatically transported to the peeling station on the carcass processing conveyor, and the peeling machine is used for mechanical peeling;

Step 6: Transfer the skinned yak carcass to the next station, cut the head, then open the chest and take the white and red viscera, and hang the yak head, white viscera and red viscera on the synchronous quarantine conveyor. Veterinary health inspection, at the same time, use a split saw to split the yak into left and right halves along the yak vertebrae, and trim the two halves;

Step 7: Clean the dyad. When flushing, use 10mg/L ozone water to spray from top to bottom to wash the entire yak carcass inside and outside, sawing (splitting) section and knife edge. The spray time is 90s.

Step 8: Pre-cooling. The cleaned two-part body is sent to a pre-cooling room with a temperature of 0°C-4°C and a relative humidity of 85%-90% for cooling, and the cooling time is 72h. To further mature and tenderize the yak meat;

Step 9: Cut the bisected body obtained in Step 8 into a yak tetrad between the 13th and 14th ribs with a tetrad saw according to a natural arc;

Step 10: Hang the tetrad on the production line. After deboning, dividing and packaging, the deboning personnel will place it in a freezing room below -28°C for freezing. When the central temperature of the product drops below -15°C, transfer it to a -18°C refrigerated room for storage.

Example 2

1 Materials and methods

1.1 Test material

In the yak slaughtering workshop of Diqing community, 3 fattening yaks were selected and slaughtered in accordance with the provisions of GB/T 19477 "Cattle Slaughtering Operation Regulations" and GB 18393 "Cattle and Sheep Slaughtering Product Quality Inspection Regulations". In peeling, splitting, and carcass ozone spraying (the relevant parameters used in ozone water are determined as: ozone water concentration 6mg/L; spraying the carcass time is 45s.) After 5 minutes, the three links were respectively used at the outer ridge of the left carcass. A bacterial scalpel was used to cut 10 × 10 cm square and 3 cm-5 cm thick muscles, put them into sterile bags, store them at 0 ° C - 2 ° C, and quickly send them to the laboratory to determine the microbial content. The carcass was pushed into the cooling workshop, and after cooling to maturity for 72 hours, yak meat was collected aseptically from adjacent positions of each carcass to detect the microbial content.

2.1.2 Test method

Determination of the total number of colonies: According to GB 4789.2-2010 "Determination of the total number of colonies in food microbiological inspection", each sample was repeated three times, and the average value was taken.

2 Results and Analysis

As shown in Figure 1, in the standard yak slaughtering workshop, hanging slaughter is adopted in accordance with good operating procedures, and the total number of yak meat colonies is maintained at 10 ² CFU/g in the links that are prone to microbial contamination, such as peeling and splitting. However, due to improper operation, such as contamination of the fur, damage to the digestive tract, etc., the total number of yak meat colonies on individual carcasses reached the order of 10 ³ CFU/g. After the carcass was split in half, and before cooling to maturity, the carcass was reduced by ozone spraying. After 5 minutes of ozone spraying, the total number of colonies in the carcass was measured. The total number of colonies was also well controlled, and the relevant values of yak meat in each carcass were all below 10 ² CFU/g. It is far superior to the limit requirement of NY/T 2799-2015 Green Food Meat (CFU/g) ^≤105 . The test showed that the total number of bacterial colonies in the yak meat remained at a lower level after 72 hours of maturation.

3. Conclusion

Appropriate concentration of ozone water can effectively kill the microorganisms on the carcass surface and reduce the contamination of yak meat by bacteria. The yak carcass after being split in half is sprayed with ozone water to effectively reduce the total number of bacterial colonies of the yak meat, and in addition to low temperature cooling and maturation, the reproduction of bacteria is further inhibited. Therefore, the slaughtering method provided by the present invention can effectively reduce the effect of bacteria on the yak meat. The risk of contamination has improved the safety quality of yak meat.

Tenderening effect of low voltage electrical stimulation

1. Materials and experimental design

1.1 Materials:

Eighteen 6-7-year-old Gannan yaks with similar body weight were randomly selected (carcass weight 210±25.1 kg after slaughter), and fasted for 12 hours before slaughter.

The yak is slaughtered according to the Islamic slaughtering method. The production process is: beef cattle acceptance → rest and fasting before slaughter → shower before slaughter → assassination and bloodletting → ultra-low voltage electrical stimulation (25V, 50Hz, 0.25A, 25V, 50Hz, 0.25A, 1min&2min)→deheading and hoof→peeling→opening and gutting→two parts (weighing mass: weight of hot carcass)→put in 0-4℃ acid depot for cooling and maturation.

1.2 Experimental Design:

18 Gannan male yak aged 6-7 years old with similar body weight were selected and randomly divided into two groups, 9 in each group. The shear force value of yak sirloin was measured at 0h and 72h after slaughter, respectively.

1.3 Determination of shear force

According to the NY/T 1180-2006 Determination of Meat Tenderness Shear Force Determination Regulations.

1.4 Statistical analysis

Statistical analysis was performed using Excel and SPSS17.0 data statistical analysis software.

2. Results and Analysis

Table 1. Effect of electric low-voltage stimulation on shear force value of yak sirloin (Kg)

Electrical stimulation group control group 0h after slaughter 11.07±0.29 11.59±0.86 72h after slaughter 5.31A±1.03 9.11B±0.18

Note: The difference between the capital letters of the shoulders is significant (P<0.05);

From the results shown in Table 1, it can be seen that low-voltage electrical stimulation significantly reduced the shear force value of yak sirloin after 72 hours of maturation (P<0.05), and the reduction range reached 41.7% compared with the control group. The tenderization effect was very obvious and effectively improved. The edible quality and economic value of yak meat.

Claims (7)

1. A method for slaughtering and processing yak, comprising successively: 1) The yak to be slaughtered with a transportation distance ≤500km or a transportation time ≤6h should stop eating and rest for 12-24 hours, and stop drinking 3 hours before slaughtering; The yak to be slaughtered with the transportation distance > 500km or the transportation time > 6h, rest for 60h-72h, stop eating for 12-24h before slaughtering, and stop drinking for 3h; 2) Stunning, slaughtering, stabbing, draining blood, and conducting low-voltage electrical stimulation; 3) Shave the skirt hair from top to bottom at the midline of the yak's abdomen, rinse, cut the front hooves and horns, pre-strip the head, and cut the back hooves; 4) Pre-peeling and tearing the yak carcass; 5) Cut the head of the yak carcass after the skin has been pulled, open the chest and take the internal organs, then split the yak and trim it to obtain a trimmed two-part body; 6) Spray the inside and outside of the entire yak carcass, the saw section, the split section and the knife edge to obtain a clean two-part body; 7) Pre-cooling the cleaned bipartites, and then cutting them into yak quadrants, deboning, dividing, freezing, and refrigerating. 2. method according to claim 1 is characterized in that: in described step 2) draining blood step, draining blood time is 6-8min; In the low-voltage electrical stimulation step, the electrical stimulation working voltage is 25V-30V, and the action time is 30s-60s. 3. method according to claim 1 and 2 is characterized in that: in described step 3), the width of skirt hair shaved is no less than 20cm; In the rinsing step, the scope of rinsing is around the abdomen, hind legs and anus of the yak; the rinsing mode is high-pressure water rinsing; In the steps of cutting front hooves and horns, pre-stripping the head and cutting back hooves, the tools used are hydraulic scissors. 4. according to the arbitrary described method of claim 1-3, it is characterized in that: in described step 4), the scope of pre-skinning is yak hind leg, chest and abdomen and front leg; The equipment used for the pre-peeling is a carcass processing conveyor and a peeling knife; The skin-pulling is mechanical skin-pushing. 5. according to the arbitrary described method of claim 1-4, it is characterized in that: in described step 5), the tool used for splitting the yak is a split saw; the splitting direction is along the yak vertebrae. 6. according to any described method of claim 1-5, it is characterized in that: in described step 6) spraying step, the shower liquid is ozone water or warm water; The concentration of the ozone water is 6mg/L-12mg/L or 10mg/L; The water temperature of the warm water is 30-35°C; specifically, 32°C; The spray method is top-down high-pressure spray; The spraying time is not less than 45s; specifically 45s-90s. 7. The method according to any one of claims 1-6, wherein in the step 7) precooling, the precooling temperature is 0°C-4°C; The relative humidity of the pre-cooling environment is 85%-90%; The cooling time is not less than 72h; specifically 72-168h; In the described truncation step of yak tetrad, the truncation method is to cross the 13th to 14th ribs according to the natural arc; The cutting tool used is a tetrad saw; In the freezing step, the temperature is below -28°C; The freezing time is to make the temperature of the product center drop below -15°C.

Images