Dietary potassium sorbate and ascorbic acid promote the shelf life of yak fresh meat under vacuum conditions Bai Qianyun (Qinghai Science and Technology Promotion Station, Xining, 810008) Blood acid (antioxidant) prolongs shelf life of fresh yak meat effect. The results showed that vacuum packaging, potassium sorbate and ascorbic acid were effective for extending the shelf life of yak meat, but the interaction between vacuum packaging and the use of potassium sorbate and ascorbic acid was not significant.

This article is to extend the shelf life of yak fresh j meat "topic e of the topic" nicPublishingHouse.Allrights vacuum packaging, organic preservatives and antioxidants to extend the shelf life of yak beef has been achieved significant results. Vacuum packaging conditions, fresh The shelf life of yak meat can reach 28 days at 0~5*C, which is prolonged by 22 days compared to unpackaged naked meat. The organic preservative potassium sorbate, sodium lactate and nisin prolong the shelf life of fresh yak meat. There are also obvious effects.The use of three preservatives can make the total number of bacteria in fresh yak beef not significantly increase within 35 days.Based on this, the research group studied the addition of organic preservatives (potassium sorbate) under vacuum conditions. And antioxidants (ascorbic acid) to extend the shelf life of fresh yak meat.

1 Materials and methods 1.1 Materials 1 Samples The fresh yak meat was from the Xiaoqiao agricultural and sideline products market in Xining City. Samples were taken on July 1, 2002 (1d) and sampled at 4h after slaughter. All samples were processed according to the test design requirements. All samples requiring vacuum packaging were vacuum-packed at Datong Xian Halal Meat Food Co., Ltd. Vacuum packaging process parameters: vacuum degree -0.0775 MPa, extraction time 25 s, heat sealing time 25 s. 2 test drugs potassium sorbate (commercial), ascorbic acid ( Analytically pure) 2% boric acid solution, 1% magnesia suspension, 0.2% methyl red ethanol solution, 0.1% methyl blue aqueous solution, 0.01 mol/L hydrochloric acid standard solution. 1.1.3 Instruments and equipment semi-micro nitrogen equipment; vacuum sealing machine.

1.2 Methods 1.2.1 Determination of shelf life using volatile base nitrogen (TVB sensory evaluation score based on the determination of sample shelf life. Judgment indicators in Table 1W. Vacuum packaging samples from the 7d measured TVB * N values, measured every 3d Once; non-vacuum packaging samples measured TVB per d from the first 4d sensory evaluation, determine the freshness of meat samples.

Table 1 Meat Quality Judgment Standard Level Item Sensory Test Standard Grade First Grade Color Muscular surface shiny, red uniform, dark red Viscosity The surface of the meat is either dry or wet, and the sticky hand is elastic After the depression, the odor is restored immediately. Grade luster surface and lack of fat luster, flesh bright red viscosity external surface or new section wet elastic recovery after acupressure is slower and can not be fully restored odor has ammonia smell or sour taste three-level luster surface lack of luster, flesh darkening viscosity new Viscous section viscous elastic finger pressure does not restore odor after sag 1.2.2 Test design and data processing The experimental design adopts split-zone design. W. Vacuum packaging is a first-class factor and is divided into vacuum packaging and vacuum packaging. The use of potassium sorbate and ascorbic acid was a secondary factor, divided into the use of potassium sorbate and ascorbic acid alone, with and without the use of four levels. For each treatment, 6 samples were set up, and each sample weight was 150 g. The specific experimental design is shown in Table 2. Variance analysis was performed on TVB-N (8d) values ​​representing freshness of meat samples.

Table 2 Factors for the design of split zone test for the preservation of yak meat with potassium sorbate and ascorbic acid under vacuum conditions. Level and result table group TVBN value of the main area sub area No. 8d (mg) Shelf life (d) Zone group 1 Vacuum non-vacuum zone group 2 Vacuum non-vacuum zone group 3 Non-vacuum vacuum Note: The vacuum in the main zone is indicated Vacuum packaging processing without vacuum means no vacuum treatment. In the secondary zone, 0 indicates that potassium sorbate and ascorbic acid are not used; 1 indicates that potassium sorbate is used; that ascorbic acid is used; and 3 indicates that potassium sorbate and ascorbic acid are used in combination.

3 Sample Treatment Potassium sorbate and anti-bad (according to 1000 mg/kg of meat and 500 mg/kg of meat, 500 mL of distilled water was used to prepare a solution, and soaked in meat.

2 Results 2.1 Shelf life and sample The 8th TVB table 2), the maximum shelf life is 14d. 2.2 Data processing and analysis of variance results (see Table 3, 4). The effect of vacuum packaging, potassium sorbate, and ascorbic acid on the preservation of yak meat is obvious. CP 3 Discussion 3.1 The use of vacuum packaging, potassium sorbate, and ascorbic acid has a significant effect on the preservation of yak meat and can significantly extend the shelf life of yak meat. .

However, the interaction between vacuum packaging and potassium sorbate and ascorbic acid was not significant. The reason is that under vacuum conditions, the deterioration of beef is mainly caused by changes in the beef itself, such as the action of proteases. The main role of preservatives and antioxidants is to limit the role of microorganisms and oxygen. Therefore, under the vacuum condition, the antiseptic effect of potassium sorbate and ascorbic acid did not show. This result raises questions about the necessity of using preservatives and antioxidants under vacuum conditions. Of course, this result still needs further experimental verification.

3.2 The shelf life of meat samples in this trial was relatively short. This phenomenon may be caused by the following reasons: The contamination of meat sample is serious; the time interval from sampling to packaging is too long, and the meat samples are always in the process from sampling to packaging. At higher temperatures, meat samples could not be placed in 0 to 5*C conditions for some reason, and meat samples were stored at room temperature for 12 hours. In the higher temperature environment, changes in the self-oxidation of the meat are aggravated, accelerating the decay of the meat. The process and results of the trial further demonstrated that the refrigerated environment is necessary to ensure the preservation of yak meat.

4 Conclusions The results of this test show that vacuum packaging, the use of preservatives and antioxidants are effective in improving the preservation of yak meat, but under vacuum conditions, the use of preservatives and antioxidants to further improve the effect of beef preservation Not obvious.

Table 3 Tearing test of potassium sorbate and ascorbic acid on yak meat under vacuum conditions Table 8 TVBN data table Horizontal main zone Total number of zones Average number of subzones Total number of vacuum zones Total number of zones Total number of zones Total number of subzones Average: The main area. Vacuum in the secondary zone. The meanings of non-vacuum and numbers are the same as those in Table 2. Table 4 Variability analysis of the crack zone test of potassium sorbate and ascorbic acid on yak meat under vacuum conditions Variations Sources of variance Sources of squares and degrees of freedom Mean squares Vacuum error e1 Preservatives in whole area Antioxidant Vacuum X Preservative and Antioxidant Error e2

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