Study On Effects Of Packaging Materials On The Quality Of Low-temperature Meat Products

Low-temperature meat is major products in the meat market, showing attractive brown-red,unique flavor, taste delicious, nutritious, the majority of consumers, but more to transport andsell in bulk, directly exposed in the air. Due to transportation and sales personnel complexenvironments,with the large flow of people and air flow, low temperature meat surfacemicrobial contamination continue to accumulate, causing serious pollution to health indicatorsexceeding the national standard in a short time, can no longer eat, greatly reduce the shelf lifeof cold meat. This caused a great deal of merchandise waste of resources and production andsales restrictions. Meanwhile low temperature meat surface due to direct contact with oxygen inthe air oxidation, resulting in low temperature meat color deterioration accelerated, reducingconsumers’ desire to buy, sell hinder low temperature meat.To solve this problem, the test for low temperature pre-packaged meat to cut off the air, toprevent microbial environment constantly attached to the meat surface to increase the initialnumber of bacteria,anti-oxidation and color deterioration,and select studies comparing commonpackaging materials,provide technical support to solve practical problems. The details are asfollows: the cooked sauce pork knuckle, lower the temperature in the broth to a batch bagging85℃,the vacuum sealing machine for vacuum sealing, vacuum degree is generally used tograsp at0.08-that is, between0.09MPa may, after taking the time to check a seamless airbags,were placed in4℃, a temperature of10℃and20℃storage. Using three different vacuumpackaging materials (PA/PE composite film, PET/PE composite film, PA/PE co-extruded film)samples were packaged and select three each material thickness (16double-sided silk,18s,20s,100s=1mm), track and analyze different shelf life of vacuum packing materials JiangZhouzi,sensory scores, volatile basic nitrogen (TVB-N), color, pH, textural properties(hardness, elasticity, cohesion variation, chewiness, resilience), coliforms, total number ofcolonies such as quality indicators. Storage samples for periodic testing. At each sampling time,each sample was extracted three bags do the reproducibility test, the test data as the averagevalue. The results showed that:1.At4℃storage conditions, sample sensory score, pH value decreased slowly, TVB-Nand the total number of colonies increased slowly. PA/PE co-extruded bags (20silk) samplechanges the slowest in the first seven days, each index values were13.3,6.58,23.78,77000(<National Standard80000), the shelf life of up to six days. Packing group did not change significantly coliforms (P>0.05) during storage (7days) in L*value and b*values decreasedslowly, a*values showed a slow upward trend, PA/PE co-extruded bags (20wire) minimumsample color change (P>0.05), better than other packaging group (P <0.05). All sampleshardness, elasticity and chewiness decreased slowly, cohesiveness and resilience showed aslow upward trend, PA/PE compound and PA/PE co-extruded packaging group hardness didnot change significantly (P>0.05), than change significant PET/PE composite packaging group(P <0.05); PET/PE compound (20s), PA/PE compound (16s,18s,20s), PA/PE coextruded(16s,18s,20s) packaging Flexible group did not change significantly (P>0.05), better than otherpackaging group; chewiness and resilience obvious changes in packaging group (P>0.05), thanthe control group (P <0.05). Reply and chewiness of all samples showed an upward trend, thereis no significant change. To sum up, PA/PE co-extruded bags (20s) for the best packagingmaterial.2. At10℃sample sensory score, pH value is gradually decreased, and the total numberof colonies TVB-N value is gradually increased. PA/PE co-extruded bags (20s) sample changesthe slowest in the first five days,each index values were11.7,6.71,24.4, about8.0×104(closeto the national standard80000), the shelf life of up to four days. Coliform packaging group didnot change significantly (P>0.05) in the storage period (5days). L*value and b*value isgradually decreased, a*value is gradually increased, PA/PE composite (20s) and PA/PEcoextruded (20s) Sample L*value did not change significantly (P>0.05), other than packinggroup and the control group (P <0.05); PA/PE compound and PA/PE co-extruded sample a*values without significant changes in the slowest (P>0.05); PET/PE composite (18s,20s),PA/PE composite (18s,20s) and PA/PE co-extrusion (18s,20s) sample b*values change moreslowly (P>0.05), significantly better than other packaging group and the control group (P<0.05). PA/PE compound (20s) and PA/PE co-extrusion (20s) bags to maintain the effect ofthe best color stability. Sample hardness, elasticity and chewiness decreased, cohesiveness andresilience increased; PA/PE compound (20s) and PA/PE co-extruded (18s,20s) samplehardness variation slowest (P>0.05) superior to other packaging group and the control group (P<0.05); PET/PE compound (20s), PA/PE compound (20s), PA/PE coextruded (16s,18s,20s)sample elasticity slow (P>0.05), better than other packaging group.Packing group of sampleschewiness and resilience did not change significantly (P>0.05), but were better than the controlgroup (P <0.05). To sum up, PA/PE co-extruded bags (18s,20s) for the best packaging material.3.At20℃storage conditions,sample sensory score, pH value decreasedrapidly, TVB-N,the total number of colonies of coliforms and rapid rise. PA/PE co-extruded bags (20s) samplechanges the slowest in the first three days, the above index values were14,6.65,24.13,79000(< National Standard80000), the shelf life of two days. L*value and b*values decreased rapidly,a*value of the fast rise, PA/PE coextruded bag (16s,18s,20s) Sample L*value the slowestchange (P>0.05), than other packaging group (P <0.05). All samples a*、b*values and valuesdid not change significantly (P>0.05), significantly better than the control group (P <0.05).Hardness, elasticity and chewiness decreased, cohesiveness and resilience gradually increased;same kind of vacuum material, with the increase in the thickness of the sample hardness andchewiness change more slowly, which PA/PE co-extruded samples slowest change significantlysuperior to PET/PE and PA/PE compound bag samples (p <0.05). To sum up, PA/PEco-extruded bags (20wires) for the best packaging material.