Preservatives and pet food shelf life
Food additives are substances added to food, aimed to preserve flavor or improve taste and appearance of food. Preservatives food additives are anti-microbial preservatives, which inhibit the growth of bacteria and fungi, or antioxidants such as oxygen absorbers, which inhibit the oxidation of food constituents. Therefore, many manufacturers add preservatives into food to prolong products shelf life. However, there are strict regulations on addition of preservatives. In this article, we will talk about some other ways to prolong pet food shelf life in terms of pet food packaging.
Published on: Mar 4, 2016
Transcripts - Preservatives and pet food shelf life
Preservatives and Pet Food Shelf Life By Yarina Gao Labthink Instruments Co., Ltd, China Trade5@labthink.cn[Abstract] Food additives are substances added to food to preserve flavour or improve its tasteand appearance. Preservatives food additives are anti-microbial preservatives, which inhibitthe growth of bacteria and fungi, or antioxidants such as oxygen absorbers, which inhibit theoxidation of food constituents. Therefore, many manufacturers add preservatives into food toprolong the shelf life. However, it has strict regulations on addition of preservatives. In thisarticle, we will talk about some other ways to prolong pet food shelf life in terms of pet foodpackaging.[Keywords] Pet Food, Packages, Preservatives, Shelf LifeP et food has been one of keen competitive industries along with countless new pet foods introduced into the market. There is a growing need for reliable methods of ensuring and prolonging shelf life of pet food. Like human being foods, pet food must be ensuredqualified for pets’ lives and health. Therefore, pet food should maintain the necessary nutritionand original flavor during the delivery, maintenance and shelf life.Preservatives are used for centuries. They may be anti-microbial preservatives, which inhibitthe growth of bacteria and fungi, or antioxidants such as oxygen absorbers, which inhibit theoxidation of food constituents. Common anti-microbial preservatives include calciumpropionate, sodium nitrate, sodium nitrite, sulfites (sulfur dioxide, sodium bisulfite, potassiumhydrogen sulfite, etc.) and disodium EDTA. Antioxidants include BHA and BHT.Food preservatives are classified as: Natural Preservatives such as salt, sugar, vinegar, syrup,spices, honey and edible oil; and Chemical Preservatives such as benzoates, sorbates, nitritesand nitrates of sodium or potassium, sulfites, glutamates, glycerides and the like. Artificialpreservatives can be produced more economically, however, have worse side effects on pet foodthan natural preservatives. More and more strict regulations have been issues on the classesand quantity added in pet food. It is harder and harder for manufacturers to rely onpreservatives to ensure shelf life. In the real productions, usage of high barrier materials as petfood packaging can also be very helpful in ensuring and prolonging pet food shelf life.TestsAs we all know, growth of microorganisms need certain and proper environment. The most
three importance factors are temperature, oxygen and water. Oxygen is primary factor thatcause food decay. The less oxygen in food package, the less possibility food gets decay. Whilewater also provides a living environment for microorganisms, it can speed up the reduction offat; shorten shelf life of pet food.During pet food shelf life, oxygen and water vapor in the packages should maintain the prefilledvolumes. Permeability is a measure of the ability of a barrier material to allow gases (O2, N2,CO2 and water vapor etc.) to permeate through it in a specific time. It usually depends on thetype of material, pressure, temperature and thickness of materials. In Labthink laboratory, wedid oxygen transmission rate and water vapor transmission rate testes, analysis andcomparison of seven commonly used pet food packaging PET, PET+CPP, Bopp/CPP, BOPET/PE,OPP/PE/CPP, BOPET/VMPET/LDPE. Higher oxygen transmission rate, lower oxygenpermeability of materials; high water vapor transmission rate, lower water vapor permeabilityof materials. Oxygen Transmission Testing Use Labthink OX2/230 Oxygen Transmission Rate Test System and base on equal pressure method. Before testing, put the specimen in a standard environment (23±2℃、50%RH) for 48h to make a air balance of specimen surface. Select the smooth without wrinkle specimen and cut it into round shape Mount the conditioned specimen on OX2/230 Oxygen transmission rate test system, in this way, the test chamber is divided into a upper chamber and lower chamber by the specimen and then Fix and close the test chambers Pour high-purity oxygen into upper chamber, high-purity nitrogen in lower chamber Because of concentration difference, oxygen will be in solution diffuses from upper chamber to lower chamber, through the specimen, then these oxygen will be taken to the oxygen sensor by the flowing Nitrogen We can get a oxygen concentration in lower chamber, and then calculate the oxygen transmission rate through the specimen. Water Vapor Transmission Rate Test Use Labthink W3/030 Water Vapor Transmission Rate Tester and Based on traditional cup method. Pre condition specimen as oxygen testing and cut the specimen into round shape Fill the test cup with certain quantity of double distilled water. Mount the specimen into the test cup so that the test cup is divided into two part Set the test environment at 38 ℃ and 90%RH WVTR could be obtained through period-measuring the reductive weight of test cup during the testing process Detailed OTR and WVTR test results of these 7 packaging materials as follow:
Test Results Specimen OTR（ml/m2/day） WVTR (g/m2/24h) PET/CPP 0.895 0.667 BOPP/CPP 601.725 3.061 PET 109.767 25.163 BOPET/PE 85.055 4.632 OPP/PE/CPP 716.226 2.214 BOPET/VMPET/LDP 0.149 0.474 E Aluminum-plastic 0.282 0.187Table 1 Test Data of Pet Food Packaging PermeabilityFrom the Analysis of test results of these 7 kinds of packaging materials, we can find thatmaterials laminated with differently can have a significant difference in oxygen permeability.From Table 1, Aluminum-plastic materials, BOPET/VMPET/LDPE, PET/CPP has a relativelower oxygen transmission rate. According to our research, pet food with these kinds ofpackaging also usually has longer shelf life。
Laminated films have a good performance in barrier of water vapor. Referring to the chartbelow, PET has high water vapor transmission rate, which means it has a poor performance inbarrier of water vapor and not suitable for pet food packaging, as it will shorten the shelf life ofpet food.TestimonialReferring to the tests, pet food manufacturers can use high barrier materials instead of moreadditional of preservatives to prolong pet food shelf life. We recommend to choose laminatedplastic, aluminum-plastic materials and metal materials as pet food packages, because all thesematerials have a good barrier properties to oxygen and water vapor. Besides consideration ofoxygen and water vapor permeation properties of materials, we should know that theenvironment also have some impacts on these properties of materials. Such as EVOH and PA,they are very sensitive about humidity. In Room temperature and relative lower humidity, bothof them have a good barrier to water vapor, while in high humidity environment, their watervapor permeability would decrease. So if there is high humidity environment during pet fooddelivery and maintenance, EVOH and PA are not suitable for packaging.