Packaging Material Analysis for Food Preservation

Packaging Material outline for Food PreservationTroullinos YannisPackaging ReportIn this practical class, contrary films for food incase were examined as far as their visible properties and their skill to preserve grapes, cheese, meat and potatoes. Appropriate measurements and tests we done on specific duration intervals.ResultsTable 1. Results for the rapid tests for the identification of packaging materials* Materials were identified using the packaging materials identification chart for films in the practical booklet.Table 2. Results of the mechanical and physical properties of the packaging materialDiscussionCalculations and Questions1. Calculate the tensile chroma of the cardinal packaging materials tested.Table 3. Physical properties of distinguishable packaging materials* More than 25% difference from the meanBy using N = 100 g, stick mean ranges for all(prenominal) of the materials butt joint be effect. Also, state = comprehensiveness (m) x Gauge (m) = X m2. pliable loudness = Force (N) / Area (m2) so for the to a blueer place materials we haveCellulose 340 DMS Tensile specialisation = 25.6 / 2.125 x 10-6 = 12.0 x 106 N/m2 = 12.0 x 106 Pa = 12.0 MPa, as 1 N/m2 = 1 Pa, epoch 1 MPa = 1,000,000 Papolypropene Tensile strength = 108.7 / 2.5 x 10-6 = 43.5 MPaPolyethylene Tensile strength = 12.5 / 0.75 x 10-6 = 16.7 MPa2.Define tensile strength and controvert what factors will affect the tensile strength of the packaging materialTensile strength is the maximum load that a material can hold up without fracture when being stretched, divided by the original cross-sectional state of the material. Generally, as tensile strength increases, the tougher the material is considered (Hui, 2008). Factors affecting the tensile strength be (Yam, 2010 Fel low-downs, 2009)Plasticiser levels ( change magnitude apprises shew less tensile strength and to a greater extent than elasticityDegree of crystallinity (crystal structure)Density of the materia l (increasing density gives more than tensile strength)Manufacturing process (orientation, treatment, coatings)TemperaturePhysical properties of the material (branching, side groups, chain length, molecular angle)Duration of the time that the fight is applied3.Compare your tensile strength results to those found in literature.According to Goodfellow Cambridge Ltd. tensile strength for regenerated cellulose is 50 MPa, which, as mentioned, is abnormal by a lot of distinct factors. In our experiment, tensile strength of the cellulose used is a lot pass up (12MPa).Paine (1990) gives values of 30 MPa for polypropylene, season in this experiment a value of 43.5 MPa was calculated.Finally, polythene gave an experimental value of 16.7 MPa, while Goodfellow Cambridge Ltd. reports 5-25 MPa for low density polyethylene (LDPE) and 15-40 MPa for gamy density polyethylene (HDPE). In this experiment it is unknown which exactly was the type of PE used, as on that point are many diverse types in market.As explained, duration of the force applied affects the tensile strength, so different testing machines give different results. There are numerous more factors as noted in question 2, which greatly affect the measurements and results. Thus, comparing values to literature cannot give objective judgement of the experiment.4.Calculate the moisture vapour transmission rate (g m-2 sidereal day-1) for each of the films testedTable 4. Results of the pee vapour permeableness test lap covering area = r2 = 0.005 m2 (r = 40mm = 0.04m)Number of Days = 4, as Day 1 is the day we started the memory boardCellulose 340 DMS fore intimately measurements get along moisture gained = Weight of Day 5 Weight of Day 1 = 84.8 83.9 = 0.9 gMoisture gained per day = tally moisture gained (g) / Nr Days = 0.9/4 = 0.225 g day-1 wet vapour permeability per 24h = Moisture gained per day / Circle Area = 0.225 / 0.005 = 45 g/m2 24h (1)second measurementsTotal moisture gained = 87.6 87.1 = 0.5 gMoisture gained per day = 0.5 / 4 = 0.125 g day-1Water vapour permeability per 24h = 0.125 / 0.005 = 25 g/m2 24h (2) look upon value of urine vapour permeability per 24h = (1) + (2) / 2 = 35 g/m2 24hPolypropylene1st measurementsTotal moisture gained = 86.0 85.9 = 0.1 gMoisture gained per day = 0.1/4 = 0.025 g day-1Water vapour permeability per 24h = 0.025 / 0.005 = 5 g/m2 24hsecond measurementsTotal moisture gained = 87.1 87.1 = 0.0 gMoisture gained per day = 0.0 / 4 = 0 g day-1Water vapour permeability per 24h = 0 g/m2 24hMean value of water vapour permeability per 24h = 2.5 g/m2 24hPolyethylene1st measurementsTotal moisture gained = 84.6 84.5 = 0.1 gMoisture gained per day = 0.1/4 = 0.025 g day-1Water vapour permeability per 24h = 0.025 / 0.005 = 5 g/m2 24h2nd measurementsTotal moisture gained = 84.6 84.5 = 0.1 gMoisture gained per day = 0.1/4 = 0.025 g day-1Water vapour permeability per 24h = 0.025 / 0.005 = 5 g/m2 24hMean value of water vapour permeability per 24h = 5 g/m2 24h5.Discuss the results of the water vapour permeability test.Water vapour permeability is a measure for breathability or for a textiles ability to transfer moisture. The results show that PP and PE have relatively low water permeability, while cellulose has a lot more. These values agree with literature (Brennan and Grandison, 2012), which states that PP has lower permeability than PE. Cellulose is alike stated as a low bulwark of water vapour permeability. These results show that using cellulose to pack food in the raw to humidity such as powders is not considered wise.6.Discuss the results of the packaging and memory board of warm fruit experiment. justify what is causing the observed changes in the fruit and how the different packaging/storage conditions influence the shelf liveliness of the fruit.Table 5. sportsmanlike fruit (grapes) 3 days interval observationsFirstly, the tissues of fruits are alive aft(prenominal) harvest and they only die through natural senesce nce, rotting or when they are consumed, cooked or similarly processed. All these tissues breath, a phenomenon called ventilation with obvious relations to maintenance of the quality and prolonging the shelf life of the product. Specifically, grapes do not respire very intensively and this is the reason they get harvested when they are ripe. Reducing respiration can strive the shelf life alone stalling it will make tissues senesce and die. Cooling temperatures can also lower undesirable effects on fruits (Jongen, 2002).As far as grapes concerned, mould is primarly because of the fungus Botrytis cinerea.Browning sight is a chemical process caused by specific enzymes changing the tissues colour to brown, while shrinkage is caused by increased respiration (tissues nonethelesstually lose water as shown in the weight measurements causing them to lose volume). Sweating is caused once again because of the respiration in packages where gas permeability is low or very low.In the above ex periments, it is shown that when using MS and heat seal, grapes got sweaty in day 2 and 3, while in the same packaging with 2 holes, sweating was only splendid. This makes maven as the 2 holes vacateed the product line transfer between package and the environment, morose the humidity because of the respiration in the package.In PE and heat seal, sweating was still more obvious as PE has lower gas permeability than MS.Finally, in the open tray, sweating was absent but mould started to show at day 3, as it partially did in the package with 2 holes. This was caused by a microorganism, probably fungus since grapes have low pH. An other change which was spotted in the open tray was the soft, dry and oxidised appearance of the grapes because of the large amounts of respiration. get on temperatures and total contact with the environment allowed this level of respiration, lowering shelf life dramatically.7.What changes would you make to the packaging/storage conditions to extend the shelf life of the grapes?The most important change to the storage conditions would be to lower the storage temperature, as it would significantly reduce respiration. The package should not have holes, as they allow environmental air to get in allowing microorganisms to grow faster.8.Discuss the results of the packaging and storage of cheese experiment. Explain what is causing the observed changes in the cheese and how the different packaging/storage conditions influence the shelf life of the cheese.Table 6. tall mallow 3 days interval observationsBrowning of cheese is significant in high storage temperatures (37C), less in fair (20C) and absent in low temperatures of 5C. Light causes the formation of lipid peroxides in medium temperatures, while compounds such as riboflavin are affected by light unrelated to storage temperature (Kristensen et al., 2001).Cheese tend to produce throw in the towel oil when they melt and sweats during storage in relatively high temperatures because of the high humidity of it. When in open air sweating is more and drying out occurs (Wang and Sun, 2004).From the above, it becomes more obvious in ours experiments why cheese dried out during storage in open tray and why this drying out is more than in aluminium foil (which was not folded enough to keep air from contacting cheese). Another way to see the above is the greater loss of weight in open tray rather in aluminium foil. On the other hand, in both MS and cryovac packages no drying out was noted, as can be seen from the differences in initial and final weight (0.1g).Relatively high storage temperatures (about 25C) caused the oiling and sweating of the cheese.9.What changes would you make to the packaging/storage conditions to extend the shelf life of the cheese?The storage temperature should be as low as about 5C (refrigerator) in dark and should be kept either in MS or cryovac packaging. Ideally, a modify atmosphere packaging should be used (Khoshgozaran et al., 2012), exte nding shelf life even more than the usual packages.10.Discuss the results of the packaging and storage of fresh meat experiment. Explain what is causing the observed changes in the meat and how the different packaging/storage conditions influence the shelf life of the meat.Table 7. Fresh meat 4 days intervals observationsFilmDayWeight (g)ChangesIn colour cloudoverMoisteningInternal and external appearance of package warehousingtemp.Type ofspoilageGeneral appearanceof productStoragehumidityOther change and/or notesPPAndHeat seal121.04C75%221.0slight honey oil slight4Ccolour changes75%321.0slight green slight4Ccolour changes75%421.0slight green and browning