The rapid growth of the food packaging field is powered by the ever growing health conscious consumers and demand for fresher and higher quality foods. Active packaging technologies provide solutions for extending products shelf life with specially altered packaging systems. Among the several shelf life enhancer systems, active packaging system for preventing oxidation is discussed in this paper. Oxidation is generally regarded as the main factor in the development of rancidity of fats and oils. The oxidative processes result in the food becoming unacceptable for consumers. Such oxidation is inhibited by exclusion of oxygen and by the presence of antioxidants. First of all, oxygen scavengers made up of substances which chemically or enzymically react with oxygen were developed to remove oxygen. The commercial oxygen scavengers such as “ageless sachet”, “platinum catalyst”, and “glucose/oxidase enzyme” have been greatly discussed in their action mechanisms and applications. The use of antioxidants in packaging manufacture has so far been limited to stabilizing the polymer during the processing or retarding the change of polymer's physical properties during storage when UV irradiated. However, a further benefit derived from incorporation of an antioxidant into the polymer is more interesting for its ability to retard lipid oxidation of the packaged food via slow migration of an antioxidant from the polymer to food. In view of which, in this paper we will review some oxygen scavenger systems as well as antioxidant-impregnated or antioxidant-coated polymer packaging material.

The actual overall migration data obtained from plastic food packaging materials into food simulants under high temperature testing conditions as described in the regulations of European Union, USA, and Korea or Japan were compared. Overall migration values(OMVs) with non-fatty food simulants under high temperature conditions were observed to be generally below 2.5 mg/dm^2 except polyamides(CPA and PA 6,6) which were tested at 121 for 2 hrs. As for the fatty food simulants, the OMVs with soybean oil were higher than other simulants. Among the films tested, PVC wrap showed higher OMVs ranging betwn 23.9 and 54.6 mg/dm^2 than others. The OMVs were measured at higher level with the elevation of contact temperature and the extension of contact time, and in fatty food simulants rather than in non-fatty simulants. Under similar testing temperature and time conditions. the OMVs tended to be increased in polar films like PA with polar simulants, and contrarily in non-polar films like PO with non-polar simulants. It is noteworthy that a discrepancy with regard to the result of OMVs was observed for some films as a result of different migration testing methods and conditions of each country areas.

The relationships between storage stability and chlorophyll contents of dried laver(DL), roasted laver(RL) and roasted seasoned laver(RSL) according to packaging during storage at 20 0.51 were investigated by measuring the acid value(A and the peroxide value(POV). The results are as follows; 1.The storage stability was decreased in the rank of 0 $lt; 3 $lt; 6 $lt; 9 months by storage term, RL $lt; DL $lt; RSL by the kind of layer products and PP/PE/AL/PE/ LLDPE(Al) $lt; PP/PE(PP) by packaging. 2. When the silica gel was added to RSL, the storage stability was improved. The more the addition level of silica gel was increased, the more the storage stability was improved. The rank order was 2g $lt; 4g in RSL. 3. Reduction of the total chlorophyll content in RSL were deacreased to 10% when packed with A1 and 24% when packed with PP.

Solid phase microextraction (SPME) was used for the determination of 6 standard solvents (methanol, isopropanol, methyl ethyl ketone, ethyl acetate, cyclohexane, toluene) in food packaging materials. SPME method is a solvent-free sample preparation technique in which a fizsed silica fiber coated with polymeric organic liquid is introduced into the headspace above the sample. SPME method using fiber coated polydimethylsiloxane (PDMS) was compared with static headspace (SHS) method used as a reference. It was found that the optimal adsorption condition using PDMS-SPME method was 20 for 15 minutes for the standard solvents. Detection limits, linearity, reproducibility, and recovery of both SHS and PDMS-SPME methods have been determined using 6 standard solvents. Both methods were characterized by high reproducibility and good linearity. Using SHS method, the mean recovery of the 6 standard solvents was ranged from 75.5% to 105.8% with a mean relative standard deviation (RSD) of 0.3% to 4.8%. With PDMS-SPME method, the mean recovery of the 6 standard solvents was ranged from 86.7% to 108.3% with a mean RSD of 0.4% to 2.5%. The detection limits of both methods were the same for toluene, cyclohexane and methyl ethyl ketone; those of PDMS-SPME method were higher than those of SHS method for methanol, isopropanol and ethyl acetate. PDMS-SPME fiber showed excellent adsorption for non-polar solvents such as toluene, while it showed relatively low adsorption for polar solvents such as methanol.

For improved preservation of boiled-dried anchovies, the current preservation method of corrugated-cardboard box packaging and freezing below - 18℃ was compared to the nylon/polyethylene(NY/PE) packaging along with cooling temperature ranging from 5℃ to 10℃ as well as ambient condition for eight months by determining physicochemical quality of stored samples. Lipid oxidation of stored anchovies and their browning increased with storage time. The phenomenon was delayed under the conditions of lower temperature and air-tight packaging. As quality-indicative criteria of stored anchovies, carbonyl value(r=-0.989), browning (r=-0.949) and color a value(r=-0.989), browning(r=-0.965), Hunter's color b value (r=-0.949) and color a value(r=-0.940) showed a highly-negative correlations with organoleptic qualities of the samples. Based on the above results, air-tight packaging in a laminated film and subsequent storage at cooling temperature was found to be a possible alternative to the current freezing-storage of boiled-dried anchovies from the physicochemical point of view.

For improved preservation of boiled-dried anchovies, the current preservation method of corrugated-cardboard box packaging and freezing below - 18℃ was compared to the nylon/polyethylene(NY/PE) packaging along with cooling temperature ranging from 5℃ to 10℃ as well as ambient condition for eight months by determining physicochemical quality of stored samples. Lipid oxidation of stored anchovies and their browning increased with storage time. The phenomenon was delayed under the conditions of lower temperature and air-tight packaging. As quality-indicative criteria of stored anchovies, carbonyl value(r=-0.989), browning (r=-0.949) and color a value(r=-0.989), browning(r=-0.965), Hunter's color b value (r=-0.949) and color a value(r=-0.940) showed a highly-negative correlations with organoleptic qualities of the samples. Based on the above results, air-tight packaging in a laminated film and subsequent storage at cooling temperature was found to be a possible alternative to the current freezing-storage of boiled-dried anchovies from the physicochemical point of view.

In order to know the quality changes of the fat and oil foods packed in plastics film by the sunlight, we examined the sunlight transmitting rate by the kind of films and measured the acid value and peroxide value according to it. The results obtained were as follows : 1. The sunlight transmitting rate of various films was explained especial permeability under the wavelength of less than 300nm, but it marked a regular form under that of more than 30nm. 2. The vacuum evaporation film with aluminum on the polyester shuts off most of the sunlight, therefore, it has the best effect that keeps the fats and oils off rancidity. 3. The sunlight transmitting rate of the white color printing film drops about 80% as compared with not printing. 4. The preventive power against the rancidity of fats and oils is PET/Al, PET, PE, nylon and OPP film in that order. The changes of peroxide value and acid value were approximately the same as that of the sunlight transmitting rate.