| The food will contact with microbes in different degrees in the process of production and processing,and to improve the packaging of food additives during storage to join in the sales process,under certain conditions,often due to mildew and yeast breeding of mildew and corruption,leading to food moldy,appear on the surface of mildew,affecting food quality and special smell,make food safety is seriously affected.Grow in mold surface and internal food,the light will make food difficult to sell,or fungal and bacterial secretions,better food,eating caused human disease,the physical and mental health of consumer safety problems threatened,seriously affect the food brand in the market economy and market benefits.A bag of ordinary food,if they are eating moldy because of terrible consequences.Therefore,in the process of food production,sales and storage,food safety and quality are maintained.Packaging is an indispensable link in the processing and supply of food.Preventing mildew is a major research problem.The research andapplication of modified fluoro resin bacteriostasis and anti mildew film is of great significance to prevent food from mouldy.On the basis of the release of the active material of the film and the mechanism of the growth and reproduction of the mold,the antibacterial and anti mildew proof polyethylene packaging film was prepared.Select the modified fluorine resin(FM),sorbic acid(SA)and calcium propionate(CA)as a fungicide,with low density polyethylene(LDPE),polypropylene(PP)film as substrate,preparation of mouldproof packaging film.We study the effects of FM,SA and CA on the basic properties of low density polyethylene film;followed by the study of the performance of three kinds of antiseptic mouldproof packaging made by different proportions of mildew film;ultimately determine the mass fraction of 4% FM,with different ratios of SA and CA compound fungicide,preparation of antibacterial and mouldproof packaging PE the film,and study the basic properties of mold thin films.At last,the effect of antimould and fresh-keeping on the toast bread at room temperature(25)was studied.The following conclusions are drawn through the study.(1)the compatibility of fungicide and plastic substrates.The modified fluoro resin,sorbic acid and calcium propionate have good compatibility with LDPE and PP within the range of mass fraction of 1%-4%.(2)study on the effect of single agent on the properties of the films.In addition the same mass fraction(0~6%)of single fungicide conditions,found the performance indicators,packaging film research of adding FM fungicide,FM and LDPE have good compatibility and optical properties of the films decreased,tensile strength decreased,oxygen transmission rate,water vapor permeability,heat resistance increased.Compared to pure LDPE film,the mildew proof performance and packaging performance of the FM mildew proof film with 4% mass fraction were good.(3)influence the content and types of preservatives on the properties of the films.FM,SA and CA have good compatibility with LDPE.Due to the high content of calcium propionate,the film properties of4%FM+2%CA films are greatly influenced by the high content of calcium propionate,and the performance of films is poor.After adding4%FM+4%SA,the haze of the films increased,the transparency decreased,the tensile strength and elongation at break decreased,the barrier property and the heat resistance of the films became worse.Compared to pure LDPE film,FM and SA with fungicides has improved anti mildew properties of films,including anti mildew properties and packing properties of 4%FM+2%SA thin films can be used as the best material,a new type of functional food packaging.(4)effects of fungicide complex on the properties of the films.Based on PE,modified antibacterial and mouldproof packaging film made of FM,SA and CA were added.The results showed that the anti mildew resistance and transparency of the films were improved by adding FM and CA.The fungicide added,the color and the light transmittance of the films changed,light transmittance decreased,haze increased,tensile strength and thermal stability increased,elongation at break and the barrier is reduced,and has a good inhibitory effect on mold;due to compatibility problems caused by compound decomposition and thermal crosslinking,fungicide and substrate the structural changes of the films is larger,the emergence of the phenomenon of holes and damage.Compared with LDPE film,4%FM+2%SA+1%CA film has the best mould proof effect,and has good bacteriostatic effect on Escherichia coli and Staphylococcus aureus.It can be used as a mould proof packaging material for toast bread.(5)study on the actual mildew proof effect of mildew proof film.The toast for packing objects,from the sensory evaluation,the weight loss rate,peroxide value,acid value,total number of colonies and other indicators,to evaluate the effect of mildew proof mildew film.Through sensory evaluation and other freshness indicators,it showed that4%FM+2%SA+1%CA modified mould resistant packaging film had the best effect on the toast bread.Compared with the control group LDPE film,the shelf life of toast bread could be extended for 10-15 days at room temperature.Mouldproof packaging films can effectively inhibit the growth of bacteria and fungi,the weight loss rate of change trend of LDPE film is slow,peroxide value,acid value and fresh bread toast than did not change significantly,so has the mildew mildew preservation effect is very good.(6)because of fungicide by the incorporation of thin film materials,optical mechanical properties to reduce the problem needs further study. |
PDF Full Text Request