Dairy product comprise a variety of food based on milk or its by-product as a major ingredient such as pasteurized milk and Sterilized Milk ( HTST milk).
Nisin is a natural food preservative with high efficiency, nontoxic, no harm to humans, be free from side effects and can meet the specific needs of dairy products to extend shelf life .
Pasteurized milk (packed by polyethylene film bag)
Based on the nisin application experiments, the experiment results shown that the shelf life of the pasteurized milk without adds Nisin is only 3 days, the total bacterial content of the pasteurized milk without adds Nisin exceed the state standard limit at the end of the seventh day.
When addition of 100 mg/kg of our nisin to the pasteurized milk, the shelf life could be expanded to 7 days.
The total bacterial contents of the pasteurized milk with 100 mg/kg of our nisin exceed the state standard limit at the end of the 14days.
If addition of 300 mg/kg of our nisin to the pasteurized milk, the shelf life could be expanded to 21 days.
The total bacterial contents of the pasteurized milk with 300 mg/kg of our nisin exceed state standard limit at the end of 28th day.
Sterilized Milk (high temperature short time pasteurization milk) (packed by glass jar)
Based on the nisin application experiments (the experiment product is kept at 37C for 7 days and observing the level of decay at regular intervals in the experiment product), results demonstrated that the effects of factors to the qualified rate of product are arranges in a degree sequence from big to small : The content of nisin, the heat process temperature and the time of heat process
Comprehending the sense (appearance) of product, heat energy consumption and the dosage of nisin, the suitable technical conditions of application experiments of glass packed milk is heat processes at
It also should be pay attention to the packing material, the hygienic conditions in packing room and avoiding second pollution after the HTST (high temperature short time pasteurization), otherwise it will reduce the storage quality and affect the storage life (shelf life).
Canned food
Nisin is a natural food preservative with high efficiency, nontoxic, no harm to humans, be free from side effects and can meet the specific needs of canned food , extending shelf life of product , improving product quality and protection against bacterial growth.
It also can reduce salt content in canned pickles.
Canned mushroom
(the type of can is 6118)Based on the application experiments made by the Institute of Food and Fermentation Industry, Ministry of Light Industry, the canned mushroom without Nisin decayed at rate of 9.5% when it was stored at 37C for 35 days and the canned mushroom without Nisin decayed at rate of 13% when it was stored at
Addition of Nisin to the canned mushroom, 100 samples would not contaminate (the canned mushroom with Nisin decayed at rate of 0 %).
The results of applying Nisin to canned mushroom showed Nisin has outstanding effect on extending shelf life of canned mushroom.
Canned pickles (packed by glass jar)
The salt contents are high in kinds of canned pickles at present. For example, the general salt content in vegetables pickled in soy sauce is 10to 15% and the general salt content in vegetables pickled in salt is 15to 20%. However, the foods contained high salt content and high sugar contents are not benefit to customers health.
It is the developmental direction of canned pickles to reduce the salt content and the sugar levels.
For this reason, we reduced the salt content and the sugar content in the experimental samples, at the same time addition of Nisin to guarantees the safety storage of the canned pickles.
The experiment results showed that it could reduce salt content in canned pickles and the hygienic quality index is up to the standard when add Nisin into the canned pickles.
The canned pickles with Nisin decayed at rate of 0 % when it was stored at
The results of applying our Nisin in the canned pickles showed Nisin still has outstanding effect on extending shelf life of canned pickles when reduce salt content in canned pickles.
Plant protein foods
Nisin is a natural food preservative with high efficiency, nontoxic, no harm to humans, be free from side effects and can meet the specific needs of plant protein food, extending shelf life of product , improving product quality and protection against bacterial growth.
The preservative efficiency of Nisin is better than chemical antiseptic agent propylparaben.
Soya-bean milk (packed by jar)
From the application experiments made by the Institute of Food and Fermentation Industry, Ministry of Light Industry., it is known that the soybean milk without Nisin decayed at rate of 80% when it was stored at 37C for 28 days and the soybean milk without Nisin decayed at rate of 90% when it was stored at 55C for 28 days.
Addition of Nisin to the soya-bean milk, 100 samples would not contaminate (the soybean milk with Nisin decayed at rate of 0%).
The results of applying our Nisin to soybean milk showed our Nisin has outstanding bacteriostasis.
All of these demonstrate our Nisin could be used in packed soya-bean milk as antiseptic agent to keep soya-bean milk freshness.
Moreover, the heat process intensity could be lowered.
Bean Curd ( Packed by plastic case )
In order to observing the preservative efficiency of our Nisin, we have done the experiment to test the preservative efficiency of our Nisin as natural anti-microbial agent and compare with chemical antiseptic agent propylparaben (propyl p-hydroxybenzoate).
The experiment results showed that our Nisin can be used as natural anti-microbial agent in bean curd to keep bean curd freshness.
If addition of our Nisin to the bean curd, the shelf life of bean curd is not less than 24 hours, however the bean curd add propylparaben are all dehydration, smell defect and deteriorate.
This showed the preservative efficiency of our Nisin is better than chemical antiseptic agent propylparaben in bean curd.
Meat Products
Cured meat product become spoilage due to bacteria such as Lactobacillus, Streptococcus, Pseudomonas, Bacillus etc. Most of these bacteria is heat proof bacteria.
It could not kill these bacteria completely by ordinary heat method.
The Residues bacteria in meat product often spoil meat product.
The package and the processing of meat product affect the kind of bacteria that polluted meat product.
For example, ham using vacuum package can inhibit those bacteria, which have a liking for air, due to bad ventilation.
After store a period time, the numbers of Lactobacillus bacteria in the meat will increasing, while the number of pseudomonas bacteria that need oxygen is still low.
If the meat product is packed with air manner, then the number of Pseudomonas will increase while Lactobacillus bacteria will still keep low.
Nisin can inhibits most of bacteria that cause cured meat bad, so it can use as an effective anti-microbial agent in cured meat and fish product to extend the shelf of these food.
For example, if add 150-200 ppm of our Nisin to the cured meat product, the shelf life could be expanded 2-3 times than that without add Nisin.
Listeria monocytogenes and E type Clostridium botulinum bacteria may easy pollute the fish and some other delicious seafood.
This is harm to health when humans eat these polluted foods.
When add 150 ppm of Nisin in fish or some other delicious seafood , it can inhibit bacteriotoxin and inhibit the food from going rotten, so it could extend the shelf of food.
Nitrate is not only usually use as chromogenic reagent, but also possesses anti-microbial activity against bacteria to extend the shelf life of meat food.
But if people eat too many food contained nitrates may have more rates to result in cancer.
Addition of Nisin in cured meat product can reduce the level of nitrate and also extend the shelf life of food.
Scientist TAYLOR have noted results that add 100-150 ppm of Nisin combine with 120 ppm of nitrate in cured meat, the shelf life can extend two weeks than that of only add nitrate (without add Nisin ).
The shelf life of Frankfurt sausage made by chicken meat is 4 weeks if addition 156 ppm of nitrate.
When addition of 50 ppm Nisin and 156ppm nitrate in the product, the shelf life could be extending to five week.
If addition of Nisin 100 ppm and 120 ppm of Nitrate in the product, the shelf life could be extended to more than five weeks.
Using Nisin together with other antiseptic agent can enlarge the scope of application of inhibit bacteria and gain good anti-microbial activity in the actual use.
The method of use Nisin is simple.
It needs not special skill.
The aqueous solution containing certain Nisin was made firstly, then mixed with meat product or injected into meat product.
It also can spurt and smear to the surface of meat product.
In the cured meat process of production, the meat is pasteurized by use heat process firstly, then cooling by natural and packing.
In this process of technology the anti-microbial effect using mixed antiseptic is better than that of single antiseptic.
It must pay attention to deal the surface of meat before being packed.
When using different process of technology and different process condition in manufacture cured meat, it needs different antiseptic and different dose.
The cured meat production process is list as following: Select good quality beef meat cutting into pieces injecting flavoring ( The injecting solution contain 200ppm Nisin, 20mmol EDTA disodium salt, 120ppm sodium nitrite) squeezing salting (pickling) cover with chili powder (The Chili powder contain 1% Nisin , 0.7% EDTA disodium salt, 120ppm sodium nitrite, 1% chitin, 0.5% potassium soubrette (potassium 2,4-hexadienoic acid salt)) heating and roasting cooling vacuum packing finished product.The experimental results showed that the shelf life of cured meat is 4-7 days without addition antiseptic when it is refrigerating (cold storage) at 4 oC.
While the shelf life of cured meat is more than 25 days with addition above mixed antiseptic at the same storage condition ( at 4 oC ) .
Some other experimental test shown that it still keep good quality when storage at room temperature.
The Nisin user can adjust according the practical condition and the request of certain national standard that user need to abide in his country.
Some new research showed that Nisin plus Chitosan can also done on meat process.
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