Russian Pickled Snack-type Cheese Production Process Research And New Product Development

This experiment utilizes fresh cow milk as raw material for new industrial technology development that combines traditional cheddar and Russian pickled cheese manufacturing processes.The in-depth study(focusing at pre-acidification and saliniation phases) and optimization of the whole manufacturing process leads to the complete product feasibility. The further stage of scientific work over the project includes product comprehensive quality assessment and cost accounting.Afterwards it comes to a new product concept of a novel snack-type food that integrates such features as manufacture span shorter than traditional cheese,mild taste,high nutrition value,convenience.The main results are as follows:1.Raw materials chemical constituents' determination.Results are:protein 3.19%, 3.52%fat,non-fat milk remains 8.69%,density 1.0283,titratable acidity 17±1°T,pH = 6.66.In accordance to the final cheese requirements,that required raw milk adjustment:its fat content regulated to 3.0%.2.Use Streptococcus thermophilus,Lactobacillus acidophilus and Lactobacillus bulgaricus as bacterial starter in the same process on the various stages of cheese making pH changing effects to the final cheese product.Sensory evaluation for bacteria selection was performed.The results of this experiment indicated Streptococcus thermophilus as the most suitable bacterial culture.3.SDS-polyacrylamide gel electrophoresis and protein determination is run for all stages of cheese manufacturing for preliminary study and discussion of protein changes in cheese.Results show:before and after rennet addition,before and after salinization corresponding protein proteolysis significant change。4.Starter dose,fermentation temperature and fermentation duration were put into the Box-Behnken experimental design variables with further analysis pre-acidification process estimation by response surface analysis which discloses that starter dose has very significant impact tocurd pH and cheese sensory parameters(P＜0.01);fermentation temperature has significantly affected to curd pH(P＜0.01);and the fermentation time has very significant effect to the curd pH(P＜0.01) and effect to sensory impact(P＜0.05). Meanwhile,various factors have different extent of interaction.According to Software analysis and actual operating parameters,the final best pre-acidification conditions were as follows:2.5%dose fermentation,fermentation temperature 44±1°C,fermentation time 2.5h,and tests were verified with good reproducibility. 5.In the process of the research cheese moisture content and pH value impact was measured in temperature range of 20°C～60°C during cheddarization process;the results show that at lower temperatures cheese requires longer time of cheddarization and that provides higher water content to cheese;in higher temperatures,cheddarization time is shown to be significantly shorter,and the water content is reduced as well with temperature increasing,but at 60°C,cheese's self-melting phenomena occurs,and the pH value does not significantly reduce.Ultimately,we determine that the temperature of experimental cheddarization lays in the range of 45°C,at this temperature cheese only needs 2h cheddarization in order to achieve the target pH values,the process is more efficient than the traditional manufacturing method.6.Selecting melting temperature range from 50°C to 90°C:the process impact to cheese pH was measured at different conditions:humidity content and fat content which showed that if the temperature is too low it causes slow heat transfer,melting time delay and poor efficiency;while the temperature is too high,melted cheese phenomenon occurs. PH value of cheese after melting indicated a slight rebound,water content after melting increased and fat content dropped after melting.Therefore the experiment provided the following data:melting temperature range is 70°C～75°C;it ensures cheese good structure and efficient raw output.7.Experiment studies the following single factors:salt concentration,salinization time and temperature impact to the cheese salt content,water content,free amino acid content and sensory evaluation.With the growth of concentration time and temperature, salinization intensity increases,water content appears to decline after rising,free amino acid content has reverse changes as during salinization.After all,the three given factors provide data for orthogonal test which indicates the best conditions for salt process is: concentration 12%,salinization time 20 min,temperature 15°C.Test validation displayed good reproducibility.8.Determination of quality in final products.Measured water content in cheese was 44%,protein content 27.19%,fat content 25.93%,salt content 1.6%.Therefore we may say it is the full-fat semi-hard cheese,in line with the intended target.Detected organic acids in cheese are succinic,lactic acid and acetic acid,relative content is 3.849%, 69.311%and 26.840%;detected water-soluble vitamin in cheese are vitaminB2,B3,B5, B6,relative content is 43.843%,217.7%,1.109%and 52.871%;detected 17 kinds of amino acids,including all the essential amino acids.Total amount of amino acids reached 265g/kg,with the highest content of glutamic acid(59.828g/kg),followed by leucine, lysine,cysteine;detected of 27 kinds of free fatty acids,in which the greater part belongs to unsaturated fatty acids - totally about 60%,and the highest concentration comes to Hexadecenoic acid and 13-octadecenoic acid;stearic acid indicated the highest content among saturated fats;further microorganisms detection we examined cheese expected shelf-life.45 days of storage display the total harmful colonies level at the amount of 7.6×102cfu / g,coliform bacteria were not detected,mold 10.3cfu / g,yeast 8.5 cfu / g, pathogens were not detected.The data above proves the fact that the product can have good quality within 45 days.9.Initial budget for the actual product yield and production costs displays product yield as 11.12%;raw materials' prices are based on Russian market prices,after conversion to RMB(3.4 yuan) / 100g.10.According to Russian quality standards we developed industrial production standards for experimental cheese,dubbing the cheese as《Алтайскийманше》,translated into Chinese as "Altai cheese sticks".Registered national standard number isту9225-255-02068315-2009.