Font Size: a A A

Process Re-engineering And Quality Control On The Reception System Of Raw Milk

Posted on:2013-01-29Degree:MasterType:Thesis
Country:ChinaCandidate:Y MaFull Text:PDF
GTID:2219330374968437Subject:Food Engineering
Abstract/Summary:PDF Full Text Request
Along with the rebuilding of the dairy industry by the government and the rising ofpeople's consumption level of in China, the demand for dairy is still increase, and consumersstill have confidence in it, although the industry had struck by a series of quality and safetyincidents of dairy products. There are some problems which has obstructed the developmentof the industry. The contradiction between raw milk supply and demand and the quality ofdairy are still need to pay close attention.The process of dairy products can be divided into two parts, reception system and dairyproduction. By improving the equipments and enhance the technological skills, the quality ofdairy products had been improved, but the quality of raw milk in reception system is still a bigissues, enterprise has the responsibility to control it.The reception system included preparing before milking, milking, stockpile in milkstation, transportation, assaying and accepting, stockpile in factory, cleaning equipments. Byre-engineering the process and find effective quality control measures on the reception systemof raw milk, the study revealed several findings as follows:(1) According to analysis the reception records of raw milk in a large-scale dairycompany about one month, we find that the company will reject the raw milk when they findsome problems in the check process. The study shows that1.75%of raw milk was rejected,which reduced the quantity of this company and brought about huge financial loss to farmerand milk station. Antibiotic positive (45.35%), nutrition indices abnormal (26.74%), alcoholpositive (6.98%) are the main reasons for rejection. Mastitis milk (3.49%), high acidity(4.65%), high temperature (10.47%), sensory bad (1.16%) and impurity (1.16%) will alsoraise the rejection ratio. We can take some effective measures to reduce the rejection rate, butin the process of reception system, we need to synthesize different measures together toenhance the whole level of raw milk.(2) The condition of microbes in raw milk will decided the grade and price of raw milk.The study intended to probe the measures of prevention microbes of raw milk in receptionsystem. The study shows that sanitary condition of equipment between different milk stationsresult in significant variations of microbes in raw milk; sanitary condition of udder andequipment, the condition of storage and transportation between different links in the same milk station result in significant variations of microbes in raw milk. By investigate the changeof total colony counts in raw milk, then research the way of cleaning and disinfection, thevolume of raw milk which should be discard, the reasonable temperatures of the cooling tankand the specific transport requirement, we find that clean cow's udder by warm water anddisinfect it with0.1%KMnO4, then dry the udder before milking, the total colony counts inraw milk reduced to2.56×103CFU/mL from2.65×104CFU/mL. Total colony counts in rawmilk reduced to1.00×103CFU/mL and is far less diverse when discard the first40mL rawmilk. Total colony counts growth slowing when the temperature of raw milk cool to0~4℃assoon as possible. In4927reception records,91.46%of the raw milk's total colony countswere below5.00×105CFU/mL, and1.99%of the raw milk's total colony counts were belowthe national food safety standard, which is2.00×106CFU/mL. The temperature of milkcontainer and the haul distance will influence the total colony counts of raw milk, so we needto check the vehicle, select a reasonable route and make sure the temperature of milkcontainer work well before conveyance, by doing this, microbes in the raw milk can bereduced effectively in the transport process.(3) By investigate the reception system in milk stations and factory, we consider that thewhole re-engineering process should include this: preparing before milking, antibiotic check,clean and disinfect, mastitis check, discard some milk, milking, disinfect after milking,retained samples, stockpile in milk station, transportation, censor before enter the factory,assaying and accepting, stockpile in factory, cleaning milking equipment, vehicle and thecontainer. We also believe that register the information about milk station, vehicle, collectnatural index, cleaning time and rejection reasons will help us to control the raw milk better.About90reception records which belong to54milk stations shows that the raw milk's totalcolony counts above5.00×105CFU/mL, these milk stations have the common problem: didn'taccording to the re-engineering process to maintain sanitary conditions or cleaningequipments. About86rejection records which belong to46milk stations, and the raw milkfrom other106milk stations were not rejected. The manageable level of different milkstations will impact the quality of raw milk, based on the re-engineering process will improvethe quality of raw milk.
Keywords/Search Tags:raw milk, reception system, rejection, microbe, process re-engineering
PDF Full Text Request
Related items