• · Milk and milk products provide a wealth of nutrition benefits. But raw milk can harbor dangerous microorganisms that can pose serious health risks.
• (NewsTarget) A single glass of pasteurized milk can contain a toxic chemical cocktail of 20 painkillers, antibiotics, and growth hormones, new research has shown.
• Even when we “have” to drink the pasteurized stuff, we still have a few options. There’s a local dairy that gently pasteurizes their milk and doesn’t.

PASTEURIZED MILK PRODUCTS Dairy Processing Handbook. Pasteurized milk products are liquid products made from milk and cream intended for use directly by consumers. This group of products includes whole milk, skim milk, standardized milk and various types of cream. Cultured products are also included in this category, but as these are made with special bacteria cultures, they are dealt with separately under Chapter 1.

Fermented milk products”. All the building blocks described in Chapter 6 are, in principle, used in the processing of pasteurized milk products. In most countries, clarification, pasteurization and cooling are compulsory stages in the processing of consumer milk products. In many countries, the fat is routinely homogenized, while in others homogenization is omitted because a good “cream- line” is regarded as evidence of quality. De- aeration is practised in certain cases when the milk has a high air content, as well as when highly volatile off- flavour substances are present in the product. This may occur, for example, if cattle feed contains plants of the onion family.

Processing of market milk products requires first- class raw material and correctly designed process lines in order to attain end products of the highest quality. Gentle handling must be ensured so that the valuable constituents are not adversely affected. To ensure milk quality, there are microbiological standards for intra- community trade in milk within Europe, set by the Council of the European Union (EU) to safeguard human and animal health.

These standards are shown in Table 8. Table 8. 1 EU standards for maximal bacteria count in milk. Product. Plate count (CFU/ml)Raw milk1.

Pasteurization or pasteurisation is a process that kills microbes (mainly bacteria) in food and drink, such as milk, juice, canned food, and others. To fully understand the differences between raw, pasteurized, and homogenized milk, let’s take a look at each and discover what it all means.

Raw milk stored in silo (6 °C) at the dairy for more than 3. Pasteurized milk after incubation for 5 days at 6 °C5. UHT and sterilized milk after incubation for 1. C 1. 0/0. 1 ml. CFU = Colony Forming Units. Another measure of raw milk quality is the amount of somatic cells that can be tolerated in raw milk. Somatic cell count is used as a criterion for ascertaining abnormal milk.

Raw milk intended for intra- community trade must not contain more than 4. EU directive. Processing of pasteurized market milk.

Depending on legislation and regulations, the design of process lines for pasteurized market milk varies a great deal from country to country and even from dairy to dairy. For instance, fat standardization (if applied) may be executed in- batch before pasteurization or in- line where the standardization system is integrated into a pasteurization unit.

Homogenization may be total or partial. The simplest process is to pasteurize the whole milk. Here, the process line consists of a pasteurizer, a buffer tank and a filling machine. The process becomes more complicated if it has to produce several types of market milk products, i. The following assumptions apply to the plant described below: Raw milk– Fat content 3. Temperature +4 °CStandardized milk – Fat content 3.

Temperature +4 °C Standardized cream – Fat content 4. Temperature +5 °CPlant capacity– 2. Figure 8. 1 shows a typical process flow in a market milk pasteurization unit. The milk enters the unit through the balance tank (1) and is pumped to plate heat exchanger (1.

Fig. 8. 1. Pasteurization unit for market milk with partial homogenization. Balance tank. Product feed pump. Flow controller. Deaerator. Separator. Constant pressure valve. Density transmitter.

Flow transmitter. Regulating valve.

Shut- off valve. Check valve. Homogenisator. Booster pump.

Holding tube. Flow diversion valve. Plate heat exchanger. Process control. The standardization of market milk takes place in an in- line system of the type already described in Chapter 6. The fat content of the cream from the separator is set to the required level and is then maintained at that level, regardless of moderate variations in the fat content and in the flow rate of the incoming milk.

The fat content of the cream is usually set at 3. Once set, the fat content of the cream is kept constant by the control system, consisting of a density transmitter (7), a flow transmitter (8), regulating valves (9) and the control system for the standardization system. In this example, partial homogenization is used, so only the cream is treated. The reason for choosing this system is that it can manage with a smaller homogenizer (1. The working principle of the system, also described in Chapter 6. After passage of the standardization device, the flow of cream is divided into two streams. One, with the adequate hourly volume to give the market milk the required final fat content, is routed to the homogenizer and the other, the surplus cream, is passed to the cream treatment plant.

As the fat content of the cream to be homogenized should be a maximum of 1. The capacity of the homogenizer is carefully calculated and fixed at a certain flow rate. In a partial homogenization arrangement, the homogenizer is also connected with the skim milk line so that it always has enough product for proper operation.

In that way, the relatively low flow of cream is compensated with skim milk up to the rated capacity. Following homogenization, the 1. The milk, now with standardized fat content, is pumped to the heating section of the milk heat exchanger where it is pasteurized. The necessary holding time is provided by a separate holding tube (1. The pasteurization temperature is recorded continuously. Chicken And Dumplings With Canned Biscuits here. A booster pump (1. If the pasteurization temperature should drop, this is sensed by a temperature transmitter.

A signal activates the flow diversion valve (1. See also Chapter 7. After pasteurization, the milk continues to a cooling section in the heat exchanger, where it is regeneratively cooled by the incoming untreated milk, and then to the cooling section where it is cooled with ice water. The cold milk is then pumped to buffer tanks and then to the filling machines. Standardization. The purpose of standardization is to give the milk a defined, guaranteed fat content.

The level varies considerably from one country to another. Common values are 1. The fat is a very important economic factor. Consequently, the standardization of milk and cream must be carried out with great accuracy. Some options applicable to continuous fat standardization are discussed in Chapter 6.

The purpose of standardization is to give the milk a defined, guaranteed fat content. Pasteurization – the heat treatment. Along with correct cooling, the heat treatment is one of the most important processes in the treatment of milk. If carried out correctly, these processes will give milk a longer shelf life. Temperature and pasteurization time are very important factors which must be specified precisely in relation to the quality of the milk and its shelf- life requirements. The pasteurization temperature for homogenized, HTST pasteurized milk is usually 7.

C for 1. 5 – 2. 0 seconds. The pasteurization process may vary from one country to another, according to national legislation.

A common requirement in all countries is that the heat treatment must guarantee significant reduction of spoiling microorganisms and destruction of all pathogenic bacteria, without the product being damaged. Homogenization. Homogenization has already been discussed in Chapter 6. The purpose of homogenization is to reduce the size of the fat globules in the milk, in order to reduce or prevent creaming. Homogenization may be total or partial. Partial homogenization is a more economical solution, because a smaller homogenizer can be used.

Determining homogenization efficiency. Homogenization must always be sufficiently efficient to prevent creaming. The result can be checked by using the homogenization index.

The index called NIZO value is commonly accepted by the industry. It Is measured according to the method described in Chapter 6. The required NIZO value varies depending on the expected shelf life of milk, for example 7. ESL milk. Quality assurance of pasteurized milk.