Raw milk and homogenized milk can be considered as two distinct different things. Agree that homogenization should not change the nutrtion, biological or flavor effect much since the milk was only exposed to limited physical force. But Pasterization to render the milk become not-raw with heat can create signifcant changes of the biological make up and flavor to milk. Some molecular can be broken down and son formed depend the degree of heating.

I think it is because of public health conrcern. In some countries people are still consuming raw or partially boiled milk, so the risks of contamination with biological agents is still there

It depends on the purpose of the investigation. If the purpose is assurance testing and there is evidence that the population does not consume or use raw milk in any form, testing of raw milk is not valuable as such. However, even in this situation, the test of raw milk provides information on the burden of  organisms (that cause disease or affect keeping quality) of concern. This information is useful as the heat treatment (time and temperature) are determined based on D-value of an organism and the load of the organism present in raw milk. It has been established that heat treatment at higher temperatures for longer duration of time significantly affects the traits, composition and taste of milk and products made from it. In this situation, the information from testing raw milk reflects the health of animals and sanitary and bio-security measures in the farm and hence provides a feed back to farm, and transportation procedures and facilities.

However, if there is evidence that raw milk is used for consumption, the test targeting pathogens of concern is essential. Likewise, if raw milk that are marketed for cosmetic purposes, then risk assessment should be done to determine the hazard and risk associated with use of the product. Test of raw milk in this situation, provides information to estimate the risk and hence identify appropriate risk mitigation measures. There are evidences that raw milk marketed for cosmetic purpose are being used for consumption. The test of milk in this case is again to identify the hazard and estimate risk and communicate the risk to public.

Raw milk it means milk non heat treated; homogenization it is a process to prepare an emulsion, as by reducing the size of the fat globules in (milk or cream).

Throughout history, raw milk has been the prime ingredient for great cheeses because of their unique flavor – aroma. When milk is heated or pasteurized, many naturally occurring flavors, enzymes and microflora, present in the raw milk, are destroyed or denatured by the heat and the cheese loses that important flavor.

Pasteurization kills pathogens such as Listeria and E. coli (plus others like Staphylococcus aureus and Salmonella) which can be present in raw milk but pasteurization is not a guarantee against bacterial contamination of cheese. There have been outbreaks of pathogens in both raw and pasteurized cheeses (secondary contamination).

In any case, using raw milk you have more flavorful cheeses, but in order to keep them safe they must be aged at least for 60 days.

So, I think it is very important to study raw milk characteristics, particularly from chemical and microbiological point of view. This when raw milk is processed into cheese, and also it is interesting to study the influence of these characteristics on the final cheese quality.

https://www.ncbi.nlm.nih.gov/pubmed/19620662