2018 ACS BODY OF KNOWLEDGE: DOMAIN 4 – MILK – FDA PASTEURIZED MILK ORDINANCE (PMO) REVIEW

Domain 4: Milk – Day 1 – Review of the FDA Pasteurized Milk Ordinance (PMO)

(Please note, I have pinned a post by Chris Luken, ACS CCP, to the top of CSG page. Chris recently toured the Iowa Dairy Center and the pictures are illuminating and filled with pertinent information re domain 4. Also, he has CCP tips for exam takers in his comments about his recent trip to England. Be sure and check it out.)

Domain 4: Milk (previously Domain 1 – the Raw Materials of Cheesemaking). While an essential part of cheesemaking, not as much emphasis is placed on this domain on the exam. Every year, after the exam, I hear the same response “I expected more about the science of cheese and raw materials”. I am not minimizing the importance, but we will spend only 3 days on this domain starting today.

The Administrators of the group feel it is important to share a well-rounded dive into the ACS Body of Knowledge rather than only “teaching to the test”.

I am also picking up one section of Domain 1 (Food Safety) that I saved for this section of instruction:

Pasteurized Milk Ordinance (PMO).

Here is the link to the FDA POM, which is downloadable as a pdf file:

https://www.fda.gov/downloads/food/guidanceregulation/guidancedocumentsregulatoryinformation/milk/ucm513508.pdf

It’s 447 pages long… 447 dry pages long… not that I personally know that (I haven’t read it all) but because it’s a government document, safe bet.

“The Grade “A” Pasteurized Milk Ordinance (PMO) is a set of minimum standards and requirements that are established by the Food and Drug Administration (FDA) for regulating the production, processing and packaging of Grade A milk. For individual states, regulation of Grade A milk is usually under the jurisdiction of either the State Department of Agriculture or the State Health Department. States often adopt the PMO standards as a minimum, and in many cases, enforce more stringent standards. “[1]

“The Grade “A” Pasteurized Milk Ordinance (PMO) is recognized by the Public Health Agencies, the milk industry, and many others as the national standard for milk sanitation. The PMO provides uniform regulations for the dairy industry that are created by the dairy industry, government, and academic representatives.

The Grade “A” Pasteurized Milk Ordinance (PMO) is considered the gold standard of regulations and is an invaluable resource for all aspects of dairy production and processing. Some sections of the PMO apply to all dairy processors, such as farm and milk plant inspections and drug residue testing, while other sections apply to those producing pasteurized, Grade “A” products. Other key features of the PMO are the standards for milk and milk products, pasteurization conditions, equipment and testing specifications, dairy farm and milk plant facility specifications, and the HACCP program.”[2]

Definition of Pasteurization:

The process of heating every particle of milk or milk product, in properly designed and operated equipment, to one of the predetermined times at a predetermined temperature to destroy pathogens.[3]

The current guidelines are based on the ability to destroy C. bumetii, an organism that is most resistant to heat treatment.

Pasteurization makes milk and milk products safer and increases the shelf life of a product by destroying pathogens and spoilage organisms.

Types of Pasteurization:

Batch (Vat) Pasteurization: 145°F (63°C)* for 30 minutes. This is the most common method used by smaller to medium size artisan cheesemakers to pasteurize milk for cheesemaking.

Continuous Flow Pasteurization: Used by larger producers and industrial producers. (HTST – High Temperature Short Time)

Temperature	Time
161°F (72°C)*	15 seconds
191°F (89°C)	1.0 seconds
194°F (90°C)	0.5 seconds
201°F (94°C)	0.1 seconds
204°F (96°C)	0.05 seconds
212°F (100°C)	0.01 seconds

*If the fat content of the milk is 10% or greater, or total solids are 18% or greater, the specified temperature shall be increased by 5°F (3°C).

(As I recall from the 2013 DPI study group, the three temperatures in bold above are the ones you need to remember.)

Ultra-Pasteurization Definition:

Milk that is thermally processed at or above 280°F (138°C0 for at least 2 seconds, either before or after packaging, so as to produce a milk which has an extended shelf-life under refrigerated conditions.[4] (UHT)

Thermization Definition:

From sciencedirect.com:

“Thermization

The thermization process is a subpasteurization heat treatment of milk at 62–65 °C for 10–20 s, followed by refrigeration. It is used as a prepasteurization treatment of raw milk to safeguard milk quality during prolonged storage in insulated silos. The process is also used as a postpasteurization treatment of dairy products. Research has shown that this process effectively reduces both the total and psychrotrophic bacterial counts, enabling thermized milk to be stored for up to 3 days longer at 8 °C. In this way, detectable sensory changes and the concomitant decrease in shelf-life are limited.

Thermization is only successful if applied to raw milk and products of good quality.”

USDA/FDA consider Thermized milk as raw milk because it is not pasteurized. More common in Europe than the US in cheesemaking.

Article regarding various definitions of heat treatments of milk:

http://www.fao.org/tempref/codex/Meetings/CCMMP/CCMMP4/mm00_15e.pdf

Technical article regarding microfiltration of milk:

https://www.researchgate.net/publication/283046614_Microfiltration_of_milk_I_Cheese_milk_modification_by_micro-and_ultrafiltration_and_the_effect_on_Emmental_cheese_quality

This article is easier to understand (at least for me):

http://www.cooksinfo.com/micro-filtered-milk

Grades of Milk:

Grade A Milk meets fluid grade standards – 90% of milk produced in US is grade “A”. Grade B does not meet fluid grade standards but can be used to produce cheese, butter and nonfat dry milk.

Here is a CRS Report to Congress regarding Grad a vs. Grade B (however if was written in 1991) (on the positive side – only 11 pages):

https://dairymarkets.org/PubPod/Reference/Library/Chite.8.1991.pdf

Definitions of Fluid Milk and Milk Products – short and ey to understand:

https://www.idfa.org/docs/default-source/resource-library/industry-facts/248_definitions-of-milk-products.pdf?sfvrsn=2

Somatic Cell Count:

The Somatic Cell Count (SCC) is a main indicator of milk quality. The majority of somatic cells are white blood cells which become increasingly higher as an immune response to a mastitis-causing pathogen.

The SCC is quantified as the number of cells per ml of milk. In general terms:

An individual cow SCC of 100,000 or less indicates an ‘uninfected’ cow, where there are no significant production losses due to subclinical mastitis.
A threshold SCC of 200,000 would determine whether a cow is infected with mastitis. Cows with a result of greater than 200,000 are highly likely to be infected on at least one quarter.
Cows infected with significant pathogens have an SCC of 300,000 or greater.[5]

Table 1 of the PMO (page 34) states that Grade “A” raw milk and milk products for pasteurization the bacterial limit for individual producer milk not to exceed 100,000 per ml. prior to commingling with other producer milk and not to exceed 300,000 per ml. as commingled milk prior to pasteurization. No positive results on drug residue detection methods as referenced in Section 6.

Grade “A” Pasteurized Milk bacterial limit to not exceed 20,000 per ml. or gm. [6]

I have seen several different numbers which are higher but lower is better.

Every truck load of milk in the United States is tested for SCC and antibiotics. BelGioioso testing procedure is to take a sample of milk picked up at each farm. Each sample is tested when the truck arrives at the facility and if a sample tests positive for antibiotics or excessive SCC, that farm “buys” the entire truck load of milk and the load is dumped. Every milk tank truck in the US is tested; no exceptions.

Milk Handling:

I looked at several websites while researching “milk handling”. A lot come at the subject from the personal use under “homesteading” sites and living off the grid. A few were very interesting so if you’re thinking about milking your own cow and drinking the milk raw, there are a lot of “experts”.

For dairy milk handling, I found this website to be pretty straightforward and easy to understand:

http://www.dairychain.org/index.php/component/k2/item/105-milk-handling

This one is a little more technical:

Hygienic Milk Handling and Processing:

http://www.fao.org/ag/againfo/resources/documents/MPGuide/mpguide1.htm

How milk is tested for antibiotics – from dairygood.org:

“Dairy farmers are proud of the system for testing milk for antibiotics that keeps our milk safe for consumption. Sometimes our cows become ill, and we treat them with medicine to help their recovery. Those cows are separated from the healthy herd and their milk is not mixed with the other cows’ milk.

When the tanker truck driver arrives at our farm, he takes a sample of our milk, along with sampling the milk from other farms that combine with ours to fill the truck. When the truck arrives at the plant, another sample of the milk is tested to determine if there is any antibiotic residue. Should the milk test positive, the entire tanker of milk is discarded, and the individual farm samples are further examined to identify the source.

That farmer is responsible for reimbursement of the entire load. This has never happened on our farm and it’s a good thing. That load of milk would cost us more than $10,000!”

YouTube video on testing milk for antibiotics: