Thermal Processing Training Course
University College Cork
4 & 5 November 2020

Who should attend / will benefit?

R&D, NPD, Operations, Technical, QA, QC personnel involved in formulating, developing, commercialising, manufacturing and troubleshooting any thermally-processed nutritional dairy-based beverages, such as UHT milk, ESL milk, clinical or sports nutrition products, infant formula, enriched milks, flavoured milks, cream liqueurs and elderly nutrition products. 
Benefits of attendance / what will you learn?

  • Update on the underpinning science for heat treatment of milk
  • Enhanced understanding of the chemistry, microbiology, enzymology and physical processes taking place when dairy-based products are heated and stored
  • Exposure to latest developments in nutritional product formulation science and technology  
  • Assistance in obtaining more consistent quality and more reliable long-term storage
  • Perspectives from UK and global UHT operations
  • Knowledge-exchange with a leading academic and industry consultant
  • Awareness of state of the art in accelerated physical stability testing approaches

Programme outline

  1. Raw Milk Quality and Fitness for Heat Treatment
  2. Thermal Processes Overview
  3. UHT Processing Technologies
  4. UHT Plant Engineering & Process Conditions
  5. UHT Product Stability
  6. Changes in UHT Products during Storage
  7. Alternative / Non-Thermal Unit Processing Operations
  8. Nutrient Stability during Thermal Processing


 Dr Mike Lewis 
 Dr Seamus O'Mahony 
 Professor Alan Kelly 
 David Waldron 
 Contact information:
Mary McCarthy-Buckley
Food Industry Training Unit
School of Food and Nutritional Sciences
College of Science, Engineering and Food Science
University College Cork

Users may have noticed that the DairyScience website was running very slowly over the last week or so. This was an unintended consequence of updating the MYSQL database that runs the main site to MYSQL 8. The  solution was provided by Nitin Jain ( and required repair of a RSSEO data table.  If I had known that this was causing the problem I could have fixed it myself.

This may be the first report of the MYSQL 8 update slowing Joomla sites due to problems with a RS Joomla application.

A new calculator that enables the conversion of the major methods for measuring the titratable acidity of milk and milk products has been added. For the first time a free On-Line calculator that enables conversion between Soxhlet Henkel degrees, Thörner degrees, Dornic degrees and percentage lactic acid milk titratable acidity measurements is available.

The Food Industry Training Unit, at University College Cork have adapted their short courses to ensure online availability. Registration is Now Open.

Part-Time Accredited Courses

Diploma in Food Science and Technology
This Diploma course is designed for those who wish to develop a good understanding of the basic principles of food science, food technology and food business. Particular emphasis is placed on linking scientific principles with their practical application in industry. Registration for 2020/2021 now open.

The article on the "Reliability of microbial sampling in assuring food safety and calculation of prevalence following negative tests" at has several calculators one of which calculates the number of samples required to meet a microbiological specification. The author has made the code for this calculator freely available. The code can be downloaded at .

I have updated an article on food sampling and microbial testing following a book chapter that I have been writing on raw drinking milk (RDM). Recent changes in legislation in the UK require critical pathogens to be absent in 25 ml of RDM and in the absence of a Critical Control Point particular emphasis is being placed on microbiological testing to ensure safety. This article consider the distribution of microorganisms including clusters in foods and the limitations of testing are discussed. The economic and public health significance of clustering is illustrated by the meticulous work of Jongenburger et al. (2011). These workers investigated why a consignment of powdered infant milk formula (PIM) produced in Europe (the batch of approximately 22,000 kg was produced in 3 shifts) was rejected because of contamination with Cronobacter spp. by the importing Chinese authorities. Jongenburger et al. (2011) sampled 31 bags  close in production time to the bag that tested positive for Cronobacter spp. in China using multiple samples (2290) and found 8 positive samples from 3-bags. The article also considers the question: assuming that all the samples taken for testing are negative, what might the probable prevalence of a pathogen or fault-causing organism in a food be? Interactive calculators to determine the statistical significance of sampling schemes and the effect of sample numbers and mass on prevalence are provided. The article is available at .

Please give a thought to the scientists who are doing the research and testing for SARS-CoV-2 virus in Italy and elsewhere. Like the front line doctors and nurses we all owe them our thanks and best wishes at this difficult time.

Readers may recall previous mentions of Dr Giuseppe Aprea. Dr Aprea, a veterinary graduate from the University of Naples, studied for part of his PhD on lactic bacteriophages with the author in Northern Ireland.

Giuseppe is currently a Veterinary Manager Officer for the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "Giuseppe Caporale" (IZSAM). Until recently his research was mostly related to the detection of foodborne viruses and bacteriophages. IZSAM is a public health institute with administrative and managerial autonomy, which operates as a technical and scientific arm of the Italian state and the Abruzzo and Molise Regions in Italy.

On March 13, the IZSAM of Teramo joined the Covid19 network in the Abruzzo Region and is performing the official analysis of human swab samples for SARS-CoV-2 virus, the causal agent of Covid-19.  Abruzzo is situated in central Italy and has around 1000 confirmed Covid-19 cases to date.

Dr Giuseppe Aprea and colleagues at the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise.

Dr Giuseppe Aprea and colleagues at the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise.

 The first phases of the analytical processes are carried out in a BSL4 mobile laboratory with high biological containment. In the maximum safety laboratory, the analysts work on 4 daily shifts. PCR analyses are performed by a group of 20 people, working in couples, on six shifts per day, in order to be able to process >400 samples per day.

Dr Aprea has  been involved since the 23rd of March in the real time PCR analysis of the swabs and is personally processing over 100 samples per day. Currently some 30% of the samples tested are positive for the virus.

We expect a lot from Marks and Spencer. Rightly so, they also expect high standards from their suppliers. However, the M&S response to Covid-19 as evidenced by their failure to protect all their bakery items in their in-store bakeries is disappointing.

I was surprised to get an Email from a former student a few days ago saying that unpacked bakery items were on display in a Marks and Spence store in Northern Ireland. I was surprised since the major mechanism for spreading the SARS-CoV-2 virus, the virus that causes Covid-19, is aerosol droplets produced from infected people that are present in the air. Infection occurs when we breathe in the droplets, touch surfaces where the droplets have landed or eat food contaminated by these droplets.

Electron micrograph of SARS-CoV-2. Copyright  NIAID.

Today I went into my local M&S in Cookstown and yes the bakery had lots of bakery items, unpackaged and potentially exposed to contamination by the the SARS-CoV-2 virus. I mentioned my concerns to a staff member whose immediate reaction was "that's what we have always done!". Obviously this needs to change.

Selection of bakery items at local Marks and Spencer store on the 20th March 2020. Note many are not packaged.

For the last month or so I have been writing a chapter on the advantages and disadvantages of drinking raw milk for a new dairy science/ technology book. Because of my interest in modelling I have been modelling the denaturation or loss of biological activity of the major humoral and non-specific antimicrobial proteins. I have provided access to a free OnLine calculator that will enable those interested to do their own calculations. IgA is the most sensitive of the Igs in milk to heat and the calculations indicate minimal loss of activity after 72 °C for 15 seconds (statutory HTST pasteurisation of milk). To use the calculator the Decimal reduction time of the biological factor or quality factor is required e.g. 319 seconds for IgA at 72 °C. See . More in the future.

Over the last 10-years or so there have been major developments in imaging technology e.g. it now possible to view components in living cells at high resolution. These developments have arisen through advances in technology, sensors in particular, staining techniques and off course software. 

One of the companies that has been responsible for some of these developments is Andor Technology, Andor is now part of Oxford Instruments. Andor have recently provided a series of articles on developments in imaging technology. See below. The science content of these articles is high and they are ideal for undergraduate and postgraduate teaching. 

Camera developments at Andor

Following my recent interview by Drs Aleks Marsh and Alan Mullan (my son) of Andor Technology about the pasteurisation of milk. Alan and Aleks turned the interview into a podcast which is now live. Listening to my responses I realize that I am not a natural for TV or radio and that I am fortunate to be retired! The article on MAP can be downloaded free from Researchgate. 


Dr Mark Tamplin, the Director of Combase, has announced new data for Salmonella in low moisture foods:

  • Salmonella in peanuts (Park et al., 2008)
  • Salmonella in x-ray treated almonds and walnuts (Jeong et al., 2012)
  • Salmonella in moist-air convection treated almonds (Jeong et al., 2009)
  • Salmonella in hot water treated almond kernels (Harris et al., 2012)
  • Salmonella in peanut butter and peanut butter spread (Burnett et al., 2000)
  • Salmonella in oil roasted almonds (Abd et al., 2012)
  • Salmonella in chamomile, peppermint, and green tea (Keller et al., 2015)
  • Salmonella in wheat flour (Smith and Marks, 2015)

Combase logo

Following my recent article "Are we closer to understanding why viable cells of Mycobacterium avium subsp. paratuberculosis are still being reported in pasteurised milk? (" I agreed to do a Podcast with Dr Aleks Marsh and Dr Alan Mullan of Andor Technology in an attempt to explain some of the questions that the general public might have about pasteurisation. The Podcast will be broadcast on the 16 January 2020 and is available from the "The Good, the Bad and the Curious" webpage at the Andor website.

I have agreed to write an article on raw milk as part of a series of chapters in a new book produced by Elsevier that will be published in 2020.  I will cover the antimicrobial factors and other topics including the presence of probiotic bacteria in modern hygienically-produced milk. The safety of raw milk for human consumption, particularly for children, will also be included.

One of the points I want to make is how easy it is for milk to become contaminated and how difficult it is to prevent some forms of contamination. I am trying to source photographs showing dirty 'drinkers', birds and rodents in/on cattle feed e.g. Total Meal Replacement (TMR), dirty udders, dirty cows. 

Below are some of the images that I have found/ obtained or been given so far.

The photograph below shows starlings (a major pest and potential carrier of many human pathogens) eating components in the TMR fed to dairy cows. Farms are not operating theatres and farmers live in the real world. Hence we need to use all the options at our disposal to reduce risk e.g. pasteurisation.

Starling eating TMR

 Image from: Anon. (2013) Practical Control Strategies for Starling Infestations. Report prepared for DairyCo by Kingshay. Download url: .


A further picture clearly showing the nuisance value of starlings in a dairy farm in the US.

Donated by Provided by Professor Amber Adams Progar, Department of Animal Sciences, Washington State University

Image kindly provided by Professor Amber Adams Progar, Department of Animal Sciences, Washington State University.

 Boetech (2019) have claimed that "half of the cows (in Europe) are drinking dirt and shit" I am trying to get some images of cow faeces in drinkers.

Below is a typical picture of crows perching on a water trough in a field.  Bird faeces in outside water troughs is not uncommon.  

Crows perched on drinking trough

Picture courtesy of Aidan Brennan Irish Farmers Journal  

If you have similar photographs please contact me.

A beta version of a calculator that uses the results of a titration with NaOH to calculate the % lactic acid, Soxhlet Henkel degrees, Thörner degrees, Soxhlet Henkel degrees and Dornic degrees of a milk sample has been added. Users may vary the molarity of the NaOH solution, note normality and molarity are identical for NaOH, and the volume of milk used. An accompaning tutorial that provides the underpinning science remains to be added.

The article "Isolating lactic acid bacteria from milk" has been updated following queries why controls are required using M17 agar to selectively enumerate Streptococcus thermophilus in environments containing L. delbrueckii subsp. bulgaricus.  While many strains of L. delbrueckii subsp. bulgaricus are inhibited by the  β-glycerophosphate in M17, Shankar and Davies (1977) found that 23% of the strains of L. delbrueckii subsp. bulgaricus tested grew well on this medium. Hence the need for controls to confirm colonies as Sthermophilus.

There is considerable interest in alternatives to thermal processing. A recent review in the International Journal of Dairy Technology by Ahmad and his colleagues looks at the effects of non thermal processes on the activity of milk enzymes. I have included the abstract below.

Impact of nonthermal processing on different milk enzymes. Ahmad et al (2019)


Milk is highly perishable and deteriorates rapidly during storage. Although the thermal processing technologies successfully inactivate many enzymes and microorganisms up to a required level, they can negatively affect the natural flavour of dairy foods and decrease their nutritional value. Alternative nonthermal technologies have been established as an interesting approach to produce safe and healthy dairy products, without compromising their nutritional quality. These techniques have the ability to inactivate milk enzymes without affecting the milk quality. In addition, the combination of two different nonthermal techniques and mild heating has proven to be more effective to provide safety to milk when compared to the treatments alone. This review aims to evaluate the impact of nonthermal technologies, in particular, ultrasound, pulsed electric field, high‐pressure processing and ultraviolet irradiation on milk enzymes.

Despite the extensive research on the effects of low temperature storage of milk on the quality and yield of cheese, cheese companies continue to experience periodic problems due to milk being stored for several days on farms. Below is an abstract of some research published in 1994. It is as relevant today as then!


Milk stored at 3°C and 7°C was used to manufacture cheese and the quality and yield of cheeses were assessed. Storage of milk at both temperatures resulted in reduced yields. Storage at 7°C for 3 or more days and 3°C for 5 days adversely affected cheese quality while storage at 3°C for 3 days resulted in an improvement in quality. There was a significant correlation between cheese quality and the psychrotrophic count and total viable count (TVC) of the raw milks. Evidence indicated that the reduction in quality was largely due to the action of extracellular lipolytic enzymes produced by psychrotrophic bacteria. It was concluded that milk for Cheddar cheese manufacture should have a TVC of < 1 x 106 cfu/ml and preferably a count of < 1 x 105 cfu/ml.


Weatherup,W. and Mullan,W.M.A. (1993) Effects of low temperature storage of milk on the quality and yield of cheese. Proceedings of IDF Seminar on Cheese Yield and Factors Affecting Its Control, Cork, Ireland, pp. 85–94.

See also .

My article on why we are still finding viable cells of Mycobacterium avium subsp. paratuberculosis (MAP) in pasteurised milk has been published On Line ahead of print. Details are given below:

Mullan, W M A (2019) Are we closer to understanding why viable cells of Mycobacterium avium subsp. paratuberculosis are still being reported in pasteurised milk? International Journal of Dairy Technology. DOI-10.1111/1471-0307.12617. 

Full Open Access is available for 1-month at . Thereafter Read Only Access is available through ReadCube at .

The Dairy Industry Student Award is sponsored by The Society of Dairy Technology.

This award recognises the efforts of new entrants to the Dairy Industry and promotes their talent to a wide audience. The work of the winning individual will be communicated to a global audience, showcasing their achievement. The award will be presented at the prestigious trade lunch (on the Tuesday of the ICA) at the Nantwich International Cheese Awards in July 2019.

The award is open to any student studying a food science and technology course in the United Kingdom or the Republic of Ireland. Courses may be vocational qualifications, diploma, degree and so on. There is no age restriction to applicants; however the student must be undertaking a dairy project or be employed within the dairy industry.

ALL submissions must be electronically submitted in both PDF and Word formats and NOT as a hard copy. It should be emailed to by May 30th and judging will take place during June.

Download an application form.

book on Polish cheeses

 There is relatively little information on the diversity of Polish cheeses. Professor Marek Kosmulski has decided to change this and has published a book detailing some 600 Polish cheeses. This is available free as a download. The book, in Polish, consists of a series of brief descriptions of each cheese accompanied by photographs. Using Google Translate it is relatively easy to get a good understanding of the major attributes of each cheese. The book can be downloaded from .

Arguably one of the most significant scientific development's in the last 10 years has been the development of an unique gene editing technology that can be applied to whole cells called CRISPR/Cas9. This technology has many applications in biomedical research, including the potential to treat human genetic disease. However, the technology also has the potential to modify the human genome and change human society.

 One of the best free videos explaining how the technology works and giving the background to the discovery is given in the animation below produced at the McGovern Institute for Brain Research, MIT where Professor Feng Zhang, a leader in the development of this technology works.

Further information can be found on Professor Zhang’s website.

Two calculators for determining equilibrium moisture values corresponding to selected Aw values using the Guggenheim–Anderson–de Boer (GAB) model and  the Brunauer-Emmett-Tellet (BET) model have been added.

To use the models, the constants for the product concerned must be inputted. Selected Aw values are then added. The calculator will then calculate the equilibrium moisture content for each value and plot it against Aw, to give a sorption or desorption isotherm.

Ireland has a well-deserved reputation as a global leader in food innovation and it is fitting that a new world food resource,, was recently launched by Michael Creed, the Irish Minister for Agriculture, Food and the Marine.

Launch of is a comprehensive online directory of valuable technical content and free training for food producers, entrepreneurs, scientists, technologists and advisers.

Reflecting the complexity and knowledge needed in today’s food and beverage industry has 13 pages, 130 sections over 2000 web links, 73 free online trainings, a global events calendar and a national regulations and support page for 112 countries. The layout, site-plan and search functionality is intuitive and user friendly.

There have been several updates to the Dairy Science and Food Technology website in May, 2018.

The article "Factors affecting plaque formation by bacteriophages" has been updated to reflect research by Luhtanen et al., 2018* on cold-active phages.

*Luhtanen,A.-M.,Eronen-Rasimus,E., Oksanen,H.M., Tison,J.-L., Delille,B.,Dieckmann,G.S.,Rintala,J.-M. and Bamford,D.H. (2018). The first known virus isolates from Antarctic sea ice have complex infection patterns. FEMS Microbiology Ecology, 94, 4, 1-15. (available from

The author with chemist colleague Ronnie Irvine visited The Echlinville Distillery at Rubane, just outside Kircubbin, in the Ards Peninsula. A brief account of our visit to Ireland's newest whiskey distillery is given here.

 Six new site calculators have been added.

Three are concerned with determining holding tube length, average holding time and Reynolds number:

 Calculator for determining Reynolds number
 Calculator for determining average holding time in a pasteurizer or UHT holding tube
 Calculator for determining holding tube length in pasteurizing and UHT plant

Following feedback from users of data loggers a unique highly flexible F value calculator designed to work with thousands of pasted values of time -temperatures has been added. This calculator allows users, for perhaps the first time, to compare F values obtained by numerical integration using the industry standard method, the trapezoid rule with the more accurate Simpson's 1/3 and 3/8 rules:

 • Calculator for determining the lethality (F, value) of a thermal process using the trapezoid and Simpson's rules. 

A calculator for predicting the concentration of HMF, lactulose and furosine in heated milks (whole, semi-skim and skimmed milk) that also calculates the F0, B* and C* values and the destruction of thiamine has been added.  The calculator has been designed to work with thousands of pasted values of time -temperatures. The values are integrated using the industry standard method, the trapezoid rule, and are compared with the more accurate method of numerical integration, Simpson's 1/3 and 3/8 rules:

 Calculator for predicting the concentration of HMF, lactulose and furosine in heated milks (whole, semi-skim and skimmed milk). It also calculates the F0, B* and C* values and the destruction of thiamine. The values are integrated using the industry standard method, the trapezoid rule, and are compared with a more accurate method of numerical integration, Simpson's 1/3 and 3/8 rules. 

A generic F calculator for UHT and similar high temperature processes has been added. The calculator has been designed to work with thousands of pasted values of time-temperatures. The values are integrated using the industry standard method, the trapezoid rule, and are compared with the more accurate method of numerical integration, Simpson's 1/3 and 3/8 rules

• Calculator for determining the lethality (F, B* values) and chemical changes (C* value) for UHT processes using the trapezoid and Simpson's rules. Applicable to all UHT processes and designed to take thousands of pasted values.

A free article, "Ultra-high-temperature (UHT) processing of milk. Process lethality, chemical effects and use of temperature-time-integrators (TTIs) to predict heat treatment and over-processing" has been added to the Dairy Science and Food Technology website.

Typical pot of UHT milkThis article investigates how to calculate the lethal effects of UHT treatment and the usefulness of TTIs for differentiating sterilised, direct and indirectly processed UHT-treated milk. The importance of accessing accurate temperature time-data and knowing holding tube dimensions, flow rate, average and minimum holding time and the flow characteristics (Reynolds number) are discussed. The reliability of a model developed by Claeys et al. (2003) to predict the effects of UHT-processing on hydroxymethylfurfural, lactulose and furosine concentrations in milk is discussed. Free On Line calculators for calculating holding time, average flow rate, holding tube length in UHT and HTST plants are provided. A free On Line calculator programmed using the thermal constants calculated by Claeys et al. (2003) is provided to calculate hydroxymethylfurfural, lactulose and furosine concentrations following heat treatment in skim, semi fat and full fat milks. This calculator also calculates F0, B*, C* and % destruction of thiamine. Two methods of numerical integration are used to measure the cumulative lethal and chemical effects of UHT treatment, namely the Trapezoid and Simpson's rules.

The article can be viewed at .

This website gets a lot of Email and occasionally one connects.

According to the Daily Mail as many as 9.75 million people - 15 per cent of the UK population - are believed to have been hit by flu symptoms this week. Some 120 flu deaths have been recorded in England, 21 are known to have died in Scotland and eight in Northern Ireland.

It was against this background that a reader who works for a major food processing company sent me a picture of unpackaged bakery-items completely exposed to the environment at a food retailers with a global reputation for producing safe food. She was surprised that the retailer was not taking action to prevent contamination of their bakery items with airborne viruses and from customers with virus-contaminated hands.

The article on "Factors affecting plaque formation by bacteriophages" has been updated and can be accessed at .

  Plaques of phage D29 produced by Mycobacterium avium spp paratuberculosis assayed using  Mycobacterium smegmatis. Image courtesy of Dr Irene Grant, Queens University  Belfast.

Lactic starter cultures have a well deserved reputation for inhibiting, and or in some instances killing, spoilage and pathogenic bacteria not just in dairy foods but in meat and vegetable products also.

While the importance of undissociated lactic acid as an inhibitor of the growth of pathogens by starters has been known for many decades it is only recently that the effect has been quantified for Listeria monocyotgenes in Gouda cheese.

Fat agglomeration is affected by the process parameters used in gelato and ice cream manufacture, the emulsifer stabiliser system and ingredients. Fat agglomeration has a significant role in dryness of extruded ice cream, slow meltdown, good shape retention and resistance to shrinkage during storage. Too much protein can result in an over stable fat emulsion and insufficient fat agglomeration. 

A calculator to determine the maximum MSNF compatible with normal fat agglomeration has been added and can be accessed here.


The latest forum post concerns raw milk and A2 milk. The posts can be viewed at .


There is a legislative requirement in most developed countries for food companies to have validated-HACCP plans for all products. The current E.coli 01507:H7 outbreak in Scotland has been linked to raw milk cheese and the death of one child has been reported. Note there are few examples of well validated HACCPs even from large companies!

There are a number of published risk assessements for raw milk cheeses. One of the most comprehensive, "Microbiological Risk Assessment of Raw Milk Cheese", has been produced by Food Standards Australia /New Zealand using quantitative models developed by the University of Tasmania. The assesment can be downloaded from .

Recent deaths associated with the consumption of lettuce and other salad vegetables have been well publicised in the media. How do you advise parents to respond to the risks associated with eating salads and maintain consumption of healthy foods? And would this advice differ if they had an immunocompromised family member? Perhaps you have a view on my response to a query from a parent?  Please see .

Is Thermus thermophilus the causal agent of pinking in cheese?

“Pinking” the development of a red / pink colour in many cheese-types has been known for many years and has been the attention of significant research interest for decades. Much of this research has been inconclusive although some association with lactobacilli has been suggested.

Recently Quigley et. al. (2016) used shotgun metagenomic sequencing to reveal the presence of bacteria corresponding to three phyla, Firmicutes, Actinobacteria, and Deinococcus-Thermus in 8 ‘continental’ cheeses exhibiting pinking. The phylum Deinococcus-Thermus was absent in control cheese.

I purchased one pot of fat-free-natural yoghurt produced by a major dairy company from the Asda supermarket in Cookstown a few days ago. I opened it this lunchtime today (12th June). It had a use before date of the 24th June 2014 (see below).




I noticed the lumps, clumps of curd on the lid immediately. See below.



Looking at the inside of the container the top part of the yoghurt was less viscous than the bottom, syneresis was starting and grains/lumps/nodules were clearly visible.


The grains / nodules can be clearly seen on the spoon images below.






It is always interesting to see how companies respond to problems. No one answered the contact phone number given on the carton. I also completed a web form on the company website and attempted to contact their PR company using the information on their website. The contact information was not correct however I managed to get the correct information from their website.  I eventually got a response of sorts from the website form.


This is the second time in a month that I have bought a stirred yoghurt with this fault. The first time was from a local company in Northern Ireland and it was a natural yoghurt made with whole milk.

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