Category Archives: Newsletter

Welcome to the new face of the Cornell Dairy Foods Extension Program! In an effort to better communicate with our constituents, we have formulated a newsletter, which will be released once every two months. We are very excited to keep you all in the loop on everything occurring in the field of dairy foods at Cornell University.

Recent Dairy Research Publications – March 2023

Callero, K. R., E. M. Teplitz, D. M. Barbano, C. R. Seely, J. A. Seminara, I. R. Frost, H. A. McCray, R. M. Martinez, A. M. Reid, and J. A. A. McArt. “Patterns of Fourier-Transform Infrared Estimated Milk Constituents in Early Lactation Holstein Cows on a Single New York State Dairy.” Journal of Dairy Science, February 22, 2023. https://doi.org/10.3168/jds.2022-22588.

Evanowski, Rachel L., Sarah I. Murphy, Martin Wiedmann, and Nicole H. Martin. “Low-Cost, on-Farm Intervention to Reduce Spores in Bulk Tank Raw Milk Benefits Producers, Processors, and Consumers.” Journal of Dairy Science, January 27, 2023. https://doi.org/10.3168/jds.2022-22372.

Martin, N. H., R. L. Evanowski, and M. Wiedmann. “Invited Review: Redefining Raw Milk Quality—Evaluation of Raw Milk Microbiological Parameters to Ensure High-Quality Processed Dairy Products.” Journal of Dairy Science, January 9, 2023. https://doi.org/10.3168/jds.2022-22416.

Sakai, Nobumitsu, Ola Yetunde Esho, and Motoko Mukai. “Iodine Concentrations in Conventional and Organic Milk in the Northeastern U.S.” Dairy 3, no. 2 (June 2022): 211–19. https://doi.org/10.3390/dairy3020017.

Dumpler, Joseph, and Carmen I. Moraru. “A Process Optimization Approach for Microwave Vacuum Drying of Concentrated Skim Milk.” Journal of Dairy Science 105, no. 11 (November 1, 2022): 8765–81. https://doi.org/10.3168/jds.2021-21459.

Griep-Moyer, E. R., A. Trmčić, C. Qian, and C. I. Moraru. “Monte Carlo Simulation Model Predicts Bactofugation Can Extend Shelf-Life of Pasteurized Fluid Milk, Even When Raw Milk with Low Spore Counts Is Used as the Incoming Ingredient.” Journal of Dairy Science, October 4, 2022, S0022-0302(22)00571-9. https://doi.org/10.3168/jds.2022-22174.

McGillin, Meghan R., Dana L. deRiancho, Timothy A. DeMarsh, Ella D. Hsu, and Samuel D. Alcaine. “Selective Survival of Protective Cultures during High-Pressure Processing by Leveraging Freeze-Drying and Encapsulation.” Foods 11, no. 16 (January 2022): 2465. https://doi.org/10.3390/foods11162465.

Basbas, Carl, Sharif Aly, Emmanuel Okello, Betsy M. Karle, Terry Lehenbauer, Deniece Williams, Erika Ganda, Martin Wiedmann, and Richard V. Pereira. “Effect of Intramammary Dry Cow Antimicrobial Treatment on Fresh Cow’s Milk Microbiota in California Commercial Dairies.” Antibiotics (Basel, Switzerland) 11, no. 7 (July 18, 2022): 963. https://doi.org/10.3390/antibiotics11070963.

Cheng, Rachel A., Renato H. Orsi, and Martin Wiedmann. “The Number and Type of Chaperone-Usher Fimbriae Reflect Phylogenetic Clade Rather than Host Range in Salmonella.” MSystems 7, no. 3 (June 28, 2022): e0011522. https://doi.org/10.1128/msystems.00115-22.

Hassoun, Abdo, Nour Alhaj Abdullah, Abderrahmane Aït-Kaddour, Mohamed Ghellam, Ayşegül Beşir, Oscar Zannou, Begüm Önal, et al. “Food Traceability 4.0 as Part of the Fourth Industrial Revolution: Key Enabling Technologies.” Critical Reviews in Food Science and Nutrition, August 11, 2022, 1–17. https://doi.org/10.1080/10408398.2022.2110033.

“In‐mouth, Self‐disintegrating Milk Protein Puffs‐I: Process Development – Arora – Journal of Food Process Engineering – Wiley Online Library.” Accessed August 30, 2022. https://onlinelibrary.wiley.com/doi/abs/10.1111/jfpe.14144.

Qian, Chenhao, Yuhan Liu, Cecil Barnett-Neefs, Sudeep Salgia, Omer Serbetci, Aaron Adalja, Jayadev Acharya, Qing Zhao, Renata Ivanek, and Martin Wiedmann. “A Perspective on Data Sharing in Digital Food Safety Systems.” Critical Reviews in Food Science and Nutrition 0, no. 0 (July 26, 2022): 1–17. https://doi.org/10.1080/10408398.2022.2103086.

Rudlong, Autumn M., Yuto T. Koga, and Julie M. Goddard. “Advances in Nonfouling and Antimicrobial Coatings: Perspectives for the Food Industry.” ACS Food Science & Technology, August 17, 2022. https://doi.org/10.1021/acsfoodscitech.2c00148.

Wang, Mingming, Lu Wang, Xiaomei Lyu, Xiao Hua, Julie M. Goddard, and Ruijin Yang. “Lactulose Production from Lactose Isomerization by Chemo-Catalysts and Enzymes: Current Status and Future Perspectives.” Biotechnology Advances 60 (July 25, 2022): 108021. https://doi.org/10.1016/j.biotechadv.2022.108021.

 

Light Oxidation

Did you know that a study from the Milk Quality Improvement Program found that consumers prefer 14-day-old fluid milk that has been protected from light over freshly pasteurized milk that has been exposed to strong lights? This light exposure results in light oxidized defects, sometimes called “light struck” defect. Check out our infographic on light oxidation in fluid milk to learn more about this defect and how to prevent it.

January 2023 MQIP Publication Date

Nicole Martin, PhD

It’s been a busy few months here in the Milk Quality Improvement Program which means we have several new peer-reviewed publications out in the Journal of Dairy Science and JDS Communications. Find brief summaries of these papers below, as well as links to the open-access articles online.

In the first study, Butyric acid-producing bacterial spore levels in conventional raw milk vary by farm, we report levels of butyric acid-producing bacterial (BAB) spores in raw milk collected from 7 similarly managed conventional dairy farms. These BAB spores can be quite a problem for farmers and cheese manufacturers’, causing a defect called late blowing that renders the product unsaleable after ~60 days of aging. Despite the similarities in management across the farms in our study, the levels of BAB spores differed a great deal from farm to farm. Read more about this study in JDS Communications https://www.sciencedirect.com/science/article/pii/S2666910222001351

 

The second article, Culture-independent bacterial cell extraction from fluid milk and oat-based beverage for basic qualitative microscopy, outlines a rapid, practical culture-independent method for quickly visualizing bacterial cells in fluid milk and other products. This method was developed because butterfat and protein in the milk matrix make microscopic visualization of bacterial cells challenging. We use an extraction technique that eliminates these components to allow for rapid diagnosis of bacterial contamination. Read more about our method and its uses in our JDS Communications paper https://www.sciencedirect.com/science/article/pii/S2666910222001582

 

Lastly, our invited review paper, Redefining raw milk quality—Evaluation of raw milk microbiological parameters to ensure high-quality processed dairy products, discusses the primary groups of microbial contaminants in raw milk and their implications on processed dairy product quality. This review further calls for a three-tiered approach to redefining raw milk quality using i) process control testing, ii) monitoring, and, iii) troubleshooting. Read our full review in the Journal of Dairy Science https://www.sciencedirect.com/science/article/pii/S002203022300005X

 

 

Services

Take Advantage of Our Dairy Foods Extension Services

There are many services offered through our Extension Program, the Food Safety Laboratory, and the Expertise of our team that can help your organization, whether it’s to address acute or persistent food safety or quality issues, to prepare for an audit,  to implement or improve continuous improvement or troubleshooting procedures, or to develop improved training programs for a team or for individuals that you want to grow in your organization. We can help you take things off your to-do list in 2021.

 

The list below encompasses many of the services we encourage businesses to take advantage of. If your organization is interested in any of the services listed below, or more specific support not outlined below, please reach out to Louise Felker at lmf226@cornell.edu at any point, or submit a request through our website. We also encourage individuals and organizations to reach out to us with any questions or issues through our “Ask an Expert” platform. These questions will be directed to the appropriate team member. These services in combination with our workshop programming allow us to equip food businesses with the knowledge and tools to flourish.

  • Lab for Molecular Typing: The lab offers a wide variety of technologies to subtype, identify, and characterize microorganisms to the genus, species, subspecies, and subtype level including Pulsed Field Gel Electrophoresis (PFGE) and Whole Genome Sequencing (WGS). Services are strictly confidential. We do not submit isolates or patterns to the CDC unless specifically requested by the submitter/customer. A considerable number of companies use our services to enhance their environmental monitoring programs or to help troubleshoot microbiological issues.
  • Pathogen Environmental Monitoring Validation Services: We are available to review or assist in the development of your pathogen environmental monitoring programs. We also validate environmental monitoring programs through plant visits with collection of samples; this will help you determine whether your program is designed and implemented correctly to identify any issues you may have; we can also design these visits to represent mock FDA “swabathons”, helping you ensure your company is ready for a visit by the FDA or another regulatory agency.
  • Process Authority Review: For those who require a scheduled process to begin processing a dairy food product, our team member Rob Ralyea will review your proposed process for food safety. This process review will then be submitted to your regulatory authority for their approval. We also will refer you to other Cornell process authorities if you need help with non-dairy processes.
  • Food Safety Plan Review: Our team members are instructors of both HACCP and Preventive Controls for Human Food curricula, and are qualified to review or assist in developing your facility’s food safety plan. This service is useful for facilities who have an existing plan, are in the process of developing a new plan, or who are modifying their HACCP plan to meet the requirements of a FSMA food safety plan.
  • Gap Audit: Gap audits are used to identify areas for improvement in your food safety or quality system, and are a great way to prepare for a GFSI audit. Kimberly Bukowski, who is also an SQF auditor, visits your facility to evaluate both documentation and personnel/operational practices to help identify gaps in your systems.
  • On-site consulting: Extension personnel visit and consult with dairy processors to help troubleshoot or improve the food safety and quality of their products. Examples include visits to assess technical issues including quality, spoilage, or food safety concerns, food defense plan review, and special project consultation, and documentation review.
  • Milk Quality Improvement Program: Offers targeted fee-for-service microbiological and sensory testing to assist dairy processors with troubleshooting quality issues. Services include testing for groups of spoilage organisms, identification and subtyping, defect identification, and more.
  • Sensory Evaluation Center: Services include Consumer Acceptability, Preference, and Discrimination Testing. In addition, the program provides consultations in all matters related to sensory product testing: appropriateness of particular test methods, study sample size, questionnaire design, statistics, and analyses, sample blinding, and serving sizes, to name a few.
  • Institute for Food Safety COVID-19 Resources: This website is consistently updated with relevant resources and information for the food industry. Resources include information on upcoming industry office hours, weekly videos, templates and trainings, and updates on laws, regulations, and regulatory guidance.
  • On-farm Rapid Response Team: Offers timely assistance to NY dairy processors to troubleshoot farm related quality and safety issues  ​
  • Alcaine Research Group (ARG) Dairy Lab: Quality control, waste reduction, and new product development opportunities
  • Food Processing Development Laboratory (FPDL): The Cornell Food Processing Development Laboratory (FPDL) is a licensed dairy plant in NY State and offers a unique food product development and manufacturing space that allows individuals and companies to perform research, develop new products, and start new food related businesses. Recognizing the diverse needs of industry, we offer an opportunity to utilize this facility under four different types of arrangements (see flyer here):
    1. Product Testing: For small scale pilot research projects that can be completed in 100 days or less.
    2. Cheese and Dairy Product Incubator: Designed for companies who do not have an existing facility, the FPDL can be used for initial product development and production.
    3. Cheese and Dairy Product Incubator (Level II): Designed for companies who do not have an existing facility, but have done prior product development or for companies that have an existing facility but require an outside facility for specialized needs.
    4. Contract Manufacturing and Product Development: For small scale manufacturing and pilot production (e.g. identifying processing issues, optimizing processes prior to large scale manufacturing, samples for market research).

 

If you need help with anything else that is not listed here, please also contact us – it is likely that we have the resources to help you.

 

Tip of the Month: Testing Finished Product for Gram-negative Bacteria

Practical tip of the month

Nicole Martin

Gram-negatives provide more information about post-pasteurization contamination than coliforms

Do you want to improve your fluid milk quality? Start testing your finished product for total Gram-negative bacteria in addition to coliforms.

It’s not surprising that after a century of monitoring processed dairy products for coliforms, much of the industry has become adept at eliminating these contaminants. In our long-term monitoring program, the Voluntary Shelf-Life (VSL) program, we’ve seen coliform prevalence in pasteurized fluid milk steadily drop over the last 20 years. But that doesn’t mean that rates of post-pasteurization contamination (PPC) in fluid milk have declined, on the contrary, this is still a major issue for many fluid milk processors. So, you may be asking yourself if coliforms are not frequently detected in the finished product, how do we know there is PPC? The answer starts with the bacterial cell wall. There are two main types of bacterial cell walls, we call these Gram-positive and Gram-negative – named for Danish bacteriologist Hans Christian Gram who developed a method for classifying bacteria by their cell wall properties. The important difference between Gram-positive and Gram-negative bacteria as it pertains to PPC, is that Gram-negative bacteria are very heat sensitive, meaning they are easily killed by pasteurization. When Gram-negative bacteria are detected in pasteurized dairy products it’s very likely that they were introduced after the heat treatment – they are therefore indicators of PPC.

In current fluid milk supplies, the primary types of bacteria that are contaminating pasteurized fluid milk after pasteurization are non-coliform Gram-negative bacteria, especially Pseudomonas. In fact, a recent study from the Milk Quality Improvement Program determined that of 132 samples with PPC, Pseudomonas was the primary cause in 101 of those samples. Fluid milk processors who aren’t testing for Gram-negative bacteria are not likely to catch PPC when it happens – this leads to marketplace failures and unhappy customers.

If you’re convinced that monitoring your pasteurized fluid milk for Gram-negative bacteria is the right move, there are a couple of methods that you can use. The standard method for detection of Gram-negative bacteria uses Crystal Violet Tetrazolium Agar (CVTA), but this method may be challenging for processors without the capability of making traditional agar in-house. Fortunately, our team recently developed a method to detect Gram-negative bacteria in fluid milk by modifying the Coliform Petrifilm method. In short, simply incubating Coliform Petrifilm for an additional 24 hours (a total of 48 hours) then counting any growth, with or without gas production, provides a simple way to quickly determine if the product is contaminated with Gram-negative bacteria like Pseudomonas.

We’ve seen great results from fluid milk processors who implement Gram-negative testing in their overall quality program. If you have any questions on how to get started with this method, feel free to reach out for more information.

Tip of the Month: Gas Production in Cheese – September 2022

Practical Tip of the Month

Gas Production in Cheese

Cheesemakers are tasked with making a product that has a life of its own while also trying to be as consistent as possible. There are several types of issues that can arise that lead to unwanted gas production, ultimately causing cheese blowing, flavor and odor defects, and the creation of slits and cracks. These issues are costly to plants, and leave consumers with an unpleasant taste in their mouth (literally)!

The below table outlines several different types of these issues, their sources, the types of cheeses that are impacted, and hallmark characteristics of these gassy issues.

 

Cause Source Types of Cheese Impacted Hallmarks of gas production
Coliforms causing early blowing

 

In-plant contamination during cheese making or poor quality raw milk used for raw milk cheeses Predominantly soft and semi-soft cheeses

 

Strong, unpleasant odors, copious gas producing many small holes within 1-2 days of manufacturing
Yeast causing early blowing

 

In-plant contamination during cheese making or poor quality raw milk used for raw milk cheeses Variety of cheeses, including white brined cheeses, soft, semi-soft and semi-hard cheeses Musty or bready odors, gas producing large eyes and spongy texture within
Anaerobic butyric acid producing sporeformers causing late blowing

 

Raw milk Hard and semi-hard aged cheeses Unpleasant odors, copious gas production 60-90 days into aging

 

Heterofermentative lactic acid producing bacteria causing a variety of defects

 

In-plant contamination, possibly raw milk used for raw milk cheeses Variety of fresh and aged cheeses

 

May result in slight to severe gas defects including puffy packages, cracks and slits with or without impact on cheese flavor and odor, typically occurring weeks to months into aging or storage

 

For further questions about cheese defects, please reach out to Dr. Sam Alcaine, alcaine@cornell.edu or Rob Ralyea, rdr10@cornell.edu.

Tip of the Month: Get a fresh pair of eyes – July 2022

Aljosa Trmcic

When I write articles and scientific papers, I find it difficult to do a proper critical review of my own work because I am so intimate with the sentences and ideas behind them that during review I often switch to just reciting the text by heart instead of truly reading it. What I need is a fresh pair of eyes to read the text for the first time and put every single detail to proper scrutiny. The same way I am intimate with my sentences and ideas, dairy industry workers are intimate with their environment, equipment and work. This intimacy means that any deviation from the usual state of their environment, equipment and work will either be immediately noticed, or it will never be noticed because it soon becomes part of the usual state. So, the same way I need fresh pair of eyes to review my text, the dairy industry workers need a fresh pair of eyes to review their environment, equipment and work.

 

First example is a problem with post-pasteurization contamination (PPC) that persisted in one of the fluid milk processing plants for months. Since the PPC problem did not seem sporadic and a relatively similar spoilage was observed across all fluid milk processed each day the multiple different fillers used by the processor were excluded as the main cause of the problem. Instead, the p-tanks, used to store pasteurized product before filling, were again and again identified as the most likely source, but what part of the p-tanks exactly was the source the workers were not able to determine. They determined each investigation that integrity of the p-tanks was not compromised in any way and the cleaning and sanitation procedures were appropriate. It took that fresh pair of eyes to determine that membrane pressure sensor, used to monitor product volume in the p-tank, was leaking and retained a lot of solid residues in the sensor port. While the sensor is designed to seal the port opening and have only the membrane of the sensor exposed to the product, it will only seal properly if the integrity of the rubber gasket surrounding the membrane is not compromised. Fresh pair of eyes identified that the sensor includes a gasket and needs to be checked and maintained regularly. Since then, the processor put the tank pressure/level sensors on their regular PM schedule and the rest is PPC history.

 

Second example is a food safety one; troubleshooting persistence of Listeria in a dairy processing environment. A processor with a five-star environmental monitoring program is dealing with persistent strain of Listeria in one the drains; 15 drains present in the processing environment only one continuously comes back positive for an entire year. It took again a fresh pair of eyes, or better yet fingers, to detect a small crack in the drain that leads to a large opening behind the drain wall. A niche that never gets scrubbed and provides Listeria with plenty of food to grow and persist in the environment. Since then, the processor replaced the drain to eliminate the crack as well as the open space behind it and rest is persistent pathogen contamination history.

So, when you look upon your perfect environment, equipment and work keep in mind the value of putting it all under additional scrutiny by taking another look with a fresh pair of eyes; and let us know if you want Cornell’s Dairy Foods Extension to be those eyes for you.

Milk Quality Improvement Program attended the DairyTech conference in Austin to support digital transformation of the dairy industry

Aljosa Trmcic

On May 18 & 19, 2022 Milk Quality Improvement Program traveled to Austin, Texas to attend DairyTech;  a conference on dairy technology innovations organized by IDFA. What promises to be an annual event aligns perfectly with the mission of MQIP; as the leaders in Digital Dairy, we are working on assisting the dairy industry in adopting the technologies of tomorrow and help them enter the fourth industrial revolution popularly referred to as the Industry 4.0. IDFA featured at the conference some of the hot topics and success stories in dairy technology innovation and the common word connecting all of it was “data” and everything about how data can be captured, stored, analyzed, and used to provide added value to the company.

First hot topic of the conference was Data Analytics where one of the companies introduced a process of determining the optimal number, type, and quantity of products a food company should be manufacturing in any given situation. The data analyzed in this process covers all aspects of food processing including (i) the price and composition of all incoming ingredients, (ii) the ingredients and ingredient components needed to make each product, (iii) the costs of making each product, and (iv) the price of the product on the market. Using advanced statistics and computer modeling, for example machine learning and artificial intelligence, the company has been able to make recommendations on the optimal processing plan to minimize the cost and waste while maximizing the profit of the entre food company. MQIP has been taking similar statistics and computer modeling approaches to develop free tools that can be used to evaluate interventions that reduce spoilage and optimize the processing plan (click here for more details). Some of the open-access tools that are already available on our Digital Dairy page can be used to predict spoilage of both milk and cheese and there are others that are currently being developed.

One of the companies that participated in the conference introduced improvements to their Laboratory Information Management System (LIMS) and encouraged entire dairy industry to move away from paper-based records which are still very common in many aspects of the dairy production, processing, and distribution. While digitization, transformation of analog information to digital, can already be considered a beneficial step, the ultimate goal is for each operation and dairy industry as a whole to embrace digitalization. Digitalization goes a step further from digitization by transforming the process of collecting and using the data itself; for example, instead of writing the pH of your yogurt on your paper make-sheet, you would type it into the make-sheet on your tablet and eliminate the paper step, or better yet have pH meter display the measurement directly into your make-sheet on your tablet and eliminate the copying part altogether. LIMS and similar electronic systems represent the key to successful digitalization of the dairy industry and the base for using the true potential of predictive modeling. A vision MQIP has is that information captured in electronic systems like LIMS could immediately be used in the type of predictive models we are developing to more accurately predict characteristics of each product batch. For example, results of spore testing on raw milk, post-pasteurization testing on pasteurized milk, and electronic temperature recordings along the entire milk supply chain could be used to provide accurate information to the end consumer about expected shelf-life of that specific jug of milk they want to buy in the grocery store.

One downside of digital transformation and replacing paper records with electronic ones is that we are not just making all this information more accessible within our organization but also potentially to people outside of our organization that want to take and misuse this information. Cyber-attacks are real and dairy industry is not speared from this risk. Therefore Industry 4.0 and IDFA consider cybersecurity equally important aspect of digital transformation. The DairyTech conference featured several experts in cybersecurity who together provided some of the most important actions you can do when cybersecurity crisis hits, and they say the first step is to seek legal counsel and engage law enforcement as soon as possible. While knowing what to do during attack is important, as always, prevention and knowing what to do so the attack does not occur in the first place is even more important; the experts say that the cyber-attackers are not only motivated by the value of the data but also by the ease of getting access to this data. You can see it similar as motivation for stealing your bicycle; it is only a matter of time when it will get stolen if you don’t keep it locked.

New technologies including digital technologies offer number of benefits to the dairy industry and will be inevitable part of the overall transformation of the dairy industry, but these technologies will need to be safe, effective, and promising for the companies for them to invest and implement these new technologies. The Milk Quality Improvement Program is continuously searching for new technologies that might be of interest to the dairy industry and are also directly supporting the transformation by developing new digital solutions. Feel free to reach out to us with any questions or concerns by emailing Aljosa Trmcic at at543@cornell.edu or Rob Ralyea at rdr10@cornell.edu.

 

 

 

 

Recent Dairy Research Publications – July 2022

Daeschel, Devin, James B. Pettengill, Yu Wang, Yi Chen, Marc Allard, and Abigail B. Snyder. “Genomic Analysis of Listeria Monocytogenes from US Food Processing Environments Reveals a High Prevalence of QAC Efflux Genes but Limited Evidence of Their Contribution to Environmental Persistence.” BMC Genomics 23, no. 1 (July 4, 2022): 488. https://doi.org/10.1186/s12864-022-08695-2.

“Heat-Stable Liposomes from Milk Fat Globule Membrane Phospholipids for PH-Triggered Delivery of Hydrophilic and Lipophilic Bioactives – ScienceDirect.” Accessed June 10, 2022. https://www-sciencedirect-com.proxy.library.cornell.edu/science/article/pii/S1466856422001151.

Qi, Xinyang, Dasong Liu, Jiajie Yuan, Joe M. Regenstein, and Peng Zhou. “Effects of Heating Temperatures and PH of Skim Milk Fortified with Milk Protein Concentrate on the Texture and Microstructure of High-Protein Yoghurts.” International Dairy Journal 131 (August 1, 2022): 105395. https://doi.org/10.1016/j.idairyj.2022.105395.

Whitt, D. M., J. Pranata, B. G. Carter, D. M. Barbano, and M. A. Drake. “Effects of Micellar Casein Concentrate Purity and Milk Fat on Sulfur/Eggy Flavor in Ultrapasteurized Milk-Based Beverages.” Journal of Dairy Science 0, no. 0 (May 4, 2022). https://doi.org/10.3168/jds.2021-21621.