Category Archives: Recent Publications

New York State, State Fair 2023 Dairy Products Competition

New York State, State Fair
2023 Dairy Products Competition
148 Stocking Hall, Cornell University

Competition Winners
Class 1- Current Cheddar
Company Entry Name Score
Gold Great Lake Cheese Cheddar Cheese 98
Silver Great Lake Cheese Cheddar Cheese 97.5
Award of Excellence Agri-Mark Inc Cheddar Cheese 97

Class 2- Aged Cheddar
Company Entry Name Score
Gold Great Lakes Cheese Cheddar Cheese 98.5
Silver Worlds Best Cheese Cheddar Cheese 98
Award of Excellence Argi-Mark Inc Cheddar Cheese 97.5

Class 3- “Super” Aged Cheddar
Company Entry Name Score
Gold Great Lakes Cheese Cheddar Cheese 98.5
Silver Agri-Mark Inc. Cheddar Cheese 97
Award of Excellence Agri-Mark Inc. Cheddar Cheese 96.5

Class 4- Cottage Cheese Full Fat
Company Entry Name Score
Gold Hood Lafargeville 4% Large Curd Cottage Cheese 99
Silver Hood Arkport Small Curd Cottage Cheese 97
Award of Excellence Hood Vernon Small Curd Cottage Cheese 96.5

Class 5- Lowfat Cottage Cheese
Company Entry Name Score
Gold Hood Lafargeville Lowfat Small Curd Cottage Cheese 96.5
Silver Hood Arkport Lowfat Cream Cottage Cheese 95.5
Award of Excellence Hood Lafargeville Lowfat Small Curd Cottage Cheese 95

Class 6- Nonfat Cottage Cheese
Company Entry Name Score
Gold Hood Lafargeville Nonfat Cream Cottage Cheese 98.5
Silver Hood Lafargeville Nonfat Small Curd Cottage Cheese 94

Class 7- Cream Cheese/ Neufchatel
Company Entry Name Score
Gold Kraft Heinz Regular Cream Cheese 99.5
Silver Kraft Heinz Whipped Cream Cheese 99
Award of Excellence Kraft Heinz Jalapeno Cream Cheese 98

Class 8- Low Moisture Mozzarella
Company Entry Name Score
Gold Great Lakes Cheese LM Whole Milk Mozzarella 96
Silver Great Lakes Cheese LM Part Skim Milk Mozzarella 95.5
Award of Excellence Lactalis American Group LM Part Skim Milk Mozzarella 95

Class 9- Mozzarella, non-pizza
Company Entry Name Score
Gold Lactalis American Group Part Skim Mozzarella 98.5
Silver Lactalis American Group Part Skim Mozzarella 98
Award of Excellence Upstate State Niagara Low Moisture Mozzarella String Cheese 97.5

Class 10- Ricotta
Company Entry Name Score
Gold Lactalis American Group Made With Whole Milk Ricotta 98
Silver Lactalis American Group Double Cream Ricotta 97
Award of Excellence BelGioioso Cheese Inc. Original Ricotta 95.5

Class 11- Provolone
Company Entry Name Score
Gold Lactalis American Group Provolone 98.5
Silver Great Lake Cheese Smoked Provolone 96.5
Award of Excellence Great Lake Cheese Provolone 96

Class 12- Cold Pack/ Process Cheese
Company Entry Name Score
Gold Yancey Fancy Maple w/Bacon Cheddar 99
Silver Agri-Mark Inc. Horseradish Cheddar 98.5
Award of Excellence Yancey Fancy Steakhouse Onion 98

Class 13- Flavored Natural Cheese
Company Entry Name Score
Gold BelGioioso Cheese Inc. Smoked Fresh Mozzarella Ball 99
Silver Old Chatham Creamery Fresh Goat Cheese with Cranberries 98.5
Award of Excellence BelGioioso Cheese Inc. Pesto Sliced Fresh Mozzarella Log 98

Class 14- Open Class Cheese
Company Entry Name Score
Gold Old Chatham Creamery Nancy’s Hudson Valley Camembert 99.5
Silver BelGioioso Cheese Inc. Fresh Mozzarella Log 99
Award of Excellence Yancey’s Fancy Bergenost 98.5

Class 16- Goat/ Sheep Cheese
Company Entry Name Score
Gold Old Chatham Creamery Fresh Goat Cheese w/Garlic &Herbs 99.5
Silver Nettle Meadow Simply Sheep 99
Award of Excellence Cotton Hill Creamery Fresh Goat Cheese 98.5

Class 18- Farmstead/Artisan Cow’s Milk Soft Cheese
Company Entry Name Score
Gold Four Fat Fowl St. Stephen 99
Silver Four Fat Fowl CamemBertha 98
Award of Excellence Chuchtown Dairy Coperthwaite 97

Class 19- Farmstead/Artisan Cow’s Milk Hard Cheese
Company Entry Name Score
Gold East Hill Creamery Silver Lake 99
Silver Eden Valley Creamery Alpine Style with Caraway 98.5
Award of Excellence Jake’s Cheese Gouda 95.5

Class 20- Sour Cream
Company Entry Name Score
Gold Hood Arkport Sour Cream 97.5
Silver Upstate Niagara Dairy Sour Cream 96
Award of Excellence Hood Arkport Sour Cream 95.5

Class 21- Buttermilk
Company Entry Name Score
Gold Hood Arkport Buttermilk-Reduced Fat 98
Silver Upstate Niagara Dairy Whole Cultured Buttermilk 97.5
Award of Excellence Argyle Cheese Factory Full Fat Buttermilk 97

Class 22- Dairy Dips
Company Entry Name Score
Gold Hood Lafargeville Heluva Good French Onion 98.5
Silver Hood Arkport Heluva Good French Onion Dip 96.5
Award of Excellence Upstate Niagara Dairy French Onion Dip 96

Class 23- Plain Yogurt
Company Entry Name Score
Gold Hood Vernon Nonfat Plain Yogurt 96.5
Silver Stoltzfus Family Dairy Plain Yogurt 95.5
Award of Excellence Argyle Cheese Factory Greek Plain Yogurt 95

Class 24- Flavored Yogurt
Company Entry Name Score
Gold Argyle Cheese Factory Maple Greek Yogurt 99
Silver Stoltzfus Family Dairy Raspberry Yogurt 97
Award of Excellence Old Chatham Creamery Ginger Sheep Milk Yogurt 96.5

Class 25- Fluid Milk
Overall Company Entry Name
Gold Stewart’s Processing Fluid Milk
Silver Upstate Farms Buffalo Fluid Milk

Small Processor Company Entry Name
Gold Weissmann Farms Fluid Milk

Company Entry Name
Gold Dygert Farms Creamery Chocolate Milk
Gold Stewart’s Processing Flavored Milk

Class 26-Ice Cream
Company Entry Name
Gold Mikey Dubb’s Frozen Custard Vanilla Ice Cream
Gold Stewart’s Processing Chocolate Ice Cream
Gold Stewart’s Processing Open Class Mint Cookie Crumble

2023 Dairy Products Competition
Grand Champion
Four Fat Fowl St. Stephen’s

Recent Dairy Research

 

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.

 

The ‘Magical’ CIP Button

The operators know it well, that magical button we push that cleans everything as if we alone possess supernatural powers!  But in fact, do we?  It’s been my experience that we do not.  While it’s safe to say the chemicals or heat are doing much of the work, it still is dependable on several factors as to whether a system is getting cleaned properly or not.  Take for example a cultured dairy plant that wanted to run a non-cultured product through their system.  After cleaning and sanitizing their system completely, the non-cultured product over shelf life started to exhibit the same flavor, smell and texture of some of the cultured products they made. Not only that, we were able to culture out of those products their original culture organisms. Without a doubt, they had biofilms of their product cultures adhering to the surfaces within their system.  Oddly enough, this was a surprise to them.  Then again, not many cultured plants will attempt to run a non-cultured product in a cultured product plant.  Whether you’re a cultured plant or a fresh product dairy processor, it’s possible to have low level biofilms in your systems, it just tends to be more obvious in fresh product plants (no competition).

Often, plants don’t pay any attention to their CIP systems, however there are a few things that come into play that you need to think about.  The power/speed of the circulation pump is critical to give you the volume of flow required to adequately clean and sanitize an enclosed CIP loop.  Restrictions and expansions in piping can change the velocity of cleaning solutions.  When cleaning volume of flow and turbulence are important.  If you are unsure you are getting proper flow, your chemical supplier should have an instrument that they can hook up to the outside of your lines to check the actual flow during CIP.  If you have restrictions/expansions, I recommend testing the flow in several different locations within the CIP loop.  And always remember the acronym TACT, which are the four tenets of cleaning:  Temperature of the solution, Action of flow through the CIP circuit (speed/turbulence), Concentration of chemical, and Time of contact.

Do You Have A Preferred Training Provider? Increase your training efficiency and effectiveness by building a solid training provider relationship

It seems that people’s time is becoming increasingly valuable. Our team is acutely aware that the companies we serve seem to be doing more with less: less resources, less people, and with an ongoing wave of retirements, less widespread and institutional expertise. At the same time, the food industry continues to grow and develop. Food processing employees will continue to need training to generally operate, meet regulatory and audit requirements, and remain preferred places of employment.

With the above-mentioned limitations, it is more important than ever that employee training hits on the precise topics that are needed. We pride ourselves on building strong, long-term relationships with our industry partners to deliver best-in-class training to employees. Please reach out to us to create a training plan for 2023 and beyond. Below are several strategies we use to become your preferred training provider.

  • Certificate Program: Our Dairy Foods Certificate Program is rounding out its 10-year anniversary and is the cornerstone of our programming. The certificate program is a great option for general employee training regardless of the type of dairy products that are made at a facility. It is also a fantastic tool for individual employee development and advancement. Courses are offered regularly, and many can be done on-site.
  • Customized Training: While we have standard course offerings through our certificate program, some organizations need more curated content to fit their needs. We can use our existing programs as building blocks to make customized courses, or we can create something entirely new. In-person customized trainings are typically done on-site, but can also be offered on our campus. If a virtual platform is preferred, we can arrange for the content to be disseminated live, or through a self-paced virtual program. We ask that companies reach out to us with plenty of lead time for customized training so that we can develop the best content possible.
  • Online or inperson: In this day in age, there doesn’t seem to be a one-size-fits-all approach to what works best. Online training has its clear efficiencies, but the in-person human connection can’t be totally replaced. Our team is willing to work with companies to find the right balance of online or in-person training to fit the needs of their culture.
  • Onboarding training capabilities: There is plenty of literature stating that a strong onboarding system improves employee longevity and retention. While onboarding isn’t limited to food safety training, it is a key component of any food processing job. Our programs go into the “why” behind plant operations, and we have specific online programs that are ideal for required basic GMP and Food Safety Training.
  • We get to know you: As trainers, there is a true benefit to knowing your audience and the environment your audience is working in. The more our team is able to interact with an organization, the deeper our understanding is, and that helps us curate the best content for the needs of those employees.
  • The land-grant advantage: Cornell University is a land-grant institution, meaning that we are charged with advancing the lives and livelihoods of the state’s citizens through teaching, research and public service. As such, our Milk Quality Improvement Program and Food Safety Laboratory provide us with up-to-date, relevant research for industry, and our training team is able to take that knowledge and share it with industry through training. In turn, our extension team provides feedback to our researchers on the challenges that the industry is facing. This dynamic gives us and the companies we serve a key advantage. Companies are also able to take advantage of our laboratory services and consulting services, making us a one-stop shop for many of your food safety and quality needs.

Please reach out to lmf226@cornell.edu to schedule a consultation on any of your training needs.

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.