Saturday, April 11, 2015

Listeria Contamination of Ice Cream and Hummus - What Can Be Learned

As reported by the news, the Blue Bell Ice Cream facility that produced the ice cream with Listeria contamination had a stellar inspection.  Inspections are good for determining that procedures are being followed, the facility is clean, as well as other things that can be ascertained in a snapshot view of an operation, but low levels of contamination in these type of production facilities may not likely to be seen, and may even be hard for the facility to detect unless they were specifically looking...hard.

In many of the Listeria contamination issues we encounter, the issue is with post-lethality exposure of the product to the environment, or where the product receives no thermal treatment, but rather a wash (apples or cantaloupes).  Listeria is a environmental pathogen that establishes itself in processing facility drains, in cooler air handling systems, in conveyor rollers, in washing flumes, and weighing equipment.  A facility controls Listeria through good sanitation and verifies that cleanliness through monitoring the environment by environmental sampling/testing for Listeria.

But in the case of humus or ice cream, they are primarily closed systems.  That is, after heating, the product is pumped through pipes, cooled to some degree, and filled.  The product has little exposure to the external environment, except for perhaps open hoppers or at the filler.  (This would not be a hazard of concern in hot filled product because the hot product provides lethal treatment all the way to the container).

Let's take a look at the hummus - Listeria issue.  If you look at the process of making hummus (a video of the process, not Sabra, but probably similar), the opportunities for cross contamination are limited.  Looking at this video, the facility may not look sterile, but it is more important however that the pipes, transfer hopper, and filler are clean and sanitized, and that there are no niches where Listeria could gain a foothold.   Thus, the fact that this product was found to be positive for Listeria probably indicates this type of in-line contamination.  If that is the case, then it could either be improper cleaning of the process lines after a contamination event, or some niche developed within the line or at the filler (worn or torn gaskets in the filler or in the pumps, etc).  Under-processing could also be an issue, but at least with the hummus, if this were the case, the product would be subject to spoilage.

Because these are closed systems, many facilities do not focus their testing as much on Listeria in finished product.  They may test finished product to verify the pasteurization process is working properly,  using general plate counts such as APC or coliforms, and maybe even Salmonella.  But these will probably not necessarily give an indication of Listeria contamination.  If Listeria is tested in the finished product, it is probably done using a small sample size, unlikely to detect a low level contamination issue.  As for environmental testing, again the focus would probably be on verification of cleanliness by using ATP (an indicator used for microorganisms) or even general bacterial counts such as APC (aerobic plate count).  Listeria testing, if done in the environment, would probably focus on non-contact surfaces.  The presence or absence of Listeria in areas such as the drain may not raise a flag for indicating a contamination issue in finished product.

There are many who avoid doing finished product testing to any great degree for organisms like Listeria.   But this is the type of organism, if present in a niche within this type of closed system, can grow due to the product / process type and serve as an ongoing contamination issue.  To eliminate such a contamination, proper cleaning and sanitizing are critical, along with the removal of any niches including replacing gaskets and seals, filling cracks, etc.

To detect low level contamination, small sized samples (25 gram) may not be sufficient to accomplish detection.  Large size samples (300 gm or 375gm) composited over the production run, or focused at the end of the run will be better for detection of such an issue.  Another method, often cited by our good friend Dr. Steve Goodfellow, is to collect waste samples for analysis.  Waste sample analysis uses the drips and drops that accumulate on the floor or on the exterior of the equipment throughout the production run.  These can provide a worst-case-scenario for product and can be useful in determining a contamination issue.

Swabbing potential in-line harborage sites may also be helpful.  This would include pinch points, dead ends in pipes, gaskets, seals, and filler nozzles.  The downside of this is that contamination may emerge until the process has been running for a number of hours.

These two events are a reminder that Listeria contamination can be an issue where there is little to no environmental exposure of the product, and that detection of low level of contamination can be an issue.

Note - This supposition is based upon general practice and may not reflect the actual practices of the facilities mentioned.
Inspection found no problem at Oklahoma ice cream plant
By DAVID WARREN and JUAN A. LOZANO, Associated Press : April 9, 2015 : Updated: April 9, 2015 7:26pm

DALLAS (AP) — Days after a foodborne illness was linked to Blue Bell ice cream products, a state inspection of an Oklahoma plant later tied to the infection praised the facility for having no violations and doing a "great job," according to a copy of the inspection report.

Inspectors had no reason to check for listeria during the routine March 18 review as no problems were detected and the facility didn't have a history of issues linked to the illness, said Stan Stromberg, director of the food safety division for the Oklahoma Department of Agriculture, Food and Forestry..

"With an organism like listeria, you cannot do a visual inspection," Stromberg said on Thursday.

Tainted Blue Bell ice cream products have sickened eight people — five in Kansas and three in Texas. Three of the five in Kansas have died and health officials there say listeria, also known as listeriosis, might have been a contributing factor in the deaths.

Blue Bell has temporarily closed its facility in Broken Arrow, Oklahoma, and shut down a production line at its facility in Brenham, Texas, where the company is headquartered. Blue Bell has also recalled more than 25 of its products since last month.

In the one-page report about the Oklahoma plant, provided to The Associated Press in response to an open records request, an inspector wrote "No Violations Observed!" and "Keep it up!"

At the time of the inspection, listeria had only been traced to Blue Bell's Brenham facility. Blue Bell issued its first recall on March 13.

Stromberg said Oklahoma officials didn't learn until March 22 that listeria was connected to a product produced by the Oklahoma plant.

Stromberg said his agency has been at the plant ever since, working with the Food and Drug Administration and other agencies to determine a cause of the listeria.

"Once you identify where it is, listeria is relatively easy to control. But it's going to be like looking for a needle in a haystack," he said.

Officials in Washington can attest to the difficulty of tracking down listeria at a plant. At least two people became ill after the listeria was detected in products manufactured by Snoqualmie Gourmet Ice Cream. The company responded by issuing a recall in December. It addressed health safety concerns and was given approval to resume operations a month later.

"You may just be working to keep your plant really, really clean, but you also need to work to keep it in good repair because that organism can slide into a crack on the door, or get into the crack where the wall and floor meet," said Lucy Severs, food safety manager for the Department of Agriculture in Washington.

Stromberg said he didn't believe there was any sort of breakdown in the inspection process in Oklahoma as officials don't normally submit samples for laboratory testing as a part of routine reviews, unless there were problems such as with cleanliness. No such problems were detected in the March 18 inspection, which is one of eight to 10 done each year at the plant.

Before the recall, the facility in Brenham had last been fully inspected in February and the Texas Department of State Health Services had found a couple of minor issues. The Brenham facility is inspected monthly.

"Over the years, Blue Bell has had a good inspection record and very few issues, none leading to any enforcement issue (i.e. penalty)," agency spokeswoman Carrie Williams wrote in an email.

In a statement Thursday, Blue Bell said "the fact that our products may be linked to these events is very distressing to us. We are sorry for this news and we are doing everything possible to determine the cause of the outbreak."

Listeria is a life-threatening infection caused by eating food contaminated with bacteria called Listeria monocytogenes, according to the Centers for Disease Control and Prevention. The disease primarily affects pregnant women and their newborns, older adults, and people with immune systems weakened by cancer, cancer treatments, or other serious conditions.

The CDC said Thursday preliminary tests indicate another three people hospitalized at some point from 2010 to 2012 appear to have a similar strain of listeria as the others, but further testing is necessary before confirming a connection.


Lozano reported from Houston.

Sabra Press Release
Sabra Dipping Company Opens Doors to Expanded Hummus Production Facility in Chesterfield County
October 07, 2014

Chesterfield, VA - Sabra Dipping Company (,) makers of the country’s best-selling hummus, opened the doors to its expanded hummus production facility in Chesterfield County, VA today. With the expansion, Sabra is doubling production capacity to meet continued increased demand for the brand’s portfolio of popular dips and spreads. With the 118,000 square foot expansion, Sabra expects to add an additional 70 jobs to the Chesterfield County location next year. Sabra first announced plans for the expansion last spring, with the opening of its Center of Excellence research and development facility.

“Sabra first opened its Virginia facility in 2010 and today marks our 3rd expansion since,” said Shali Shalit-Shoval, Company CEO. “The hummus category continues to grow at a double digit rate each year and we are proud to lead the category with more than 65% market share. This expansion now allows the Sabra facility to eventually produce 8,000 tons of quality, delicious, kitchen-fresh hummus each month.”

Sabra’s expanded facility leverages proprietarily engineered solutions designed to support further innovation and enhanced food preparation at all areas of production. From receipt of fresh ingredients to raw vegetable preparation and packaging efficiencies, as a silver LEED certified facility, all elements of the expansion maintain Sabra’s commitment to support the environment.

“We are so proud that the country’s favorite hummus is made in Chesterfield County,” said Dorothy Jaeckle, Bermuda District Supervisor, Chesterfield County Board of Supervisors. “Sabra also continues to be a wonderful corporate citizen, prioritizing employee satisfaction, nurturing the environment and giving back to the local agricultural community, having recently donated $25,000 of proceeds from its DC pop-up restaurant Hummus House to FFA in Virginia.”

"Sabra’s business has grown more than 400% since 2007, with the brand driving growth throughout the category,” continued Shalit-Shoval. “This expansion not only furthers our ability to produce higher quantities of hummus but allows us to create an optimal environment for the Sabra family … our employees in Chesterfield County."

The expanded facilities include additional state-of-the-art office spaces and meeting rooms as well employee-focused amenities including an inviting cafeteria, an outdoor patio with benches and picnic tables, a full company store, and a fresh coffee shop with dedicated on-site Barista.

The facility will begin production today immediately following a ribbon cutting ceremony, taking place on site. New jobs will be added throughout 2015 with more expected in 2016.

About Sabra Dipping Company, LLC

Sabra Dipping Company, LLC is a leader in the refrigerated dips and spreads category and producer of America’s top-selling hummus. Sabra’s award-winning hummus, available in more than a dozen flavors, and a wide range of authentic, healthy and vegetarian dips and spreads, including salsa, guacamole, and Greek yogurt vegetable dip, can be found nationwide in club stores, supermarkets, specialty retailers and through food service. Sabra operates a silver LEED, SQF Level 2 certified factory in Virginia, and has received an A-Classification from the British Retail Consortium (BRC) audit board for food safety for its California Salsa plant every year since 2011. Find Sabra at, and @Sabra on twitter. Sabra Dipping Company was formed as a U.S./Canadian joint venture between Strauss Group and PepsiCo.

No comments:

Post a Comment