Advances in fungal and microbial control from farm to fork
Microbial control strategies are needed in the food industry to prevent foodborne illnesses and outbreaks and prolong product shelf life, says Joe O’Neill, VP sales & business development, A&B Ingredients, Fairfield, NJ. The case for continued use of new antimicrobial strategies is also needed to reduce food spoilage and global food loss.
“In order to develop strategies to better control microbial spoilage and pathogenic bacteria in food products, it is beneficial to understand their specific conditions for growth so one can limit or change conditions conducive to growth,” he explains.
Best ingredients for fungal and microbial control
The first line of approach is often sourcing quality ingredients, employing good manufacturing practices at the plant and quality controls throughout the supply chain to avoid microbial contamination, notes O’Neill.
“The manufacturer should also consider antimicrobial food formulation strategies to create a safe and quality product for the consumer,” he says.
However, “there is no one magic bullet,” O’Neill adds.
“Different microbes have different and selective growing conditions, preferred environments, times, pH and temperatures, and many finished food products have different water activity values which affect microbial growth.”
Classic chemical preservatives have include many chemicals ending in –ates, O’Neill continues.
“[These include] Sorbate, Benzoate, Propionate, Lactate, Diacetate, Citrate and Nitrate/Nitrate. The organic acids and salts of these products fall into the category of classic chemical preservatives, many of which are widely used today.”
Bill Haines, VP, marketing & strategy, Lesaffre, Milwaukee, says that Lesaffre offers a range of clean label ESL and antimicrobial solutions.
“Our Saf-Pro STAR-ZYME, XTENDLife, and Encore lines deliver antimicrobial functionality that extends the shelf life and quality of the eating experience of breads, sweet goods, and snacks. In tests, Encore Fresh successfully extended the shelf life of pita from 10 to 21 days—delivering mold inhibition while maintaining a desirable eating experience,” he adds.
“With Encore Soft anti-staling ingredients, we’ve extended the freshness of a shelf-stable snack cake from 30 to 45 days, and doubled the lifespan of a yeast-raised doughnut from 18 to 36 hours.”
Rob Ames, senior business development manager, Corbion, Lenexa, KS, says that the best ingredient in an application for fungal and microbial control is dependent on the unique needs of each application: factors like pH levels, water activity, moisture content, target microorganisms and expected shelf life.
“Our expertise in preservation technologies allows us to help our customers make an educated decision about which of our ingredient solutions is best for them, based on all these factors,” Ames notes.
The preservative that is best for food safety is dependent on factors specific to the application, such as which microorganism is being targeted, he says.
“Conventional preservatives are highly effective at achieving enhanced shelf life and food safety, but contain chemical ingredients ending in '-ates,' which consumers may shy away from. Fermented ingredients, by contrast, offer a more natural solution to preservation, one which has been used for centuries to effectively preserve foods,” Ames adds.
Depending on the food manufacturer and their application’s specific challenges, a fermented solution may be the better choice if their aim is to create a product with a cleaner label and no effect on taste, he says.
“In short, there is no single preservation solution which is best for every manufacturer. The right approach is to conduct a thorough assessment of the application, its needs and the microorganisms at play, in order to choose the appropriate antimicrobial solution,” Ames recommends.
Kathy Sargent, global strategic innovation director, Corbion, says that to help bakers create on-trend products consumers want, Corbion has invested in its portfolio of mold-inhibition solutions, with products like Verdad MP 100.
“This product is a naturally fermented solution that functions as a clean-label mold inhibitor to provide extended shelf life in bakery products. Unlike traditional preservation solutions, Verdad MP 100 has no effect on the flavor of baked goods, allowing bakers to maintain excellent taste, while meeting their goals around microbial control,” she explains.
Technology today has advanced from the routine use of synthetic antimicrobials to newer clean-label versions which address and meet the needs for clean label and the health-conscious consumer, O’Neill adds. These clean label products range from bacteriocins, live cultures, and fermentates, to Natural Extracts.
- Bacteriocins include Nisin, Pediocin and Natamycin.
- Live cultures include various Probiotics, Pediococcus, and lactic acid starter cultures
- The fermentate category includes Cultured Dextrose, Cultured Dairy and cultured wheat starch where organic acids are the active antimicrobial ingredient.
Plant and Animal extracts include essential oils, bioflavonoids and phyto-phenols and lysozyme and organic acids, to name a few, O’Neill finishes.
To better understand the latest advances in antimicrobial strategies it is best to consider some of the current thinking and strategies on the subject, he says, including hurdle technology and the “Potentiator Effect.”
“These approaches are among the best strategies to counter pathogens and spoilage microorganisms,” expands O’Neill.
Hurdle technology involves the combination of a number of preservation factors for the production of safe stable, nutritious, tasty and economical foods, he says.
“The hurdle effect is of fundamental importance for food safety and for the preservation of food and its application has become more prevalent now, because the principles of major preservation factors for foods—temperature, pH, water activity (Aw), redox potential (Ew), competitive flora, and their interactions.”
One example used in the meat industry is the synergism between the use of Lauric Arginate (LAE) and bacteriostatic ingredients, O’Neill says.
“The Lauric Arginate (LAE) acts as a bactericidal when used to treat the surface treatment of hot dogs and whole muscle meats bactericidal product. When used in combination with bacteriostatic agent such as liquid smoke, lactate/diacetate or buffered vinegar, it has been shown that the sanitizing step coupled with the bacteriostatic inhibition gives an enhanced level of food safety and allows for shelf life extension.”
Cytoguard lauric arginate (LAE) is an FSIS approved antimicrobial and can be used at levels up to 200 ppm, he notes.
“Under certain conditions the Lauric Arginate (LAE) may be considered a processing aid and have label exemption in USDA meat products.”
A new concept in the use of Cytoguard Lauric Arginate is the use of the ingredient as a “potentiator,” O’Neill explains.
“It is useful to consider Lauric Arginate, a broad spectrum antimicrobial, as a ‘kill step,’ analogous to cold pasteurization. While the product may kill 99-99.9 percent of food spoilage and pathogenic bacteria, a few remaining cells are injured or damaged. Those damaged cells may recover and grow under normal conditions; however, if those pathogenic or spoilage microorganisms are subject to an additional antimicrobial factor (liquid smoke or another antimicrobial), the antimicrobial proves to be more efficacious than if it was used alone.”
Studies in hot dogs have shown significant pathogenic bacteria reduction and optimal shelf life extension when a multiple of hurdles are implemented during processing, O’Neill adds.
“Specifically, the combination of a Lauric Arginate ‘kill step’ with a bacteriostatic antimicrobial (liquid smoke), followed by a deep chill prior to refrigeration, resulted in the spoilage and pathogenic never having a chance to recover. The synergistic actions of multiple antimicrobials and the potentiating effect of Lauric Arginate resulted in a safer food product with the added bonus of extended shelf life.”
Yeast and mold control
A&B Ingredients continues to innovate and source new plant extracts and natural compounds that are effective against yeast and mold, O’Neill says.
“One new recent breakthrough to control yeast and mold includes a source of plant-based natural carbonyl compounds and organic acids,” he notes.
The product has been found to be an effective replacement for the synthetic potassium sorbate in high water activity, sugar solutions, O’Neill continues.
“Studies have shown that the new product out-performed potassium sorbate at pH ranges from pH3 to ph5. The results indicate that this new innovation will have promising yeast and mold inhibition benefits in applications such as sugar syrups, refrigerated foods, dips, dressings, dried meats and in baked goods. Many of these antimicrobial products are marketed under the name of CYTOGUARD at A&B Ingredients.”
In addition, the industry continues to strive for new innovations to improve food protection and safety, says O’Neill.
“One such innovation was the development of a composite antimicrobial film (CAF) with Lauric Arginate. The Lauric Arginate was incorporated into a pullulan/polyethylene film as a model packaging material. Challenge studies have demonstrated the antimicrobial film had significant benefit and promise in controlling a range of pathogenic microorganisms on RTE muscle foods over 28 days of storage,” he explains.
A recent study at Cal Poly demonstrated the inactivation of foodborne spoilage and pathogenic microorganisms in commercial juices by the synergistic application of Lauric Arginate and mild thermal processing, O’Neill says. This technology may prove to be a potential novel food processing strategy to be applied in food and beverage processing.
Janelle Crawford, regional marketing lead, DuPont Nutrition & Biosciences, New Century, KS, says that they have quite a few options when it comes to antimicrobials. These include fermentates, antimicrobial blends, antimicrobials, and protective cultures.
“MicroGARD fermentates have their microbial inhibition spectra based in naturally occurring organic acids and peptides that have been used to ensure food safety for generations. DuPont has mastered the art of capturing these naturally occurring antimicrobials,” she states.
“Our antimicrobial solutions are the result of culturing high-quality ingredients with starter cultures that have a long history of safe use in the food industry. This combination of technology and tradition brings proven food protection technology into the 21st century.”
Corbion’s MicroGARD ingredient range provides customers with the protective solutions and technology they need to produce fresh, natural foods with a simplified ingredient label, says Crawford.
“This comprehensive product line enables effective, non-synthetic solutions for protecting flavor, ensuring optimal shelf life and greater control of a wide range of spoilage organisms. Specifically, MicroGARD can protect against Gram-positive bacteria, Gram-negative bacteria, and yeasts and molds.”
Corbion’s antimicrobial blends include NovaGARD and BioVia.
“NovaGARD offers powerful combinations of ingredients to control both spoilage and pathogenic microorganisms and extend shelf life, all while maintaining the organoleptic qualities of food—primarily meat and culinary applications. NovaGARD enables the reduction of Listeria risks and control of spoilage organisms and is also efficient against Gram-negative organisms and selected yeasts and molds,” Crawford explains.
Meat processors are now required by their customers to provide products that have both a cleaner label and stay fresher over a longer period of time, she says. BioVia CL 600, part of the DuPont Danisco range of food ingredients, helps achieve extended shelf life with the advantage of a consumer-friendly ingredient statement with robust microbial spoilage control for raw, cured or uncured meat and poultry products, seasoned and marinated meat products. Added benefits of this product include favorable flavor impact and effective control of Listeria monocytogenes.
DuPont’s antimicrobials lineup includes Nisaplin and Natamax.
“Nisaplin is a heat-stable non-dairy based antimicrobial product used in a wide range of foods. It is DuPont’s commercial preparation of Nisin A, a naturally occurring antimicrobial that has demonstrated its efficacy for more than 60 years. It is considered in the food industry as one of the most effective available antimicrobials against Gram positive and spore formers,” Crawford says.
Nisaplin is now approved in Canada, and can be used to secure quality and improve safety over shelf-life, for Canadian food manufacturers in multiple applications, adds Crawford. Natamax is a naturally-occurring antimicrobial with broad spectrum anti-mycotic activity.
“With natamycin as its active compound, the effect of Natamax antimicrobial has been demonstrated in many food products over a wide range of pH values and after heat treatment. It is heat stable, active for long periods of time, and has no adverse effects on taste, odor, or food appearance—all with a proven safety record. DuPont offers several forms of this product tailored to the different applications such as cheese, fresh dairy, baked goods, processed meat and beverages.”
DuPont also offers HOLDBAC. HOLDBA protective cultures is a range of label-friendly solutions to maintain the natural quality of fresh dairy products over shelf-life and reduces food waste, says Crawford.
“Our latest addition to the HOLDBAC range of protective cultures is HOLDBAC YM VEGE, optimized for plant-based fermented food & beverages. HOLDBAC YM VEGE helps producers reduce spoilage by inhibiting the growth of yeasts and molds, thereby improving the quality of the fresh fermented product and extending its shelf life. If combined with our extensive range of Danisco VEGE cultures, the potential for reducing food waste is significant.”