Food Safety / R&D

Manufacturers Seeking Natural Ways to Extend Foods' Shelf Life

Keeping food fresh, safe and appealing is the ultimate goal of any food manufacturer, but there are new challenges now that clean, free-from ingredients and minimal processing are in such high demand.

By Lauren R. Hartman, Product Development Editor

working dough siteWith the trend toward clean labels, consumers are carefully checking ingredient lists to find the fewest or safest-sounding ingredients and the least amount of "processing." One of the most difficult challenges in that regard is to find natural ways to extend shelf life.

Shelf life isn't just a way to track days or weeks on a store shelf; it involves microbial activity, mold/yeast development, lipid oxidation, flavor, aroma and color as well as usability at home. A food's shelf life relies on such factors as the type of process and formulation involved, the packaging used and storage conditions. But in the end, shelf life extension involves additives.

"Shelf life extension is a multifaceted need," observes Angie Singer, sales and marketing director at Delavau Food Partners (www.delavaufood.com), Philadelphia. "It’s more than a matter of inhibiting mold growth; it’s a priority to maintain texture and mouthfeel as well as achieve a clean label. It's challenging to reformulate for a clean label while retaining the necessary shelf life and maintaining the eating experience customers know and love."

In many ways, shelf life is synonymous with food safety. The two goals are intertwined in the IsoStat Products Group from Newly Weds Foods (www.newlywedsfoods.com), Chicago. Rosemary extracts, vinegar and lemon juice, as well as sodium citrate, potassium citrate and sodium diacetate form the basis of a handful of products that improve levels of food safety by extending shelf life and otherwise controlling the oxidation and spoilage of several categories of food.

Jerry Erdmann, principal scientist at DuPont Nutrition & Health (www.dupont.com), New Century, Kan., finds the challenges facing extended shelf life are the removal of historical approaches or hurdles used to control spoilage and reduce oxidation. "Chemical preservatives have a history of success, and significant scientific data supports their effectiveness," he says. "They're cost-effective, easy to use and forgiving when incorporated into the product.

"Alternative antimicrobials or antioxidant products are still relatively new in the market, with much less historical understanding," he continues. "It's important that customers understand the use, cost, flavor impact, effectiveness and shelf life expectation of finished products using chemical alternatives." It's also critical, he says, that manufacturers do their due diligence to assure the desired antimicrobial properly addresses their concerns. "The changing or removal of fats from a food system will change how the antimicrobials and antioxidants function," Erdmann notes. For example, "Going to more unsaturated fats increases the potential risk of oxidation."

Maintaining meat's color

Many consumers base their meat purchases on a product’s color. An indicator of freshness and wholesomeness is a bright red hue, whereas discolored meat often gets discounted or is wasted, though it might still be safe to eat. "For consumers, discoloration determines whether or not a meat product is still safe to eat," says Paul Janthial, food & beverage business unit director at France's Naturex (www.naturex.com). "As even highly processed meat products such as sausages are now subject to clean and clear label trends, manufacturers need to find ways to keep the color appeal of these products while losing the artificial additives."

Rosemary is gaining ground in the market as a safe, effective alternative to synthetic shelf life extenders such as BHA, BHT and the antioxidant TBHQ. Naturex provides a range of natural antioxidants obtained from rosemary, acerola, celery, Swiss chard, pomegranate and green tea. "They can enhance microbiological stability to keep foods safe for consumption or enhance organoleptic stability to keep colors and flavors intense and prevent off-notes," Janthial explains. "Each ingredient must be backed by exhaustive shelf life studies conducted on each application type. The antioxidants in these extracts protect the color, flavor and aspect of the finished product while keeping the label clear of unfriendly additives."

Naturex's XtraBlend is a new acerola cherry powder and onion blend that boosts shelf life of meat products by as much as five days in chilled products and can also preserve color. Xtrablend OA antioxidant uses acerola powder in ascorbic acid and onion extract in polyphenols to protect color without impacting meat's overall taste. In tests on fresh, refrigerated pork sausages, Xtrablend OA performed similarly to conventional BHA/BHT antioxidants, helping the sausages keep their color while exhibiting a low oxidation rate.

Vitamin E and tocopherols, which are fat-soluble alcohols with antioxidant properties, can improve the stability of myoglobin in ground beef, better retaining the color of final products. Archer Daniels Midland Co. (www.adm.com), Chicago, says the natural form of vitamin E, d-alpha-tocopherol, is better retained by the body than the synthetic form (dl-alpha-tocopherol). Tocopherols are important to stabilize cell membranes and can be used in fats, oils and many fat-containing food products.

Naturex Pack Raw Pork Sausages

Mixed tocopherols from ADM's Novatol Natural-Source vitamin E line provide plant-based alternatives that comply with the FDA's new Nutrition Facts labeling regulations that went into effect in July -- these require manufacturers using synthetically produced vitamin E to incorporate twice as much to meet the same amount of naturally-sourced vitamin E. ADM sources Novatol vitamin E from vegetable oils. Mike Zora, general manager of Natural Health and Nutrition for ADM, says Novatol delivers a more concentrated level of vitamin E than synthetically produced alternatives.

With low-salt demands so prevalent, especially since the FDA's June release of its draft on sodium reduction targets, processors are cutting back on salt to control moisture and water activity. Corbion Caravan Ingredients (www.corbion.com) says its recently expanded Verdad Avanta line delivers low-salt benefits with a blend of vinegar and either jasmine tea extract, citrus flour or celery powder to provide fresh meats and poultry with color and flavor stability days longer, as they control oxidation. They can also enhance yield, depending on the application, control Listeria and improve texture.

Shelf life extension was not the goal behind Newly Weds Foods' new DefenStat product, but it's a side benefit of this clean-label antimicrobial. Aimed at raw meat and poultry, DefenStat addresses the three systemic failures leading to E. coli and Salmonella outbreaks: It inhibits pathogen proliferation, reduces cross-contamination risk and enhances pathogen susceptibility to heat. A liquid, it can be applied directly to ground products and to whole muscle meats by marination.

Fresh baked goods

Baked goods are another category with major shelf life concerns. Delavau's Encore Fresh antimicrobial agent can more than double the shelf life of pita bread, from 10 to 21 days, while Encore Soft AM combines antimicrobial and anti-staling capabilities and helps maintain softness of baked goods so they taste fresh from 30 to 45 days.

French PastriesNaturex's NatStabil antioxidants are derived from rosemary, which is lipid soluble, and preserves color and flavor. It keeps baked goods, seasonings, cereal-based snacks, sauces and stocks, oils and fats and meat and poultry fresher longer. According to Janthial, rosemary extracts work well in many applications as replacements for BHT and BHA.

DuPont Nutrition & Health's array of antimicrobial and antioxidant products address microbiological spoilage and oxidation with a focus on cleaner label solutions. But the products also include chemical and synthetic solutions to address spoilage and oxidation where cleaner label solutions are not needed.

Antimicrobials include MicroGuard whole faction fermentates, purified metabolites, such as Nisaplin Nisin A (a natural mold inhibitor), Natamax natamycin and the BioVia product line of yeast and mold inhibitors derived from dextrose and plant extracts.

Designed for fat- and oil-containing foods, BioVia includes YM 10, which guards against mold and yeasts at levels comparable to those experienced with the synthetic preservative potassium sorbate, but is a cleaner label ingredient, Erdmann explains. HoldBAC protective cultures can be added as an adjunct to fresh fermented dairy products to produce metabolites that combat microbes like yeast and mold spoilage.

Guardian antioxidant plant extracts are available in natural options like rosemary, green tea and tocopherols that help guard foods from spoilage and maintain their intrinsic sensory qualities.