Sweet or simple describe two areas of interest in improving the shelf life of grain-based foods. Sweet refers to ingredient suppliers offering shelf life systems designed specifically to preserve freshness and quality in sweet items, such as cakes. Simple refers to simple, natural preservatives that thus may give a grain-based food product a "cleaner" label.

In the United States, product launches with a natural claim grew by 16% in 2008 when compared to 2007 and made up 33% of all product launches in 2008, according to Mintel International’s Global New Products Database. A "natural" claim may include all-natural, no additives/preservatives, organic and whole grain, according to Mintel.

"There is a negative connotation by the consumer, right or wrong, that artificial or non-natural ingredients are not healthy," said Rodger Jonas, director of national sales for P.L. Thomas, Morristown, N.J.

Bill McKeown, vice-president of technical development for Fleischmann’s Yeast, Chesterfield, Mo., has noticed a trend of customers making more natural requests. They seek to avoid chemical preservatives that may make a label less friendly to a consumer.

Many natural preservatives such as vinegars, raisin juices and cinnamon may add off flavors, Mr. McKeown said. Often usage requirements for these natural preservatives are so high that off flavors are detected readily in the bread, he said.

In response to those concerns, Fleischmann’s Yeast has launched AB Mauri Nabitor, an all-natural mold inhibitor made from a process that uses cultured corn syrup solids and citric acids along with selected microbes. The product allows for friendly labeling, and the term "no artificial preservatives" may be used, according to Fleischmann’s Yeast.

"Our team of bakery scientists has developed a better clean-label solution for bakers that are wanting to meet consumer demand for healthier baked products," said Scott Wise, product development specialist.

The scientists tested Nabitor against typical chemical mold inhibitors and other natural mold inhibitors in bread produced using no-time dough and sponge-and-dough processes. Nabitor increased shelf life in both studies.

"In laboratory testing, we have seen an increase in mold inhibition without any off flavors," Mr. McKeown said. "The mold inhibition period is dependent on application or bakery process."

Paul Bright, vice-president of product development for Fleischmann’s Yeast, added, "In straight dough systems, use levels of Nabitor are generally higher than use levels in sponge and dough systems. We have seen mold-free baked products ranging from 21 to 30 days when using Nabitor."

The usage level of Nabitor in an application depends on what a company is trying to achieve, Mr. Bright said. The level on a flour basis may range from 0.4% to 1.4%, he said.

Fleischmann’s Yeast recommends Nabitor for such bakery applications as bread, buns, tortillas, bagels and English muffins.

Raisin juice concentrate, another natural preservative, is used at about 2% or more in bread, according to the California Raisin Marketing Board, Fresno, Calif. Raisin juice concentrate contains a minimum of 70% natural fruit soluble solids (70 degrees Brix).

In baked goods, confectionery and snacks, raisin juice concentrate not only sweetens and colors the product, it maintains moisture in chewy cakes and soft cookies; reduces breakage in crisp cookies and crackers; acts as a natural binding agent in cereal bars; extends the shelf life of bread products and functions as a natural preservative.

Vitiva, Markovci, Slovenia, offers a natural preservative in its Inolens line of rosemary extracts. P.L. Thomas in 2006 became a strategic partner of Vitiva in the sale of Vitiva products, including Inolens. In rosemary extract, camosic acid, camosol and rosmarinic acid are the most active compounds in terms of antioxidant capacity.

Grain-based foods are just one application area for the rosemary extracts. In breakfast cereals, Inolens 12 works with extruded products at dosages of 0.2 to 0.3 grams while Inolens 4 works with sprayed products at dosages of 0.5 grams to 1 gram. Inolens 12 works in cakes, cookies, specialty bread, frozen dough, frozen pastry and bread crumbs at dosages of 0.15 to 0.3 grams.

"Baked goods have multiple attack points for preservation that occur at different stages of the life cycle of the product," Mr. Jonas of P.L. Thomas said. "The fat/oil used is the primary point for initial preservation."

Inolens 12, and also organic-certified Inolens 15, inhibits the oxidation impact on the fat or oil used. The delay in activity helps to extend shelf life. Formulation, process conditions and the length of the shelf life all will impact the required levels of Inolens, Mr. Jonas said.

"We have found that Inolens is also effective for nuts and creams," Mr. Jonas said. "These ingredients need protection or they can accelerate the changes observed in flour, color and odor in baked goods."

The amount of sugar plays a factor in the shelf life of sweeter grain-based foods such as cakes. A higher water activity generally leads to faster microbial growth, but sweet goods have sugar, said Mr. Bright of Fleischmann’s Yeast.

"Those systems lower the water activity," Mr. Bright said. "You end up getting a little bit better shelf life with sweet goods."

A partnership between Novozymes, Bagsvaerd, Denmark, and Puratos, based in Belgium, is designed to create cakes that stay fresher longer. Puratos develops and produces ingredients for the cake, bread and chocolate sector.

Novozymes’ enzyme technology keeps cake crumbs more cohesive and soft. It slows down the process of breaking down starch molecules, which may cause a gummy, non-elastic and sticky crumb, according to Novozymes. Puratos optimizes synergies between enzymes and other ingredients such as emulsifiers.

"We have the technology, but we needed partners to bring them to market in a fast manner," said Thomas Erik Nilsson, global launch manager, Cereal Food and Beverages, Novozymes.

Gary Johnson, global marketing manager for Novozymes North America, Inc., Franklinton, N.C., added, "As cakes contain high amounts of sugar, an improved version of this maltogenic amalyse was needed to give the same level of fresh-keeping as in bread. Our new cake fresh-keeping enzyme technology nicely meets this need."

Mr. Johnson said cakes with longer shelf life may fit into several trends. For one, ready-to-eat single portions need to stay fresh at convenience stores. For another, reduced-fat and reduced-sugar cakes created for the health and wellness trend tend to stale sooner and may benefit from improved softness. In the indulgence category, premium cakes need to maintain superior eating quality, Mr. Johnson said.

Positive results have been obtained in cakes that have been stored for upwards of 30 days, said Todd Forman, a scientist with Novozymes. He added results will depend on cake type and formulation.

"There have been numerous studies outlining the staling mechanism of bread, but there has been precious little published on the mechanism of caking staling," Mr. Forman said. "Although starch plays a role in both bread and cake staling, the change it undergoes is different in the two products.

"Bread can become stale in a matter of days, and the maximum rate of staling occurs at refrigerated temperature. It can take weeks for cakes to become stale, and the rate of staling is lowest at refrigerated temperature."

Several other companies offer specific systems designed to improve the shelf life of cakes.

Caravan Ingredients, Lenexa, Kas., last year launched Cakesoft, which keeps cakes soft, moist and resilient for at least 60 days, according to the company. It works in cakes ranging in size from snack cakes and muffins to large gourmet styles. Cakesoft, a blend of enzymes and emsulfier, allows refrigerated storage while inhibiting mold growth.

DSM Food Specialties, which has a U.S. office in Parsippany, N.J., offers CakeZyme, which extends shelf life by providing a fresh, spongy crumb for a longer period of time. Other CakeZyme benefits include allowing manufacturers to use up to 20% fewer eggs and improving the emulsifying properties of egg lecithin.

CakeZyme is a microbial phospholipase that may be applied as a processing aid to convert lecithin into lsyolecithin, thus boosting emulsifying properties of the egg yolk. The enhanced emulsification results in lower batter density, improved batter viscosity and delayed crumb setting.

Grindamyl Powersoft from Danisco, Copenhagen, Denmark, may be used in creating cakes that keep their freshly baked qualities for up to twice as long as standard cake products, according to the company.

Shelf life studies examine wheat bread, cookies

Vitiva, Markovci, Slovenia, has studied the effects of its Inolens rosemary extracts on whole wheat bread with seeds and also cookies and biscuits.

Whole wheat bread with seeds and nuts are prone to oxidation because of the high fat content, according to Vitiva. Product rancidity may manifest itself in the form of an unpleasant taste, odor or color. The rancidity may occur as early as while the flour, seeds and nuts are stored in a warehouse or when the bread is on the shelf at retail.

The study on the whole wheat bread involved adding Inolens 12 to the flour at the two concentrations of 0.015% and 0.03%. Samples then were stored in plastic foil at room temperature. Vitiva performed rancidity measurement 14 days after production and sensory evaluations after 14 days of storage. A seven-person trained panel did not sense any flavor or taste contribution of extracts or a change of the organoleptic profile of whole wheat bread with seeds. No microbial changes such as yeast and mold contamination were observed.

Turning to cookies, Vitiva pointed out they are made in a variety of styles and with a variety of ingredients added, such as spices, chocolate, extra butter and sour cream, nuts and seeds. Cookies containing a lot of fat, such as Danish butter cookies and cookies with seeds or nuts, are prone to oxidation and rancidity more often than other cookies.

Vitiva added Inolens 12 to flour at the two concentrations of 0.015% and 0.03%. Samples of the cookies then were stored in plastic boxes at room temperature. Rancidity measurement was done one month after production. Sensory evaluations were performed after production and after one month of storage. A seven-person panel did not identify any flavor or taste contribution of extracts or any change of the organoleptic profile.

Ingredient toolbox: shelf life

The following ingredient product lines may be used to extend the shelf life of grain-based foods:

Fresh-N

Enzyme Development Corp., New York, offers Fresh-N, a heat-resistant alpha amylase from B. subtillis to extend shelf life in baked foods. It is available as a powder.

Grindamyl Powerfresh

Danisco, Copenhagen, Denmark, offers Grindamyl Powerfresh with G4 amylase, a baking enzyme that offers anti-staling technology for bread and tortillas. The G4 amylase has an impact on starch retrogradation, a main contributor to the staling process, according to the company. The enzyme improves the strength and flexibility of breadcrumb and reduces crumbliness.

Soft-Power

Cain Food Industries, Dallas, offers Soft-Power enzyme systems. Soft-Power P-CDA, a balanced enzyme anti-staling system, extends the shelf life of chemically leavened products and may be used in cakes, donuts, muffins and snack cakes. Soft-Power P-SG, an anti-staling/softening enzyme system, is designed for use in sweet goods and other goods containing high levels of shortening and sugar. Soft-Tabs, an anti-staling enzyme system, is designed to enhance the softness and extend the shelf life of bagels, bread and other yeast-raised products.