Natural Hops Flavor Offers Food Protection

Prepared Foods, Nov, 2000 by Laura A. Brandt

Consumer demand for fresher-tasting convenience items in the refrigerated section of the supermarket means food manufacturers must protect against unwanted microbial growth in order to extend shelf life and help ensure safety.

Researchers have been exploring new ways in which to protect food products and prolong shelf life by tapping the great variety of natural extracts and flavors derived from plants that show antimicrobial activity.

For example, certain components in hops (Humulus lupulus L.), such as hop acids, inhibit several food pathogens. Rhodia Food, Cranbury, N.J., has incorporated a natural flavor from hops as a key component in its new line of MicroGARD(r) 25 series ingredients (MG225 and MG325). This is an extension of its family of MicroGARD natural antimicrobial ingredients.

Rhodia is also formulating hops acids into a future new product rollout for cooked meats.

These products are effective against a number of gram-positive bacteria that include lactic acid bacteria, Staphylococcus, Listeria and various spore-forming bacteria.

"MicroGARD 25 series ingredients can be labeled as 'natural flavor,' which is desirable for manufacturers looking for clean labels and the reduction of synthetic preservatives," says Jan Payne, market development manager in the Food Protection business of Rhodia Food.

MicroGARD's patented process consists of food grade dairy cultures grown on skim milk or dextrose, then pasteurized and spray dried. The new MG225 is a non-dairy product that contains cultured dextrose and a natural hops flavor with specific antimicrobial properties. Through the fermentation of dextrose, natural metabolites are produced that can retard microbial growth and protect freshness in various foods. MG225 is especially effective against cold-loving gram-negative bacteria, certain yeasts and molds and select gram-positive bacteria, including heterofermentative Lactobacilli.

"Although usage rates vary according to the particular formulation, MG225 has been successful in providing microbial protection and extending the shelf life of refrigerated, non-fat salad dressings, salsas and sauces, and refrigerated soups at levels of 0.75 to 1.5%," says Payne.

MicroGARD MG325 is based on cultured skim milk and natural hops flavor. MG325 is effective in retarding the growth of selected gram-positive bacteria that can produce off-flavors and gas spoilage.

Applications of MG325 and usage levels include flavored milks at 0.2 to 0.5%; spreads at 0.5 to 1.0%; lowfat salad dressings at 1.0 to 1.5%; and refrigerated soups, sauces, and pasta fillings at 0.5 to 1.5%.

Although hops have been traditionally used in brewing beer for its bittering properties, at the recommended usage levels, undesirable flavors are not an issue, Payne says. The MG25 series is used commercially in salsa products, however; they have potential in chilled entrees and foods.

The products work synergistically with other antimicrobial hurdles to optimize shelf life and maintain packaged freshness. "There are many untapped plant-based extracts and flavors that may show antimicrobial activity," Payne says. 'We will be seeing the use of more of these naturally occurring compounds in the future."