Development of a method to manufacture uncured, no-nitrate/nitrite-added whole muscle jerky

Abstract

“Natural curing” is accomplished by use of vegetable juice/powder high in naturally occurring nitrates combined with a nitrate reducing starter culture to result in indirectly “cured” products. Since the starter culture used is not water soluble, making “naturally cured” whole muscle jerky with current manufacturing techniques has been found ineffective. The objective was to investigate processes for whole muscle beef jerky that might provide cured meat characteristics similar to those of a nitrite-added control. Treatments where jerky was placed in a barrier bag during incubation were found to be the least similar to the nitrite-added control. Jerky placed in a 40.6 °C smokehouse during incubation resulted in significantly more (P < 0.05) converted cured pigment than the barrier bag treatments but less (P < 0.05) than the control. The processing methods investigated to manufacture “naturally cured” whole muscle jerky in this study were ineffective in resulting in products similar to those cured with sodium nitrite.

Introduction

Natural and organic products continue to represent one of the fastest growing categories of food products in the marketplace. The meat, poultry, and fish category, for example, reported a market growth of over 55% from 2004 to 2005 (Mitchell, 2006). Furthermore, “natural” was the second most common claim on new labels in 2005–2006 (Martinez, 2007). Nearly all major meat and poultry brands have a line of natural, fresh meat products. Increasing numbers and varieties of natural processed products such as ham and hotdogs have also been appearing in the marketplace (Major, 2006). The United States Department of Agriculture (USDA) requires that products labeled “natural” be minimally processed with no artificial colors, flavors, preservatives, or sweeteners added (USDA, 2005). These rulings forbid the addition of synthetically manufactured ingredients, such as sodium nitrate or nitrite. Organic standards also prohibit nitrate and nitrite use.

Nitrates/nitrites are added to processed meat products to develop color and flavor characteristics typical of cured products, inhibit oxidation of lipids, and inhibit the growth of bacteria (Aberle et al., 2001, Pearson & Tauber, 1984). Without the use of nitrate/nitrite, many natural and organic processed products result in appearances and flavors appreciably less consumer desirable than those conventionally manufactured with nitrate/nitrite.

Sebranek and Bacus (2007) described a process for curing meat that has been called “natural curing”. This process utilizes natural ingredients containing a relatively high content of naturally occurring nitrate in conjunction with a bacterial starter culture with the ability to reduce nitrate to nitrite. Several vegetables, such as celery, have been shown to possess high levels of naturally occurring nitrate (Fujihara et al., 2001, Walker, 1990). The use of vegetable juices or powders carefully manufactured for their nitrate content combined with a nitrate reducing starter results in the occurrence of normal curing chemistry yielding color development and other properties typical of a nitrite-cured product.

The reduction of nitrate to nitrite by the starter culture is accomplished by an incubation step, at temperatures meeting specific growth requirements of the microorganisms used, held for a period of time prior to normal thermal processing steps. Previous research has recommended a minimum of 2 h incubation for sufficient nitrite generation for subsequent cured meat characteristic development (Sindelar et al., 2007a, Sindelar et al., 2007b).

Whole muscle meats have provided a unique challenge for “natural curing” as the starter cultures utilized are not water soluble and are consequently unable to reach the center of whole muscle cuts if absorption is the method for solution pick-up. Thus, injection is required to physically deposit the starter culture into the interior of the product so it may come in contact and react with the nitrate containing vegetable juices or powders (Sebranek & Bacus, 2007). Since absorption of ingredients by marinating or tumbling (rather than injection) is the typical method for jerky manufacture, an effective means for “naturally cured” whole muscle jerky production does not currently exist.

The objective of the study was to investigate options for a “natural curing” process for whole muscle jerky utilizing vegetable juice powder (VJP) and a lactic acid starter culture containing Staphylococcus carnosus providing cured meat characteristics similar to those of a nitrite-added control.