The shelf life of low-temperature sterilized pre-prepared foods is usually limited by two factors: the late-stage reproduction of microorganisms and lipid oxidation rancidity. Carnosic Acid (CA) can intervene in these two pathways simultaneously, helping enterprises gain an additional 3 days of safe turnover time on the basis of the existing cold chain, while avoiding the common residue and labeling problems of potassium sorbate.

The Dual Roles of CA in Low-Temperature Systems

1. Bacteriostatic Mechanism

CA molecules have a fat-soluble main chain and ortho-diphenol active groups. During the slow cooling process after pasteurization, CA can embed into the bacterial cell membrane, interfere with membrane potential and hinder ATP generation, making the remaining spores enter a longer lag phase. Its ability to chelate metal ions further weakens the oxidative environment required for spore resuscitation. As a result, the logarithmic growth phase of the total number of colonies is shifted backward as a whole.

2. Antioxidant Mechanism

Pre-prepared food sauces and meats are rich in unsaturated fatty acids, which will undergo chain oxidation even in the cold chain at 0–4 ℃. The ortho-diphenol structure of CA preferentially captures free radicals, terminating the lipid peroxidation reaction in the primary step, reducing the accumulation of aldehyde and ketone odorous substances, thus delaying color browning and flavor deterioration.

Comparison with Potassium Sorbate

The effective form of potassium sorbate is undissociated sorbic acid, and its bacteriostatic efficiency increases with the decrease of system pH. In the typical pre-prepared food environment with a pH of around 6.0, the proportion of effective acid form decreases, so the addition amount needs to be increased to achieve the target bacteriostatic level. The excess part is easy to form salts with calcium and magnesium ions, causing residue concerns in export testing.

The bacteriostatic activity of CA is not limited by pH and remains stable in the range of 4.5–7.0. Its plant origin allows it to be directly labeled as "rosemary extract" in the ingredient list without an E number, meeting the clean label requirements of many countries and reducing compliance communication costs.

NaturAntiox^®——A Natural Rosemary Extract Solution

NaturAntiox^® provides oil-soluble and water-soluble carnosic acid products with stable activity and friendly labeling, offering pre-prepared food enterprises a natural extension solution without chemical preservatives. Welcome to contact the technical service team to obtain samples and formula support.