Natural preservative tackles fruit juice spoilage

Purac is launching a new natural preservative for fruit and juice-based beverages, which is said to counter the spore-forming spoiler Alicyclobacillus.

A division of Dutch firm CSM, Purac has almost 80 years of history in working with preservatives, and its core portfolio is based on lactates and lactic acid. This year it is branching out with its new line of PuraQ ingredients, which retain the focus on shelf life extension and safety but may come from different sources.

The latest product in this line tackles the tricky issue of spoilage in juice-based drinks. Called PuraQ Xtend AX37, the ingredient is highly purified crystalline lactic acid.

Ivo van der Linden, category manager for food preservation at Purac, told FoodNavigator.com that the reason it is highly purified is to minimize the flavour impact.

He explained the preservative works because “lactic acid in its acidic form can diffuse through the cell wall of the bacteria, causing the pH to drop in the bacteria”.

“Bacteria have neutral pH so either the bacteria stops or in most cases the cell has to work hard to get the pH increased, causing the cell to spend energy, slowing growth.”

Alicyclobacillus can be a problem for juice firms because it is hard to detect. If it shows up only a few days after bottling, the manufacturer may not notice. By the time the consumer receives the product, however, it could have an off-flavour or odour. In the long run this could be damaging to the beverage brand.

The problem is said to affect both refrigerated and shelf-stable drinks, made with apple, pear, peach, orange, white grape, tomato juice and blends. According to the company, Alicyclobacillus can be resistant to preservatives like sorbate and sulphite, and can not only survive most heat treatments but they can actually make it grow faster.

Van der Linden said the new PuraQ preservative “allows the manufacturer to avoid the use of more rigorous methods and so helps preserve the flavour intensity of the fruit”.

PuraQ roll out

The launch of PuraQ Xtend AX37 follows the announcement last month of a cultured sugar for refrigerated foods, called PuraQ Safe RS50.

Other launches in the line are expected. The company has hinted that these will be specifically geared to fighting pathogens and spoilage in products including beverages, dips, deli products, gravies and meats.