With food manufacturers busy reformulating or developing products to cut ‘nasties’ such as salt and sugar, Leatherhead Food Research has warned that associated food safety issues should not be an afterthought.
Evangelia Komitopoulou, head of food safety at food research organisation Leatherhead told FoodManufacture.co.uk that new product development (NPD) takes from a few days (for flavour variants) to one month (using existing processes) or several months for something new.
It’s a bug’s life…
But given that salt and sugar, for instance, are vital food preservatives that reduce water activity (lower values will decrease water available for microorganisms to grow), Komitopoulou warned that lowering levels raises potential safety issue, which if only compensated for at the end a given project risks jeopardising its success.
“Examples …would involve the reduction of salt at levels below 3.5% in meat or fish products with prolonged storage at chilled conditions, as this would allow for the growth of Cl. Botulinum,” she said.
“Total sugar levels below circa. 65% in jam or conserves could allow for the growth of osmophilic yeasts or moulds. Replacement of acetic acid by, for example, citric or lactic acid in mayonnaises or pickles would reduce the level of preservation, as the latter acids are much less active as antimicrobials.”
Delicate balancing act
With formulation a delicate balancing act, Dr Wayne Morley, Leatherhead head of food innovation, also warned that reducing the ‘fat phase’ in a given product risks increasing water levels in some cases – with associated salt and sugar that could compromise a brand’s health credentials.
Komitopoulou said that product formulation teams are increasingly turning to free or bespoke predictive modelling tools, to get preliminary indications of the safety and microbiological stability of new products, as well as ‘spiking’ them and using real time ‘product challenge testing’ to assess safety.
She added that one method used to curb microbial growth involves increasing the acidity of foods: this depends on the acids used to deliver specific levels, water activity and the type and level of sugars/salts used.
“For example, growth of Campylobacter spp is observed under pH (4.9-9.0) and water activities of 0.98-0.99aw [water activity]. Salmonellae are able to grow in water activities as low as 0.94aw and pH conditions of pH 3.8-9.5,” Komitopoulou said.
Although low pH (highly acidic) products such as mayonnaises and pickles do not generally present food hazard issues, she added, microorganisms such as lactics, yeasts and moulds can still cause spoilage.
Modified atmosphere packaging
In tandem with formulation expertise, modified processing techniques can also extend product shelf life, said Komitopoulou: “Such techniques include drying, modified atmosphere packaging (MAP) and nitrogen packing of ingredients such as unsaturated fish oils, or other ingredients that have an easily oxidisable oil: [such as] rice, coffee powder.”
She added that MAP combined with low temperatures is being used to extend the shelf life of cured hams and other meat products, as well as part-baked breads (the latter stored in ambient conditions), cut vegetables and fruit.