Decontamination of Spores on Model Stainless-Steel Surface by Using Foams Based on Alkyl Polyglucosides

Abstract

In the food industry, the surfaces of processing equipment are considered to be major factors in the risk of food contamination. The cleaning process of solid surfaces is essential, but it requires a significant amount of water and chemicals. Herein, we report the use of foam flows based on alkyl polyglucosides (APGs) to remove spores of Bacillus subtilis on stainless-steel surfaces as the model-contaminated surface. Sodium dodecyl sulfate (SDS) was also studied as an anionic surfactant. Foams were characterized during flows by measuring the foam stability and the bubble size. The efficiency of spores’ removal was assessed by enumerations. We showed that foams based on APGs could remove efficiently the spores from the surfaces, but slightly less than foams based on SDS due to an effect of SDS itself on spores removal. The destabilization of the foams at the end of the process and the recovery of surfactant solutions were also evaluated by using filtration. Following a life cycle assessment (LCA) approach, we evaluated the impact of the foam flow on the global environmental footprint of the process. We showed significant environmental impact benefits with a reduction in water and energy consumption for foam cleaning. APGs are a good choice as surfactants as they decrease further the environmental impacts.

Ultrastable and Responsive Foams Based on 10-Hydroxystearic Acid Soap for Spore Decontamination

“…Then, the stainless-steel plates were removed, and the effect of contact with the foam was quantified by measuring the spore log reduction after 30 min, as shown in Figure 5a. The spores' log reduction was around 1.13 ± 0.14 for the water due to the hydrophilicity of the spores, as already observed previously, which could be removed by water [29]. The spores' log reduction for the pure 10-HSA dispersion was 0.92 ± 0.20, which was similar to water.…”

“…In our case, we assume that even if the average liquid fractions were different, they were still within the range of wet foams, and we also assume that only the bubble size had an effect on foam imbibition [32]. Moreover, by comparing the log reduction obtained for the DS foam to the log reduction obtained for foam flow in dynamic conditions using the same spore model and the same surface, we observed that the values are similar, showing that foams in static conditions are very effective for efficiently removing spore contamination, thanks to the imbibition process [29].…”

“…All the cleaning experiments were carried out on rectangular (45 mm × 15 mm) AISI 316 stainless-steel plates (APERAM, Isbergues, France) with a 2R factory finish. In order to have similar surface properties to those found in the food industry, the surfaces were subjected to a conditioning process that has been described previously [29]. In brief, the plates were immersed in milk at room temperature for 30 min and then they were rinsed for 5 min under osmosis water by overflow.…”

Green approaches for biofilm eradication: Enhancing cleaning efficiency

“…Notably, immersing the contaminated surfaces in biosurfactant alone did not have any effect on cleaning. Furthermore, recent experiments with foam flows based on alkyl polyglucosides have shown promising results in efficiently removing spores from surfaces while minimizing the environmental impact (Dari et al, 2023). The combination of the mechanical effect of air–liquid interfaces and the chemical effect of biosurfactants presents an alternative cleaning procedure that could further enhance cleaning efficiency and decrease environmental impact.…”

Mixture of fatty alcohols and alkyl polyglucosides stabilizing water-in-water emulsions

“…Alkyl polyglucoside (APG) is one of the well-known families of natural surfactants, derived from natural glucose and a fatty alcohol. It is considered as non-toxic, mild and environmentally friendly emulsifier (Dari et al, 2023). Our aim here was to study the stabilization of W/W emulsions by using LGNs based on various APGs.…”