Life cycle assessment of a semi-industrial infant milk formula powder and of a low-heat alternative process involving membrane filtration

Infant formulas provide the necessary nutrients to infants aged 0–6 months whenever breastfeeding is restrained. Their production must balance nutritional quality, environmental sustainability and economic profitability in the manufacturing process. Traditional heat treatment processes, such as pasteurization, ensure microbiological safety but lead to protein denaturation and Maillard reaction, thereby diminishing the nutritional quality of the product. New processes involve low-heat sanitation using membrane microfiltration to also maintain protein quality. Life Cycle Assessment was used to compare the potential environmental impacts of the production of infant formula powder via the classic route (using pasteurization) or the alternative route (using microfiltration) at a semi-industrial scale. No matter the sanitation procedure, the production of milk and oil ingredients exhibited the largest contribution to impacts, followed by evaporation and spray-drying, i.e. unit operations with energy-consuming water evaporation. Closer insight on sanitation operations revealed that while pasteurization and microfiltration are comparable across various impact categories, microfiltration demands significant water and detergent for cleaning, whereas pasteurization is energy-intensive during its steady-state phase. Although energy consumption is reduced, 1 kg of infant formula produced through the alternative route emits 11.1 kg of CO₂ equivalent, against 10.4 for the classic route. The higher impact of the alternative route on climate change, as well as on other agriculture-related impact categories, is primarily attributed to the increased demand for skim milk to implement microfiltration. Sensitivity analyses revealed strategies to reduce infant formula's environmental impacts, such as using liquid ingredients to avoid drying or increasing pre-evaporation dry matter to save energy.