Assessing the economic viability, environmental sustainability, and scalability of microbial protein from cheese whey permeate in Europe

Abstract

Cheese whey permeate (CWP), a nutrient-rich by-product of the dairy industry, holds untapped potential for conversion into microbial protein (MP). This study presents a comprehensive techno-economic analysis and life cycle assessment (LCA) of two distinct MP production routes from CWP: a one-step conversion of lactose to MP, and a two-step route involving lactic acid fermentation prior to MP production. Furthermore, centralised and decentralised MP production systems were compared based on CWP spatial distribution, valorisation scale, and logistical constraints. The two-step MP production, despite higher capital and raw material inputs, achieved the lowest minimum selling price (MSP) of 3.9–5.0 €/kgprotein. This MSP makes the two-step MP production route competitive with other food-grade protein sources, including plant-based (2.5–9.2 €/kgprotein) and animal-based sources (5.9–13.5 €/kgprotein). According to the LCA, the two-step configuration demonstrated a 95.7–99.3% lower overall environmental burden than animal-derived proteins (beef, pork, chicken) and outperformed plant-based alternatives such as pea protein. Decentralised MP production at 100 ton CWP/h emerged as the most viable scale due to reduced MSP and compatibility with mid-sized cheese producers. Centralised production was restricted in scale due to the heterogeneous distribution of CWP across Europe. Valorisation of 80% of Europe's CWP into food-grade MP through decentralised facilities could replace up to 7.2% of the European animal protein needs and substantially reduce the environmental impact. This work provides key insights into economic feasibility, environmental sustainability, and deployment strategies for MP production from CWP, highlighting its potential as an alternative protein source.