Life Cycle Assessment of Plant-Based Milk Incorporating Functional Ingredients

Abstract

As a sustainable source, the plant-based product has gained popularity in the food industry over the last decade. This study adopted a life cycle assessment (LCA) to evaluate the environmental impacts and identify critical points of plant-based milk incorporating functional ingredients, addressing the existing gap in understanding their incorporation from an environmental perspective. The cradle-to-gate analysis encompassed raw material acquisition, including the agricultural stage, functional ingredient procurement, processing-stage resource consumption (emission, water, steam, and electricity), and waste treatment in manufacturing. Six investigated scenarios were formed by combining three types of plant-based milk (soybean, rice, and pea) with two sources of additional alternative protein (pea protein concentrate and insect powder), mangosteen peel extract as antioxidant, and fructo-oligosaccharide (FOS) as dietary fiber, defining 1 L of milk without packaging as a functional unit (FU). The modeling was conducted using Simapro software 9.0, and the assessment was implemented via the IMPACT 2002+ method. The results showed that pea milk had a lower environmental impact in 8 out of 15 categories, followed by rice and soybean milk in 3 and 4 out of 15 categories. The fortification of plant-based milk with FOS should not be utilized in formulation due to the potential for problem shifting and the occurrence of significant adverse environmental impacts. The major hotspot comes from energy consumption in processing and freeze-drying. The adoption of insect powder exhibited a lower impact than pea protein concentrates in carcinogens, non-carcinogens, aquatic ecotoxicity, terrestrial ecotoxicity, land occupation, aquatic eutrophication, and mineral extraction. The results also indicated that producing functional ingredients, especially FOS, generated a substantial environmental impact. Improvement solutions are also discussed. A large amount of generated biowaste from plant-based milk production could be promising feed to insects due to their residue nutritional value. Therefore, the credits of biowaste for the avoided animal feed mitigated the environmental impact. The incorporation of functional ingredients for nutritional fortification in plant-based milk could be assessed through a comprehensive life cycle assessment to prevent problem shifting.