Category Archives: LCA

Assessing circular food systems: Fish oil substitute produced from food waste

Imagine that you buy three bags of food at the grocery store and throw away one of them before you get home. Seems crazy right? But the truth is that about one-third of the food produced today is wasted, meaning that a considerable amount of food is produced in vain. Overproduction, cosmetic standards, inefficient logistics and overconsumption are some examples that cause wastage of still edible food along the food supply chain. This waste leads to considerable environmental impact, economic losses and critical social consequences.

Recovering valuable resources and circulating them back to the food supply chain instead of wasting them could lead to important benefits compared to the current system. In fact, using already available resources and reduce waste is considered essential to maintain future food security, enable the transition towards a circular economy and support sustainable development. So, how should we use these resources then? One solution could be to produce a fish oil substitute via microalgae using food waste as feedstock.

Food from waste

Today, aquaculture is one of the fastest growing food-producing sectors globally, and each year we produce about 1-million-ton fish oil rich in the essential fatty acid DHA (found in Omega-3). Since Omega-3 must be obtained through diet, it is often added to food and feed production (often in the form of fish oil) to enhance nutrition levels in dairy, meat and fish consumed by humans. In the beginning, aquaculture was considered a solution to decreased biodiversity and diminished ecosystems, as a result of overfishing. However, the fish oil industry required to support traditional aquaculture is highly dependent on fossil energy and marine raw materials, which leads to depletion of natural resources and ecosystems as the global demand for fish increases. Instead of solving the problem of overfishing, aquaculture has created new ones. At the same time, about 1.3 billion tons of food is wasted globally every year.

In aquatic ecosystems, the essential fatty acid DHA is produced by microalgae and accumulated in fish via the food web. Therefore, one promising solution is to gain DHA directly from microalgae. Research shows that heterotrophic microalgae can be cultivated in bioreactors using volatile fatty acids (VFA) derived from food waste as primary carbon feedstock.

Feeding algae VFA to produce an algae oil rich in DHA could provide multiple benefits in comparison to traditional fish oil, especially since biogas can still be produced alongside. This means that we can produce multiple valuable products from food waste, which would further reduce pressure on natural resources. Producing a fish oil substitute using already available recourses could also support circular food systems and improve global food security. However, assessing and evaluating the environmental implications of new technologies is crucial to ensure that the suggested solutions also support future sustainability.

Environmental impact and loss of biodiversity

This study aimed to evaluate the future potential of DHA produced from algae with a primary carbon feedstock from food waste, by assessing and comparing its environmental impact to that of DHA from Peruvian anchovy oil. The studied systems were modelled as two parallel scenarios to assess large-scale production of DHA: a conceptual Algae scenario and a conventional Fish scenario.

Simplified scenario illustration, created using

A life cycle assessment (LCA) approach was used to obtain a holistic quantification of the impact caused by the Algae scenario and the Fish scenario, from the extraction of raw materials via production to finished product. Using LCA indicators at both midpoint and endpoint along the cause-effect chain can provide a vital dimension of total impact to policymakers, the research community and industry. Moreover, including endpoint impact such as damage to ecosystem quality is especially important in systems dependent on biotic resources, such as fish oil production. By definition, biodiversity refers to the variability among all living organisms and maintaining biodiversity is essential for life on Earth. As natural systems and species are dependent on each other, damaged ecosystem quality or loss of even a small number of species could lead to irreversible consequences. Therefore, the endpoint indicator Ecosystem damage was included in this study as a complement to the midpoint indicators global warming, acidification, eutrophication, and land use.

Algae oil VS Fish oil

The main findings were that DHA produced from the Algae scenario inferred lower impact with respect to global warming, acidification and land use compared to the Fish scenario. Moreover, algae oil also resulted in lower climate impact when compared to rapeseed oil and linseed oil, two common plant-based Omega-3 sources. And even though established LCA methods cannot fully account for the total impact on biodiversity, the result showed that DHA from algae inferred lower Ecosystem damage compared to fish oil even when future energy development, improved efficiency, increased energy demand and impact on biotic resources were simulated.

This study showed that DHA produced by microalgae using VFA from food waste can reduce dependency on marine raw materials while also enabling increased resource efficiency by recovering nutrients in food waste for value addition. By using agricultural and food industry by-products to produce DHA, overfishing could be counteracted which in turn would benefit maintained ecosystem quality. Algae oil holds a promising potential for increased sustainability within aquaculture, provided that continued development and optimization of this emerging technology are enabled through active decision-making and purposeful investments. So, recovering valuable fatty acids from food waste and reusing them to produce a fish oil substitute could indeed be a way to increase circularity and sustainability both within aquaculture and the future food system.

Read more

Want to learn more about this project? Then we invite you to read the full article:

L. Bartek, I. Strid, K. Henryson, S. Junne, S. Rasi, M. Eriksson (2021). Life cycle assessment of fish oil substitute produced by microalgae using food waste. Sustainable Production and Consumption, vol 27, pp 2002-2021. doi:

Organic and conventional Swedish pork production compared

Organic Swedish pig production according to KRAV’s regulations performed better than conventional Swedish pig production on 11 of 20 sustainability indicators if the comparison was made per kg of pork, and on 18 out of 20 indicators if the comparison was made per hectare. The indicators included both environmental, social and economic aspects. The organic pork had poorer economic sustainability at the farm and slaughterhouse level, but better at retail compared to the conventional one. Climate impact was the same for both systems, while organic production had a higher risk of eutrophication and acidification, but lower for ecotoxicity, negative impact on biodiversity and loss of soil carbon. The social risk for the pigs was significantly lower in organic production, but there are risks for social problems for workers and local communities associated with imported soy and the use of renewable energy.

In a so-called Life Cycle Sustainability Assessment (LCSA), the environmental, social and economic sustainability of Swedish organic pig production has been compared with that of Swedish conventional pig production. The results were calculated per 1000 kg of boneless cooked pork and per 1000 hectares of pig production. For the environmental part, common indicators such as climate impact, eutrophication and acidification were used, but also indicators that are less common such as toxicity to assess adverse effects from emissions of toxic substance (for example as a result of the use of pesticides), effects on biodiversity and the change in soil carbon.

With regard to social sustainability, so-called social life cycle analysis (SLCA) was used in which the “social risk” for workers (in feed production, on the pig farm and in the slaughterhouse), the local community, actors in the value chain, society, consumers and pigs was assessed based on a large number of social aspects on a scale from 0 (no risk) to 100 (very high risk). One aspect for workers was, for example, the risk of child labor. For example this was judged to be low for soy workers in Brazil (applies to imported soy in conventional production). The welfare of the pigs was assessed using 19 indicators that included, for example, the incidence of various diseases and injuries, outdoor access, access to roughage and distraction materials, etc. Data was obtained from previous scientific studies, statistics, reports and from a global database of social aspects (Soca). Risks in different subsystems were aggregated based on how long it took to produce 1000 kg of pork or conduct 1000 hectares of pig production. This means, for example, that the conditions for the pig during rearing plays a greater role than the conditions during slaughter, as the pig spends much longer time on the farm.

Economic sustainability was measured with the indicator Value Added / Life Cycle Costing (VA / LCC). This was calculated separately for the pig farm, the slaughterhouse and the retail. The Life Cycle Cost includes all running costs (including wages) that an operator (farm, slaughterhouse or retail) has for production and the Value Added is calculated as the price an operator receives for pork. The quota thus says something about the profitability of the farm, slaughterhouse and retail.

Life cycle sustainability assessment of Swedish organic and conventional pig production. The organic production is compared to the conventional one (normalised to 0.5 for all indicators) – gray dotted line. The gray solid black line is the organic production if the comparison is made per kg and the gray solid line if the comparison is made per hectare.

The results showed that the organic pig farm performed better than the conventional one on 18 of the 20 indicators examined when the production systems were compared per unit area. Conventional production performed better for the economic indicators for the farm and the slaughterhouse. Although the price of organic pork is higher, organic production had higher costs due to it being more labor-intensive and since it uses more feed than conventional production. This means a VA / LCC quota of less than one for organic production, which means that the price the farmer gets does not even cover the running costs. On the other hand, this quota for retail is significantly higher, 27 for organic and 13 for conventional, which signals a high willingness to pay for organic pork among consumers and high margins in the retail sector for both organic and conventional pork.

If the comparison is instead made based on the production of 1000 kg of pork, organic production performed better than the conventional one on 11 of the 20 indicators. In terms of environmental impact, both production systems had the same climate impact, while eutrophication, acidification and consumption of fossil resources were higher in organic production. Ecotoxicity, impact on biodiversity and ground carbon loss were lower in the organic production. In terms of social sustainability, the “social risk” was higher in organic production for workers and the local community, a result of social risks linked to organic soy from China and from accidents linked to renewable energy production. But for other actors, the social risk was lower for organic production, especially for pigs, it was significantly lower in organic production due to, among other things, larger spaces, outdoor access and access to roughage. However, there were indicators for pigs where the conventional system had a lower risk, for example in terms of the presence of parasites.

The authors conclude by stating that LCSA has the advantage of including both environmental, social and economic aspects in the sustainability analysis. Previous LCAs on pork have mainly dealt with the environmental aspects. However, choosing a number of relevant indicators can be difficult and the choice also affects the result, as well as how the indicators are designed and weighed together.

Read the whole study here:

Zira S, Rydhmer L, Ivarsson E, Hoffman R, Röös E (2021) A life cycle sustainability assessment of organic and conventional pork supply chains in Sweden. Sustainable Production and Consumption 28, 21-38.

See also this study on SLCA for the two systems but using a slightly different methodology:

Zira S, Röös E, Ivarsson E, Hoffman R, Rydhmer L (2020) Social life cycle assessment of Swedish organic and conventional pork production. International Journal of Life Cycle Assessment.