Insect margarine: Processing, sustainability and design
Butter is one of the foods with a high impact on the environment. Margarine on the other hand is recognized as a less environmentally impacting spreadable product if it is based on plant hydrogenated oils. However, hydrogenated trans-fats bear health associated risks, which induce the search for new materials to substitute milk and plant lipids. The study aimed at identification of processing (solid fat content and color), environmental impact and product design properties of lipids derived from insect biomass of two species (Hermetia illucens and Tenebrio molitor) to be applied as an alternative for plant and animal lipids in spreadable products like margarine or butter. Pilot scale processing trials identified the potential of classical margarine technologies application for the use of insect lipids in spreadable products with high fat content (more than 80%). It was possible to substitute up to 75% of lipids with insect fats without negative effects on spreading abilities and with improvement of product coloring (yellowish color). Substitution of up to 50% of plant lipids with insect oils (both H. illucens and T. molitor) resulted in insignificant increase of environmental impact of margarine. Substitution of 75% of lipids in margarine resulted in a product which had higher environmental impact than conventional margarine, but lower than those reported for butter. Designed for the first time, insect-based margarine opens multiple possibilities for further product design, which should be further explored.
Introduction First margarine was developed by Hippolyte Mege-Mouries by mixing beef tallow and skimmed milk in response to the call of Napoleon III to design a cheaper product for armies and lower classes at the end of 19th century (McGee, 2007). World War II gave another push for the general acceptance of margarine, by that time based on hydrogenated vegetable oils rather than animal fats, which was much cheaper than producing butter from the butterfat of milk (McGee, 2007). The distinguishing characteristic for both margarine and butter is considered today to be fat content of no less than 80% (EU, 1994), and thus the analysis in this article will be devoted to such products.
Butter is also responsible for a relatively high environmental impact. It is among the most environmentally impacting dairy products (Djekic et al., 2014; Finnegan et al., 2017; Meier and Christen, 2012). Comparatively to the production of margarine,the production of butter has higher environmental impacts: 4.3e8.7 times higher in global warming potential (GWP), 2.7e4.2 times in eutrophication potential (EP), 2.1e4.9 times higher in acidification potential (AP), 1.9e2.6 higher land competition rates (Hu et al., 2007; Nilsson et al., 2010). However, some studies indicate that such results could be altered depending on the allocation rules (Campos et al., 2019). Food producing companies increasingly search for innovative development solutions for more sustainable (less environmentally impacting and more economically feasible) and nutritionally relevant products. Novel fat sources originated from insects are currently considered as a viable alternative to animal and plantbased materials such as butter substitute in bakery product (Delicato et al., 2020) or as oil ingredients in food industry (Purschke et al., 2017; Tzompa-Sosa et al., 2019). Insects derived biomass and proteins can be viable sustainable alternative for animal-based foods and feeds (Halloran et al., 2016; Oonincx, 2017; Oonincx and de Boer, 2012; Smetana et al., 2019, 2016, 2015a). Insect derived lipids can have rather diverse physical properties and be characterized with diverse melting points,odours and colours, thus presenting diverse possibilities for the innovation in food industry (Tzompa-Sosa et al., 2019). Insect oils can be present in liquid (e.g. Tenebrio molitor, Alphitobius diaperinus) or solid form (e.g. Hermetia illucens) at room temperature and can have different applications related to the properties e.g. bakery, frying or table oils (Delicato et al., 2020; TzompaSosa et al., 2019).
Even though first studies on the application of insect lipids in food define the positive potential for the application, no holistic comparison in sustainable perspective is available. Potentially it can be explained by the higher impacts of other animal-derived products such as meat, milk and cheese, associated with higher consumed amounts (Meier and Christen, 2012). Several studies available on Life Cycle Assessment (LCA) of butter and margarine (Djekic et al., 2014; Finnegan et al., 2017; Hu et al., 2007; Meier and Christen, 2012; Nilsson et al., 2010) indicate their high environmental impact per weight unit. They, however, do not include product development and design for the establishing of a relevant comparison basis (functional unit) based on new ingredients from novel biomass sources. Current study is aimed to cover the gap, by first designing the novel product on the comparative scale and then comparing its environmental impact by means of LCA. Currently no studies provide results on environmental impact of food products based on insect lipids.
Although butter and margarine are emulsions of fat and water, production of both shows substantial differences. Traditionally butter is made by churning separated milk cream. Here, fat globules get destroyed, inner fat leaks out, agglutinates and forms a network where water and proteins get embedded partially. Initial margarine processing imitated the production of butter. By adding olein to skimmed milk and supplementary cold water to the churn, the fat solidified, water was drained, and remaining mass was kneaded and salted (Young and Wassell, 2008). Today’s margarine production, on the other hand, is based on a combination of vegetable oils. However, compared to saturated fatty acids, which tend to be solid at ambient temperature, vegetable lipids are mainly liquid at room temperature due to their higher amounts of polyunsaturated fatty acids (Gurr et al., 2016). In order to generate a spreadable butter substitute, invention of the hydrogenation, interesterification and fractionation process allowed generation of solidified vegetable lipids for margarine production. Actual margarine processing can be divided into: preparation of fat and water phase, pre-emulsion, controlled crystallization inside a votator (scraped surface heat exchanger) and pin stirrer (Arellano et al., 2015).
In addition to processing of margarine, consumer insights are important for understanding the commercialisation and adoption of insect-based food such as margarine. Consumer studies on insect-based burgers and meat replacers show that insects are challenging to integrate into Western consumers diets providing long-term consumption (House, 2019, 2016). However, consumer studies on insect-based margarine have not yet been conducted. Design could be used as one of the adoption strategies to facilitate adoption of insects (Kauppi et al., 2019), hence this article also explores ideas for insect-based margarine. Findings from the consumer research on insect-based food are linked to this study, providing suggestions and discussions on specific case of commercialisation of insect-based margarine.
Therefore, this paper concentrates on analysis of processing and environmental feasibility of margarine production with inclusion of insect-based fats. The study also includes the overview of consumer perception towards the design of insect margarine as part of product innovation process.