Bringing plant-based Cli-meat closer to original meat experience: insights in flavor

Plant-based food is the new worldwide trend for healthier processed food to promote better human heath and implement ways to eliminate animals from the food chain equation. Our food system and society are already under tremendous pressure with a food production that is no longer sustainable and is part of the planetary crisis we are currently experiencing (The Eat-Lancet Commission, 2019). One of the big global challenges is to feed the fast-growing human population while reducing the impact of the food systems on the planet and preserve economic viability, social welfare, and healthy nutrition. Overall, the food sector accounts for about 26% of the global Greenhouse Gas (GHG) emissions (Poore & Nemecek, 2018). Livestock derived products alone accounts to 18% of the global GHG emission (Steinfeld et al., 2006). Therefore, there is a gradual shift towards plant based diet, which is evident in modern time due to consumer demands for a innumerable variety of foods that can reduce or replace meat consumption will help to address animal welfare as well. In addition, the recent COVID-19 crisis challenged the world population with regards to consumption of animal sourced food products (meat and processed meat etc.), which were linked with potential ability of zoonotic pathogens to infect humans (Mascaraque, 2020). During the pandemic and subsequent lockdown periods, a disruption in supply chain of meat products has been observed and reflects the consumers’ desire to embrace healthier dietary habits (FutureBridge, 2021). At the same time, multiple factors call for better utilization of food side streams generated by the food industry which is otherwise used as fodder and fertilizer or discarded due to their short shelf life. Improved sustainability by utilizing food grade biomass in the food value chains as new functional and nutritional ingredient for application in foods, is well documented and articulated among global authorities, experts, industry and is an increased demand by consumers worldwide. There is a high need for innovative solutions for complete utilization of raw materials as a means of reducing the environmental footprint for each meal, which will contribute to a more resource efficient and sustainable industry is an extraordinary ultimatum for the future need to feed a growing world population (de Bakker & Dagevos, 2012). Worldwide, 90 million tones of food per year are wasted in the food chain, which has an apparent environmental impact. Smarter waste management and reduction of discarded food material has a positive impact on the environment and help to mitigate climate change. This can be achieved by developing models that combine food processing with valorization of side stream materials. The modern plant-based meat analogues (PBMA) are often refered to as “meat analogues 2.0” or “next generation meat” (Tziva et al., 2020) (in this review “Cli-meat). The concept of Cli-meat (climate-friendly meat) is a realization that, a decrease in meat consumption is a pivotal part of meeting climate targets through use of sustainable sources, and reflects the growing disapproval of animal-sourced meat from an environmental perspective. PBMA are categorized as ultra-processed foods. A combination of selected ingredients, that are not resembling the respective whole food they derived from, undergo mixing and texturization techniques to yield products with similar properties to either meat muscle or processed meat. Meat replacements or analogues should mimick meat characteristics, and its nutritional values which inturn makes them more appealing to meat eaters and potentially will be convincing enough to incorporate them to their daily diets. The challenge with plant-based food is to match meat sensory qualities in interms of taste, texture, flavour and other sensory parameters. Proteins extracted from industrial side stream processing shown certain issues which is limiting their direct inclusion as food ingredients in other foodstuffs (proper separation, solubility, texture and flavour). There is a lack of optimal taste and high-quality with balanced nutrition in many industrialy produced plant-based food systems. Therefore, a deeper understanding of the process and enabling of protein rich products that fulfil nutritional, technological and sensory requirements need to be addressed. Major and critical nutritional factors are amino acid profile, digestibility and bioavailability, potential allergens and antinutritional factors. Many marketed products lack authentic “meaty-like” flavour, umami and kokumi sensations. Most plant proteins contribute off flavours to plant-based food in many cases. Additionally the flavour-protein interaction affect the release of flavors results in unbalanced flavour profile and shelf life of the product during storage (Fischer & Widder, 1997). The available technologies to produce good quality meat analogues, which closely mimics key attributes of meat are still at starting point, nevertheless are evolving with rapid rates. Resemblance of meat alternative food to conventional meat, with respect to its physical characteristics like texture and flavor has been proven one of the major obstruction for food producers (Szejda et al., 2020). Development and deeper understanding in texture related technologies demonstrated that a meat-like structure can be formulated with plant-based ingredients such as High-Temperature Short-time extrusion (HTST), shear cell technology, freeze structuring and mixing of components (Kyriakopoulou et al., 2020). So far, the complexicity of meat flavor is challenging to achieve and imitate, especially due to the development of off-flavors either derived from the plant-based materials or during procesessing. The components and structuring strategies of modern meat substitutes have been thoughroughly reviewed over the past decade (Bohrer, 2019; Joshi & Kumar, 2015; van der Weele et al., 2019), while more updated versions are emerging from new worldwide studies (He et al., 2020; McClements & Grossmann, 2021; Sha & Xiong, 2020). The present review addresses the emerging field of plant-based foods and meat analogues, and possible strategies to produce novel sustainable flavour ingredients with high culinary quality. The focus will provide a detailed and comprehensive assesment of bio-transforming processing methods for novel flavor formation strategies and emphasis on utilization and sustainable up-cycling of agricultural by-products, followed by a brief introduction to current regulations related to the reviewed processing methods and novel raw materials.