Challenges and Innovations in Sustainable Protein Alternatives

Developing PBFs can provide viable options for health-conscious consumers while minimizing environmental impact, continuously refining the production processes, and incorporating supplementary nutrients.

FREMONT, CA: A sustainable diet, as defined by the Food and Agriculture Organization (FAO), encompasses safety, nutrition, and low environmental impact. Various plant-based and alternative protein sources have created products such as meat substitutes, dairy alternatives, bakery goods, beverages, and dietary supplements. However, when producing alternatives like plant-based cheese and meat, manufacturers must carefully consider ingredient interactions, processing methods, proportions, and formulations to achieve replication and optimization while maintaining unique taste and flavor characteristics.

In plant-based meat products, consumers expect a resemblance to conventional protein sources in terms of taste, flavor intensity, texture (firmness and hardness), and nutritional value. Several methods and innovations have been explored, including blending, cell culture, precision fermentation (PF), and genetic engineering. Manufacturers of plant-based foods (PBFs) aim to mimic traditional protein sources' sensory properties and nutritional characteristics to attract a broader market beyond vegetarians.

Fermentation has emerged as a convenient and adaptable technology in developing new food products. It preserves food, extends shelf life, enhances nutritional quality, and improves organoleptic properties. Substrates can be transformed through fermentation into value-added products such as enzymes, peptides, probiotics, and other biotechnological products using endogenous microbes, starter cultures, or previously fermented products. PF is a cutting-edge technology employed in producing PBFs, wherein microbes are genetically modified to produce specific, customized, and recombinant molecules to create new food ingredients. The ultimate goal of PF is to generate protein sources with desirable texture and taste characteristics to increase consumer acceptance. This technology focuses on modifying the microbial genome to alter the genetic information of specific proteins.

Cell culture techniques, including tissue engineering and cell-based therapeutics, are also used to produce PBFs. Additionally, extrusion is a common processing technique employed for commercial production, wherein all ingredients are mixed, preconditioned, cooked, and extruded through dies. Depending on the product specifications, the extruded PBF undergoes further processes such as trimming, marinating, and grinding.

Although consuming PBFs has been associated with better consumer and environmental health, the impact of these products can vary significantly. Unhealthy plant-based diets, characterized by high consumption of refined grains, sugary drinks, fruit juice, potatoes, and sweets/desserts, have been linked to negative health outcomes. Furthermore, some plant-based ingredients, such as legumes and cereals, contain anti-nutrients like phytates, saponins, tannins, protease, amylase inhibitors, and goitrogens. These anti-nutrients can limit the usage of such ingredients in formulations due to their ability to form complexes with proteins and minerals, thereby reducing protein digestibility and overall nutritional quality. They can also hinder mineral absorption, cause stomach discomfort, and become toxic when accumulated. To address this, soaking pulses for several hours is a common practice to reduce anti-nutrient content and cooking time, although this may be inconvenient for some consumers. The bioavailability of certain minerals (calcium, zinc, iron, and iodine) and the low content of vitamins (A, B2, B12, and D) in PBFs necessitate critical examination and the inclusion of supplementary or alternative sources of these nutrients. Compared to meat, poorly formulated PBFs using legumes with low non-heme iron content and absorption require consumers to consume larger quantities to meet their iron requirements. Conversely, consuming high levels of heme iron raises body iron content and increases the risk of type-2 diabetes. Commercial meatless burgers, for example, may contain high amounts of sodium and heme per serving.