Exploring Alternative Proteins for Meat Industry: From Nutritional and Functional Properties to Recent Applications

Overcoming barriers to sustainable, healthy diets

Alternative proteins denote non-traditional, high-protein foods. These innovative sources aim to compete with conventional animal products by providing protein-rich, sustainable, nutritious, and flavorful options. Currently, five main categories of alternative proteins are being developed: plant-based proteins, cultured meat, single-cell proteins, edible insects, and seaweed. Nonetheless, several chemical and microbiological food safety hazards are associated with these alternatives Incorporating novel protein sources into food products may heighten the prevalence of existing food allergies. This could arise from extracting proteins from their natural matrices and utilizing them at significantly higher concentrations. Additionally, the introduction of new proteins may lead to the development of novel food allergies. Proteins that are currently seldom or never consumed may cause primary sensitisation or trigger cross-reactivity with known allergens. To date, alternative proteins have not been thoroughly studied for their allergenic potential, and there is no standardised method for assessing this risk. This review aims to explore non-traditional protein sources, discussing their nutritional and functional properties, as well as their potential allergenicity based on available research. We conducted a literature search in PubMed and Embase databases. We used specific keywords and MESH terms. A total of 157 studies were included in the review. The studies reviewed in our analysis reveal significant limitations, such as inconsistent methodologies, limited participant numbers, and a lack of long-term data, which hinder the ability to make clear conclusions regarding the safety of these new proteins for individuals with allergies. To address current challenge, future research should integrate food science, regulatory perspectives and advanced technologies.

Trends and prospects in dairy protein replacement in yogurt and cheese

Consumer interest in a shift toward moderating animal products in their diets (flexitarian) is constantly increasing. One way to meet this consumer demand is through hybrid meat products, defined as those in which a portion of the meat is substituted by plant protein. This review article aims to analyze literature regarding the impact of replacing meat proteins with other alternative proteins on the functional and nutritional properties of hybrid products. Different food matrices created by hybrid products have impact on the digestive processes and outcomes in vitro and in vivo, and the bioavailability of protein, lipid, and mineral nutrients is modified, hence these aspects are reviewed. The functional properties of hybrid products change with regard to type of alternative protein source used. In hybrid products, deficiencies in amino acids in alternative proteins are balanced by amino acids from meat proteins, resulting in wholesome products. Additionally, animal protein degrades into peptides in the gut which bind non-animal iron and increase the availability of iron from the alternative protein material. This relationship may support the development of hybrid products offering products with increased iron bioavailability and a previously unseen beneficial nutritional composition. The effects of alternative protein addition in hybrid meat products on protein and mineral digestibility remains unclear. More research is required to clarify the interaction of the protein-food matrix as well as its effects on digestibility. Very little research has been conducted on the oxidative stability and microbiological safety of hybrid products.

Simple SummaryAquaculture is now well-established as a provider of protein for human consumption, and its contribution will be paramount to providing food for a nine billion population in 2050. Protein is usually the major constituent of fish feeds and the most expensive ingredient. For years, fishmeal was the preferential protein source in fish diets, but environmental and economic concerns led to the search for more sustainable proteins. Hence, research on alternative protein sources to fishmeal was fruitful, being firstly directed to terrestrial plant ingredients. Recently, research on novel ingredients, such as insect meals, macroalgae, microalgae, and yeasts, has proliferated. However, the impacts of protein and its constituents (amino acids) go beyond fish growth. Thus, this review will provide knowledge on the impacts of alternative/novel protein sources on fish stress and immune responses, disease resistance, and health. Although some negative impacts of alternative ingredients, for instance, on gut integrity and immune responses have been observed, research results also point to the potential beneficial effects of novel ingredients, such as insect meals, on fish health. This information is essential to the development of innovative diets that guarantee the production of healthy fish with high quality standards and optimised welfare conditions.Aquaculture has been challenged to find alternative ingredients to develop innovative feed formulations that foster a sustainable future growth. Given the most recent trends in fish feed formulation on the use of alternative protein sources to decrease the dependency of fishmeal, it is fundamental to evaluate the implications of this new paradigm for fish health and welfare. This work intends to comprehensively review the impacts of alternative and novel dietary protein sources on fish gut microbiota and health, stress and immune responses, disease resistance, and antioxidant capacity. The research results indicate that alternative protein sources, such as terrestrial plant proteins, rendered animal by-products, insect meals, micro- and macroalgae, and single cell proteins (e.g., yeasts), may negatively impact gut microbiota and health, thus affecting immune and stress responses. Nevertheless, some of the novel protein sources, such as insects and algae meals, have functional properties and may exert an immunostimulatory activity. Further research on the effects of novel protein sources, beyond growth, is clearly needed. The information gathered here is of utmost importance, in order to develop innovative diets that guarantee the production of healthy fish with high quality standards and optimised welfare conditions, thus contributing to a sustainable growth of the aquaculture industry.

Simple SummaryFish meal (FM), as the main protein source, is used in aquafeeds due to its good nutritional profile and palatability. In recent years, because of the high cost and uncertainty in FM supply, studies have been focused to identify and evaluate alternative protein ingredients to minimize FM and reducethe cost of formulated feeds. Currently, plant protein ingredients and animal by-products are used as alternative protein sources to FM, but these components have some nutritional limitations, such as beingrich in anti-nutritional elements and deficient in certain essential amino acids. Among alternative protein sources, single-cell protein (SCP) such as bacteria, yeasts and microalgae, is considered a promising substitute for animal- or plant-derived ingredients. In this work, we aimed to evaluate the replacement of FM with a bacterial SCP, a by-product of the monosodium L-glutamic acid produced by microbial fermentation of vegetal raw materials, in diets for rainbow trout (Oncorhynchus mykiss) fry. Results indicated that the maximum replacement of FM by SCP in terms of growth and feed efficiency performance was up to 50%, while the broken-line regression analyses using DHA muscle content and weight gain showed that this value ranged between 46.9 to 52% SCP depending on the parameter considered.A 60-day trial was conducted in rainbow trout (Oncorhynchus mykiss) fry (initial weight = 2.5 ± 0.6 g) to evaluate the potential use of a bacterial single-cell protein (SCP) as an alternative protein source. Five experimental diets with different levels of fishmeal replacement (0, 25, 50, 75 and 100%) and no amino acid supplementation were tested. At the end of the trial, we found that fry fed diets, replacing 25 and 50% of fishmeal with bacterial SCP, were 9.1 and 21.8% heavier, respectively, than those fed the control diet (p < 0.05), while Feed Conversion Ratio (FCR) values were also lower in comparison to the reference group. These results were also supported by Protein Efficiency Ratio (PER) and Lipid Efficiency Ratio (LER) values that improved in fish fed diets replacing 50% fishmeal by bacterial SCP. The inclusion of SCP enhanced Feed intake (FI) (p < 0.05), although FI was reduced at higher inclusion levels (>50%), which was associated to feed palatability. High levels of bacterial SCP (>50%) affected the muscular amino acid and fatty acid profiles, imbalances that were associated to their dietary content. The broken-line regression analysis using muscle DHA content and weight gain data showed that the maximum levels of fishmeal replacement by bacterial SCP were 46.9 and 52%, respectively.

Plant protein is rapidly becoming more of a prime interest to consumers for its nutritional and functional properties, as well as the potential to replace animal protein. In the frame of alternative protein new sources, mung bean is becoming another legume crop that could provide high quality plant protein after soybean and pea. In particular, the 8S globulins in mung bean protein have high structural similarity and homology with soybean β-conglycinin (7S globulin), with 68% sequence identity. Currently, mung bean protein has gained popularity in food industry because of its high nutritional value and peculiar functional properties. In that regard, various modification technologies have been applied to further broaden its application. Here, we provide a review of the composition, nutritional value, production methods, functional properties and modification technologies of mung bean protein. Furthermore, its potential applications in the new plant-based products, meat products, noodles, edible packaging films and bioactive compound carriers are highlighted to facilitate its utilization as an alternative plant protein, thus meeting consumer demands for high quality plant protein resources. © 2023 Society of Chemical Industry.

Protein diversification

Food for Thought: The Protein Transformation

The global demand for protein is rapidly increasing due to population growth and changing dietary preferences, highlighting the need for sustainable alternatives to traditional animal-based proteins. This review explores cultivated meat and microbial alternative proteins, focusing on their potential to meet nutritional needs while mitigating environmental impacts. It also examines the production of cultivated meat as well as various sources of microbial proteins, including mycoproteins, bacterial proteins, and microalgae, highlighting their nutritional profiles, production methods, and commercial applications. This includes an evaluation of the state of commercialization of mycoproteins and the innovative use of agricultural and industrial by-products as substrates for microbial fermentation. The integration of microbial protein production with the bioenergy sector is evaluated as a relevant alternative to attain a synergetic effect between energy and food production systems. Ultimately, this work aims to underscore the importance of microbial proteins in advancing towards a more sustainable protein production system, offering insights into current challenges and future opportunities in the field of fermentation to produce alternative proteins.

Physicochemical, structural, and functional characterization of guar meal protein isolate (Cyamopsis tetragonoloba)

The pet-food sector has experienced rapid innovation between 2023 and mid-2025 driven by sustainability goals, advances in microbiome science, and new processing and packaging scrutiny. This review synthesizes recent developments across four major domains: (1) alternative and novel proteins (insects, single-cell proteins, and cultivated meat), (2) microbiome-targeted nutrition with emphasis on postbiotics and early precision approaches, (3) safety-by-design processing—particularly high-pressure processing (HPP) for raw and minimally processed diets—and (4) contaminant and packaging concerns (mycotoxins, antimicrobial resistance, PFAS). We discuss regulatory milestones, summarize key data (nutrient compositions, validated processing parameters, surveillance outcomes), identify critical knowledge gaps (feline requirements, long-term feeding trials, formulation-specific process validation), and propose an R&amp;D agenda for industry and academic stakeholders. In the near term, research should focus on well-designed feeding trials specific to pets, validation of processes at the formulation level, and clear supply-chain traceability to ensure that sustainability claims are supported by nutrient-adjusted impact data. Progress will also depend on close collaboration among industry, academia, and regulators to advance innovations from pilot projects into safe, affordable, and beneficial pet foods for the wider market.

In order to alleviate the pressure on environmental resources faced by meat and dairy production and to satisfy the increasing demands of consumers for food safety and health, alternative proteins have drawn considerable attention in the food industry. However, despite the successive reports of alternative protein food, the processing and application foundation of alternative proteins for meat and dairy is still weak. This paper summarizes the nutritional composition and physicochemical characteristics of meat and dairy alternative proteins from four sources: plant proteins, fungal proteins, algal proteins and insect proteins. The difference between these alternative proteins to animal proteins, the effects of their structural features and environmental conditions on their properties, as well as the corresponding mechanism are compared and discussed. Though fungal proteins, algal proteins and insect proteins have shown some advantages over traditional plant proteins, such as the comparable protein content of insect proteins to meat, the better digestibility of fungal proteins and the better foaming properties of algal proteins, there is still a big gap between alternative proteins and meat and dairy proteins. In addition to needing to provide amino acid composition and digestibility similar to animal proteins, alternative proteins also face challenges such as maintaining good solubility and emulsion properties. Their nutritional and physicochemical properties still need thorough investigation, and for commercial application, it is important to develop and optimize industrial technology in alternative protein separation and modification.

Animal production and consumption is at the root of many of the world's most pressing environmental, public health, and ethical issues. As well as contributing directly to greenhouse gas emissions, animal agriculture is incredibly resource-intensive and disruptive to ecosystems, driving water use, land use, biodiversity loss, and deforestation (1-3). Moreover, animal farms act as an incubator for emerging diseases, and a catalyst for antibiotic resistance (4, 5). Globally, over 90% of farmed animals are on factory farms, entailing small cage confinement, painful mutilations, and overall low welfare (6). Increasingly, institutions including governments, public services, universities, and commercial food outlets are playing a role in reducing animal production and consumption (7). We have seen initiatives such as investments in alternative proteins (8), mandatory carbon and animal welfare labeling (9, 10), and nudges to encourage more sustainable food choices (11). While these institutions have an important role to play, they are ultimately beholden to individuals: generally, governments cannot implement policies without the support of voters, and companies cannot reshape their offerings without buy-in from consumers. Therefore, research into the public's attitudes about animal-product reduction and alternative proteins is a vital field of study. This Research Topic called upon psychologists, behavioral scientists, and the broader scientific community to investigate the psychology of meat reduction, design and test interventions, and recommend ways forward to reduce the consumption of animal products. The resulting Research Topic contains over a dozen high-quality scientific studies covering a range of topics including vegetarian and vegan identity, moral psychology, behavior change, alternative proteins, health outcomes, and political science. All of these papers contribute to our understanding of relevant issues, which, in turn, can help to advance a more sustainable food system. vegetarian identity and moral psychology, behavioral scientists in Belgium provided an identity-based motivational account of resistance to veg * n advocacy. They theorized that veg * n (i.e., vegetarian and/or vegan) advocacy can threaten the moral and meat-eating identities of omnivores, which often causes them to engage in motivated reasoning to justify their consumption. They argue, however, that this apparent resistance often masks privately held beliefs that align with veg * n attitudes, and can precede later behavioral change (De Groeve et al.).

Meat substitution in burgers: nutritional scoring, sensorial testing, and Life Cycle Assessment