This scoping review aimed to answer the question “What are the known sensory characteristics of CM and how have those characteristics been evaluated?” The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline for scoping review (PRISMA-ScR) was used as a reporting guideline with the Joanna Briggs Institute (JBI) guidance as the methodological guideline (38). The inclusion and exclusion criteria were defined with an emphasis on the presence of comments on the sensory characteristics of CM regardless of actual product evaluation. CM was defined as a meat alternative produced through animal cell culture to grow meat in vitro.

The literature included in this study are peer-reviewed journal articles published between the years 2000 and (June) 2023. The date range was chosen because, even though the concept of CM was introduced in 1912 (4, 5), the approach was not used to produce meat until the early 2000s. To be included in this review, articles had to meet the following criteria:

Studies with the following characteristics were excluded:

Articles from peer-reviewed publications were the primary studies used for this scoping review. The primary studies were retrieved through electronic searches of the following databases: Web of Science Core Collection (WOSCC; Web of Science), Food Science and Technology Abstracts (FSTA; EBSCOhost), and Center for Agriculture and Bioscience International (CABI; CAB Abstracts).

With support and feedback from the University Libraries at Virginia Tech (author CC), the following search strategy was developed iteratively to ensure optimal search results. The final search string as applied in Web of Science is shown in Table 1.

Title, abstract, and keywords search was conducted for all concepts in WOSCC and FSTA; all fields were searched in CABI. In all databases, limits were applied using built-in filters for document type (journal article) and publication year (Appendix 1). The format of this search string was modified for application on the other databases. Appendix 1 contains the detailed search strings used in each database. The initial search was performed in January 2023. Considering the rapid increase in publications on CM, monthly searches were performed in each database until June 2023 - the original search strings were reapplied to each database, but limited to (using built-in filters) from 2022 to 2023 to reduce the number of duplicate results. The work cited by articles that were related to topic but did not fully meet criteria (and were excluded) were scanned for additional relevant records (backward citation chasing).

All search results were exported from each database and imported into the systematic review management software Covidence (39), where duplicates identified by the software were removed automatically. Screening proceeded in stages detailed in Figure 1. First, the studies were screened based on the title and abstract, and obviously irrelevant studies were excluded. The full-text of potentially relevant studies was collected and further examined to ensure the studies met eligibility criteria (see Section 2.3). Both title and abstract screening and full-text screening were conducted by two independent reviewers (KT and JL). Discrepancies were resolved through discussions.

Data extraction was conducted in Covidence using a data extraction template developed by the authors. The full data extraction form is attached as Appendix 2. Data extracted included general information (e.g., article title, authors’ name and affiliations, publication year, and DOI), country in which the study is conducted, framed value of CM, sampling methods, survey/sensory evaluation methods, types of sample tested, sensory/acceptance measures, and proposed determinant factors toward CM acceptance, among others. The extraction was focused to identify information related to the expected or actual sensory characteristics of CM, the evidence/ experiment supporting the claim, and the determining factor(s) of CM acceptance. Relevant data were extracted by one author (KT) and reviewed for consistency by a second author (JL).

A total of 491 citations were obtained from the database search (WOS = 386 articles, CABI = 50 articles, FSTA = 55 articles) and 4 articles from backward citation chasing. Once duplicates were removed, 303 articles were screened by title and abstract. This first screening excluded 238 publications that were found to be irrelevant to the review objectives. Full texts of the remaining publications were then evaluated according to the eligibility criteria; 43 publications were excluded. Finally, 22 publications from the database search and 4 publications from backward citation chasing were included in the review, resulting in a final count of 26 publications (Figure 1).

Information about each study’s characteristics is presented in Table 2. Of the studies included in this review, most involved participants from the “Global North”: Europe (N = 21 studies) and North America (N = 7 studies). A minority involved participants from Asian countries (N = 5 studies), Australia (N = 1 study), and New Zealand (N = 1 study). No studies involved participants from countries in South America or Africa. Typically, subjects were selected using simple, random sampling (N = 15 studies) or convenience sampling (N = 7 studies). Most studies employed online surveys (N = 21 studies) while only 2 studies used in-person, paper questionnaires. Qualitative methods (interviewing and focus groups) were in the minority of the selected studies (N = 3 studies) and only 5 studies conducted an actual sensory evaluation—using human subjects to assess some aspect of the sensory properties of a food product—to evaluate CM products.

Although by definition of the search strategy all papers were related to the sensory evaluation of CM, the most common research question was only tangentially related to sensory evaluation: consumers’ “willingness to try/eat” (N = 17 studies) and “willingness to buy” (N = 11 studies) CM were the main acceptance measures used among the included studies. Some studies measured their participants’ willingness to replace conventional meat (N = 4 studies) or other meat alternatives (N = 2 studies) with CM and their willingness to recommend CM to other people (N = 2 studies) to support their studies. Through close reading of study objectives, we concluded that evaluating the sensory properties of CM was considered a primary outcome in 6 studies, while 2 studies inferred the importance of CM’s sensory properties. The majority (N = 18 studies) included sensory evaluation as a secondary outcome.

The majority of the included studies examined consumers’ attitudes toward CM as a food product (i.e., instead of as a technology or a social innovation). Each paper opened by reporting positive actual or (frequently) potential impacts of CM (Table 3). Most proposed CM as part of a solution to reducing environmental pollution (N = 22 studies), minimizing the use of natural resources (N = 18 studies), promoting animal welfare (N = 19 studies), or promoting food security (N = 7 studies) along with fulfilling the increasing demand for animal proteins (N = 6 studies). CM was also said to have the same or possibly better nutritional value (N = 8 studies), to be safer to consume than (N = 11 studies), and to have the same sensory characteristics as conventional meat (N = 6 studies).

Despite these proposed possible benefits of CM from the studies’ authors, the factors measured in these studies and consumer responses often indicate alternative and more negative perspectives. Table 4 presents various factors that authors explicitly or implicitly hypothesized as impacts on consumers’ acceptance of CM. Common author-hypothesized determinants include views of animal welfare (N = 11 studies), concern over environmental impact of CM and the current systems of meat production method (N = 13 studies), familiarity and curiosity toward CM (N = 11 studies), perception of naturalness of CM (N = 6 studies), and psychological factors related to the individual such as food neophobia and disgust (N = 10 studies). The need to evaluate these determinants indicates that the authors of these studies are concerned with and well aware of alternatives to the positive narratives and impacts proposed in the introductions to these studies. Moreover, participants frequently mentioned concerns about CM’s health impacts, nutrition quality, or food safety (N = 18 studies) and, often, the sensory properties of CM (e.g., how it would taste, N = 18 studies), indicating that consumers echoed some of the concerns about whether CM will be a universally positive replacement for conventional meat products.

Because most of these studies examined consumers’ holistic attitudes toward CM, it could be argued that understanding the sensory characteristics of CM was not the primary focus of the studies’ research designs. However, 18 out of the 26 included studies stated explicitly that sensory experience is a key determining factor for acceptance of this (or any) novel food product. When measuring participants’ willingness to accept CM, the questions were always framed to compare CM to conventional meat or meat products. This is implicitly a sensory comparison in the context of a consumer choice study. Unless the type of CM was specified (e.g., cultured seafood), CM was generally compared to a red meat or red meat product. In the reviewed articles, sensory experiences of CM among consumers were evaluated under two conditions: in the absence or the presence of actual products (Table 5).

The main discussion in this section revolves around the CM sensory characteristics claim and consumer acceptance based on evaluation of CM as an idea (positive information framing), not an actual product evaluation. As shown in the results (section 3.3.1), a majority of studies’ respondents had negative expectations of CM as an imagined product, and particularly of its sensory qualities. Novel-product unfamiliarity was hypothesized as the main reason for consumer skepticism toward CM. For example, according to Weinrich et al. (65), pre-knowledge of a product was a mediator between one’s demographic background and attitudes toward the product. On a similar note, Lin-Hi et al. (66) considered CM as a “radical innovation in food sector” - an innovation that radically breaks with familiar logic and habits - which they hypothesized explained the tendencies for consumers’ skepticism toward this product. The implication is that this skepticism manifested in multiple ways including perceptions of disgust (67), and perceptions that CM is more unsafe and unnatural, leading to further rejection of new food products (33, 67–70).

In order to determine whether unfamiliarity, skepticism, or neophobia might drive negative expectations around CM, information framing was used in many of these studies to determine if different frames increased acceptance. Various positive framings from labeling to the use of ‘placebo’ products were conducted and, overall, these all tended to improve expected consumer acceptance toward the product when properly directed (section 3.3.1). Positive framing focused on aspects such as product safety, health benefits, and environmental sustainability was found to increase consumer acceptance. This aligned with suggestions from many studies to highlight the key drivers of consumer acceptance namely safety and health benefits as well as showing that CM is a natural product that resembles conventional meat (18, 71–73). These framing approaches to increasing acceptance may be necessary as some studies reported that while some consumers (initially) were willing to support CM because of the benefits to animal welfare and the environment (65, 70), many consumers are not actually aware of these adverse environmental and animal-welfare impacts of the conventional system of producing meat. Therefore, in many studies these frames may be simultaneously informing consumers of a problem and providing CM as a solution (13, 74).

It is important to note that all 26 studies reviewed framed CM positively, regardless of the specific frame. The selection criteria for the scoping review were not designed to select papers with a particular position on this sometimes-controversial biotechnology (75), so this result is itself noteworthy. Since many of the study authors are apparently invested in the potential of CM as a meat-production method, this preponderance of positive framing may not have been the explicit intention of authors of the reviewed studies, either. However, since there have apparently been no sensory- or consumer-evaluation papers that investigated the effect of a negative framing on CM, this may be a source of bias in the literature, particularly confirmation bias.

As reported by Ryynänen and Toivanen [(22); see also (76)], based on their exploration of the role of written and online media in framing and presenting CM, most articles highlighted only benefits of CM, and presented the only challenges for CM as the current high cost of production and the possible imperfect reproduction of the sensory characteristics of conventional meat. This absence of real critical framing may create a critical knowledge gap, since CM cannot truly be said to be risk-free. For example, based on their intensive review, Bhat et al. (4) predict CM to be more likely to have a substrate contamination risk from the growth media, in contrast to the bacterial contamination from processing that is a problem for conventional meat. An overview by Broucke et al. (77) claims that the “addition of compounds and solutions like sera, growth-hormone factors (GHF), (bovine serum) albumin (BSA), and transferrin, withhold an additional risk due to possible introduction of harmful or pathogenic agents, especially in the case of in vivo gained animal sera (mostly fetal, but also new-born or adult source). Examples of possible contamination are prions, bacteria (including mycoplasma), and viruses (e.g., hepatitis virus)” (p. 7). Risks may also arise within the cell-handling and -cultivation process; not only additional contamination, but also potential genetic drift that can cause unintentional genome alteration of the cultured cells (78). Furthermore, it is possible for adult stem cells to become malignant in long-term culture (79). The effect of these more negative counter-narratives on consumer acceptance have yet to be explored, thus it may be premature to conclude that only positive framing has an effect on consumer willingness to buy/eat CM and their perceptions of its quality.

Despite the many promises and the insistence in the literature that CM will have sensory characteristics equivalent to conventional meat (18, 80, 81), there was very limited evidence of the actual sensory characteristics of CM. In this review, (meat) product evaluation was only found in 5 studies, with 1 conducted on a “placebo” consisting solely of conventional meat, and 4 on CM (see section 3.3.2). Overall, these studies did conclude that the evaluated CM closely resembled its conventional counterpart in both sensory characteristics and reaction to cooking. These studies speak to the potential for CM products to ultimately resemble their conventional equivalents.

However, the claim that CM products will always have, or even currently have, the same sensory characteristics as conventional meat products is not well-established in this current literature. Three main issues are as follows: (1) only one study reports an actual sensory evaluation with tasting of CM products; (2) in all studies excepting Rolland et al. (18) (which did not actually involve CM products), evaluations were conducted with unacceptably low numbers of human panelists (this standard is described with more detail in section 4.2.2); and (3) the CM products evaluated were not comparable to their target, conventional equivalents.

The majority of papers included in this review (N = 24 studies) present CM as an entirely positive, transformational biotechnology. This is emphasized especially in studies that communicated these concepts to participants as framing (N = 18 studies). In framing studies, participants are asked to believe that the given, invariably positive frame about CM is an unproblematic truth. These frames are typically consumer-appropriate versions of the arguments given in support of CM as a technology in the literature (N = 18 studies; examples in Table 5 in “positive framing”). However, as reported in an increasing number of studies, these arguments in favor of CM are exactly that—arguments, not inevitable truths (77, 88). Predicting the future development of CM as both a process for producing a food and as a consumer product has turned out to be considerably more complicated.

Typically, arguments in the papers reviewed here imply that CM is isomorphic with conventional meat but produced in a more sustainable way. However, as long as CM has continued to be a hypothetical product, this claim has not been supported by enough evidence. CM typically is argued to be more sustainable because it would cause less environmental damage—requiring fewer natural resources and less land use, and causing lower greenhouse-effect gas-emission—than conventional forms of livestock production for meat (2, 4, 6). However, those statements are typically based on theoretical projections with large uncertainties (97, 98). In addition, although in vitro CM production may require lower agricultural inputs, including land use, it would require more intensive energy use in return. Lynch and Pierrehumbert (99) also reported that, although cattle farming has grater peak (global) warming effect, the warming effect would not persist nor accumulate under reduced ‘farming’ system as would in vitro meat production. While CM production’s benefits in terms of sustainability are likely to be much more complex and contingent, the papers reviewed here presented CM production only in terms of maximal, unalloyed benefits, both in argumentation (N = 24 studies) and in experimental design (N = 18 studies).

As for CM being exactly the same as ‘real meat’, the burger grown in Professor Mark Post’s laboratory and presented in 2013 has been, to this date, the only consumed ‘pure (cultured) meat’ in real life. According to the three tasters, “…the burger was dry and a bit lacking in flavor” (85) in which one of them described “the bite [texture] feels like a “conventional hamburger” but that the meat tasted “like an animal-protein cake.”” (85). The recently sold cultured chicken and fish products are a hybrid of animal cells and plant-based materials (100). This reality is reflected in this review; the only CM product that was evaluated by taste was a hybrid product of soy protein and chicken cells and not just ‘animal meat’ (53) as is typically presented in the framing and narratives documented in these studies.

Beyond the challenge of developing a CM product that can be an acceptable sensory substitute for conventional meat, high production costs have remained a hurdle. Proponents of CM have claimed that Moore’s law - formulated for microprocessors, and arguing that the cost of production of novel products will always reduce exponentially over time - would apply to CM (88). Moore’s law has, however, not typically been applied to biological systems, which are the basis of CM production, due to the complexity and unpredictability of biological events and the mechanisms behind it (88). Ten years ago, a five ounce burger costed over $300,000 to make (85, 101) and so far, CM products have been sold for about $18 per meal—a loss regarding which producers were not willing to share further details on (102). Thus far, reframing CM as a plant/animal-cell hybrid product seems to be more realistic both from a product-formulation and a production-cost point of view. Using cell cultures as flavorings of a plant-based meat is what most CM producers are moving toward (102). The future of CM has once again been proven unpredictable, suggesting the importance of sober and realistic interpretation of the literature in order to avoid bias and overexcitement.

Other than to further understand potential consumer attitudes toward CM, many consumer acceptance studies were directed to ensure the increase in consumer acceptance of CM (34–36). For example, after determining drivers for consumer acceptance and rejection of CM, the authors suggested ways to market CM such as framing CM as a solution to the existing food safety problems (68) and portraying CM as more natural, favorable, and addressed consumer concerns about the technology could improve consumer perceptions of the product (70). A similar pattern was also found in more recent publications (66, 72). This indicated that increasing consumer acceptance is the main interest of CM proponents which could be a critical source of bias throughout literature in this area.

The intense promotion of CM as a world-changing biotechnology makes research around this topic prone to bias. To investigate this, conflict of interest statements, study supports (source of funding, panelist, and samples), and authors affiliations were examined (Appendix 5). Based on the results, the panelists and sample sources were unlikely to be a source for bias/conflict of interest. This was because the studies used random participants from a crowd sourcing website, conducted national/cross-country survey, or obtained random internal participants such as college students. Only the study by Benjaminson et al. (7) acknowledged using panelists who were their own lab members. As for sample sources, almost all studies that conducted a sensory panel made their own sample. Only one study bought commercial samples [hamburger; (18)]. Further details can be seen in the Supplementary material.

Possible sources of bias were sought in the conflict of interest statement, author affiliations, and funding sources (Appendix 5). Eight of the included studies did not include a conflict of interest statement while most studies (N = 17) declared no conflict of interest. Ong et al. (55) was the only study that declared potential conflict of interest. Ong et al. (55) declared that portions of the reported research has been submitted for a patent (patent application no. PCT/SG2020/050432) to two of their authors, Shujian Ong and Hanry Yu. Furthermore, both Shujian Ong and Hanry Yu were affiliated with Ants Innovate Pte Ltd., a Singapore deep tech start-up that focuses on developing cultivated whole meat cuts. Studies’ funding sources showed that many included studies were funded through a government grant and/or internal funding (N = 12 studies), from independent-nonprofit organizations (N = 12), and from the CM industry (N = 2 studies). Upon examining the authors’ affiliations, almost all authors were university affiliates, with only a few independent or industry researchers (N = 3 studies). These 3 studies included at least an author that is affiliated with a CM industry: Ants Innovate Pte Ltd., Believer Meats, and Mosa Meat (Appendix 5).

While the development of cultured meat is happening across public research labs and private industry, most of the reported success in producing CM products is in private industries such as Upside foods, Good Meat Inc., Scifi foods, and Blue Nalu (100, 103). With CM formulation becoming companies’ best-kept secret, perhaps for this reason the real sensory characteristics of CM are still unreported in the scientific literature. In this review, CM products that were evaluated were all made in-house by the research teams. This implies that CM products produced by industry were not made available for independent assessments. If CM is only developed by a handful of individuals that are likely proponents of this product, implicit bias of reporting positive results is very likely to take place; it is very unlikely that negative results will be published at all. In fact, the known consumer related studies and information given to the media are mostly the success stories of CM development (22, 76).