Soybean (Glycine max [L.] Merr.) oil ranks as the second most produced vegetable oil worldwide, with an output of 60.7 million tons, second only to palm oil (Statista, 2024). The oil fraction of soybean seeds typically averages around 20%, although this value can vary depending on genotype and environmental conditions (Priolli et al., 2015). Soybean oil is used in the food, chemical, and biodiesel industries due to its versatility (Clemente and Cahoon, 2009).

Soybean oil is composed of five major fatty acids: palmitic, stearic, oleic, linoleic, and linolenic. Due to its fatty acid profile, soybean oil has low oxidative stability, which reduces shelf life and limits its use in applications that require long-term heat (Pham et al., 2010). Saturated fatty acids such as palmitic acid have been associated with adverse health outcomes, including insulin resistance, obesity, cardiovascular disease, and hyperlipidemia (Mozaffarian et al., 2009; Sears and Perry, 2015; Kaikkonen et al., 2021). Despite this, soybean oil is generally considered healthier than other fat sources, particularly those of animal origin (Messina et al., 2021). Likewise, polyunsaturated fatty acids (PUFAs) like linoleic acid (LA) and α-linolenic acid (ALA) are essential for human health and provide recognized benefits, including roles in cardiovascular protection and metabolic regulation (Yang et al., 2025).

Historically, partial hydrogenation was used to increase the shelf life of soybean oil-derived products, but this process results in the formation of trans fatty acids (TFA), up to 40% (Steele et al., 2024). However, the intake of TFAs has been strongly associated with coronary heart disease, systemic inflammation, high LDL cholesterol, and other metabolic disorders (Mozaffarian et al., 2009; Brouwer et al., 2010). In response to growing public health concerns, many countries have restricted or banned the use of partially hydrogenated oils in food production (Anvisa, 2019; WHO, 2024). The food industry has since sought alternatives to partial hydrogenation, including oil blending and interesterification, to improve the functionality of soybean oil without producing TFAs (Memon et al., 2024). While effective, these techniques introduce additional costs and processing complexity (Costales-Rodríguez et al., 2009).

Given these challenges, there is increasing demand for soybean varieties with improved oil profiles—particularly those with high-oleic acid content and lower PUFAs—thus eliminating the need for hydrogenation, oil blending, or interesterification (Wilkes and Bringe, 2015; Hudson and Hudson, 2021). Additionally, other alternatives have focused on the development of soybean cultivars with specific oil quality traits, such as high α-linolenic acid to improve nutritional properties and low palmitic acid content to produce oils with reduced saturated fat.

To achieve these improvements, a wide array of biotechnological tools has been explored, including genetic engineering, RNA interference (RNAi), and genome editing. These technologies have enabled the development of elite soybean lines with customized oil profiles. This review aims to synthesize the current biotechnological approaches for improving soybean oil composition and functionality, highlighting cutting-edge strategies.

A balanced diet that includes fats and oils is essential for growth and the maintenance of physiological functions (Meijaard et al., 2022). In human nutrition, oil consumption plays multiple roles: it contributes to cell construction and maintenance, provides energy, aids in the absorption of fat-soluble vitamins, serves as a precursor for steroid hormones, and helps prevent various chronic diseases (Yao et al., 2020). Soybean oil is one of the most widely consumed vegetable oils worldwide, largely due to its affordability, availability, and versatility in culinary applications. China, the United States, and Brazil are the primary consumers, with average consumption of approximately 14.7, 12.29, and 8.45 million metric tons, respectively (Reportlinker, 2023).

Its widespread use is largely attributed not only to its availability but also to its chemical composition. The lipid fraction is particularly relevant due to its fatty acid composition, which is essential for its nutritional and functional quality, flavor, and oxidative stability (Fehr, 2007). Soybean oil is composed of various fatty acids, including saturated fatty acids (SFAs) such as approximately 11% palmitic acid (16:0) and 4% stearic acid (18:0); monounsaturated fatty acids (MUFAs), with about 25% oleic acid (18:1); and polyunsaturated fatty acids (PUFAs), with approximately 55% linoleic acid (18:2) and 8% linolenic acid (18:3).

Oils with more PUFAs and fewer MUFAs tend to have lower oxidative stability (Maszewska et al., 2018). The presence of multiple double bonds in linolenic and linoleic acids increases their reactivity with oxygen, making the oil more susceptible to oxidation (Liu and White, 1992). Oxidative stability is crucial to preserve oil quality during storage and cooking, particularly at high temperatures. During thermal processing (e.g., frying at 180 °C–250 °C), PUFA-rich oils undergo rapid degradation, leading to the accumulation of polar compounds and the formation of toxic products such as aldehydes and ketones (Liu and White, 1992; Bhardwaj et al., 2011).

Partial hydrogenation of soybean oil has historically been employed by the food industry to improve oxidative stability. This process extends the shelf life and is cost-effective; however, this process generates TFAs (Steele et al., 2024). TFAs are a type of unsaturated fatty acid characterized by at least one non-conjugated double bond in the trans configuration, which confers a straighter shape. This structural rigidity reduces their fluidity and leads to a higher melting point compared to their cis isomers (Bhardwaj et al., 2011). In human diets, the main source of TFAs is industrial hydrogenation of vegetable oils used in processed foods such as snacks, margarine, fast food, and cooking fats for deep frying (Pipoyan et al., 2021).

High TFA intake is widely recognized as harmful to health, being associated with increased low-density lipoprotein (LDL) cholesterol, reduced high-density lipoprotein (HDL) cholesterol, and greater risk of cardiovascular diseases (Mozaffarian et al., 2009; Brouwer et al., 2010). The World Health Organization (WHO) has issued warnings about the health impacts of TFA consumption (WHO, 2024). Since 2003, the WHO has recommended that TFAs account for less than 1% of total energy intake. Regulatory measures have been implemented globally to reduce or eliminate TFAs from the food industry.

Since 2021, the European Union has restricted industrial TFA content in fats to a maximum of 2% (Pipoyan et al., 2021). In the United States, the Food and Drug Administration (FDA) declared in 2015 that TFAs were no longer “generally recognized as safe” and banned their use in 2018 (Anderson, 2024). In Brazil, TFA labeling has been mandatory since 2003, and in 2019, the National Health Surveillance Agency (ANVISA) limited TFA content to 2% and required the elimination of partially hydrogenated oils by 2023 (Anvisa, 2019).

One common strategy to replace partial hydrogenation is oil blending, in which soybean oil is combined with more stable oils, such as palm or canola, to achieve desired textural properties and oxidative stability (Memon et al., 2024). Another widely applied approach is chemical or enzymatic interesterification, which rearranges the fatty acids on the glycerol backbone without creating trans fatty acids (Costales-Rodríguez et al., 2009). Interesterification modifies melting behavior and crystallization properties, enabling the production of margarines, shortenings, and bakery fats with improved performance (Berry, 2009). However, both blending and interesterification add complexity and cost to oil processing, reinforcing the need for soybean cultivars with inherently improved fatty acid profiles.

High-oleic oils (over 70% oleic acid content), oil blending, and interesterification are employed to replace partially hydrogenated vegetable oils (Zambelli, 2021). High-oleic oils are also considered healthier dietary components, offering improved oxidative stability and longer shelf life. One example is olive oil, a key element of the Mediterranean diet, which contains approximately 70%–80% oleic acid (Riolo et al., 2022). High intake of this fatty acid has been associated with anti-inflammatory effects, reduced cardiovascular risk, improved lipid profiles, and decreased abdominal fat (Owen et al., 2000; Tutunchi et al., 2020). Moreover, global dietary guidelines recommend that MUFAs comprise 10%–25% of total energy intake, depending on national policies (Schwingshackl et al., 2022).

In parallel, although PUFA-rich oils have lower oxidative stability, other strategies have focused on increasing their levels because of their nutritional benefits. Soybean oil contains high concentrations of linoleic acid (omega-6). High PUFA intake, particularly omega-3 (α-linolenic) and omega-6 (linoleic) fatty acids, is considered essential for a healthy diet and is associated with reduced cardiovascular risk and overall mortality (Chen et al., 2021). PUFAs have also been linked to the prevention of neurodegenerative diseases, inflammation, cancer, obesity, and LDL cholesterol reduction (Nogoy et al., 2020; Kotlyarov and Kotlyarova, 2022). Another study indicates that supplementation with omega-3 fatty acids significantly reduces adverse cardiovascular events (Huang et al., 2023).

In addition to MUFAs and PUFAs, oils with a low content of saturated fatty acids (SFAs), such as palmitic (16:0) and stearic acid (18:0), also offer nutritional advantages. Palmitic acid (16:0) is the predominant saturated fatty acid (SFA) in soybean oil, accounting for approximately 10%–11% of its composition. High intake of SFAs, particularly palmitic acid, has been associated with adverse health outcomes, including increased levels of low-density lipoprotein (LDL) cholesterol, insulin resistance, central adiposity, and elevated cardiovascular risk (Briggs et al., 2017; Kaikkonen et al., 2021). Reducing SFA content in edible oils is therefore considered beneficial for cardiovascular health. According to the U.S. Dietary Guidelines for Americans, the recommended intake of saturated fats should not exceed 10% or less of total caloric consumption (Astrup et al., 2021).

Soybean oil has many nutritional benefits but also presents some challenges from an industrial perspective. To meet the diverse demands of the consumer market, biotechnological strategies can be employed to develop soybean varieties with tailored characteristics, addressing the needs of increasingly health-conscious consumers.

Biotechnology provides a set of tools that can accelerate and refine plant breeding. Several methods can be applied in this context, including transgenesis, RNA interference (RNAi), and gene editing (Figure 1A). The application of these technologies aims to increase crop productivity, improve nutritional quality, and confer tolerance to biotic and abiotic stresses, in addition to meeting consumer market demands and promoting agricultural sustainability.

Transgenic plants contain in their genome one or more genes that have been artificially inserted (Jhansi Rani and Usha, 2013). The inserted sequence, known as a transgene, may originate from a closely related species or from a completely different one (Benfey and Chua, 1989). The insertion of a transgene can confer a desirable trait that the target plant does not have, silence a gene from the same species, or even overexpress a gene of interest (Herrera-Estrella et al., 2005). Most transgenic plants used in agriculture involve the insertion of a cassette containing a gene encoding a foreign protein (Shewry et al., 2008). However, this tool can also be employed to reduce the expression of native proteins through RNA-mediated post-transcriptional gene silencing.

RNA interference (RNAi) is a defense mechanism against viruses and retrotransposons in eukaryotic organisms that mediates post-transcriptional gene silencing (Christie et al., 2011). This silencing process can be triggered by an exogenous double-stranded RNA (dsRNA) molecule or by the expression of a genetic construct that releases these molecules. Once inside the cell, the dsRNA is recognized and cleaved by the Dicer enzyme into 21 to 24 nucleotides small interfering RNAs (siRNAs). These siRNAs are incorporated into the RNA-induced silencing complex (RISC), whose main component is an Argonaute (AGO) protein (Cai et al., 2018). The RISC complex uses the guide strand of the siRNA to locate and cleave complementary messenger RNA (mRNA), which is subsequently degraded by 5′-3′ exoribonucleases and/or 3′-5′ exosome activity, leading to reduced mRNA levels and post-transcriptional gene silencing (Baulcombe, 2004; Zhang and Guo, 2017).

Another approach currently being used to develop soybean cultivars with improved oil traits is genome editing. In this context, gene editing technologies include Transcriptional Activator Effector Nucleases (TALENs) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) systems. These tools share two core components: a programmable endonuclease capable of inducing double-strand breaks (DSBs) in DNA and a targeting mechanism for sequence-specific recognition (Belhaj et al., 2013; Jiang et al., 2015).

TALEN technology introduced significant innovations by offering greater design flexibility and specificity (Boch et al., 2009). TALENs consist of a FokI nuclease domain fused to a customizable DNA-binding domain composed of transcription activator-like effectors (TALEs) derived from Xanthomonas spp. (Joung and Sander, 2013). The TALEs contain conserved 34-amino-acid repeats, with target specificity conferred by variable di-residues (RVDs) at positions 12 and 13 (Boch et al., 2009). The most common RVDs are NN, NG, HD, and NI. The TALEN system consists of two DNA-binding domains from TALEN proteins, each linked to FokI nuclease. FokI nuclease dimerizes to generate a double-strand break at the target DNA site, triggering the cellular repair machinery (Bhardwaj and Nain, 2021).

The CRISPR-Cas system is a defense mechanism of bacteria against viruses and has become a central tool in plant genome editing due to its precision and simplicity (Wiedenheft et al., 2012). Fragments of exogenous DNA are integrated into the CRISPR locus; these loci are associated with Cas genes that synthesize proteins with nuclease domains (Mojica et al., 2005). The CRISPR/Cas9 system, a class 2 type II from Streptococcus pyogenes, uses a guide RNA to direct the Cas9 endonuclease to the target sequence, promoting double-strand breaks near a PAM region (5′-NGG-3′) (Hsu et al., 2014; Jiang F and Doudna JA, 2017). Variants of the Cas12, Cas13, and Cas14 systems expand the applications for DNA and RNA editing (Liu et al., 2020), consolidating CRISPR as an essential platform in modern biotechnology.

As a biotechnological tool, CRISPR/Cas has been widely used since its first functional demonstration in eukaryotic cells (Jinek et al., 2012). Adapted for use in gene editing, the Cas endonuclease is guided by guide RNA (gRNA) that leads the enzyme to a genome-specific site, promoting cleavages that may be repaired by non-homologous end joining (NHEJ) or homologous recombination (HR) machinery (Jiang et al., 2015; Li et al., 2024). The technique allows for knockouts, insertions, gene regulation, and new methods such as base editing and prime editing (Anzalone et al., 2020). Advances in CRISPR-Cas genome editing have expanded the molecular tools for plant genome engineering to generate new traits in crop plants.

The quality of soybean oil is a decisive factor in enhancing the product’s value in global markets. Modern biotechnology is crucial to the development of new cultivars, particularly through genome editing using CRISPR/Cas. This technology enables precise and simultaneous modifications at multiple loci, while in some cases minimizing concerns typically associated with genetically modified organisms (GMOs). The development of genome-edited soybeans can employ multiplex strategies to target multiple key genes in lipid metabolism simultaneously, thereby accelerating the generation of oil profiles optimized for different applications.

Within this context, the development of non-GMO soybean cultivars with high oleic acid content to be used by the main soybean-producing countries emerges as a strategic alternative to meet the demands of the food and biodiesel industries, as well as those of the end consumer. Furthermore, soybean cultivars with specific traits, such as high α-linolenic acid content - an essential omega-3 fatty acid - could serve the functional food and dietary supplement markets. Likewise, low-palmitic soybean oil cultivars, with reduced levels of saturated fatty acids, aim to address the demand for healthier food products. Altogether, these targeted modifications illustrate the diverse possibilities for improving soybean oil quality and creating differentiated products that increase the added value of soybean oil.

Biotechnology can also improve gene discovery related to the oil biosynthetic pathway. Although several genes associated with the lipid metabolic pathway in soybean are already known, advances in omics-based approaches–such as genomics, transcriptomics, metabolomics, epigenomics, and lipidomics–and the integration of these datasets may provide new insights into fatty acid biosynthesis, as well as reveal crucial gene interactions. Such knowledge will be essential for soybean genetic improvement.

At the same time, the food industry has been increasingly demanding oils with enhanced processing characteristics, both for industrial applications and for the consumer market. The major soybean producers worldwide–Brazil, the United States, and Argentina–must remain attentive to shifts in industry and consumer preferences. While the United States has already developed and commercialized soybean cultivars with improved lipid traits, Brazil, as the world’s leading soybean producer, must advance in the developing of the new technologies. This advancement is essential not only to maintain its leadership but also to assume a prominent role in supplying healthier food products. The lack of nationally developed cultivars may otherwise reduce Brazilian soybean to a commodity with lower added value, targeting less demanding markets.

Looking ahead, the soybean production chain must remain aligned with the evolving requirements of the consumer market. Soybean oil with enhanced functional properties and specific attributes tailored to diverse industrial and nutritional demands has the potential to consolidate soybean not merely as a commodity, but as a versatile platform for the production of specialty oils.