Control of Beany Flavor from Soybean Protein Raw Material in Plant-Based Meat Analog Processing

Competitive binding of flavors in the preparation of soy protein: Screening based on molecular docking

Competitive binding of flavor compounds to proteins offers a strategy for mitigating off-flavors in soy protein isolate (SPI). We hypothesized that highly competitive pleasant flavor compounds can facilitate the release of off-flavors by occupying their binding sites during SPI preparation. Molecular docking identified four binding pockets on β-conglycinin (7S) and glycinin (11S) proteins interacting with off-flavors. From 54 pleasant flavors, 30 were screened, focusing on seven: δ-nonalactone, δ-decalactone, δ-undecalactone, furaneol, geraniol, nerol, and geranyl acetate. Sensory evaluation and gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that these compounds significantly reduced the intensity of unpleasant flavor attributes and decreased off-flavor content under high concentration neutral conditions (10 % w/v, pH 7.0) and low concentration acidic conditions (3 % w/v, pH 4.0). Structural differences influenced binding efficacy, with shorter-chain compounds like furaneol outperforming long-chain lactones. These findings provide a novel strategy for off-flavor removal in SPI, supporting the development of consumer-preferred soy products.

Effect of myoglobin on the flavor, color and texture of high-moisture soy protein concentrate -wheat gluten extrudates

The rising demand for plant-based meat analogues presents challenges in replicating the sensory qualities of animal meat. This study investigates the impact of Pichia-derived porcine myoglobin (PMb) and bovine hemoglobin (BHb) on the flavor profile, sensory attributes, macrostructure, color, and texture of high-moisture extruded soy protein concentrate-wheat gluten. The addition of PMb and BHb significantly altered the flavor profile by decreasing aldehyde content (hexanal and nonanal), while the contents of ketones (2,3-octanedione and 3,5-octadien-2-one), pyrazines (2-ethyl-6-methylpyrazine), and furans (2-pentylfuran) were increased. The structure of 0.5 % PMb and BHb extrudates exhibited a laminar arrangement, whereas 1 % PMb resulted in a uniform, gelatinous texture. Color analysis showed 0.5 % PMb darkened and reddened the extrudates, with the a⁎ value increasing from 5.51 ± 0.50 to 6.44 ± 0.57, and the a⁎ value reached 8.33 ± 0.37 when 1 % PMb was added. These findings offer valuable insights into the development of plant-based meat analogues.

Enhancing the flavor of plant-based meat analogues using flavor-capturing alginate/β-cyclodextrin hydrogel beads

Lack of flavor is a major disadvantage that hinders the widespread intake of plant-based meat analogues (PMA). Alginate-based hydrogel beads have flavor encapsulation capabilities. However, its low flavor retention rate and high viscosity limit its application in PMA. Therefore, novel alginate hydrogel beads suitable for PMA were formulated by mixing polysaccharides (such as β-cyclodextrin, gum arabic, agar, or κ-carrageenan). The beads and plant-based patties (PP) containing beads were characterized. Results showed that replacing half of the alginate with each polysaccharide decreased the viscosity. These modifications provided the proper thermal properties, size, and microstructure of the beads for application to PP. Particularly, β-cyclodextrin markedly increased the encapsulation efficiency of flavor up to 91.78 %. Adding four types of fabricated beads to each PP improved quality characteristics by reducing cooking loss and maintaining consistent color and texture profiles during 10 days of storage at 4 °C. The principal component analysis using an electronic nose demonstrated that alginate/β-cyclodextrin beads blocked flavor release in PP during the storage period. Sensory evaluation confirmed the maintenance of flavor intensity in the same PP. Collectively, these data suggest that alginate/β-cyclodextrin hydrogel beads could retain flavors and serve as an ingredient for PMA and other plant-based food systems.

The development of volatile off-flavor compounds in soy protein isolates and plant meat during storage

The off-flavor associated with soy protein isolate (SPI) has negatively impacted the full acceptance of plant meat. This study investigated the factors that contribute to the development of volatile compounds as well as the volatile compounds responsible for the off-flavors. The main objective of this study was to investigate the formation of volatile off-flavor compounds in soy protein isolates and plant meat during storage. The samples were stored at 4 ± 0.5 °C, 25 ± 2 °C, and 37 ± 1 °C for durations of 0, 2, 4, 6, and 8 weeks, respectively. They were investigated using physicochemical properties, sensory, electronic nose (E-nose), and gas chromatography-mass spectrometry (GC-MS). The volatile off-flavor compounds were identified and plant meat exhibited significantly higher levels of off-flavors than SPI. Oil bodies, excessive moisture, elevated temperature, and extended storage were recognized as the main factors contributing to the development of off-flavors. Therefore, the extended storage of SPI and plant meat resulted in a continuous reaction that eventually caused the development of volatile off-flavor compounds.

Relationship between breaking load and protein composition of acidic heat-induced gels prepared from the acidic precipitate of soy flour aqueous dispersions

As one of the constituent materials of plant-based meat, a heat-induced gel was prepared from the aqueous paste (protein-to-water ratio: 0.30-0.35) of an acidic precipitate from soy flour called AP-SF. Among the broader pH range of 4.5-7.5, heat-induced gels prepared from the AP-SF paste adjusted to a pH range of 5.0-5.5 exhibited the similar breaking load (617 gf) and displacement (5.22 mm), to that of heat-induced gels prepared from minced beef, breaking load (667 gf) and displacement (6.45 mm). The results of two experiments, that is, the addition of fractionated protein components (7S, 11S, polar lipid-associated protein (PLAP), and oil body-associated protein (OBAP)) to the original AP-SF gels and the examination of a correlation between the breaking load of AP-SF gels and the protein composition of soybean cultivars used for the AP-SF preparation suggested that 7S globulin has an ability to effectively increased the breaking load of AP-SF gels. In globulins that contribute to gelation, the correlation between the content of 7S and 11S and the breaking load is 0.75 and 0.50, respectively, and the correlation coefficient of 7S is much higher than that of 11S. Analysis using dithiothreitol (DTT)-free SDS-PAGE confirmed that homodimers of the α' and α subunits of 7S globulin play a dominant role in the heat-induced gelation via the formation of intermolecular disulfide bonds with themselves or other protein components.

Perforated imprinting on high moisture meat analogue confers long range mechanical anisotropy resembling meat cuts

Meat cuts, when cooked and masticated, separate into fibrous structures because of the long-range mechanical anisotropy (LMA) exhibited by muscle fascicles, which is not fully recapitulated in alternative proteins produced using molecular alignment technology like high moisture extrusion. We have developed a scalable perforated micro-imprinting technology to greatly enhance LMA in high moisture meat analogue (HMMA). By imprinting 1 mm thick HMMA sheets with perforated patterns (optimized by AI), we observed up to 5 × more anisotropic separation of fibrous structures in a one-dimensional pulling LMA analysis, to match the fibrousness of the cooked chicken breast, duck breast, pork loin and beef loin. We stacked and bound imprinted sheets with transglutaminase (TG) to produce imprinted whole-cuts. Controlling fiber separation in the imprinted cuts achieved hardness ranging from 6578 g to 18467 g (2 cm × 2 cm × 1 cm, 50% strain), which matched meats from different species. Imprinted cuts improved meat-like fiber separation over HMMA when masticated, measured by Euclidean distances (0.057 and 0.106 respectively) to animal meat cuts on image features. In sensory evaluation, imprinted cuts improved consumer acceptance by 33.3% and meat-like fibrousness by 20%, by significantly enhancing the HMMA appearance, texture, and mouthfeel.

Modulating the aroma and taste profile of soybean using novel strains for fermentation

A key factor influencing consumer acceptance of soybean products is the aroma and taste profile, which can be modulated through fermentation using unique microbial strains. This study aimed to identify and characterize novel microbial strains with the potential to enhance flavour profiles including umami, while reducing undesirable flavour notes such as beany aromas. The results showed an 800% (8-fold) increase in free amino acids in samples fermented with Rhizopus oryzae, which correlated with an increase in umami intensity as measured using an E-tongue. Samples fermented with Neurospora crassa also demonstrated an increase in methionine and cysteine, sulfur-containing amino acids that are deficient in raw soybean. Fermentation additionally resulted in a significant increase in fatty acids and alterations to the fatty acid profile. Notably, samples fermented with Penicillium camemberti, Penicillium nalgiovense, Penicillium chrysogenum, and Leuconostoc mesenteroides containing omega-3 fatty acids. Lastly, fermentation introduced desirable aroma compounds, including 'smoky', 'cheesy' and 'floral' notes, enhancing the sensory appeal of certain samples. This study demonstrates the innovative use of novel microbial strains in soybean fermentation as a promising strategy to modulate the aroma and taste profile of soybean products.

Plant-based seafood alternatives: Current insights on the nutrition, protein-flavour interactions, and the processing of these foods

Fish are an important food source; however, the sustainability of current seafood supplies is a major concern for key stakeholders. The development of plant-based seafood alternatives may be suitable products to alleviate some of the pressures on aquatic ecosystems and help support environmental sustainability. However, the wide-spread adoption of these products weighs heavily on the ingredients used in the formulations which should not only satisfy nutritional and sustainability targets but must also meet consumer approval and functionality. In this review, we highlight recent advances in our understanding of the nutritional quality and sensory challenges in particular flavour (which includes taste and aroma), that have so far proven difficult to overcome in the development of plant-based seafood alternatives. Protein interactions that contribute to flavour development in plant-based seafood alternatives and the factors that impact these interactions are also discussed. We also review the recent advances in the innovative technologies used to improve the texture of products in this emerging food category. Finally, we highlight key areas for targeted research to advance the development of this growing segment of food products.

Investigation into the Sensory Properties of Plant-Based Eggs, as Well as Acceptance, Emotional Response, and Use

Consumers have become interested in plant-based alternatives to animal-based products. One of the under-studied alternatives is plant-based eggs (PBEs). This research investigated PBEs relative to conventional eggs and tofu scramble-another plant-based alternative. Firstly, participants (n = 93) completed a word association task asking them about PBEs. Participants then evaluated the different food samples using hedonic scales, check-all-that-apply (CATA), and temporal check-all-that-apply (TCATA), as well as identified their emotional response and proposed use for PBEs. Participants were interested in plant-based alternatives, including PBEs, but they were concerned about the sensory properties. When they evaluated the different samples, the flavour and texture of the PBEs were disliked in comparison to the eggs. This result may be due to the beany, bitterness, and off-flavour attributes associated with the PBEs. Participants also associated the PBEs with negative emotions. The liking of tofu scramble was not significantly different from the eggs, and the eggs and tofu scramble were mainly associated with positive emotions. During the TCATA evaluation, the participants focused on the flavour attributes of PBEs, while their evaluation of the eggs was dominated by the textural attributes. Whether following a plant-based diet or not, consumers are interested in PBEs, but the sensory properties of PBEs need to be improved before they are willing to adopt them into their diet. This study is one of the first to evaluate the sensory properties of PBEs, as well as consumers' emotional response to them and their attitudes about PBEs.

Effect of l-cysteine on functional properties and fibrous structure formation of 3D-printed meat analogs from plant-based proteins

The development of three-dimensional (3D) printed meat analogs with fiber, texture, and sensory resembling meat remains challenging. This study investigated the effect of l-cysteine on functionality enhancement and fibrous structure formation in mixtures of mung bean protein isolate (MBPI) and wheat gluten (WG) for meat analog production. 3D printing was used to construct fibrous filaments. Raw MBPI-WG mixtures decreased rheological properties when increasing l-cysteine contents (0.0%-0.6%), promoting ink extrudability. The cys-0.4% ink exhibited the highest printing resolution and structural stability, correlated with its higher mechanical strength and increased disulfide cross-links. After cooking, the cys-0.4% sample showed a pronounced fibrousness in agreement with its microstructure image. This meat analog displayed a muscle-meat-like structure, improved texture, and reduced beany odor and bitter taste. Excessive cysteine contents (0.5%-0.6%) negatively affected the functionality of meat analogs. This study provides guidance for optimizing the amount of l-cysteine in meat analogs to improve product quality.

Preparation and characterization of vitamin E/calcium/soy protein isolate nanoparticles for soybean milk beverage fortification

Soybean milk is a rich plant-based source of protein, and phenolic compounds. This study compared the nutritional value of soybean milk, flour, soy protein isolate (SPI) and evaluated the impact of prepared vitamin E/calcium salt/soy protein isolate nanoparticles (ECSPI-NPs) on fortification of developed soybean milk formulations. Results indicated that soybean flour protein content was 40.50 g/100 g, that fulfills 81% of the daily requirement (DV%), the unsaturated fatty acids (USFs), oleic and linoleic content was 21.98 and 56.7%, respectively, of total fatty acids content. In soybean milk, essential amino acids, threonine, leucine, lysine achieved 92.70, 90.81, 77.42% of amino acid scores (AAS) requirement values respectively. Ferulic acid was the main phenolic compound in soybean flour, milk and SPI (508.74, 13.28, 491.78 µg/g). Due to the moisture content of soybean milk (88.50%) against (7.10%) in soybean flour, the latest showed higher nutrients concentrations. The prepared calcium (20 mM/10 g SPI) and vitamin E (100 mg/g SPI) nanoparticles (ECSPI-NPs) exhibited that they were effectively synthesized under transmission electron microscope (TEM), stability in the zeta sizer analysis and safety up to IC50 value (202 ug/mL) on vero cell line. ECSPI-NPs fortification (NECM) enhanced significantly phenolic content (149.49 mg/mL), taste (6.10), texture (6.70) and consumer overall acceptance (6.54). Obtained results encourage the application of the prepared ECSPI-NPs for further functional foods applications.

Properties of texturized protein and performance of different protein sources in the extrusion process: A review

The need for protein is increasing due to the rapid growth of the global population. However, conventional animal meat production has caused severe environmental, land usage, and other issues. Meat substitutes can provide consumers with a high-quality alternative to protein. Texturized protein (TP) is a critical ingredient in meat substitutes and is mainly obtained through extrusion processing. Therefore, this review first discussed the essential physical properties of TP, including appearance and structure, water-holding capacity (WHC) and oil-holding capacity (OHC), texture, and sensory properties. The performance of plant and novel source proteins in extrusion processing is also summarized. The properties of the desired TP should be considered first before extrusion processing. Under different extrusion parameters, proteins from the same source can exhibit varying properties. Although the novel source proteins can adversely affect TP quality, their high yield and environmental protection are worthy of further study. This paper aims to review the impact of proteins from different sources on the properties of TP during the extrusion process and discuss practical research methods for TP.

Descriptive Sensory Attributes and Volatile Flavor Compounds of Plant-Based Meat Alternatives and Ground Beef

The objective of this study was to characterize descriptive sensory attributes and volatile compounds among ground beef (GB) and plant-based meat alternatives (PBMA). The Beyond Burger, Impossible Burger, a third brand of PBMA, regular GB, and lean GB were collected from local and national chain grocery stores. Patties were formed and cooked on an enamel-lined cast iron skillet to an internal temperature of 71 °C. A trained descriptive sensory panel evaluated patties for 17 flavor attributes and 4 texture attributes. Volatile compounds were extracted using solid phase microextraction and analyzed via gas chromatography-mass spectrometry. Distinct differences in sensory and volatile profiles were elucidated (p < 0.05). PBMA possessed decreased beef flavor intensity and increased umami, nutty, smokey-charcoal, and musty/earthy flavor compared to GB. Sensory differences corresponded with pyrazine, furan, ketone, alcohol, and aldehyde concentration differences between products. These data support the conclusion that ground beef and PBMA possess different flavor and texture characteristics. Furthermore, the flavor of PBMA varied among available retail brands.