Search Results (5)

Plant-based meat alternatives (PMAs), as an emerging food category gaining increasing popularity, face potential food safety risks and ethical concerns for vegetarians due to the illegal adulteration of animal-derived components. To address these challenges and enhance regulatory oversight, the development of a rapid, sensitive, and highly specific detection method is essential. In this study, five DNA extraction methods were evaluated and optimized to identify the most effective approach for PMA products. The optimal conditions were determined to be 60 mmol/L NaCl, 10 mmol/L Tris HCl, and a centrifugation speed of 12,000× g. Additionally, specific primers targeting four common animal-derived adulterants, namely pork, chicken, duck, and beef, were designed and screened for targeted amplification. To establish a rapid and visually interpretable detection system, the recombinant polymerase amplification conditions were optimized. The final protocol used 0.4 µmol/L primer and isothermal amplification at 39 °C for 25 min, with the incorporation of SYBR Green I dye enabling the rapid and specific visualization of animal-derived DNA. This optimized method is characterized by its simplicity, sensitivity (capable of detecting beef-derived components as low as 0.0514% w/w), and rapidity, significantly reducing detection time and providing a reliable tool for the identification of animal-derived adulteration in PMA products. Full article

Leghemoglobin (LegHb) is a plant-derived heme-containing globin found in the root nodules of legumes like soybean that can be used as a food additive for red color and meaty flavor as a plant-based meat alternative. However, conventional extraction methods face challenges of low yield and high costs. To address this issue, precision fermentation with recombinant microorganisms has been applied for the sustainable large-scale production of plant leghemoglobins. This study attempted the production of plant legHbs using recombinant yeast strains, Saccharomyces cerevisiae and Komagatella phaffii. The plant legHb genes were identified from the genome of legumes such as soybean, chickpea, mung bean and overexpressed in yeast via extracellular secretion by the signal peptide and inducible promoters. Subsequently, hemin as a heme provider was added to the fermentation, resulting in increased levels of plant legHbs. In S. cerevisiae, gmaLegHb expression reached up to 398.1 mg/L, while in K. phaffii, gmaLegHb showed the highest production level, reaching up to 1652.7 mg/L. The secretory production of plant legHbs was further enhanced by replacing the signal peptide in the recombinant yeast. The secreted plant legHbs were purified by His-Tag from a culture supernatant or concentrated via precipitation using ammonium sulfate. These results suggest that the production of plant legHbs is significantly influenced by hemin and signal peptide. This study successfully demonstrates the production of the various plant legHbs other than soy legHb that can be used as natural colors and flavors for plant-based meat alternatives. Full article

Soy leghemoglobin (LegH) has been gaining interest over the last years as an efficient flavor and aroma compound in plant-based meat substitutes. Hence, in the following article, we demonstrate the methods for LegH production using a recombinant Komagataella phaffii strain. Multiple fed-batch fermentation with an alternative to a BSM medium, where glucose was used as the main carbon source, was implemented and the growth kinetics, e.g., a maximal specific biomass growth of 0.239 g·g⁻¹·h⁻¹, a biomass yield from the substrate of 0.298 g·g⁻¹, and a maximal specific substrate consumption rate of 0.81 g·g⁻¹·h⁻¹ were identified. Leghemoglobin production resulted in a yield of 0.513 mg·gDCW⁻¹, while the highest biomass density achieved in this study was 121.80 gDCW·L⁻¹. The applied medium that showed potential for additional optimization studies, which, in contrast to BSM, made it possible to separate pH control from nitrogen supply, does not affect medium turbidity measurements and does not induce metabolite synthesis during yeast biomass growth. Full article

Plant-based meat alternatives, exemplified by Impossible Foods’ Impossible Burger, offer a sustainable, ethical substitute for traditional meat, closely mimicking the taste and appearance of meat by utilizing soy leghemoglobin (LegH), a 16 kDa holoprotein found in soy plants structurally similar to heme in animal meat. Cultivation medium plays an important role in bioprocess development; however, medium development or optimization can be labor intensive, and thus the use of previously reported media can be enticing. In this study, we explored the expression of recombinant LegH in Pichia pastoris in various reported cultivation media (BSM, BMGY, FM22, D’Anjou, BSM/2, and RDM) and using different feeding approaches (µ-stat and mixed feed with sorbitol). Our findings indicate that optimization techniques tailored to the specific process did not increase LegH yields, highlighting the need to investigate strain-specific strategies. We also utilized the collected process data to create and train a novel artificial neural network-based soft sensor for estimating cell biomass, relying solely on standard bioreactor measurements (such as stirrer speed, dissolved oxygen, O₂ enrichment, base feed, glycerol feed, methanol feed, and reactor volume). This soft sensor proved to be robust and exhibited a strong correlation (3.72% WCW) with experimental data. Full article

Recombinant plant-based meat alternatives are a kind of product that simulates animal meat with complete structure by assembling plant-tissue protein and other plant-based ingredients. The market is growing rapidly and appears to have a promising future due to the broad culinary applicability of such products. Based on the analysis and summary of the relevant literature in the recent five years, this review summarizes the effects of raw materials and production methods on the structure and quality of specific components (tissue protein and simulated fat) in plant-based meat alternatives. Furthermore, the important roles of tissue and simulated fat as the main components of recombinant plant-based meat alternatives are further elucidated herein. In this paper, the factors affecting the structure and quality of plant-based meat alternatives are analyzed from part to whole, with the aim of contributing to the structural optimization and providing reference for the future development of the plant meat industry. Full article