Search Results (52)

This paper proposes a method for E. coli detection in a microplate format using low-molecular-weight compounds that specifically interact with the lipopolysaccharides (LPSs) of E. coli cell walls. These compounds can amplify analytical signals by binding to multiple repeating cell surface structures, while the selectivity for E. coli is ensured by preliminary cultivation on selective media, such as Endo or MacConkey agar. 3-Aminophenylboronic acid (APBA) was selected as the binding reagent for detecting E. coli LPSs. Conjugates of streptavidin (STP) and bovine serum albumin (BSA) with APBA and conjugates of biotin and soybean trypsin inhibitor (STI) and BSA were synthesized. The conditions for the sequential formation of “sandwich” type complexes (BSA-APBA conjugate/E. coli/STP-APBA/STI–biotin/STP–peroxidase) and their colorimetric detection using chromogenic peroxidase substrate were determined. The detection limit was 3 × 10² cells/mL, and the range of quantitative determination covered five orders of magnitude—from 10³ to 10⁸ cells/mL. The developed assay was successfully tested using inactivated cells of pathogenic E. coli strains, confirming its potential for application. The assay was demonstrated to have universality, with the ability to detect E. coli, other bacterial pathogens, and LPS alone. This method could be adopted for the quantitative determination of different specific bacterial species using different selective media. Full article

A soybean meal is a key protein source in human foods and animal feed, yet its digestibility is constrained by endogenous trypsin inhibitors (TIs). Thermal processing is the mainstream tool for TI inactivation, but high-intensity heat treatments increase energy consumption and can potentially denature proteins, diminishing nutritional quality. Reducing the thermal input while maintaining nutritional quality is, therefore, a critical challenge. One promising strategy is the use of soybean cultivars bred for low-TI expression, which may allow for milder processing. However, the performance of these low-TI cultivars under reduced heat conditions remains unstudied. This study treated soybean samples under four different temperatures (60, 80, 100, and 121 °C) for 10 min and investigated the impact of heat treatment on TI concentration, in vitro protein digestibility, and nutritional properties of meals from a conventional high-TI variety (Glenn) and a novel low-TI variety (VT Barrack). Results showed that heat treatment at 100 °C significantly improved protein digestibility and lower TI concentrations in both varieties. A negative correlation was observed between protein digestibility and TI concentration in both soybean varieties. At 100 °C, the low-TI variety achieved 81.4% protein digestibility with only 0.6 mg/g TIs, whereas the high-TI variety required 121 °C to achieve comparable protein digestibility and a TI reduction. These findings highlight that low-TI soybeans can lower the necessary thermal treatment to 100 °C to minimize TIs while simultaneously preserving protein quality and cutting energy demand, offering a practical, cost-effective approach to producing higher-quality soybean meals. Full article

The growing consumer awareness of functional foods has increased interest in fermented plant-based products with enhanced nutritional and health-promoting properties. This comprehensive narrative literature review examines the potential of diverse raw materials for tempeh production beyond traditional soybeans, analysing their nutritional composition, bioactive compounds, and functional properties. A structured literature search was conducted on peer-reviewed publications up to July 2025, focusing on tempeh fermentation technology, chemical composition, and bioactive compounds from various substrates using recognised analytical methods according to Association of Official Analytical Collaboration (AOAC) standards. The analysis of over 25 different substrates revealed significant opportunities for enhancing tempeh’s nutritional profile through alternative raw materials including legumes, cereals, algae, seeds, and agricultural by-products. Several substrates demonstrated superior nutritional characteristics compared with traditional soybean tempeh, notably tarwi (Lupinus mutabilis) with exceptional protein content ((32–53% dry matter (DM)) and mung bean (Vigna radiata) exhibiting remarkably high polyphenol concentrations (137.53 mg gallic acid equivalents (GAE)/g DM). Fermentation with Rhizopus oligosporus consistently achieved substantial reductions in anti-nutritional factors (64–67% decrease in trypsin inhibitors, up to 65% reduction in phytates) while maintaining consistent antioxidant activities (39–70% 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition) across most variants. The diversity of bioactive compounds across different substrates demonstrates potential for developing targeted functional foods with specific health-promoting properties, supporting sustainable food system development through protein source diversification. Full article

The diversification of plant protein sources is a strategic priority for European food systems, particularly under the EU Green Deal and Farm to Fork strategies. In this study, dual production of full-fat soy (FFS) and expanded soybean cake (ESC) was evaluated using non-GMO soybeans cultivated under semi-organic conditions in Central Poland. Two agronomic systems—post-emergence mechanical weeding with rotary harrow weed control (P1) and conventional herbicide-based control (P2)—were compared over a four-year period. The P1 system produced consistently higher yields (e.g., 35.6 dt/ha in 2024 vs. 33.4 dt/ha in P2) and larger seed size (TSW: up to 223 g). Barothermal and press-assisted processing yielded FFS with protein content of 32.4–34.5% and oil content of 20.8–22.4%, while ESC exhibited enhanced characteristics: higher protein (37.4–39.0%), lower oil (11.6–13.3%), and elevated dietary fiber (15.8–16.3%). ESC also showed reduced anti-nutritional factors (e.g., trypsin inhibitors and phytic acid) and remained microbiologically and oxidatively stable over six months. The semi-organic P1 system offers a scalable, low-input approach to local soy production, while the dual-product model supports circular, zero-waste protein systems aligned with EU sustainability targets. Full article

Soybean meal (SBM) is extensively used as a predominant protein source in animal feed. However, raw soybean cannot be directly utilized in animal feed, due to the presence of the Kunitz trypsin inhibitor (KTi) and the Bowman–Birk protease inhibitor (BBi). These antinutritional factors inhibit the digestive enzymes in animals, trypsin and chymotrypsin, resulting in poor animal performance. To inactivate the activity of protease inhibitors, SBM is subjected to heat processing, a procedure that can negatively impact the soybean protein quality. Thus, it would be beneficial to develop soybean varieties with little or no trypsin inhibitors. In this study, we report on the creation of experimental soybean lines with significantly reduced levels of Bowman–Birk protease inhibitors. RNA interference (RNAi) technology was employed to generate several transgenic soybean lines. Some of these BBi knockdown soybean lines showed significantly lower amounts of both trypsin and chymotrypsin inhibitor activities. Western blot analysis revealed the complete absence of BBi in selected RNAi-derived lines. RNA sequencing (RNAseq) analysis demonstrated a drastic reduction in the seed-specific expression of BBi genes in the transgenic soybean lines during seed development. Confocal fluorescence immunolabeling studies showed that the accumulation of BBi was drastically diminished in BBi knockdown lines compared to wild-type soybeans. The absence of BBi in the transgenic soybean did not alter the overall protein, oil, and sulfur amino acid content of the seeds compared to wild-type soybeans. The seed protein from the BBi knockdown lines were more rapidly hydrolyzed by trypsin and chymotrypsin compared to the wild type, indicating that the absence of BBi enhances protein digestibility. Our study suggests that these BBi knockdown lines could be a valuable resource in order for plant breeders to incorporate this trait into commercial soybean cultivars, potentially enabling the use of raw soybeans in animal feed. Full article

Angiotensin-converting enzyme 2 (ACE2) is a cell-surface receptor that helps the body regulate blood pressure and endocrine secretions. Transmembrane serine protease 2 (TMPRSS2) is a cell surface protein expressed mainly by endothelial cells of the respiratory and digestive tract, which participates in the cleavage of protein peptide bonds with serine as the active site. These two proteins have been studied to be highly associated with infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Soybean trypsin inhibitor (SBTI) has special bioactivities such as anticarcinogenic and anti-inflammatory functions, which can be widely used in functional foods or drugs. Our study involved in vitro and in vivo experiments to elucidate the effect of SBTI on SARS-CoV-2 host invasion. First, it was confirmed that being under 250 μg/mL of SBTI was not toxic to HepG2, HEK293T, and Calu-3 cells. The animal study administered SBTI to mice once daily for 14 days. In the lungs, liver, and kidneys, the histopathologic findings of the SBTI group were not different from those of the control group, but the expression of ACE2, TMPRSS2, and CD147 was reduced. Thus, our findings suggest that the inhibition of ACE2, TMPRSS,2 and CD147 proteins by SBTI shows promise in potentially inhibiting SARS-CoV-2 infection. Full article

The Kunitz trypsin inhibitor (KTI) gene family encompasses a category of trypsin inhibitors, and the KTI proteins are important components of the 2S storage protein fraction in soybeans. In this study, fifty members of the GmKTI family were identified in the soybean genome, and their physicochemical properties, domain compositions, phylogenetic relationships, gene structures, and expression patterns were comprehensively analyzed to explore their impact on soybean seed protein content. The results revealed significant gene expansion within the GmKTI family in soybean. The gene structures and conserved motifs of GmKTI members exhibited both regularity and diversity, with distinct expression patterns across different soybean tissues. Haplotype analysis identified 7 GmKTI genes significantly associated with seed storage protein content, and the combination of superior haplotypes was found to enhance seed storage protein content. This is crucial for the improvement of soybean varieties and the enhancement of storage protein content. Additionally, the GmKTI family demonstrated evolutionary conservation, with its functions likely linked to light induction, biotic stress, and growth development. This study characterizes the structure, expression, genomic haplotypes, and molecular features of the soybean KTI domain for the first time, providing a foundation for functional analyses of the GmKTI domain in soybean and other plants. Full article

Trypsin inhibitors (TI) are naturally occurring antinutritional factors found in soybean seeds [Glycine max. (L.)] that decrease the growth rate of livestock, causing malnutrition and digestion troubles. The current accurate method to quantify TI levels in soybean seeds or meals is by high-performance liquid chromatography (HPLC); however, it is time-consuming, creating bottlenecks in industrial processing. Establishing a near-infrared reflectance spectroscopy (NIR) model for estimating TI in seeds and meals would provide a more efficient and cost-effective method for breeding programs and feed producers. In this study, 300 soybean lines, both seeds and meals, were analyzed for TI content using HPLC, and calibration models were created based on spectral data collected from a Perten DA 7250 NIR instrument. The resulting models demonstrated robust validation, achieving accuracy rates of 97% for seed total TI, 97% for seed Kunitz TI, and 89% for meal total TI. The findings of this study are significant as no NIR calibration models had previously been developed for TI estimation in soybean seed and meal. These models can be used by breeding programs to efficiently assess their lines and by industry to quickly evaluate their soybean meal quality. Full article

Soybean Trypsin Inhibitors (STIs) in soy-based foods have negative effects on soybean protein digestion and pancreatic health of humans. The inactivation of STIs is a critical unit operation aimed at enhancing the nutritional properties of soy-based foods during processing. This paper reviews the structure of STIs and soybean proteins, as well as the mechanisms of digestion. Various technologies (physical, chemical, biological) have been used to inactivate STIs. Their parameter settings, operating procedures, advantages, and disadvantages are also described. Mechanisms of inactivation of STIs (Kunitz trypsin inhibitor (KTI) and Bowman–Birk inhibitor (BBI)) conformations under different treatments are clarified. In addition, emerging technologies, e.g., Ohmic Heating, Electron Beam Irradiation, Dielectric-Barrier Discharge, and probiotics, have demonstrated great potential to inactivate STIs. We advise that multiple emerging technologies should combine with other unit operating systems to maximize inactivation efficiency. Full article

Food aid commodities are essential food items in global food aid programming. Some are primarily made from an extrusion of corn and soybeans. However, there are concerns about the genetically modified organisms (GMOs) of some of these grains. Hence, there is a need for alternatives to grains, like sorghum, which is not GMO. It is critical to ensure that products from this new ingredient meet the quality requirements, hence the need to profile them. An expanded formulation sorghum-soy blend (SSB), obtained from extrusion cooking, was ground using a hammer mill and analyzed for changes in properties that were affected by the transformation of starch and protein during processing. Macro- and micro-nutrients were added to these milled blends to prepare fortified blended foods (FBFs) that could meet the recommendations of Food Aid Quality Review (FAQR) report on energy, protein, and micronutrient content. The water absorption index (WAI) ranged from 2.82 to 5.90 g/g, the water solubility index (WSI) ranged from 6.22 to 18.50%, and the blends were affected by the formulation—whole/decorticated sorghum and different levels of fat. Extrusion processing caused starch gelatinization in the range of 90.69–96.26%. The pasting properties indicated that whole grain blends of SSB had lower peak time and higher final viscosity when compared to decorticated sorghum blends. The Bostwick flow rate of cooked porridges with 20% solids was within the recommended range of 9–21 cm/min. Starch digestibility significantly increased after extrusion, with a 149.65% increase in rapidly digestible starch (RDS). The protein digestibility did not vary significantly when subjected to extrusion and wet cooking. There was a significant reduction in anti-nutritional factors in the extruded binary blends of SSB when compared to respective raw blends: phytic acid was reduced by 25.33%, tannins were not found, and trypsin inhibitors were reduced by 19.50%. Thus, the extrusion processing of SSB with the subsequent addition of macro- and micro-ingredients was effective in producing FBFs with high nutritive value, comparable to FBF made from traditional ingredients. Full article

Feed accounts for up to 80% of poultry production costs, with high-quality grains such as soybean meal and corn traditionally serving as primary ingredients. However, increasing costs and competition for these grains have driven interest in low-grade and unconventional feed ingredients, including by-products like rapeseed meal and cottonseed meal. These alternatives are often constrained by high fiber content, anti-nutritional factors, and reduced nutrient bioavailability. Fermentation has emerged as a promising strategy to address these limitations, enhancing digestibility, palatability, and antioxidant properties while degrading harmful compounds such as tannins, trypsin inhibitors, and free gossypol. Solid- and liquid-state fermentation techniques utilize microbial inoculants, including lactobacilli and Bacillus species, to enzymatically break down complex macromolecules, thereby releasing essential nutrients. When combined with pretreatments like enzymatic hydrolysis, fermentation significantly improves the nutritional quality of feed ingredients while reducing costs without compromising poultry health or performance. This review examines the mechanisms, benefits, and challenges of fermentation techniques in poultry feed production, underscoring the importance of further research to optimize fermentation parameters, identify novel microbial strains, and ensure scalability and safety in industrial applications. Full article

Soybean (Glycine max) is the most widely grown legume crop in the world, providing important economic value. Pest herbivory damage by insects and mammalian wildlife, in particular the white-tailed deer (Odocoileus virginianus), limits yields in soybean. Incorporating trypsin inhibitors (TIs) as plant protectant against herbivory pests has been of interest. We previously showed that the overexpression of soybean TIs in soybean conferred insect deterrence under greenhouse experiments. In this study, we examined the potential of transgenic TI-overexpressing lines in deterring insects under field conditions at Knoxville, Tennessee. Our results indicate that the overexpression of TI could lead to a significant reduction in leaf defoliation of the transgenic compared to non-transgenic lines without negatively impacting plant growth and yield under field conditions. Furthermore, we extended our study by comprehensive evaluation of these transgenic plants against the white-tailed deer herbivory in a separate field setting at Jackson, Tennessee, and with controlled deer feeding experiments. No significant differences in growth characteristics were found between transgenic and non-transgenic lines under field conditions. There were also no significant differences in deer deterrence between transgenic and non-transgenic lines in ambient deer herbivory field or controlled deer feeding trials. Our study provides further insights into more exploration of the role of TI genes in pest control in this economically important crop. Full article

Understanding plant-insect interactions can help control the harm of herbivorous pests. According to transcriptome data, transcripts of Solanum lycopersicum responding to feeding by Tuta absoluta were screened for important endopeptidase inhibitors. These genes were annotated as serine-type endopeptidase inhibitors from the potato inhibitor I family, potato type II proteinase inhibitor family, and soybean trypsin inhibitor (Kunitz) family. Based on the analysis of expression patterns, Solyc09g084480.2, Solyc03g020080.2, Solyc03g098760.1, and Solyc01g009020.1 were identified as key genes in the defense system of S. lycopersicum. The major endopeptidase genes such as Tabs008250, Tabs007396, and Tabs005701 in the larval stages of T. absoluta were also detected as potential targets of the plant endopeptidase inhibitors. The interaction mode between these endopeptidase and endopeptidase inhibitors was predicted based on the protein structure construction. This study aims to reveal the molecular response of S. lycopersicum to feeding by T. absoluta with high throughput sequencing and bioinformatics analysis. Full article

When developing immunochemical test systems, it is necessary to obtain specific antibodies. Their quality depends, among other things, on the immunogen used. When preparing hapten–protein conjugates to obtain antibodies for low-molecular-weight compounds, the key factors are the structure of the hapten itself, the presence of a spacer, the size of the carrier protein and the degree of its modification by hapten molecules. This work shows that one additional factor—the conditions for obtaining the hapten–protein conjugate—is overlooked. In this work, we have synthesized conjugates of bisphenol A derivative 4,4-bis(hydroxyphenyl)valeric acid (BVA), the protein carrier soybean trypsin inhibitor (STI), and bovine serum albumin (BSA) in reaction media combining water with two organic solvents: dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). Namely, BSA_DMF–BVA, STI_DMF–BVA, BSA_DMSO–BVA and STI_DMSO–BVA conjugates were obtained. Rabbit polyclonal antibodies against the BSA_DMF–BVA conjugate demonstrated basically different interactions in the developed ELISA systems using either STI_DMF–BVA or STI_DMSO–BVA conjugates. The use of the STI_DMF–BVA conjugate demonstrated the absence of competition in combination with antisera obtained from BSA_DMF–BVA in an ELISA. A competitive interaction was observed only with the use of the STI_DMSO–BVA conjugate. Under the selected conditions, the detection limit of bisphenol A was 8.3 ng/mL, and the working range of determined concentrations was 18.5–290.3 ng/mL. The obtained data demonstrate the possibility of achieving sensitive immunoassays by simply varying the reaction media for the hapten–protein conjugation, which could provide an additional tool in the development of immunoassays for other low-molecular-weight compounds. Full article

Trypsin inhibitors (TI) in raw soybean grain, mainly represented by the Kunitz trypsin inhibitor protein (KTI), prevent the normal activity of the digestive enzymes trypsin and chymotrypsin in humans and monogastric livestock. The inactivation of TI is achieved through costly and time-consuming heat treatment. Thermal processing also impairs the solubility and availability of the soybean grain protein. Therefore, the genetic elimination of KTI has been proposed as a suitable alternative to heat treatment. The aim of this study was to screen the collection of European soybean cultivars with six genetic markers (one SSR marker and five SNP markers) previously proposed as tightly linked to the KTI3 gene encoding the major Kunitz trypsin inhibitor seed protein of soybean and validate their usability for marker-assisted selection (MAS). The six markers were validated on a subset of 38 cultivars with wide variability in KTI content and in the F₂ and F_3:5 progenies of two crosses between the known high- and low-KTI cultivars. Three genetic markers (SSR Satt228 and two SNP markers, Gm08_45317135_T/G and Gm08_45541906_A/C) were significantly associated with KTI content in a subset of 38 cultivars. Low-KTI alleles were detected in both low- and high-KTI genotypes and vice versa, high-KTI alleles were found in both high- and low-KTI genotypes, indicating a tight but not perfect association of these markers with the KTI3 gene. The genetic marker SSR Satt228 showed a significant association with KTI content in the F₂ progeny, while the SNP markers Gm08_45317135_T/G and Gm08_45541906_A/C allowed significant discrimination between progeny with high- vs. low-KTI progenies in the F_3:5 generation. These three markers could be applied in MAS for low-KTI content but not without the additional phenotyping step to extract the desired low-KTI genotypes. Full article