Relationship between sensory attributes and instrumental texture properties in meat analog patty system substituted with sweet potato stem.

BACKGROUND: Understanding the relationship between perceived sensory attributes and measurable instrumental properties is crucial for replicating the distinct textures of meat in plant-based meat analogs. In this study, plant-based patties composed of textured vegetable protein (TVP) and 10%, 20% and 30% TVPs were substituted with fibers from sweet potato stem (SPS), and their instrumental texture and sensory properties were evaluated. RESULTS: Samples with 20% SPS showed hardness, cohesiveness and chewiness, which are the mechanical indicators most similar to those of meat. A descriptive sensory analysis by ten trained participants indicated that the SPS-supplemented meat analog patties exhibited characteristics similar to pork patties in terms of firmness, toughness, cohesiveness and smoothness compared to the TVP-only sample. A strong positive correlation between instrumental hardness and sensory firmness was observed (P < 0.01); however, cohesiveness, springiness and chewiness did not show any correlation between instrumental and sensory analyses. Warner-Bratzler shear force (WBSF) values showed positive correlations with sensory cohesiveness, chewiness, toughness, fibrousness, moistness, firmness and springiness (P < 0.05). CONCLUSION: The results demonstrated the feasibility of physically treated fibers from SPS as a partial substitute for TVP in developing meat analogs. Additionally, this study suggested that instrumental hardness and WBSF measurements can be sound parameters for representing sensory texture characteristics while further developing plant-based meat analogs. © 2024 Society of Chemical Industry.

Tri-component hydrocolloid as egg white replacement in meringues: gellan gum with soy protein isolate and maltodextrin.

BACKGROUND: In the quest for sustainable food ingredients, the present study delves into the potential of a tri-component hydrocolloid blend, comprising gellan gum (GG), soy protein isolate (SPI) and maltodextrin (MD), as a replacement for egg white in meringue production. The research aims to elucidate the intricate physical properties of meringue containing this tri-component structure, focusing on foaming dynamics, rheological behavior and the textural properties of the resulting meringue cookies. RESULTS: Experiments were conducted with various hydrocolloids (k-carrageenan, GG, and locust bean gum) and GG was identified as optimal for improving foaming capacity and foaming stability. Rheological evaluations showed a positive correlation between increased GG concentration within the tri-component matrix and an increase in both storage modulus (G') and loss modulus (G"), indicating improved structural integrity. Furthermore, a comparative analysis of the texture profiles of cookies prepared with this blend highlighted the ability of higher GG concentrations to satisfactorily replicate the tactile and visual qualities of traditional egg white-based meringues. This result was particularly evident compared to formulations utilizing solely SPI or the combined SPI-MD configuration. CONCLUSION: Conclusively, the results of the present study highlight the significant potential of the GG-SPI-MD tri-component structure to closely mimic the critical properties of egg white, thus offering a promising plant-based alternative for meringue production. © 2024 Society of Chemical Industry.

A label-free aptamer-based colorimetric biosensor for rapid gliadin detection in foods: a focus on pasta, bread and cookies.

Despite numerous advancements in gluten detection, a substantial need remains for innovative, cost-effective, in situ methods that can be employed without complex analytical instruments. Addressing this demand, this study introduces a pioneering label-free colorimetric biosensor for the in situ detection of gliadin, a major component of gluten, which is a prevalent trigger of food allergies. Our novel approach employs the strategic coating of gold nanoparticles (AuNP) with gliadin-specific aptamers. In the absence of gliadin, these aptamers stably disperse AuNP, preventing their aggregation. However, upon the introduction of gliadin and in the presence of sodium chloride, AuNP aggregate, yielding a measurable colorimetric signal that facilitates the precise quantification of gliadin. Under rigorously optimized conditions, this AuNP/aptamer-based colorimetric biosensor demonstrated exceptional sensitivity and selectivity, with a detection limit of 32.1 ng mL-1 and a linear response range of 0-300 ng mL-1. Critically, the sensor maintained reliable performance when applied to real-world food samples, including gluten-free bread, cookies, and pasta. Due to its simplicity, selectivity, speed, and cost-effectiveness, this assay represents a significant advancement over current gluten detection methods. Moreover, the developed AuNP/aptamer-based colorimetric biosensor design holds promising potential for adaptation to detect other food allergens or protein toxins through selective aptamer modifications.

Effect of the physical fibrillated sweet potato (Ipomoea batatas) stem on the plant-based patty analogues.

In this study, a dietary fiber extracted from sweet potato stems (Ipomoea batatas, PS) was evaluated for its ability to improve the quality of vegetable patty analogues. A patty analogues containing 0-50 wt% dietary fiber were prepared to analyze the utilized dietary fiber's performance. To evaluate the manufactured patty analogues, texture profile analysis, color analysis, emulsion stability, and microstructural analysis were conducted. As the PS increased, the hardness decreased, while the total expressible fluids tended to increase. The color analysis revealed that the a* value, which represents red, declined as the PS content increased, and heterogeneous colors showed at least 40 wt% of PS. According to the microstructural analysis, PS is a structure in which massive fiber bundles are integrated between textured vegetable protein networks, which is believed to have given the patty analogue soft characteristics. The findings of this study can serve as a foundation for future research into the application of carbohydrates to plant-based meat analogues. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01211-y.

Reducing the production of acrylamide during the roasting of balloon flower roots in consumer appliances and industrial equipment.

This study aimed to determine what conditions were needed to reduce the production of acrylamide when balloon flower roots [Platycodon grandiflorum (Jacq. A. DC.)] were heated. The conditions of temperature, time, and the type of equipment (i.e., consumer appliance or industrial equipment) were the important variables in the experiment. The official criterion for a recommended standard of acrylamide in tea product is less than 1000 µg/kg as determined by the Ministry of Food and Drug Safety in South Korea. A response surface methodology was used to determine whether the heated samples met the safety requirements. The most significant condition for consumer appliances was time and for industrial equipment was temperature. The optimal roasting time was 3.01 min with a consumer appliance and 4.18 min with industrial equipment at 110 â„ƒ, a typical temperature in the field. The acrylamide content of the tested sample was significantly in agreement with the predicted amount (R2 > 0.950). Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01242-z.

Development of flaxseed gum/konjac glucomannan with agar as gelling agents with enhanced elastic properties.

In this study, a natural-based gelling agent comprised of blended flax seed gum (FSG), konjac glucomannan (KG), and agar gel (AG) was developed for application to control the textural properties of foods. The compound gels, including FSG, KG, and AG, were investigated to determine their moisture affinity, including minimum gelling concentration, water binding capacity, water soluble index, and swelling power. In addition, we analyzed the rheological properties of the compound gel through texture analysis, frequency sweep, and creep and recovery. The microstructure of the compound gel was identified and compared with the viscoelastic properties of the gel. Overall, these results showed that the F4K6 (4:6:2 of FSG:KG:AG) could serve as an excellent gelling agent, which endowed food gel with the promoted elastic properties, water capacity, and rigid surface morphology. This work suggests that novel gelling agents, including FSG, KGM, and AG, successfully prepared food gels with improved physicochemical properties. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01179-9.

Development of a novel technology for high-moisture textured soy protein using a vacuum packaging and pressurized heat (vacuum-autoclaving) treatment.

Although the demand for meat analogues is increasing, aspects of the analogues' textural characteristics continue to be problematic. To solve these problems, a new technique for applying vacuum packaging and pressurized heat (i.e., vacuum-autoclaving) to low-moisture TSP has been proposed. An analysis of the morphological characteristics of the analogues showed that the vacuum-autoclaving treatment affected the packing structure of the materials. The density was increased by about 0.25 g/mL by vacuum-autoclaving, and the movement of water was restricted by the formation of a packed structure. The disulfide bonds increased by 3 µM/g or more and the ß-sheets and α-helixes increased by 7 % or more; this contributed to structural changes due to protein aggregation. The texturization index and hardness tended to decrease by more than 30 %, indicating a decrease in overall structural strength. The newly proposed technology has potential for use in the commercialization of meat analogues.

Influence of a post-processing heat treatment method on the textural properties of textured vegetable protein.

Textured vegetable protein (TVP) is gaining popularity as the market for meat analogues grows, but research on processing to improve the texture of TVPs is needed. Heat treatments can change the textural properties during the processing of meat and meat analogues. Therefore, this study analyzed the textural characteristics of low-moisture TVPs following heat treatments using steaming, oven-cooking, microwaving, and vacuum-autoclaving, which combines vacuum packaging and autoclaving. The moisture content of the meat analogues had different patterns depending on the treatment used, with the most significant decrease in moisture occurred with microwaving. The morphological analysis of the meat analogues showed that oven-cooking and microwaving preserved a large air-cell structure and that steaming and vacuum-autoclaving caused a small air-cell structure to form. The texturization index tended to increase only with microwaving. Disulfide bonds were increased with steaming and vacuum-autoclaving; this was thought to be related to the increase in tiny air-cell structures. In conclusion, the most helpful cooking method was vacuum-autoclaving since it allowed the treated meat analogues to trap moisture well, and this led to the formation of a dense structure and a lowering of the texturization index. Therefore, the proposed technique of vacuum-autoclaving was shown to be significant for its potential as a way of processing meat analogues. Practical Application It is expected to improve the quality of plant-based meat analogue products by controlling the physical properties of low-moisture textured vegetable protein (TVP) through steaming, oven, microwave, and vacuum autoclave as post-heat treatments.

The effect of curdlan and the resting process on the quality of the dried whole tofu noodles.

The aim of this study is to make dried noodles having high contents of whole tofu (60% (w/w)). To control the high moisture of the whole tofu, curdlan was added and a high-temperature resting process was applied. The elasticity of the dough sample rested at 45°C for 45 min increased over 50% more than the non-rested one. The addition of curdlan and the high-temperature resting process helped to form a compact internal structure in the dough, which might have been induced by the gelation of curdlan and the swelling of starch. In addition, these treatments resulted in about 20% and 15% reduction in cooking time and cooking loss, respectively. Whole tofu noodles having high protein content with improved texture and cookability was developed. These results could be helpful to the development of the bread based on a high hydration dough. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-01020-9.

Elastic gels based on flaxseed gum with konjac glucomannan and agar.

In this study, we prepared hydrocolloid gels in which flaxseed gum (FSG), konjac glucomannan (KGM), and agar (AG) were blended in different ratios for use as a viscoelastic food. The prepared hydrogels' physicochemical properties were analyzed concerning their water solubility index (WSI), swelling power (SL), frequency sweep results, and microstructures. As the FSG ratio decreased, the WSI value of the compound gel tended to increase. However, it showed a tendency to have a relatively high SP value and a low tan δ value according to a specific KGM/FSG/AG mixing ratios (8:2:1.5 and 6:4:1.5). Through microstructure analysis, the FKA821.5 sample showed a relatively small, monodispersed gel building structure, correlated with the rheological results. In conclusion, the FKA821.5 gel was determined to have good water retention capacity and high structural strength. These results are expected to increase the applicability of FSG-based gelling agents in the food industry.

Visible on-site detection of Ara h 1 by the switchable-linker-mediated precipitation of gold nanoparticles.

Biosensors have been widely applied in tests for allergens, but on-site detection remains a challenge. Herein, we proposed a detection procedure for peanut Ara h 1 as a representative allergen, which was extracted from a cookie, thereby minimising the need for any complex pretreatment that was difficult to perform, and enabling the visual detection of the target without the use of analytical equipment. The extraction procedure was performed in less than 30 min using a syringe and filter (0.45 µm). The detection method for Ara h 1 was based on the aggregation of switchable linkers (SL) and gold nanoparticles (AuNP), and the presence of 0.19 mg peanut protein per 30 g of cookie could be confirmed within 30 min based on the AuNP/SL concentration ratio by the precipitation. This proposed procedure could be successfully applied to the detection of a wide range of food allergens.

Development of a portable lab-on-a-valve device for making primary diagnoses based on gold-nanoparticle aggregation induced by a switchable linker.

We have developed a low-cost, portable lab-on-a-valve (LOV) integrated microdevice for the detection of pathogens in primary-diagnosis settings. This system was designed for field-based pathogen detection based on the aggregation of gold nanoparticles induced by a switchable linker. A three-way valve, which has attracted much attention as a functional mesofluidic platform for pressure-driven flow, has been designed as a universal reaction platform that combines the functions of fluid flow and a reaction chamber. In addition, we obtain rapid and enhanced visual signals by the use of a syringe filter to remove gold nano-aggregates (Au NAs). Using this device, Salmonella Typhimurium down to 101 CFU mL-1 can be visually detected within 30 min by performing a simple operation that requires no complex equipment. This prototype device has great potential for use in the semi-quantitative and qualitative identification of pathogens in on-site primary diagnoses.

Colorimetric switchable linker-based bioassay for ultrasensitive detection of prostate-specific antigen as a cancer biomarker.

The use of colorimetric bioassays for protein detection is one of the most interesting diagnostic approaches, but their relatively poor detection limits have been a critical issue. In this study, we developed an efficient colorimetric bioassay based on switchable linkers (SLs) for the detection of prostate-specific antigen (PSA), which is one of the most widely used protein biomarkers for the diagnosis of prostate and breast cancers. SLs can cross-link gold nanoparticles (AuNPs) to generate large-scale aggregates and thereby induce precipitation to achieve visual signal amplification. In addition, when SLs are occupied by target proteins (referred to as 'switch-off'), highly sensitive detection is enabled. To maximize sensitivity, we adjusted the total surface area of AuNPs by controlling their concentration. As a result, PSA was detected at an ultralow concentration of 100 fg mL-1. This SL-based assay is shown to be simple, easy to handle and visualize, and highly sensitive. Therefore, in addition to PSA, the proposed SL-based assay could be used to detect other protein biomarkers.

Bifunctional linker-based immunosensing for rapid and visible detection of bacteria in real matrices.

Detection of pathogens present in food and water is essential to help ensure food safety. Among the popular methods for pathogen detection are those based on culture and colony-counting and polymerase chain reaction (PCR). However, the time-consuming nature and/or the need for sophisticated instrumentation of those methods limit their on-site applications. We have developed a rapid and highly sensitive immunosensing method for visible detection of bacteria in real matrices based on the aggregation of AuNPs without requiring any readout device. We use biotinylated anti-bacteria antibodies as bifunctional linkers (BLs) to mediate the aggregation of streptavidin-functionalized gold nanoparticles (st-AuNPs) to produce visually recognizable color change, due to surface plasmon resonance (SPR), which occurs in about 30min of total assay time when the sample is mildly agitated or within three hours in quiescent conditions. The aggregation of st-AuNPs, which produces the indication signal, is achieved very differently than in visual detection methods reported previously and hence affords ultrahigh sensitivity. While BLs can both bind to the target and crosslink st-AuNPs, their latter function is essentially disabled when they bind to the target bacteria. By varying the amount of st-AuNPs used, we can tailor the assay effectiveness improving limit of detection (LOD) down to 10CFUmL-1 of E. coli and Salmonella. Test results obtained with tap water, lake water and milk samples show that assay performance is unaffected by matrix effects. Further, in a mixture of live and autoclaved E. coli cells our assay could detect only live cells. Therefore, our BL-based immunosensor is suitable for highly sensitive, rapid, and on-site detection of bacteria in real matrices.

A Switchable Linker-Based Immunoassay for Ultrasensitive Visible Detection of Salmonella in Tomatoes.

On-site detection for sensitive identification of foodborne pathogens on fresh produce with minimal use of specialized instrumentation is crucial to the food industry. A switchable linker (SL)-based immunoassay was designed for ultrasensitive on-site detection of Salmonella in tomato samples. The assay is based on large-scale aggregation of gold nanoparticles (GNPs), induced by a quantitative relationship among the biotinylated Salmonella polyclonal antibody (b-Ab) used as the SL, the functionalized GNPs, and Salmonella. Important factors such as the concentration of SLs, time required for large-scale aggregation, and selectivity of b-Ab were optimized to minimize the detection time (within 45 min with gentle agitation) and achieve the lowest limit of detection (LOD; 10 CFU/g in tomato samples) possible. This SL-based immunoassay with its relatively low LOD and short detection time may meet the need for rapid, simple, on-site analysis of pathogens in fresh produce. PRACTICAL APPLICATION: The novel switchable linker-based immunoassay is a rapid, specific, and sensitive method that has potential applications for routine diagnostics of Salmonella in tomato products. These advantages make it a practical approach for general use in the processing industry to detect Salmonella rapidly and to implement appropriate regulatory procedures. Furthermore, it could be applied to other fresh products including cantaloupe, strawberry, and cucumbers.