Location: Food Processing and Sensory Quality Research
2024 Annual Report
Objectives
Objective 1: Resolve the underlying biochemical mechanisms involved in effective texturization of plant proteins to enable increased commercial use of bean-based ingredients.
Objective 2: Develop innovative methods for texturization of plant-based proteins and assess the effects of these technologies on food product quality and sensory characteristics to enable the development of new products.
Approach
In recent times, there has been a rising demand from consumers for high protein foods. As a result, global protein markets are expected to expand with increasing consumer health consciousness and growing demand for plant-based food. Along with these current trends, there is a looming food deficit on the horizon. By 2050, global food production will need to increase by 70% to feed the rapidly growing world population. To accomplish this, roughly 33% of dietary protein will need to come from protein isolates derived from alternative sources. US agricultural commodities like pulse crops, oil seeds, cereals, hemp, and others can be utilized to fill these protein deficits. To support utilization of these commodities, research is needed to identify components linked to functional, nutritional, and organoleptic quality of protein isolates and texturized vegetable protein, and high moisture meat analogs made from them. Because this is an emerging area of study, there is a lack of scientific literature and understanding related to the biochemical and processing factors that influence quality of these products. Identifying the mechanisms behind product variability will provide avenues to reduce it. The goals of this research are to decrease global food shortages and increase value of US agricultural commodities by advancing strategies to incorporate alternative proteins into the human diet. This research will enhance the functionality of alternative protein isolates, texturized vegetable proteins, and high moisture meat analogs through optimization of processing and biochemical modifications while maintaining or improving their sensory quality. Technologies such as extrusion will be used to yield texturized proteins and meat analogues, and analytical and affective sensory analysis methods will be used to assess end-use quality. The central hypothesis of this project is that alternative protein functionality and quality is dependent on the synergistic effects of processing techniques as well as the biochemistry of the starting material.
Progress Report
This project initiated after the deadline for ad hoc review (April 2022). Therefore, there is no 5-year plan and no milestones. It is currently operating at 0.2/1.2 SY FTE. Two post docs with expertise in sensory analysis and food process engineering have been hired to facilitate research.
FPSQ has significantly advanced the modernization of facilities and infrastructure to accommodate the new research project in previous and current fiscal cycles. The research unit has acquired an extruder for producing texturized vegetable proteins and high moisture meat analogues. Additionally, they have refurbished an existing membrane filtration system for protein isolations, and a 30mm extruder for scale-up studies.
ARS researchers at New Orleans, Louisiana continue biochemical characterization and screening of seed germplasms. Pulse crops and other less common alternative protein sources exhibit a highly variable protein profile compared to soy and many cereal grains. Methods have been developed to screen the protein profiles and composition of these crops to better define the variability. This information will lead to potential processing solutions to the problem and this information will be provided to breeders and geneticists to identify causes and solutions. Ultimately, this work will result in more uniform protein isolates, improving performance during the scale-up of alternative protein products.
Scientists completed a consumer study of plant and mushroom-based jerky products with 152 participants. The study will reconcile sensory quality with other consumer traits and instrumental texture measurements. Additionally, researchers have begun training the FPSQ descriptive sensory panel on texture evaluation. This involves development of texture lexicons and quantitative analysis of texture attributes, based on the type of product and raw materials used. The information gathered will help identify sensory deficits and areas for improvement as well as characterize key quality attributes by product type.
Under a NACA agreement with Washington State University, ARS researchers are producing and supplying pulse proteins for evaluation of their texturizing abilities. The researchers are assessing the biochemical characteristics of the raw materials and protein isolates before and after extrusion. Washington State University is conducting experiments to vary extrusion processing parameters, such as material feed rate, feed moisture, screw speed, screw configuration, and die dimensions, to control mechanical and thermal energy input. The resulting samples are being analyzed using physicochemical analyses, confocal and scanning electron microscopy, and rheological techniques to determine texturization and potential protein modifications. This data, combined with protein chemistry of the raw seeds and isolated proteins, will be used to identify pulse varieties that consistently produce high-quality, high-moisture meat analogues. Additionally, ARS scientists have optimized a semiquantitative method to assess protein cross-linking in the extruder. Generally, it is very challenging to solubilize these megadalton Mw range proteins for analyses.
Accomplishments
1. Defining biochemical parameters of plant protein texturization. This research focuses on addressing the scale-up challenges associated with high moisture meat analogs. The field has struggled to consistently achieve the critical attribute of fibrousness necessary for mimicking the texture of meat. In research led by Washington State University in collaboration with ARS researchers at New Orleans, Louisiana gained insights into the biochemical and mechanical requirements necessary to achieve fibrousness in texturized plant proteins. They discovered that reducing disulfide bonds, although having a relatively small impact on the total amount of these bonds, enhanced crosslinking between the proteins. They obtained samples with high fibrousness when they included cysteine or sodium metabisulfite, which suggested the splitting of existing disulfide bonds and their reformation into a large disulfide-linked network. Despite exhibiting the same amount of disulfide bonds, single and dual extruded materials differed in their properties, indicating that protein characteristics, including primary and secondary structures, as well as rheological and melting properties, play a significant role. ARS scientists also optimized a semiquantitative method to assess protein cross-linking occurring in the extruder. This method is crucial given the challenges in solubilizing proteins in the megadalton molecular weight range for analysis. This research provides insights into the biochemical changes required for texturization of plant proteins. By demonstrating that reducing disulfide bonds during extrusion improves material flow and cysteine crosslinking in the final product, the study offers potential to improve fibrousness in texturized plant proteins. These findings could pave the way for more effective scale-up processes, thus facilitating the entry of high moisture meat analogs into the marketplace and advancing the field of plant-based protein development.
Review Publications
Paladugula, M., Smith, B., Ardoin, R.P., Morris, C.F., Kiszonas, A. 2024. Effects of pea flour substitution and sodium metabisulfite on physical and sensory properties of pancake formulations. Cereal Chemistry. 101(4):858-870. https://doi.org/10.1002/cche.10785.
Richter, J., Smith, B., Saunders, S., Finnie, S.M., Ganjyal, G. 2024. Protein functionality is critical for the texturization process during high moisture extrusion cooking. ACS Food Science and Technology. 4(5):1142-1151. https://doi.org/10.1021/acsfoodscitech.3c00682.
Richter, J., Watanabe, P., Bernin, J., Smith, B., Mitacek, R., Ganjyal, G. 2024. Cysteine, sodium metabisulfite, and glutathione enhance crosslinking between proteins during high moisture meat analog extrusion processing and may improve the fibrousness of the products. Journal of the Science of Food and Agriculture. https://doi.org/10.1002/jsfa.13569.
Gao, Y., Chonpracha, P., Li, B., Ardoin, R.P., Prinyawiwatkul, W. 2024. The impact of information presentation on consumer perceptions of cricket-containing chocolate chip cookies. Foods. 13(3),479. https://doi.org/10.3390/foods13030479.