Rheological properties of dry-fractionated mung bean protein and structural, textural, and rheological evaluation of meat analogues produced by high-moisture extrusion cooking

Extrusion of plant proteins: A review of lipid and protein oxidation and their impact on functional properties

Extrusion processing can improve the functional and nutritional value of plant proteins, making them a sustainable source for various applications. During both low- and high-moisture extrusion, raw materials are subjected to harsh process conditions, leading to lipid and protein oxidation. In general, oxidation products are associated with adverse effects on product properties and human health. The oxidation rates are influenced by a number of factors, including temperature, water, oil content, and protein source, with lipid-protein interactions playing a significant role in oxidation dynamics and measurement accuracy. Higher extrusion temperatures and water content promote oxidation, yet are also necessary for fiber formation. Mild protein oxidation can improve functional properties and digestibility, while extensive oxidation tends to reduce both. Therefore, adjusting extrusion parameters is critical for controlling oxidation. In addition, natural antioxidants may reduce oxidation during extrusion, but their impact on functional properties requires further investigation.

Effects of screw configuration and interfacial properties on oil incorporation in high moisture extrusion

Routes to include oil in meat alternative products made through high moisture extrusion were investigated. We investigated effects of screw configuration and oil-water interfacial properties of the incorporated emulsion on the behavior of the oil during extrusion, and the characteristics of the extrudate after extrusion. Oil was incorporated in the form of an emulsion, and for comparison also directly added without prior emulsification. For oil addition by emulsion, several plant-based protein sources were compared as emulsifier. The choice of protein emulsifier had a strong effect on wedge length of the extrudate, the maximum linear strain and value of G' in shear, and the rupture strength of the extrudate. Two screw configurations were used. One with 1 kneading disc section and another with 4 kneading disc sections. It was found that fewer kneading discs in the screw led to less mechanical energy input, leading to less shear on the dough in the extruder. The use of fewer kneading elements resulted in less oil leakage from the product, while the product also was stronger, as demonstrated by the higher rupture strength in the texture analysis, and higher storage modulus G' in oscillatory shear rheology. Less deformation of the air pockets between protein structures could be seen in the screw with fewer kneading discs in multiphoton microscopy. As a result, both the screw configuration and the interfacial properties of the plant protein emulsifier need to be considered when developing meat alternative products containing oil as a route to control the texture of these products.

Tenderness in meat and meat alternatives: Structural and processing fundamentals

The demand for meat alternatives based on ingredients sourced from nonanimal materials with equivalent quality of muscle tissue is increasing. As more consumers switch to meat alternatives, a growing body of research has investigated the tenderness and related texture attributes in plant-based meats to increase consumer acceptance. A deeper understanding of tenderness including the differences and similarities between meat and meat alternatives is crucial to developing products that meet consumer expectations, as it directly influences consumer acceptance. Meat tenderness is commonly quantified using sensory evaluation and instrumental tests and is influenced by various factors such as the intrinsic features of the animal before the slaughter, naturally occurring proteolysis during the post-slaughter process, and several tenderization techniques. In contrast, meat alternative tenderness can be actively tailored through the selection of ingredients and the operating conditions of the structuring process. Especially, extrusion parameters such as moisture content and barrel temperature can greatly modulate tenderness-related attributes. Postprocessing methods that have traditionally been utilized for tenderizing have also been applied to meat alternatives, but more studies are needed to fully reveal the underlying mechanisms. This review offers an overview and critical discussion on tenderness, covering the structural origins, influencing factors, analytical methods, oral processing, and tenderization processes for both meat and meat alternatives. The discussion is based on the existing knowledge of muscle tissue, which evolves to critically reviewing how this understanding can be applied to the textural attributes of meat alternatives and what kind of novel tenderization techniques can be developed for these new sustainable food products.

Techno-functional, rheological, and chemical properties of plant-based protein ingredients obtained with dry fractionation and wet extraction

Dry fractionation is a promising technology for producing plant protein ingredients, owing to its minimal environmental impact and adaptability to diverse plant sources. Dry-fractionated proteins are still under development with limited applications in food industry due to lack of extensive knowledge about their physicochemical, rheological and chemical properties. Wet extraction though widely used, consumes high energy, water, and chemicals. In this research, the techno-functional, rheological, and chemical properties of commercial protein ingredients of various botanical species obtained via wet extraction (WE, n = 8) and dry fractionation (DF, n = 9) were investigated in order to identify their potential food applications. Compared to DF ingredients, WE proteins showed the lowest water solubility index and protein solubility at pH 7 and 9, as well as the lowest foaming and emulsifying capacities. This behavior can be explained by the presence of denatured protein structures in WE ingredients as suggested by the analysis of the secondary structure which revealed a higher presence of random coil structures. On the contrary, the presence of non-denatured structures in combination with other constituents like carbohydrates may have contributed to the high solubility and gelling properties of the DF proteins ingredients. While wet extraction technologies can offer a wide modulation of ingredient functionality, providing a broad spectrum of food applications, dry fractionation seems to guarantee a narrow range of techno-functional properties, although with potentially higher performance in certain areas like solubility and foaming.

Toward Diverse Plant Proteins for Food Innovation

This review highlights the development of plant proteins from a wide variety of sources, as most of the research and development efforts to date have been limited to a few sources including soy, chickpea, wheat, and pea. The native structure of plant proteins during production and their impact on food colloids including emulsions, foams, and gels are considered in relation to their fundamental properties, while highlighting the recent developments in the production and processing technologies with regard to their impacts on the molecular properties and aggregation of the proteins. The ability to quantify structural, morphological, and rheological properties can provide a better understanding of the roles of plant proteins in food systems. The applications of plant proteins as dairy and meat alternatives are discussed from the perspective of food structure formation. Future directions on the processing of plant proteins and potential applications are outlined to encourage the generation of more diverse plant-based products.

Multi-layered structure and physicochemical properties of reconstituted meat-based products from minced fish by physical extrusion: Impact of extrusion strength

Multi-layered structure of reconstituted meat-based products from minced fish was formed by physical extrusion, followed by an investigation into the impact of extrusion strength on structural and physicochemical properties before and after frying. Under an appropriate pressure (3-9 kPa), the air within minced fish underwent enrichment and rearrangement to form a stratified phase, promoting the formation of multi-layered structure during frying. Conversely, the lower pressure (≤1.5 kPa) was insufficient for phase separation and directional rearrangement, while the higher pressure (≥15 kPa) would cause the stratified phase to flow out of food system. Moreover, by directly increasing water mobility and meat compactness, physical extrusion indirectly caused more water loss and stronger ionic bonds during frying, which was positively correlated with multi-layered structure. However, an excessive pressure caused an increase in random coil and hydrophobic interactions during frying, which was negatively correlated with multi-layered structure. In conclusion, appropriate physical extrusion strength promoted the formation of multi-layered structure.

Smart proteins as a new paradigm for meeting dietary protein sufficiency of India: a critical review on the safety and sustainability of different protein sources

India, a global leader in agriculture, faces sustainability challenges in feeding its population. Although primarily a vegetarian population, the consumption of animal derived proteins has tremendously increased in recent years. Excessive dependency on animal proteins is not environmentally sustainable, necessitating the identification of alternative smart proteins. Smart proteins are environmentally benign and mimic the properties of animal proteins (dairy, egg and meat) and are derived from plant proteins, microbial fermentation, insects and cell culture meat (CCM) processes. This review critically evaluates the technological, safety, and sustainability challenges involved in production of smart proteins and their consumer acceptance from Indian context. Under current circumstances, plant-based proteins are most favorable; however, limited land availability and impending climate change makes them unsustainable in the long run. CCM is unaffordable with high input costs limiting its commercialization in near future. Microbial-derived proteins could be the most sustainable option for future owing to higher productivity and ability to grow on low-cost substrates. A circular economy approach integrating agri-horti waste valorization and C1 substrate synthesis with microbial biomass production offer economic viability. Considering the use of novel additives and processing techniques, evaluation of safety, allergenicity, and bioavailability of smart protein products is necessary before large-scale adoption.

Recent advances in mung bean protein: From structure, function to application

With the surge in protein demand, the application of plant proteins has ushered in a new wave of research. Mung bean is a potential source of protein due to its high protein content (20-30 %). The nutrition, structure, function, and application of mung bean protein have always been a focus of attention. In this paper, these highlighted points have been reviewed to explore the potential application value of mung bean protein. Mung bean protein contains a higher content of essential amino acids than soybean protein, which can meet the amino acid values recommended by FAO/WHO for adults. Mung bean protein also can promote human health due to its bioactivity, such as the antioxidant, and anti-cancer activity. Meanwhile, mung bean protein also has well solubility, foaming, emulsification and gelation properties. Therefore, mung bean protein can be used as an antioxidant edible film additive, emulsion-based food, active substance carrier, and meat analogue in the food industry. It is understood there are still relatively few commercial applications of mung bean protein. This paper highlights the potential application of mung bean proteins, and aims to provide a reference for future commercial applications of mung bean proteins.

Near-infrared spectroscopy to quantify overall thermal process intensity during high-moisture extrusion of soy protein concentrate

High-moisture extrusion (HME) is widely used to produce meat analogues. During HME the plant-based materials experience thermal and mechanical stresses. It is complicated to separate their effects on the final products because these effects are interrelated. In this study we hypothesize that the intensity of the thermal treatment can explain a large part of the physicochemical changes that occur during extrusion. For this reason, near-infrared (NIR) spectroscopy was used as a novel method to quantify the thermal process intensity during HME. High-temperature shear cell (HTSC) processing was used to create a partial least squares (PLS) regression curve for processing temperature under controlled processing conditions (root mean standard error of cross-validation (RMSECV) = 4.00 °C, coefficient of determination of cross-validation (R2CV) = 0.97). This PLS regression model was then applied to HME extrudates produced at different screw speeds (200-1200 rpm) and barrel temperatures (100-160 °C) with two different screw profiles to calculate the equivalent shear cell temperature as a measure for thermal process intensity. This equivalent shear cell temperature reflects the effects of changes in local temperature conditions, residence time and thermal stresses. Furthermore, it can be related to the degree of texturization of the extrudates. This information can be used to gain new insights into the effect of various process parameters during HME on the thermal process intensity and extrudate quality.

An Overview of Ingredients Used for Plant-Based Meat Analogue Production and Their Influence on Structural and Textural Properties of the Final Product

Plant-based meat analogues are food products made from vegetarian or vegan ingredients that are intended to mimic taste, texture and appearance of meat. They are becoming increasingly popular as people look for more sustainable and healthy protein sources. Furthermore, plant-based foods are marketed as foods with a low carbon footprint and represent a contribution of the consumers and the food industry to a cleaner and a climate-change-free Earth. Production processes of plant-based meat analogues often include technologies such as 3D printing, extrusion or shear cell where the ingredients have to be carefully picked because of their influence on structural and textural properties of the final product, and, in consequence, consumer perception and acceptance of the plant-based product. This review paper gives an extensive overview of meat analogue components, which affect the texture and the structure of the final product, discusses the complex interaction of those ingredients and reflects on numerous studies that have been performed in that area, but also emphasizes the need for future research and optimization of the mixture used in plant-based meat analogue production, as well as for optimization of the production process.