Effects of rice bran content on plant-based simulated meat: From the aspects of apparent properties and structural characteristics

High-moisture extrusion of rice bran-peanut proteins: Changes in structural properties and antioxidant activity simulating gastrointestinal digestion

In this experiment, we investigated the structural properties, digestibility, and variations in antioxidant activity of rice bran-tissue peanut protein (RB-TPP), which was created through high-moisture extrusion between peanut protein powder (PPP) and various additions (0 %, 5 %, 10 %, 15 %, and 20 %) of rice bran (RB). The disulfide bonding and hydrophobic interactions were strengthened, and the hydrogen bonding in the RB-TPP was weakened by adding 5-10 % RB. Additionally, the β-sheet content reached its maximum at RB-10 %, which allowed the hydrophobic groups to be encapsulated ina stable protein network fiber structure, enhancing degree of organization, the thermal stability and digestibility of RB-TPP. On the other hand, RB-10 % showed increased total phenolic content and antioxidant activity, in which the ABTS radical scavenging rate was increased by 22.14 % compared with that of RB-0 %, while the DPPH radical scavenging rate in simulated gastric digestion was increased by 10.59 %. RB addition at 15-20 % hindered the aggregation of proteins, which was not conducive to the rearrangement of protein molecules, and the increase in the irregular curls made the RB-TPP structure loose and disordered. This study provides valuable information for producing tissue proteins with stable fiber network structure and better nutritional and functional properties by adding RB.

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.

A mechanistic investigation into combined influences of NaCl and extrusion temperature on fibrous structures of high-moisture textured yeast protein

NaCl and extrusion temperature have an important influence on the qualities of high-moisture textured proteins, but the influence mechanism is still unclear. Therefore, this study prepared high-moisture textured yeast protein (HMTYP) with different NaCl contents (0%-4%) under different extrusion temperatures (170 °C, 180 °C) and characterized their physicochemical properties. The results showed that the HMTYP containing 1% and 2% NaCl prepared at 180 °C contained a strong fibrous structure. The possible mechanism was as follows: YP could not be sufficiently melted at 170 °C after adding NaCl, causing a decrease in the structural strength; however, at 180 °C, YP still reached a fully molten state even though 1%-2% NaCl was added. After YP sufficiently melted, NaCl enhanced the cross-linking and aggregation of proteins during cooling, which improved the textural properties of HMTYP. Accordingly, NaCl and extrusion temperature could combine to adjust the fibrous structure and texture of HMTYP.

Mulberry (Morus alba L.) leaf powder modified the processing of meat alternatives: Principal component analysis from apparent properties to chemical bonds

For texture control in plant-meat alternatives, the interrelationship between apparent characteristics and chemical bonds in high-fiber formulations remains unclear. The influence of mulberry leaf powder on apparent characteristics and chemical bonds of raw materials, block and strip products at addition amounts of 0.5-25% was analyzed. The results showed that 8% addition significantly increased the chewiness of the block by 98.12%. The strips' texture shows a downward trend, and the processing produced more redness and color difference. Additives promoted the formation of voids, lamellar and filamentous structures, and the strip produced more striped structures. Disulfide bonds significantly increased in the block, and the β-turn in the secondary structure enhanced by 12.20%. The β-turn transformed into a β-sheet in strips. Principal component analysis revealed that the texture improvement was associated with producing disulfide bonds and β-turn, providing a basis for high-fiber components to improve products' apparent characteristics by chemical bonds.

High moisture extrusion of soybean protein isolate: Effect of β-glucan on physicochemical properties of extrudates

This study is focused on exploring the effect of twin-screw high-moisture extrusion technology on the physico-chemical properties of β-glucan-soybean protein isolate (SPI-BG) extrudates. Different proportions (0 %, 1 %, 2 %, 3 %, 4 %, 5 %) of oat β-glucan (BG) were added with soybean protein isolate (SPI) to prepare SPI-BG extrudates. Results showed that the addition of a high quantity of β-glucan (BG) decreased the elastic properties of soy protein isolate (SPI) extrudates and then increased. The strengthening of S1-S2-S3 interactions (hydrogen bonds, hydrophobic interactions, and disulfide bonds) was primarily responsible for this trend. Fourier transform infrared (FTIR) spectral analysis was conducted which revealed that BG did not significant affect random coil content of SPI. However, it was observed that α-helix content was increased significantly and the β-sheet content was decreased. An observation was noted in the value of enthalpy (ΔH) change that increased from 115.80 J/g to 159.68 J/g.

Biochemical and protein nutritional potential of mulberry (Morus alba L.) leaf: partial substitution improves the nutrition of conventional protein

BACKGROUND

With the requirements of environmental, cost and economic sustainability, new sources of alternative proteins in the livestock industry are receiving increasing attention. Mulberry (Morus alba L.) leaves are a unique feed resource because of their high protein content and large availability. Therefore, mining sustainable protein suitable for the animal husbandry industry in sericulture resources could achieve a win-win situation.

RESULTS

The protein content in mulberry leaves is 232.10-386.16 g kg-1 , and the mean value of crude fat content is 43.76 ± 8.48 g kg-1 , which has the advantages of protein content and energy. In addition, the average content of phytic acid in mulberry leaves is only 1.88 ± 0.56 g kg-1 , which means that it is not inhibited in terms of nutrient absorption. Meanwhile, the digestibility of protein was Bean pulp > Sample 8 ≈ Alfalfa ≈ Sample 13 ≈ Cottonseed meal > Fish meal, and the β-turn and particle size of mulberry leaf protein are more conducive to digestion in vitro. Furthermore, the protein of Sample 13 had the richest essential amino acids (252.00 g kg-1 ) and the highest essential amino acid index (EAAI), which was superior to conventional feed protein. In addition, the partial substitution of mulberry leaf protein (15%) significantly increased the EAAI value of conventional feed protein. However, to balance nutrition, it is necessary to combine mulberry leaf protein with other proteins to further broaden its application field.

CONCLUSION

Mulberry leaves are a new source of feed protein, which helps to alleviate the two major problems of mulberry resource surplus and feed protein resource shortage. © 2023 Society of Chemical Industry.

Changes in physicochemical and structural properties of pea protein during the high moisture extrusion process: Effects of carboxymethylcellulose sodium and different extrusion zones

This study investigated effects of carboxymethylcellulose sodium (CMC) on the conformational evolution of pea protein during the high moisture extrusion process. The morphological observation showed that the addition of CMC facilitated the formation of fibrous structure of pea protein. In comparison with the pea protein in the melting zone and extrudate, the combination of CMC increased the denaturation enthalpy of pea protein by 2.09 % and 2.34 %. Compared with the material in the mixing zone, the degree of grafting between CMC and pea protein in the die was enhanced by 98.95 %. In general, the supplementation of CMC depressed the exposure of hydrophobic groups in the pea protein. In the extrusion barrel, the CMC increased the unfolding of protein molecular chains while it promoted the refolding of protein chains in the die. For the extrudate, the addition of CMC decreased the contents of α-helix and β-sheet of pea protein by 9.67 % and 6.93 % while the contents of β-turn and random coil were increased, leading to changes in the molecular weight distribution of protein molecules. In conclusion, these results provided new strategies toward producing the high-quality pea protein-based meat analogues by adding CMC.

Effects of Haematococcus pluvialis Addition on the Sensory Properties of Plant-Based Meat Analogues

Due to the increase in population and the deficiency of land resources, the cost of raising livestock is gradually increasing. Plant-based meat analogues (PBMAs) are considered excellent substitutes for animal meat. Our research investigated the effect of Haematococcus pluvialis (HP) on gluten-based soybean and wheat PBMA with contents of 1%, 3%, 5%, and 7%. Compared with the control group, HP significantly improved the color of the extrudates, showed visual characteristics similar to red meat, and achieved a soft texture and apparent rheological properties. The 7% HP had negative effects on the organizational degree and viscosity. In addition, the E-nose indicated that the different contents of HP changed the flavor of the extrudates. The extrudates with 3% and 5% HP were most similar to each other among all of the extrudates for volatile compounds, and the extrudates with 1% HP and 7% HP had significantly different flavors compared to the control group. Furthermore, 20 different volatile compounds were compared according to their retention indices and retention areas. The results showed that the proportions of alcohol, ester, terpenes, acid, and furan were increased. When the threshold was referenced, HP was considered to provide PBMAs with grassy and healing grain flavor properties. Therefore, the results proved that the addition of HP can improve PBMAs sensory properties.

Stabilization of Rice Bran: A Review

One of the major problems in food science is meeting the demand of the world's growing population, despite environmental limitations such as climate change, water scarcity, land degradation, marine pollution, and desertification. Preventing food from going to waste and utilizing nutritive by-products as food rather than feed are easy and powerful strategies for overcoming this problem. Rice is an important staple food crop for more than half of the world's population and substantial quantities of rice bran emerge as the main by-product of rice grain milling. Usually, rice bran is used as animal feed or discarded as waste. Although it is highly nutritious and comprises many bioactive compounds with considerable health benefits, the rapid deterioration of bran limits the exploitation of the full potential of rice bran. Hydrolytic rancidity is the main obstacle to using rice bran as food, and the enzyme inactivation process, which is termed stabilization, is the only way to prevent it. This study reviews the methods of stabilizing rice bran and other rice-milling by-products comprising rice bran in the context of the efficiency of the process upon storage. The effect of the process on the components of rice bran is also discussed.

Recent Advances in the Processing and Manufacturing of Plant-Based Meat

Plant protein technology is a core area of biotechnology to ease the problem of human protein demand. Plant-based meat based on plant protein technology is a growing concern by global consumers in alleviating environmental pollution, cutting down resources consumption, and improving animal welfare. Plant-based meat simulates the texture, taste, and appearance of animal meat by using protein, lipid, carbohydrate, and other plant nutrients as the main substances. This review summarizes the main components of plant-based meat, processing technology, standard formula, market competition, and formula and texture of future research directions. According to the existing methods of plant-based meat fiber forming, the development process and characteristics of four production processes and equipment of plant-based meat spinning, extrusion, shearing, and 3D printing are emphatically expounded. The processing principles and methods of different processing technologies in plant-based meat production are summarized. The production process and equipment of plant-based meat will pay more attention to the joint production of various processes to improve the defects of plant-based meat production process.

Physicochemical Characteristics and Flavor Properties of Texturized Dual-Proteins Extrudates: Effect of Surimi to Soybean Flour Ratio

This study investigated the effects of surimi to soybean flour ratio (0:10, 1:9, 2:8, 3:7, 4:6) on the physicochemical characteristics and flavor properties of dual-proteins extrudates. The increasing ratio of surimi improved the color of extrudates and raised the apparent viscosity of the mixed raw materials, which led to the decrease of extrudates' thickness. The excess ratio of surimi and soybean flour (more than 2:8) was bad for extrudates' physicochemical characteristics with sharply decreased tensile strength, macroscopic longitudinal fracture, broken and unevenly distributed microstructure, increased water mobility and decreased free water content. However, the increasing ratio of surimi had no effect on the protein secondary structure of extrudates. Sensory evaluation, E-tongue and E-nose analysis suggested that adding surimi significantly changed the flavor properties of extrudates, with increased sweetness and umami taste, and an appropriate ratio (2:8 or 3:7) could reduce the beany flavor and without an obvious fishy off-flavor.

Twin-Screw Extrusion of Oat: Evolutions of Rheological Behavior, Thermal Properties and Structures of Extruded Oat in Different Extrusion Zones

Further investigation of material properties during the extrusion process is essential to achieve precise control of the quality of the extrudate. Whole oat flour was used to produce low moisture puffed samples by a twin-screw extruder. X-ray diffraction (XRD), Scanning electron microscopy (SEM), infrared spectroscopy (FTIR), thermal analysis, and rheological experiments were used to deeply characterize changes in the structure and cross-linking of oats in different extrusion zones. Results indicated that the melting region was the main region that changed oat starch, including the major transformation of oat starch crystal morphology and the significant decrease of enthalpy representing the starch pasting peak in the differential scanning calorimeter (DSC) pattern (p < 0.05). Moreover, the unstable structure of the protein increased in the barrel and then decreased significantly (p < 0.05) after being extruded through the die head. The viscosity of oats increased in the cooking zone but decreased after the melting zone. A transformation occurred from elastic-dominant behavior to viscoelastic-dominant behavior for oats in the melting zone and after being extruded. This study provides further theoretical support for the research of the change of materials during extrusion and the development of oat-based food.

The Protein Composition Changed the Quality Characteristics of Plant-Based Meat Analogues Produced by a Single-Screw Extruder: Four Main Soybean Varieties in China as Representatives

Plant-based meat analogues (PBMs) are increasingly interesting to customers because of their meat-like quality and contribution to a healthy diet. The single-screw extruder is an important method for processing PBMs, and the characteristics of the product are directly affected by the composition of the raw materials; however, little research focuses on this issue. To explore the effect of protein composition on the quality characteristics of PBMs produced by a single-screw extruder, four soybean varieties used in China (Heihe 43 (HH 43), Jiyu 86 (JY 86), Suinong 52 (SN 52), and Shengfeng 5 (SF 5)) were selected. The 11S/7S ratios for these varieties ranged from 1.0: 1 to 2.5: 1 in order to produce PBMs with different protein compositions. The structure, processing, nutrition, and flavor characteristics were explored to analyze their differences. The results showed that protein composition affected the structure of PBMs, but the correlation was not significant. Meanwhile, a lower 11S/7S ratio (HH 43) did not prove to be a favorable characteristic for the processing of PBMs. From the perspective of nutrition and flavor, it seems acceptable to use a moderate 11S/7S ratio (JY 86 and SN 43) to produce PBMs. This study proved that the protein composition of raw materials affects the characteristics of PBM products produced by a single-screw extruder. To produce PBMs of higher quality, soybeans with a markedly different 11S/7S ratio should not be selected.