Modification of hemp seed protein isolate (Cannabis sativa L.) by high-intensity ultrasound treatment. Part 1: Functional properties

Sustainable proteins from wine industrial by-product: Ultrasound-assisted extraction, fractionation, and characterization

Plant proteins are increasingly being used in the food industry due to their sustainability. They can be isolated from food industry waste and converted into value-added ingredients, promoting a more circular economy. In this study, ultrasound-assisted alkaline extraction (UAAE) was optimized to maximize the extraction yield and purity of protein ingredients from grapeseeds. Grapeseed protein was extracted using UAAE under different pH (9-11), temperature (20-50 °C), sonication time (15-45 min), and solid/solvent ratio (10-20 mL/g) conditions. The structural and functional attributes of grapeseed protein and its major fractions (albumins and glutelins) were investigated and compared. The albumin fractions had higher solubilities, emulsifying properties, and in vitro digestibilities but lower fluid binding capacities and thermal stability than the UAAE and glutelin fraction. These findings have the potential to boost our understanding of the structural and functional characteristics of grapeseed proteins, thereby increasing their potential applications in the food and other industries.

Soluble hemp protein-xylose conjugates fabricated by high-pressure homogenization and pH-shifting treatments

BACKGROUND

The process of Maillard conjugation occurs with plant proteins and sugars and can be influenced by several factors, such as processing time, pH, and shear force. By utilizing cavitation processes such as high-pressure homogenization (HPH) and pH-shifting, it is possible to regulate the degree of grafting, functional characteristics, and structural changes in the formation of conjugates. The present study aimed to improve the hemp protein concentrate (HPC) through two different conjugation techniques: HPH and pH-shifting-assisted processes.

RESULTS

The best conjugation conditions for the conventional method were identified as a 1:2 HPC to xylose ratio, a pH of 10, and 3 h of treatment at 70 °C. The use of HPH and pH 12-shifting methods resulted in a remarkable 2.5-fold increase in grafting degree, requiring less processing time. Fourier transform infrared spectra confirmed the formation of conjugates. Conjugates produced through HPH with pH 12-shifting (MPHX) transformed into soluble glycoproteins with a particle size of 74 nm. MPHX solubility increased by 5.7-fold than HPC, reaching 85.7%, with a more negatively charged surface at -32.4 mV. Microimages showed cracked and sharp forms for conjugated proteins compared to untreated HPC. Additionally, MPHX conjugates demonstrated superior properties in emulsion stability, foaming capacity, and antioxidant activity compared to HPC and classical conjugates.

CONCLUSION

The use of HPH and pH-shifting-assisted Maillard conjugation was highly effective in enhancing the functional attributes of hemp protein conjugates. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A comprehensive review on the recent trends in extractions, pretreatments and modifications of plant-based proteins

Plant-based proteins offer sustainable and nutritious alternatives to animal proteins with their techno-functional attributes influencing product quality and designer food development. Due to the inherent complexities of plant proteins, proper extraction and modifications are vital for their effective utilization. This review highlights the emerging sources of plant-based proteins, and the recent statistics of the techniques employed for pretreatment, extraction, and modifications. The pretreatment, extraction and modification approach to modify plant proteins have been classified, addressed, and the recent applications of such methodologies are duly indicated. Furthermore, this study furnishes novel perspectives regarding the potential impacts of emerging technologies on the intricate dynamics of plant proteins. A thorough review of 100 articles (2018-2024) shows the researchers' keen interest in investigating novel plant proteins and how they can be used; seeds being the main source for protein extraction, followed by legumes. Use of by-products as a protein source is increasing rapidly, which is noteworthy. Protein studies still lack knowledge on protein fraction, antinutrients, and pretreatments. The use of physical methods and their combination with other techniques are increasing for effective and environmentally friendly extraction and modification of plant proteins. Several studies explore the effect of protein changes on their function and nutrition, especially with a goal of replacing ingredients with plant proteins that have improved or enhanced qualities. However, the next step is to investigate the sophisticated modification methods for deeper insights into food safety and toxicity.

Improving the solubility and interfacial absorption of hempseed protein via a novel high pressure homogenization-assisted pH-shift strategy

A pH shift treatment aided by high pressure homogenization (HPH) with various pressures (0-120 MPa) was employed to structurally modify hempseed protein isolate (HPI). Compared with individual pH shift or HPH treatment, HPH-assisted pH shift improved the structural flexibility of HPI, as revealed by the increased random coil in protein secondary structure. With the incorporation of HPH into pH shift, the intrinsic fluorescence intensity was remarkably attenuated and redshifted, whereas the surface hydrophobicity was pronouncedly boosted, indicating the extensive unfolding of protein structure. Moreover, the cotreated HPI exhibited a smaller and more homogenous particle size, notably at a higher pressure. Consequently, the solubility was drastically raised by the cooperated treatments, to the maximum value (62.8 %) at 120 MPa. These physicochemical changes in the cotreated HPI facilitated a consolidated interfacial activity. Moreover, the cooperated treatment, especially highly pressured (120 MPa), facilitated the penetration and rearrangement of proteins at the oil-water interface.

Unraveling the potential of non-thermal ultrasonic contact drying for enhanced functional and structural attributes of pea protein isolates: A comparative study with spray and freeze-drying methods

The challenge of preserving the quality of thermal-sensitive polymeric materials specifically proteins during a thermal drying process has been a subject of ongoing concern. To address this issue, we investigated the use of ultrasound contact drying (USD) under non-thermal conditions to produce functionalized pea protein powders. The study extensively examined functional and physicochemical properties of pea protein isolate (PPI) in powder forms obtained through three drying methods: USD (30 °C), spray drying (SD), and freeze drying (FD). Additionally, physical attributes such as powder flowability and color, along with morphological properties, were thoroughly studied. The results indicated that the innovative USD method produced powders of comparable quality to FD and significantly outperformed SD. Notably, the USD-PPI exhibited higher solubility across all pH levels compared to both FD-PPI and SD-PPI. Moreover, the USD-PPI samples demonstrated improved emulsifying and foaming properties, a higher percentage of random coil form (56.2 %), increased gel strength, and the highest bulk and tapped densities. Furthermore, the USD-PPI displayed a unique surface morphology with visible porosity and lumpiness. Overall, this study confirms the effectiveness of non-thermal ultrasound contact drying technology in producing superior functionalized plant protein powders, showing its potential in the fields of chemistry and sustainable materials processing.

Optimization of sensory properties of ultrasound-treated strawberry vinegar

Vinegar is renowned for its benefits to human health due to the presence of antioxidants and bioactive components. Firstly, this study optimized the production conditions of ultrasound-treated strawberry vinegar (UT-SV), known for its high consumer appeal. The sensory properties of UT-SV were optimized by response surface methodology (RSM) to create the most appreciated strawberry vinegar. Secondly, various quality parameters of conventional strawberry vinegar (C-SV), UT-SV, and thermally pasteurized strawberry vinegar (P-SV) samples were compared. RSM was employed to craft the best strawberry vinegar based on consumers ratings of UT-SV. Sensory characteristics, bioactive values, phenolic contents, and organic acid contents of C-SV, UT-SV, and P-SV samples were assessed. Through optimization, the ultrasound parameters of the independent variables were determined as 5.3 min and 65.5 % amplitude. The RSM modeling levels exhibited high agreement with pungent sensation at 98.06 %, aromatic intensity at 98.98 %, gustatory impression at 99.17 %, and general appreciation at 99.26 %, respectively. Bioactive components in UT-SV samples increased after ultrasound treatment compared to C-SV and P-SV samples. Additionally, the amount of malic acid, lactic acid, and oxalic acid increased after ultrasound treatment compared to C-SV samples. Ultimately, UT-SV with high organoleptic properties was achieved. The ultrasound treatment positively impacted the bioactive values, phenolic and organic acid content, leading to the development of a new and healthy product.

Antisolvent precipitation for the synergistic preparation of ultrafine particles of nobiletin under ultrasonication-homogenization and evaluation of the inhibitory effects of α-glucosidase and porcine pancreatic lipase in vitro

To further enhance the application of nobiletin (an important active ingredient in Citrus fruits), we used ultrasonic homogenization-assisted antisolvent precipitation to create ultrafine particles of nobiletin (UPN). DMSO was used as the solvent, and deionized water was used as the antisolvent. When ultrasonication (670 W) and homogenization (16000 r/min) were synergistic, the solution concentration was 57 mg/mL, and the minimum particle size of UPN was 521.02 nm. The UPN samples outperformed the RN samples in terms of the inhibition of porcine pancreatic lipase, which was inhibited (by 500 mg/mL) by 68.41 % in the raw sample, 90.34 % in the ultrafine sample, and 83.59 % in the positive control, according to the data. Fourier transform infrared spectroscopy analysis revealed no chemical changes in the samples before or after preparation. However, the crystallinity of the processed ultrafine nobiletin particles decreased. Thus, this work offers significant relevance for applications in the realm of food chemistry and indirectly illustrates the expanded application potential of nobiletin.

Ultrasonic-Assisted Extraction of Dictyophora rubrovolvata Volva Proteins: Process Optimization, Structural Characterization, Intermolecular Forces, and Functional Properties

Dictyophora rubrovolvata volva, an agricultural by-product, is often directly discarded resulting in environmental pollution and waste of the proteins' resources. In this study, D. rubrovolvata volva proteins (DRVPs) were recovered using the ultrasound-assisted extraction (UAE) method. Based on one-way tests, orthogonal tests were conducted to identify the effects of the material-liquid ratio, pH, extraction time, and ultrasonic power on the extraction rate of DRVPs. Moreover, the impact of UAE on the physicochemical properties, structure characteristics, intermolecular forces, and functional attributes of DRVPs were also examined. The maximum protein extraction rate was achieved at 43.34% under the best extraction conditions of UAE (1:20 g/mL, pH 11, 25 min, and 550 W). UAE significantly altered proteins' morphology and molecular size compared to the conventional alkaline method. Furthermore, while UAE did not affect the primary structure, it dramatically changed the secondary and tertiary structure of DRVPs. Approximately 13.42% of the compact secondary structures (α-helices and β-sheets) underwent a transition to looser structures (β-turns and random coils), resulting in the exposure of hydrophobic groups previously concealed within the molecule's core. In addition, the driving forces maintaining and stabilizing the sonicated protein aggregates mainly involved hydrophobic forces, disulfide bonding, and hydrogen bonding interactions. Under specific pH and temperature conditions, the water holding capacity, oil holding capacity, foaming capacity and stability, emulsion activity, and stability of UAE increased significantly from 2.01 g/g to 2.52 g/g, 3.90 g/g to 5.53 g/g, 92.56% to 111.90%, 58.97% to 89.36%, 13.85% to 15.37%, and 100.22% to 136.53%, respectively, compared to conventional alkali extraction. The findings contributed to a new approach for the high-value utilization of agricultural waste from D. rubrovolvata.

Viscoelastic behavior, gelation properties and structural characterization of Deccan hemp seed (Hibiscus cannabinus) protein: Influence of protein and ionic concentrations, pH, and temperature

This study investigates the viscoelastic behavior, gelling properties, and structural characteristics of Deccan hemp seed protein (DHSP) to overcome limitations in its application in food formulations. Small amplitude oscillatory shear measurements were employed to investigate the impact of protein concentration, pH, ionic concentration, and temperature on DHSP's rheological features. The study revealed that the 20 % protein dispersion had the highest storage modulus (G') and yield stress at 63.96 ± 0.23 Pa and 0.61 Pa, respectively. DHSP dispersion exhibited pseudo-plastic behavior across various conditions. The gelling performance was higher at pH 4 and 8 and at ionic concentration in the range of 0.1 M - 0.5 M. Gelation time and temperature were observed from the temperature ramp test. Structural characterizations, including fluorescence spectroscopy, circular dichroism spectra, FTIR spectra, SEM, AFM images, zeta potential analysis, and DSC, provided insights into DHSP's tertiary and secondary conformation, surface characteristics, and thermal properties. Notably, the study highlighted DHSP's exceptional rheological properties, making it a promising gelling material for the food and nutraceutical industries. The findings also offer new insights into DHSP's structural characteristics, suggesting potential applications in food packaging and product development within the food industry.

Microfluidized hemp protein isolate: an effective stabilizer for high-internal-phase emulsions with improved oxidative stability

BACKGROUND

Hemp protein isolates (HPIs), which provide a well-balanced profile of essential amino acids comparable to other high-quality proteins, have recently garnered significant attention. However, the underutilized functional attributes of HPIs have constrained their potential commercial applications within the food and agriculture field. This study advocates the utilization of dynamic-high-pressure-microfluidization (DHPM) for the production of stable high-internal-phase emulsions (HIPEs), offering an efficient approach to fully exploit the potential of HPI resources.

RESULTS

The findings underscore the effectiveness of DHPM in producing HPI as a stabilizing agent for HIPEs with augmented antioxidant activity. Microfluidized HPI exhibited consistent adsorption and anchoring at the oil-water interface, resulting in the formation of a dense and compact layer. Concurrently, the compression of droplets within HIPEs gave rise to a polyhedral framework, conferring viscoelastic properties and a quasi-solid behavior to the emulsion. Remarkably, HIPEs stabilized by microfluidized HPI demonstrated superior oxidative and storage stability, attributable to the establishment of an antioxidative barrier by microfluidized HPI particles.

CONCLUSION

This study presents an appealing approach for transforming liquid oils into solid-like fats using HPI particles, all without the need for surfactants. HIPEs stabilized by microfluidized HPI particles hold promise as emerging food ingredients for the development of emulsion-based formulations with enhanced oxidative stability, thereby finding application in the food and agricultural industries. © 2023 Society of Chemical Industry.

A comprehensive review on hempseed protein: Production, functional and nutritional properties, novel modification methods, applications, and limitations

With the global population on the rise, challenges in meeting protein demands are amplified by recent crises, prompting a swift shift to alternative protein sources due to disruptions in the supply chain. Plant-based proteins are gaining momentum due to economic, cultural, and environmental considerations, aligning with the preference for sustainable diets and resulting in more affordable plant-based products. The distinction between drug and industrial hemp fuels demand for its nutritional value, digestibility, low allergenicity, and bioactive properties. Industrial hempseed, featuring minimal Δ9-Tetrahydrocannabinol (THC) content (<0.2 %), emerges as a promising crop, offering high-quality protein and oil. The de-oiled hempseed cake stands as an eco-friendly and promising protein source enriched with phenolic compounds and fiber. Ongoing research seeks to enhance techno-functional properties of hempseed protein, surmounting initial limitations for integration into various foods. A range of techniques, both conventional and innovative, optimize protein characteristics, while modifying plant-based protein structures augments their application potential. Modification approaches like ultrasound, high-pressure homogenization, conjugation, complexation, fibrillization, and enzymatic methods enhance hempseed protein functionality. The review critically evaluates the techno-functional attributes of hempseed protein and explores strategies for customization through structural modifications. Lastly, the review assesses its composition, potential as a plant-based source, addresses challenges, and discusses strategies for enhanced functionality.

Non-thermal ultrasonic contact drying of pea protein isolate suspensions: Effects on physicochemical and functional properties

Pea protein isolate (PPI) is a popular plant-based ingredient, typically produced through alkaline-isoelectric precipitation and thermal drying. However, high temperatures and long drying times encountered in thermal drying can denature PPI and cause loss of functionality. This study investigated the use of an innovative ultrasonic dryer (US-D) at 30 °C for drying PPI suspensions, compared to conventional hot air drying (HA-D) at 60 °C. US-D led to an increase in the drying rate and correspondingly reduced the drying time by 55 %, when compared to HA-D. The average effective moisture diffusivity in the US-D process was 325 % higher than that in the HA-D process. The resulting PPI exhibited higher solubility, emulsification, and foaming properties than HA-D PPI, with a unique surface morphology and higher surface area. This study demonstrated that drying with acoustic energy is a promising approach for producing dried plant protein ingredients with improved functional properties, reduced processing time, and increased production efficiency.

Techno-functional attributes of oilseed proteins: influence of extraction and modification techniques

Plant-based protein isolates and concentrates are nowadays becoming popular due to their nutritional, functional as well as religious concerns. Among plant proteins, oilseeds, a vital source of valuable proteins, are continuously being explored for producing protein isolates/concentrates. This article delineates the overview of conventional as well as novel methods for the extraction of protein and their potential impact on its hydration, surface properties, and rheological characteristics. Moreover, proteins undergo several modifications using physical, chemical, and biological techniques to enhance their functionality by altering their microstructure and physical performance. The modified proteins hold a pronounced scope in novel food formulations. An overview of these protein modification approaches and their effects on the functional properties of proteins have also been presented in this review.

Production and identification of immunomodulatory peptides in intestine cells obtained from hemp industrial by-products

Hemp seeds have attracted the interest of the food industry recently, to be employed as functional food, considering their nutritional composition, highlighting the high content and quality of the proteins. In this study, ten hemp protein hydrolysates (HPHs) were obtained by enzymatic hydrolysis with two food-grade proteases from a hemp protein isolate and the inflammatory properties were evaluated in Caco-2 cell line. To this end, the gene expression and the release of proinflammatory and anti-inflammatory cytokines by Caco-2 cells stimulated with bacterial lipopolysaccharide and treated with HPHs at concentrations of 50 and 100 μg/mL were analyzed. The peptides contained in each HPH were identified and those with higher quality of the match in the spectrum were subjected to in silico analyses to determine which peptides were bioactive and contributing to the immunomodulatory activity of the hydrolysates. The results suggest that the immunomodulatory properties of these HPHs could have a beneficial effect at the level of the intestinal epithelium. The HPH20A and HPH60A + 15F exerted high immunomodulatory properties based on the cytokine levels release. The oligopeptides MAEKEGFEWVSF and GLHLPSYTNTPQLVYIVK were proposed as the most active ones. The potential of these peptides as nutraceuticals to prevent or pretreat intestinal inflammation is promising, though requires validation by in vivo assays.

Effects of slit dual-frequency ultrasound-assisted pulping on the structure, functional properties and antioxidant activity of Lycium barbarum proteins and in situ real-time monitoring process

To improve the protein dissolution rate and the quality of fresh Lycium barbarum pulp (LBP), we optimized the slit dual-frequency ultrasound-assisted pulping process, explored the dissolution kinetics of Lycium barbarum protein (LBPr), and established a near-infrared spectroscopy in situ real-time monitoring model for LBPr dissolution through spectral information analysis and chemometric methods. The results showed that under optimal conditions (dual-frequency 28-33 kHz, 300 W, 31 min, 40 °C, interval ratio 5:2 s/s), ultrasonic treatment not only significantly increased LBPr dissolution rate (increased by 71.48 %, p < 0.05), improved other nutrient contents and color, but also reduced the protein particle size, changed the amino acid composition ratio and protein structure, and increased the surface hydrophobicity, zeta potential, and free sulfhydryl content of protein, as well as the antioxidant activity of LBPr. In addition, ultrasonication significantly improved the functional properties of the protein, including thermal stability, foaming, emulsification and oil absorption capacity. Furthermore, the real-time monitoring model of the dissolution process was able to quantitatively predict the dissolution rate of LBPr with good calibration and prediction performance (Rc = 0.9835, RMSECV = 2.174, Rp = 0.9841, RMSEP = 1.206). These findings indicated that dual-frequency ultrasound has great potential to improve the quality of LBP and may provide a theoretical basis for the establishment of an intelligent control system in the industrialized production of LBP and the functional development of LBPr.

The foaming properties of sweet potato protein hydrolysates produced by Alcalase and Ficin

BACKGROUND

The processing of sweet potatoes generates a waste by-product rich in sweet potato protein (SPP).

OBJECTIVE

In this study, the effects of the concentrations of Alcalase and Ficin, hydrolysis time and pH value on the foaming properties of SPP hydrolysates (SPPHs) determined via gas sparging method were investigated.

RESULTS

The results showed that SPPH prepared by Alcalase exhibited a significantly higher foaming expansion (the highest of 576%) than that of the SPP (462%) but displayed a weaker liquid volume stability compared with SPPH hydrolyzed by Ficin. The molecular weight of SPPH prepared by Alcalase was distributed in 10-30 kDa. A good microbiological quality of the SPPH prepared by Alcalase in pH 13 has been confirmed, and it is suitable for food application with respect to its microbiological safety profile.

CONCLUSIONS

SPPH (pH 13) could be further safely applied in food, especially as a food additive at low concentrations to create a better organic plant-based foaming agent for the food industry. © 2023 Society of Chemical Industry.

Research Progress on Cannabinoids in Cannabis (Cannabis sativa L.) in China

Cannabis (Cannabis sativa L.) is an ancient cultivated plant that contains less than 0.3% tetrahydrocannabinol (THC). It is widely utilized at home and abroad and is an economic crop with great development and utilization value. There are 31 countries legalizing industrial cannabis cultivation. Cannabis fiber has been used for textile production in China for 6000 years. China is the largest producer and exporter of cannabis. China may still play a leading role in the production of cannabis fiber. China has a long history of cannabis cultivation and rich germplasm resources. Yunnan, Heilongjiang, and Jilin are three Chinese provinces where industrial cannabis can be grown legally. Cannabinoids are terpenoid phenolic compounds produced during the growth, and which development of cannabis and are found in the glandular hairs of female flowers at anthesis. They are the active chemical components in the cannabis plant and the main components of cannabis that exert pharmacological activity. At the same time, research in China on the use of cannabis in the food industry has shown that industrial cannabis oil contains 13-20% oleic acid, 40-60% omega-6 linoleic acid, and 15-30% omega-3 α-linolenic acid. At present, more than 100 cannabinoids have been identified and analyzed in China, among which phenolic compounds are the main research objects. For instance, phenolic substances represented by cannabidiol (CBD) have rich pharmacological effects. There are still relatively little research on cannabinoids, and a comprehensive introduction to research progress in this area is needed. This paper reviews domestic and foreign research progress on cannabinoids in cannabis sativa, which is expected to support cannabis-related research and development.

Effects of ultrasound on the oxidation and structures of the myofibrillar protein in the presence or absence of soybean oil

BACKGROUND

Ultrasound is widely used as a novel non-thermal processing technique to improve protein properties. In recent decades, applying ultrasound-assisted emulsification (UAE) to produce protein-stabilized emulsion has attracted people's attention. Instead of applying ultrasound to treat a single protein solution, UAE treatment refers to the use of sonication to a mixture of protein and oil. The purpose of this study was to compare the different effects of ultrasound treatment on the properties of the myofibrillar protein (MP) in the presence or absence of soybean oil. A suitable sonication power was selected based on the change in emulsion properties.

RESULTS

The 300W sonication power was selected due to its most effectively decreased emulsion droplet size and increased absolute zeta potential. Sonication more significantly increased the protein carbonyl content and disulfide bonds of the MP-soybean oil sample than MP sample. Due to the existence of oil, ultrasound could unfold more protein molecules illustrated by a lower α-helix content and intrinsic fluorescence intensity, and a higher surface hydrophobicity. LC-MS/MS results illustrated that sonication enhanced the myosin heavy chain and actin content at the soybean oil interface as well as accelerated the myosin light chain to separate from myosin in the MP-soybean oil system.

CONCLUSION

In summary, ultrasound treatment could lead to a higher level of protein oxidation and more protein molecule exposure in the MP with the presence of oil system than in the oil-free MP system. This article is protected by copyright. All rights reserved.

Hemp seed protein and chlorogenic acid complex: Effect of ultrasound modification on its structure and functional properties

In this study, the effects of ultrasound and chlorogenic acid (CA) on the structural and functional properties of hemp seed protein (HSP) was investigated. Compared with natural HSP, the UV-vis spectra intensity of ultrasound-treated HSP (UHSP) and UHSP-CA increased, the fluorescence spectra intensity decreased with a red shift in the maximum intensity peak. The results showed that ultrasound modification and complexation with CA unfolded the structure of HSP exposing its internal groups. Fluorescence quenching analysis showed that the best binding between UHSP and CA (binding constant 2.94 × 10² L/mol) was achieved at 450 W for 15 min of ultrasound treatment. In addition, the same ultrasound conditions minimized the particle size and surface roughness of UHSP and UHSP-CA. The solubility of UHSP and UHSP-CA increased by 23.3 and 38.7 %, the emulsifying activity index increased by 16.9 and 16.2 %, and the emulsion stability index increased by 20.9 and 20.8 %, respectively. These results indicated that appropriate ultrasound treatment and complexation with CA can significantly modify the structural and functional properties of HSP, improving its application value in the food field.

The Impact of High-Intensity Ultrasound-Assisted Extraction on the Structural and Functional Properties of Hempseed Protein Isolate (HPI)

Hempseed protein has become a promising candidate as a future alternative protein source due to its high nutritional value. In the current study, hempseed protein isolate (HPI) was obtained using ultrasonic-assisted extraction with the aim to improve the functionality of HPI via protein structure modification. The solubility of HPI could be improved twofold under 20 kHz ultrasound processing compared to conventional alkaline extraction-isoelectric point precipitation. The protein solubility was gradually enhanced as the ultrasonic power improved, whereas excessive ultrasound intensity would cause a decline in protein solubility. Ultrasonic processing was found to have beneficial effects on the other functionalities of the extracted HPI, such as emulsifying and foaming properties. This improvement can be ascribed to the physical effects of acoustic cavitation that changed the secondary and tertiary structures of the protein to enhance surface hydrophobicity and decrease the particle size of the extracted protein aggregates. In addition, more available thiols were observed in US-treated samples, which could be another reason for improved functionality. However, the results of this study also revealed that prolonged high-power ultrasound exposure may eventually have a detrimental impact on HPI functional properties due to protein aggregation. Overall, this study suggests that high intensity ultrasound can enhance the functionality of HPI, which may ultimately improve its value in HPI-based food products.

Improving the Functional Performance of Date Seed Protein Concentrate by High-Intensity Ultrasonic Treatment

Date kernel is a plant-derived byproduct that has the potential to be converted into a high-value-added food ingredient, such as protein concentrate, in the food industry. Ultrasound, which is an alternative method for improving the functional properties of food proteins, is an effective physical treatment for modifying protein functionality. Solubility is the main criterion that primarily affects other functional properties of protein concentrates, such as emulsification, foaming, and water and oil binding. The aim of this study is to enhance the techno-functional performance of date seed protein concentrate (DSPC) by maximizing the solubility via a high-intensity ultrasound (HIUS) treatment at a fixed frequency of 20 kHz. The effect of ultrasonic homogenization under varying amplitudes and times (amplitude of 40, 60, and 80% for 5, 10, and 15 min, respectively) on the functional properties of the DSPC was investigated by using the response surface methodology (RSM). A face-centered central composite design (FC-CCD) revealed that the optimal process conditions of HIUS were at an amplitude of 80% for 15 min. The physicochemical and functional properties of the ultrasound-applied concentrate (DSPC-US) were determined under the optimum HIUS conditions, and then these properties of DSPC-US were compared to the native DSPC. The results showed that the solubility of all DSPC samples treated by HIUS was significantly (p < 0.05) higher than that of the native DSPC. In addition, emulsion activity/stability, foaming activity/stability, and oil-binding capacity increased after HIUS homogenization treatments, whereas the water-binding capacity decreased. These changes in the techno-functional properties of the DSPC-US were explained by the modification to the physicochemical structure of the DSPC (particle size, zeta potential, SDS-PAGE, SEM, FTIR, DSC, free SH content, surface hydrophobicity, and intrinsic emission). This work revealed that HIUS could be an effective treatment for enhancing the functional properties of date seed protein concentrate.

Physicochemical and Antioxidant Properties of Industrial Hemp Seed Protein Isolate Treated by High-Intensity Ultrasound

Ultrasound is one of the non-thermal, green, and novel technologies used to functionalize plant proteins. We recently determined the optimum conditions of high-intensity ultrasound (HIUS) treatment for maximum solubility and investigated the functional properties of hemp seed protein isolate (HSPI) under the optimal conditions. In this study, we analyzed changes in primary, secondary, and tertiary structures, physical microstructures, thermal stability, and antioxidant capacity of ultrasound-applied hemp protein isolate (HSPI-HIUS). The free SH group content (+59%) and zeta potential (+25%) increased upon ultrasound treatment. The electrophoretic protein patterns of HSPI showed no significant change after HIUS treatment. The FTIR spectrum revealed the wavenumber shifts in Amid 1 and 2 regions of protein. The denaturation temperature and the ratio of β-structure increased after sonication. Antioxidant properties of hemp seed protein isolates were increased by 38% by ultrasound treatment. The obtained data in this study showed that HIUS treatment would be promising for improving the functional, physicochemical, and antioxidant properties of HSPI.

Structural and functional modification of proteins from black soybean Aquasoya via ultrasonication

Plant-based proteins obtained from agricultural by-products have garnered growing interest in response to consumer awareness of health and environmental issues. This study aimed to improve the functionalities of the proteins recovered from black soybean Aquasoya (PBSA) by modifying their structure via ultrasonication. PBSA was ultrasonicated with a frequency of 40 kHz at 350 W for different time periods (0, 20, 40, and 60 min), and its structural characteristics, physicochemical properties, and functional properties were investigated. Ultrasonication left the primary structure intact but altered the secondary and tertiary structures of the PBSA; α-helix and β-sheet contents decreased, random coil contents increased, and buried non-polar amino acid residues were exposed. Moreover, ultrasound promoted an increase in free sulfhydryl content and a reduction in particle size. Consequently, functional properties, such as solubility, emulsion stability, and foaming performance were improved by modifying the structure and physicochemical properties of PBSA. This work demonstrates the potential of ultrasound, which is favorable for modifying the spatial conformation and related functionalities of proteins, thus meeting the needs of manufacturers to use function-enhanced proteins as food additives.

Nutritional Quality, Chemical, and Functional Characteristics of Hemp (Cannabis sativa ssp. sativa) Protein Isolate

(1) Background: Hemp seeds are a source of plant-based protein, making them an appropriate supplement to a plant-based diet. The current work was focused on the preparation of the protein isolate from the hemp seeds with eco-friendly and cheap technology. Moreover, it evaluated the physicochemical and functional properties of hemp protein isolate for its potential application in food manufacturing. (2) Methods: The protein content of hemp seeds has been isolated through two main steps: (1) extraction of the protein content of an alkaline pH (10-12); (2) precipitation of the extracted protein on an acidic pH as an isoelectric point (pH = 4.5). (3) Results: The edastin protein is the most predominant protein in the protein profile with a molecular weight of 58.1 KDa beside albumin with a molecular weight of 31.5 KDa. The FTIR spectrum detected the absorption peaks of the amide I at 1750 and 1600 cm^-1, which pointed to C=O stretching while N-H stretching at 1650-1580 cm^-1. The peak at 3250 is found to be related to N-H stretching of the aliphatic primary amine (3400-3300 cm^-1) and the N-H stretching for the secondary (II) amine appeared at 3350-3310 cm^-1. The Hemp protein isolate (HPI) showed a high content of arginine (15.52 g/100 g), phenylalanine + tyrosine (9.63 g/100 g), methionine + cysteine (5.49 g/100 g), leucine + isoleucine (5.21 g/100 g), and valine (4.53 g/100 g). It contains a moderate level of threonine (3.29 g/100 g) and lysine (2.50 g/100 g) with tryptophan as the limiting amino acid (0.22 g/100 g). The HPI showed an appropriate water-and-oil holding capacity (4.5 ± 2.95 and 2.33 ± 1.88 mL/g, respectively). The foaming capacity of the HPI was increased with increasing the pH values to reach the maximum value at pH 11 (67.23 ± 3.20%). The highest emulsion ability index of the HPI was noted at pH 9 (91.3 ± 2.57 m²/g) with low stability (19.15 ± 2.03). (4) Conclusions: A strong positive correlation (r = 0.623) was shown between protein concentration and solubility. The current easy-to-use, cheap, and eco-friendly technology provides the industrial sector with a cheap protein isolate for manufacturing protein-rich diet and beverages. The HPI showed a good nutritional quality and functional properties that might be helpful in utilizing it in different food products such as beverages and bakery products.

Recent advances on the impact of novel non-thermal technologies on structure and functionality of plant proteins: A comprehensive review

The recent trend in consumption of plant-based protein over animal protein opens up a new avenue for sustainable agriculture practice, less environmental impact and greenhouse gas emission. The modification of plant-based proteins by novel non-thermal technologies includes the structural transformation followed by the modulation of their functional properties that are exploited to develop a protein ingredient system for application in food formulation. This review explores the impact of non-thermal process technologies on structural modification of plant proteins followed by improvement in protein's function in food formulation. Novel concepts articulating the impact of non-thermal technologies on structural and functional modification of plant proteins affecting it's digestibility and bioavailability are addressed. Limitations and prospects of applying non-thermal technologies in developing an alternative plant-based protein food system are also summarized. Non-thermal processes are considered as the emerging technologies that results in conformational changes in secondary, tertiary and quaternary structure of plant proteins which helps in modification of functional properties without jeopardizing the organoleptic properties and bioactivity of the protein. However, extensive future study is needed to optimize the non-thermal process parameters along with the finding of new protein sources to achieve healthy and sustainable plant-based food system.