Amino Acid Composition Analysis Research Articles

Glycation of sunnhemp protein with dextran via dry heating: Thermal, micro-structural characterization, and amino acid profiling.

This study aims to obtain sunnhemp protein isolate (SHPI) and dextran conjugates by dry heating method of Maillard conjugation. The effects of different incubation time (0, 1, 3, 5, 7, and 9 days) on the molecular flexibility, available lysine content, antioxidant properties, molecular structure, and thermal and micro-structural properties of conjugates were compared with SHPI (no conjugation) at 60°C and 79% relative humidity. The results indicated the formation of SHPI-dextran conjugates as confirmed by the change in molecular flexibility, lysine content, antioxidant activities, color, and water activity values. The molecular structure revealed the confirmation of covalent bonding between SHPI and dextran. Differential scanning calorimetry and thermo-gravimetric analysis results exhibited improvement in the thermal stability of SHPI when conjugated with dextran. The microstructural characterization showed that Maillard conjugation changed the surface structure of SHPI. The analysis of amino acid composition displayed that lysine, arginine, and phenylalanine were the dominant Maillard reaction sites of SHPI and dextran. Among all the conjugated samples, 5 days of incubation time was selected as an optimum condition for the development of SHPI-dextran conjugates on the basis of the aforementioned characterization. Overall, it was concluded that Maillard conjugation of sunnhemp protein with dextran via dry-heating technique could modify and improve its various attributes. PRACTICAL APPLICATION: The conjugation of plant proteins with polysaccharide through the Maillard reaction under dry heating conditions represents a natural and green technique for improving the techno-functional properties of proteins. The study has the potential to establish framework for the utilization of Sunnhemp protein isolate-dextran conjugates. This approach offers the potential for cost-effective production of emulsifiers and development of effective encapsulating matrices. The investigation expands on an underutilized plant protein source facilitating an alternative to animal-based proteins and contributing to the development of a sustainable circular bioeconomy.

Genomic insights into codon usage bias in Cannabis sativa and pathogenic interactions

This study delves into codon usage bias (CUB) across Cannabis sativa and its associated pathogens (Meloidogyne incognita, Alternaria alternata, Aspergillus flavus, Aspergillus niger, and Fusarium oxysporum). It finds an AT-bias in C. sativa and M. incognita, favouring AT ending codons, while fungal pathogens lean towards GC-ending codons. Analysis suggests weak codon bias overall, with host and nematode showing similar preferences, and fungal pathogens preferring GC-ending codons. In ENC/GC3 plot, parity plot analyses both natural selection and mutational pressure influence CUB, slightly favouring T-ending codons.Neutrality plot analysis demonstrated varying degrees of mutational pressure and selection across the organisms. Correspondence analysis revealed indistinguishable CUB effective in all pathogens, despite differences in evolutionary forces. Correlation analysis illustrated the impact of nucleotide composition, mutational pressure, and natural selection on CUB. Additionally, amino acid composition analysis indicated differential usage of amino acids across organisms. Codon context analysis unveiled common trends in codon pairing, emphasizing the prevalence of preferred codons in C. sativa and M. incognita. This comprehensive analysis provides insights into the factors shaping CUB and the evolutionary forces influencing the genomes of the host plant and its associated pathogens, contributing to a deeper understanding of molecular interactions in host-pathogen systems. This data informs conservation for Cannabis sativa by identifying pathogen-resistant genetic traits, guiding breeding and management for biodiversity preservation.

Lotus seed protein ameliorates hepatic lipid metabolic disorders in high-fat diet-fed mice via activating the PPARα signaling pathway

Obesity, one of the prevalent chronic diseases globally, is a serious threat to human health. Dietary natural compounds intervention is an effective means to alleviate obesity. The objective of this study was to investigate the potential protective role of lotus seed protein (LSP) against obesity. The results of amino acid composition analysis indicated that LSP possessed a well-balanced distribution of amino acids and was rich in branched-chain amino acids (BCAAs). Meanwhile, LSP exhibited better ABTS radical scavenging, DPPH radical scavenging, hydroxyl radical scavenging, and Fe2+ chelating ability in vitro. In vivo, LSP intervention remarkably alleviated body weight gain, organ index gain, dyslipidemia, and hepatic lipid deposition in high-fat diet (HFD)-fed mice. Meanwhile, LSP enhanced hepatic antioxidant enzyme activities (superoxide dismutase (SOD) and catalase (CAT)) and decreased malondialdehyde (MDA) levels, subsequently alleviated liver injury. In addition, LSP intervention significantly improved insulin sensitivity and glucose tolerance in obese mice, thereby alleviating hyperglycemia and insulin resistance. At the molecular level, LSP intervention up-regulated the mRNA and protein expression of fatty acid oxidation-related genes (FATP1, CPT-1a, ACOX1) and down-regulated the mRNA and protein expression of lipid synthesis-related genes (SREBP-1c, ACC, SCD-1, FASN) by activating the PPARα signaling pathway, thereby promoting hepatic fatty acid oxidation and reducing lipogenesis. These results demonstrate that LSP has the potential as a dietary supplementation to prevent and ameliorate obesity.

Rheological Properties of Fish and Mammalian Gelatin Hydrogels as Bases for Potential Practical Formulations.

Hydrogels have the ability to retain large amounts of water within their three-dimensional polymer matrices. These attractive materials are used in medicine and the food industry; they can serve as the basis for structured food products, additives, and various ingredients. Gelatin is one of widely used biopolymers to create hydrogels that exhibit biocompatibility and tunable rheological properties. In this study, we offer a comparative analysis of rheological properties of gelatin-based hydrogels (C = 6.67%), including mammalian gelatins from bovine and porcine skins and fish gelatins from commercial samples and samples extracted from Atlantic cod skin. Mammalian gelatins provide high strength and elasticity to hydrogels. Their melting point lies in the range from 22 to 34 °C. Fish gelatin from cod skin also provides a high strength to hydrogels. Commercial fish gelatin forms weak gels exhibiting low viscoelastic properties and strength, as well as low thermal stability with a melting point of 7 °C. Gelatins were characterized basing on the analysis of amino acid composition, molecular weight distribution, and biopolymer secondary structure in gels. Our research provides a unique rheological comparison of mammalian and fish gelatin hydrogels as a tool for the re-evaluation of fish skin gelatin produced through circular processes.

Comprehensive analysis of botanical origin and amino acid composition of bee pollen samples from various regions of Turkey

This study aimed to investigate the botanical diversity in bee pollen and amino acid composition of Turkish bee pollen samples collected from different regions. The monofloral bee pollen samples belonged to three different plant families: Asteraceae, Fabaceae, and Ranunculaceae. Additionally, Agean, Central Anatolian, Black Sea, and Marmara Regions have monofloral bee pollen samples with higher than 85% pollen frequency. The free amino acid (FAA) composition and content of the bee pollen samples were analyzed, with the essential amino acids comprising 13.13–18.28% of the total amino acid content. The Central Anatolian region displayed the highest ratio of essential amino acids, and the Aegean region exhibited a more diverse profile of FAA. Principal Component Analysis was performed to evaluate the variation in the data, with the eigenvalues of the two factors explaining 68.58% of the total variability. Moreover, cluster analysis revealed distinct dendrograms based on palynological characteristics and FAA composition.

Fenugreek seed proteins: Ultrasonic‐assisted extraction, characterization, and cupcake application

AbstractIn this study, fenugreek seed proteins were extracted using ultrasonic‐assisted extraction with varying solid:solvent ratios (20–60 g/L) and sonication amplitudes (30%–80%) to determine optimal conditions for the highest extraction yield. The functional, structural, and nutritional characteristics of the protein isolates of fenugreek seeds were investigated. The highest yield (98.74 ± 0.49%) was achieved at a solid:solvent ratio of 43.83 g/L and an amplitude of 67.51%. The coagulated protein values of fenugreek seed protein isolates ranged from ~15.8% to 31.2%, water‐holding capacities ranged from ~2.2 to 3.2 g/g, oil‐holding capacities ranged from ~2.6 to 4.1 g/g, foaming capacities ranged from ~16.3% to 21.3%, foam stabilities ranged from ~59.7% to 78.1%, emulsion stabilities ranged from ~30.2 to 34.5 min, emulsion activities ranged from ~73.8 to 76.8 m2/g, and emulsion capacities ranged from ~26.9% to 30.5% under different extraction conditions. SDS‐PAGE analysis revealed three distinct bands (46, 59, and 80 kDa) for the protein isolates. FT‐IR spectroscopy showed a high presence of β‐sheet structures. The amino acid composition analysis of fenugreek seed protein isolates was determined, revealing richness in essential amino acids (317.97 g amino acid/kg protein isolate). In addition, cupcakes enriched with protein isolates (5%, 10%, and 20% as flour substitutes) were produced, and quality properties such as color change, browning index, moisture content, water activity, baking yield, bulk density, hardness, volume, symmetry, and uniformity indexes were determined. The application of protein isolates in cupcake production demonstrated the potential of fenugreek seeds as valuable ingredients for enhancing the nutritional profile of bakery products.

Contribution of Gamma-Aminobutyric Amino Acid and Free Amino Acids to Low-Salt Whole-Wheat Bread through the Addition of Spice Extracts-An Approach Based on Taste Quality.

Given the link between excessive salt consumption and hypertension, reducing salt levels in bread, an important staple food in Japan, is essential. γ-Aminobutyric acid (GABA) has a salty taste-enhancing effect in vivo, and its production is influenced by the type of spice extract in vitro. However, the effects of spices on GABA levels, total free amino acid composition, and taste quality in whole-wheat bread remain unclear. Therefore, this study aimed to investigate whether the addition of spice extracts, which do not affect bread flavor and taste, can increase the GABA level in low-salt whole-wheat bread and whether free amino acid content affects the taste quality of bread using an automatic home bread maker. Through free amino acid composition analysis and sensory testing, we evaluated the influence of six spice extracts on the composition of free amino acids, including GABA, in whole-wheat bread. We found that cumin and anise extracts were effective in increasing the GABA level to approximately twice that in whole-wheat bread. Moreover, both the preference and saltiness of the bread were favorable, indicating that these extracts are useful for reducing the salt content of whole-wheat bread. This study provides a theoretical basis for guiding industrial production.

Valorisation of Spent Yeast Fermentation Media through Compositional-Analysis-Directed Supplementation

Spent fermentation media from bioprocessing represent a significant waste stream, and interest in recycling them as part of the developing circular bioeconomy is growing. The potential to reuse yeast spent culture media (YSM) to feed secondary bacterial fermentations producing recombinant protein was investigated in this study. Elemental and amino acid compositional analysis using inductively coupled plasma mass spectrometry (ICP-MS) and LC-MS/MS identified significant differences in the concentrations of 6 elements and 18/20 amino acids in YSM compared with rich microbiological media (LB). Restoration of levels of magnesium and sodium through addition of their salts and amino acids from tryptone supplementation led to the expression of equivalent titres of recombinant proteins by E. coli (0.275 g/L), compared to that in LB media (0.296 g/L) and BMMY media (0.294 g/L) in shake flask culture. When this supplementation strategy was employed in a bioreactor system, we observed a significant increase in recombinant protein titre using the supplemented YSM (2.29 (±0.02) g/L) over that produced using LB media (1.29 (±0.09) g/L). This study demonstrates through highly sensitive compositional analysis and identification of supplementation strategies the potential to valorise spent media from yeast fermentations that underpin industrial processes of significant scale, creating a circular approach to waste stream management.

One-step high efficiency separation of prolyl endopeptidase from Aspergillus niger and its application

Prolyl endopeptidase from Aspergillus niger (An-PEP) is an enzyme that recognizes C-terminal peptide bonds of amino acid chains and cleaves them by hydrolysis. An aqueous two-phase system (ATPS) was used to separate An-PEP from fermentation broth. Through single factor experiments, the ATPS containing 16 % (w/w) PEG2000 and 15 % (w/w) (NH4)2SO4 at pH 6.0 obtained the recovery of 79.74 ± 0.16 % and the purification coefficient of 7.64 ± 0.08. It was then used to produce soy protein isolate peptide (SPIP) by hydrolysis of soy protein isolate (SPI), and SPIP-Ferrous chelate (SPIP-Fe) was prepared with SPIP and Fe2+. The chelation conditions were optimized by RSM, as the chelation time was 30 min, chelation temperature was 25 °C, SPIP mass to VC mass was two to one and pH was 6.0. The obtained chelation rate was 82.56 ± 2.30 %. The change in the structures and functional features of SPIP before and after chelation were investigated. The FTIR and UV–Vis results indicated that the chelation of Fe2+ and SPIP depended mainly on the formation of amide bonds. The fluorescence, SEM and amino acid composition analysis results indicated that Fe2+ could induce and stabilize the surface conformation and change the amino acid distribution on the surfaces of SPIP. The chelation of SPIP and Fe2+ resulted in the enhancement of radical scavenging activities and ACE inhibitory activities. This work provided a new perspective for the further development of peptide-Fe chelates for iron supplement.

Characterization of Fish Skin Hydrolysates Exhibiting Dipeptidyl Peptidase IV Inhibitory Activity

Dipeptidyl peptidase IV (DPP-IV) inhibitors are antidiabetic drugs that can lower blood sugar levels. There are still few reports on the DPP-IV inhibitory activity of peptides obtained from discarded fish skin. Therefore, we prepared various enzymatic hydrolysates using the skins of six fish species and investigated their DPP-IV inhibitory effects. As a result, it was found that the DPP-IV inhibitory activity of yellowtail hydrolysate by Alcalase was higher than that of other enzymes. In addition, the IC50 after ethanol fractionation was found to be lower in yellowtail and eel skin hydrolysate. Amino acid composition analysis showed that the hydrolysate obtained from the skin of the yellowtail contained the highest amount of Gly, followed by Pro, Hyp, and Ala, indicating that it was a peptide derived from type I collagen. Fractionation with ethanol showed that the DPP-IV inhibitory components were contained in the low molecular weight fraction. The artificial digestion test observed no DPP-IV inhibitory activity or average molecular weight change. The DPP-IV inhibitory peptide obtained from fish skin has the potential to be applied as a food material to various food products.

The potential benefits of Oreochromis mossambicus derived hydrophobic peptides in protecting the skin against UVA-induced damage

This study explores the bioactive properties of peptide fractions obtained from tilapia fish scale collagen peptide, with a focus on their potential for skincare applications. Peptide fraction F5 demonstrated significant anti-UVA activity by effectively reducing oxidative stress and inhibiting elastase activity. Analysis of amino acid composition revealed a high concentration of specific amino acids in F5, suggesting antioxidant and elastase inhibitory actions. Moreover, compared to conventional antioxidants, F5 exhibited superior efficacy in scavenging free radicals such as ROS. In vitro studies demonstrated F5's ability to promote fibroblast proliferation and migration, contributing to cell repair and tissue regeneration. Mechanistic insights revealed F5's downregulation of MMP-1, MMP-3, and MMP-12 expression, which helps preserve collagen and elastin. Peptide identification and molecular docking analysis provided further understanding of F5's inhibitory mechanism against MMP-12. Overall, these findings indicate the potential of F5 in skincare products and functional foods, offering protection against UVA-induced damage and promoting skin health.

Investigation of the amino acid composition of gluten-free biscuit with carob

The article studies the amino acid composition of the developed biscuit semi-finished products. When developing the recipe for gluten-free products, special attention was paid to the protein composition of the raw materials and the calculation of the amino acid score, since the lack of a certain amino acid affects the ability of gluten formation during the kneading process. In addition, an unbalanced amino acid composition can cause an imbalance in the human body and negatively affect the functioning of muscles, heart, brain and other organs, leading to diseases. The objectives of the research included the following: determination of the amino acid composition of gluten-free biscuit semi-finished products; analysis of amino acid composition and calculation of the amino acid score of gluten-free biscuit products. The amino acid composition was calculated according to well-known methods, taking into account the chemical composition of food products. During the calculation, the biological value of proteins was assessed, the utility coefficient, the amino acid composition balance coefficient, and the amino acid score difference coefficient were determined. It was established that the developed gluten-free biscuit contained a significant amount of threonine, namely 11.38 g per 100 g of protein. As a result of calculations, it was determined that the first limiting amino acid was tryptophan, the second was the compound «phenylalanine + tyrosine», the shares of which in the amino acid score were 0.12 and 0.90, respectively. An assessment of the complex balance of a gluten-free biscuit semi-finished product showed an insufficient level of balance in human nutrition, but the indicators of individual amino acids compared to the control made from wheat flour were higher, for example, valine by 1.8 times, isoleucine, leucine and lysine by 1.1 times, metheonine + cysteine 2.7 times and threonine 2.8 times.

Analysis of Free Amino Acid Composition and Honey Plant Species in Seven Honey Species in China.

Honey is well-known as a food product that is rich in active ingredients and is very popular among consumers. Free amino acids (FAAs) are one of the important nutritional components of honey, which can be used not only as a nutritional indicator of honey but also as an indicator of plant source identification. In this study, the contents of 20 FAAs in seven types of honey from 11 provinces in China were examined for the first time. The 20 FAAs were analyzed by ultra-performance liquid chromatography-mass spectrometry/mass spectrometry (UPLC-MS/MS). By analyzing 93 honey samples from seven types of honey, the FAAs were found to range from 394.4 mg/kg (linden honey) to 1771.7 mg/kg (chaste honey). Proline ranged from 274.55 to 572.48 mg/kg, and methionine was only present in some of the linden honey, chaste honey, acacia honey, and rape honey. Evaluated by amino acid principal component analysis, multifloral grassland honey had the highest overall evaluation score, acacia and jujube honey were the most similar, while chaste honey was the least similar to the other types of honey. In addition, DNA was extracted from 174 Xinjiang grassland honey samples and different plant leaves for PCR and sequencing to identify the species of nectar plants. As a result, 12 families and 25 species of honey plants were identified. The results confirmed the diversity of FAAs in dissimilar types and sources of honey. This study provides a reference for expanding honey quality standards and verifying the authenticity of honey.

Exploring lipid health indices and protein quality in ninety Indian linseed varieties by comprehensive analysis of fatty acid composition, lignan content, and amino acid composition

Biochemical profiling of 90 linseed (Linum usitatissimum L.) varieties was done to have insights into their health benefits and nutritional properties. The analysis of fatty acid (FA) composition revealed 5 major FAs as α-linolenic acid (ALA), linoleic acid (LA), oleic acid (OA), palmitic acid (PA), and stearic acid (SA) ranging from 1.68% to 59.19%, 5.61–62.44%, 18.14–45.54%, 5.69–9.5%, and 3.94–10.29%, respectively. Secoisolariciresinol diglucoside (SDG) content varied significantly with a wide range of 0.02–3.60% in the seed with highest SDG content recorded so far as 3.60% in variety KL-226. Amino acid (AA) composition analysis revealed the variation in average amino acid content of essential amino acids (EAA) (His, Thr Val, Met, Trp, Phe, Ile, Leu, Lys) and non-essential amino acids (NEAA) (Asp, Glu, Ser, Gly, Arg, Ala, Tyr, Cys). Total NEAA content ranged from 3.24% to 23.69% while total EAA content ranged from 1.89% to 14.89%. Lipid heath indices such as atherogenicity index, thrombogenicity index, cholestrolemic index and peroxidisability index along with other fatty acid ratios such as n-6/n-3 ratio, UFA/SFA, PUFA/SFA were calculated to determine the stability of the varieties against auto-oxidation. It also revealed the positive effect of all varieties providing protection against atherosclerosis, coronary heart diseases, cancer and inflammatory diseases. Oleic desaturation ratio (ODR) and linoleic desaturation ratio (LDR) calculated to determine the desaturation efficiency of fatty acids, while protein efficiency ratio (PER) value calculated using amino acid composition determine the nutritional quality of protein. PER value ranged from 1.92 to 4.12 making all 90 varieties a good quality protein plant source. Principal component analysis revealed a significant variation between the fatty acid composition, amino acid composition and SDG content with a total variation of 69.95%. Hierarchical cluster analysis calculated using Pearson correlation coefficient revealed that 89 varieties are mostly similar except TL-99 variety.

Microencapsulation of Lactobacillus plantarum with Improved Survivability Using Pufferfish Skin Gelatin-Based Wall Materials.

To improve the survivability of probiotics, Lactobacillus plantarum was microencapsulated using pufferfish skin gelatin (PSG)-based wall materials by spray-drying. This work investigated the protective effect of three different pH-dependent proteins (sodium caseinate (SC), soy protein isolate (SPI), and whey protein isolate (WPI)) combined with PSG on L. plantarum. The experimental results of spray-drying with an inlet temperature of 120 °C and an outlet temperature of 80 °C, storage at 4 °C for 6 months, simulated digestion, and turbidity indicated that PSG/SC had better stability and encapsulation effects and was more suitable to encapsulate L. plantarum than PSG/SPI and PSG/WPI. The optimum preparation conditions for L. plantarum microcapsules were a PSG/SC mass ratio of 2:1, an SC concentration of 20 g/L, and a cell concentration of 10 g/L. The encapsulation efficiency of the obtained microcapsules was 95.0%, and the survival rate was 94.2% in simulated gastric fluid for 2 h and 98.0% in simulated intestinal fluid for 2 h. Amino acid composition analysis exhibited that the imino acid and aspartic acid contents of PSG were 27.98 and 26.16 g/100 g protein, respectively, which was much higher than commercial bovine gelatin. This characteristic was favorable to the high encapsulation efficiency and stability of microcapsules. In vitro release experiments showed that the PSG/SC microcapsules did not disintegrate in simulated gastric fluid for 2 h but could completely release in simulated intestinal fluid for 2 h, which can maintain the high survivability of L. plantarum in simulated digestion. In general, this study demonstrated that microcapsules using PSG/SC as wall materials can effectively improve the survivability of probiotics and have great potential for application in probiotic products.

Excellent iron-chelating capacity of Yesso scallop (Patinopecten yessoensis) skirt hydrolysate fermented by Bacillus subtilis M17-b7

Peptide ferrous chelate is a new type of biological iron, which has the advantages of high absorption rate, safety and no digestive tract irritation. In this study, microbial fermentation was used for the first time to prepare iron-chelating peptides. Forty-eight strains were applied to ferment scallop skirts. A dominating strain was eliminated by using the iron binding capacity of the scallop skirt hydrolysate as the screening index. The scallop skirt hydrolysate fermented by Bacillus subtilis M17-b7 showed excellent iron-chelating capacity (96.20% ± 0.03%). Meanwhile, the structure, morphology and bioactivity of fermented scallop skirt hydrolysate (FSH) and fermented scallop skirt hydrolysate-iron (FSH–Fe) were measured. Based on the amino acid composition and spectral analysis, it was confirmed that the significant amino acids contains carboxyl, carbonyl, and amino groups. The result of scanning electron microscope indicated that the surface of FSH became porous and the particles were bigger after chelating with ferrous. Moreover, the peptide-ferrous chelate was more stable in salt solutions and simulated gastric juice compared with ferrous sulfate. It is also noteworthy that the preparation of ferrous chelate peptides by fermentation is cost-effective compared with enzymatic hydrolysis. Therefore, this study provides theoretical support for the use of fermentation as a promising tool to produce peptide-ferrous chelate.

Genomic basis of environmental adaptation in the widespread poly-extremophilic Exiguobacterium group.

Delineating cohesive ecological units and determining the genetic basis for their environmental adaptation are among the most important objectives in microbiology. In the last decade, many studies have been devoted to characterizing the genetic diversity in microbial populations to address these issues. However, the impact of extreme environmental conditions, such as temperature and salinity, on microbial ecology and evolution remains unclear so far. In order to better understand the mechanisms of adaptation, we studied the (pan)genome of Exiguobacterium, a poly-extremophile bacterium able to grow in a wide range of environments, from permafrost to hot springs. To have the genome for all known Exiguobacterium type strains, we first sequenced those that were not yet available. Using a reverse-ecology approach, we showed how the integration of phylogenomic information, genomic features, gene and pathway enrichment data, regulatory element analyses, protein amino acid composition, and protein structure analyses of the entire Exiguobacterium pangenome allows to sharply delineate ecological units consisting of mesophilic, psychrophilic, halophilic-mesophilic, and halophilic-thermophilic ecotypes. This in-depth study clarified the genetic basis of the defined ecotypes and identified some key mechanisms driving the environmental adaptation to extreme environments. Our study points the way to organizing the vast microbial diversity into meaningful ecologically units, which, in turn, provides insight into how microbial communities adapt and respond to different environmental conditions in a changing world.

Extraction and characterization of collagen and gelatin from body wall of sea cucumbers Stichopus horrens and Holothuria arenicola.

Marine invertebrates, including sponges, molluscs, jellyfish, mussels, and sea cucumbers, are abundant sources of high-quality collagen and offer advantages such as availability, ease of processing, lower inflammatory response, and good metabolic compatibility. Approximately 70% of the total protein in the body wall of sea cucumbers is collagen. Gelatin is a water-soluble protein produced from heat-denatured collagen and has various industrial applications. Pepsin-solubilized collagen was extracted from the body wall of two sea cucumber Stichopus horrens and Holothuria arenicola, species found in the Oman Sea and characterized with SDS-PAGE and amino acid composition. Then gelatin was extracted from pepsin-solubilized collagen of S. horrens and some rheological properties were measured. Amino acid composition and SDS-PAGE analysis showed that the collagen from both species was type I, with one α1 chain and β chains, with molecular weights of 125 and 250 kDa, respectively. Glycine was the most abundant amino acid in the collagen from both sea cucumber species. The pepsin-soluble collagens from both species had high levels of glycine, proline, alanine, glutamic acid, and hydroxyproline. The gelatin from S. horrens had a melting point of 30 °C and displayed exceptional thermal stability, surpassing that of mammalian gelatin. Its gelling point was 5 °C, like that of cold-water fish gelatin, with a viscosity of 2.065 cp-lower than mammal gelatins. These findings suggested that collagen and gelatin from sea cucumbers could be useful in nutraceutical, pharmaceutical and cosmetic industries.

Comprehensive amino acid composition analysis of seed storage proteins of cereals and legumes: identification and understanding of intrinsically disordered and allergenic peptides

The seed storage proteins of cereal and legumes are the primary source of amino acids which are required for sustaining the nitrogen and carbon demands during germination and growth. Humans derive most of their dietary proteins from storage proteins in form of a wide variety of foods, for consumption. The amino acid content of most of these proteins is biased and the need for this biasness is not understood. The high abundance of proline, glutamine, and cysteine in cereals makes the gluten fraction viscoelastic. The cereal proteins have less charge and legume proteins have more charge on them. Their non-polar amino acid distribution has large variations. These characteristics are strongly responsible for the partial and complete unfolding of several domains of the storage proteins. Many of the storage proteins share a highly conserved structural feature within the cupin superfamily spread across all kingdoms of life. The intrinsically disordered viscoelastic proteins help in making dough which is vital for the quality of bread. Unfolded regions harbor more immunogenic sequences and cause food-related allergies and intolerance. We have discussed these properties in terms of comparison of cereal and legume storage protein sequences and allergy. Our study supports the findings that large disordered regions contain allergen-representative peptides. Interestingly, a high number of allergen-representative peptides were cleavable by digestive enzymes. Furthermore, unfolded storage proteins mimic microbial immunogens to induce a memory immune response. Results findings can be used to guide the understanding of immunological characteristics of storage proteins and may assist in treatment decisions for food allergy. Communicated by Ramaswamy H. Sarma

Orange fleshed sweet potato-rice bran flour: Optimization, proximate and amino acid composition for dough meal production

This study focuses on optimizing the proximate composition of dough meal made from blends of orange-fleshed sweet potato, defatted sesame, and rice bran flour. The utilization of these readily available local ingredients demonstrates significant potential for enhancing the nutritional value of staple foods. The research employs a systematic approach to determine the optimal proportions of these three flours, with the goal of achieving a balanced profile of essential nutrients. Parameters such as moisture, protein, fat, carbohydrate, and dietary fiber content were analyzed for the optimized blends. The observed ranges for moisture, ash, protein, fat, fiber, and carbohydrates in the flour samples were 0.99–3.31, 1.44 - 8.88, 6.25 - 13.97, 6.09 - 12.22, 2.22 - 5.00, and 66.22 - 77.21g/100g, respectively. The optimal blends were determined using response surface methodology software, with a focus on achieving high protein and fiber content. Functional, pasting, and amino acid composition analyses were performed on these optimum blends. In conclusion, the optimized flour blends of orange-fleshed sweet potato, defatted sesame, and rice bran present a viable alternative to conventional unripe plantain flour for dough meal production. This research bridges the gap between traditional staples and nutritional enrichment, offering potential solutions for addressing nutritional deficiencies and promoting sustainable dietary practices. The findings contribute to the development of innovative food formulations that cater to both nutritional needs and consumer preferences.