The rapid growth of the global population has led to an unprecedented demand for dietary protein. Canola seeds, being a widely utilized oil resource, generate substantial meal by-products following oil extraction. Fortunately, canola meals are rich in protein. In this present review, foremost attention is directed towards summarizing the characteristics of canola seed and canola seed protein. Afterwards, points of discussion related to pretreatment include an introduction to pulsed electric field treatment (PEF), microwave treatment (MC), and ultrasound treatment (UL). Then, the extraction method is illustrated, including alkaline extraction, isoelectric precipitation, acid precipitation, micellization (salt extraction), and dry fractionation and tribo-electrostatic separation. Finally, the structural complexity, physicochemical properties, and functional capabilities of rapeseed seeds, as well as the profound impact of various applications of rapeseed proteins, are elaborated. Through a narrative review of recent research findings, this paper aims to enhance a comprehensive understanding of the potential of canola seed protein as a valuable nutritional supplement, highlighting the pivotal role played by various extraction methods. Additionally, it sheds light on the broad spectrum of applications where canola protein demonstrates its versatility and indispensability as a resource.

Developing a low-protein feed is important for the sustainable advancement of aquaculture. The aim of this study was to investigate the effects of essential amino acid (EAA) supplementation in a low-protein diet on the growth, intestinal health, and microbiota of the juvenile blotched snakehead, Channa maculata in an 8-week trial conducted in a recirculating aquaculture system. Three isoenergetic diets were formulated to include a control group (48.66 % crude protein (CP), HP), a low protein group (42.54 % CP, LP), and a low protein supplementation EAA group (44.44 % CP, LP-AA). The results showed that significantly lower weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), and feed efficiency ratio (FER) were observed in fish that were fed LP than in the HP and LP-AA groups (P < 0.05). The HP and LP-AA groups exhibited a significant increase in intestinal villus length, villus width, and muscular thickness compared to the LP group (P < 0.05). Additionally, the HP and LP-AA groups demonstrated significantly higher levels of intestinal total antioxidant capacity (T-AOC), catalase (CAT), and superoxide dismutase (SOD) and lower levels of malondialdehyde (MDA) compared to the LP group (P < 0.05). The apoptosis rate of intestinal cells in the LP group was significantly higher than those in the LP and HP groups (P < 0.05). The mRNA expression levels of superoxide dismutase (sod), nuclear factor kappa B p65 subunit (nfκb-p65), heat shock protein 70 (hsp70), and inhibitor of NF-κBα (iκba) in the intestine were significantly higher in the LP group than those in the HP and LP-AA groups (P < 0.05). The 16s RNA analysis indicated that EAA supplementation significantly increased the growth of Desulfovibrio and altered the intestinal microflora. The relative abundances of Firmicutes and Cyanobacteria were positively correlated with antioxidant parameters (CAT and T-AOC), whereas Desulfobacterota was negatively correlated with sod and T-AOC. The genera Bacillus, Bacteroides, and Rothia were associated with the favorable maintenance of gut health. In conclusion, dietary supplementation with EAAs to achieve a balanced amino acid profile could potentially reduce the dietary protein levels from 48.66 % to 44.44 % without adversely affecting the growth and intestinal health of juvenile blotched snakeheads.

Non-alcoholic fatty liver disease (NAFLD), also known as metabolically associated fatty liver disease (MAFLD), is a systemic metabolic disease characterized by lipid accumulation in the liver, lipid toxicity, insulin resistance, intestinal dysbiosis, and inflammation that can progress from simple steatosis to nonalcoholic steatohepatitis (NASH) and even cirrhosis or cancer. It is the most prevalent illness threatening world health. Currently, there are almost no approved drug interventions for MAFLD, mainly dietary changes and exercise to control weight and regulate metabolic disorders. Meanwhile, the metabolic pathway involved in amino acid metabolism also influences the onset and development of MAFLD in the body, and most amino acid metabolism takes place in the liver. Essential amino acids are those amino acids that must be supplemented from outside the diet and that cannot be synthesized in the body or cannot be synthesized at a rate sufficient to meet the body\'s needs, including leucine, isoleucine, valine (collectively known as branched-chain amino acids), tryptophan, phenylalanine (which are aromatic amino acids), histidine, methionine, threonine and lysine. The metabolic balance of the body is closely linked to these essential amino acids, and essential amino acids are closely linked to the pathophysiological process of MAFLD. In this paper, we will focus on the metabolism of essential amino acids in the body and further explore the therapeutic strategies for MAFLD based on the studies conducted in recent years.

This study highlighted the nutritional importance of Catostylus perezi (an edible jellyfish) in Pakistan; a society where a large proportion of the population suffers from malnutrition, while C. perezi, a blessing of the sea, is wasted or exported. In the present study, the amino acid and fatty acid profiles of the oral arms and umbrella of C. perezi were determined by HPLC. The total amino acid concentration (ΣAA) in the oral arms was 151.19 mg/100g, while in the umbrella it was 100.17 mg/100g. The ratio of total essential amino acids to total non-essential amino acids (TEAA/TNEAA) was 0.72 in the oral arms, while it was 0.70 in the umbrella. Higher amount of ω-3 with lower ratio of ω-6/ω-3 in oral arms (0.52), rather umbrella (ω-6/ω-3 ratio; 0.62). The antimicrobial activity, MIC, MBC, and MFC of the whole body of the edible jellyfish were determined. On the basis of polarity, different solvents were used, e.g. water, methanol, dichloromethane, chloroform, and n-hexane. Among all the extracts, the water extract gave the highest ZOI against C. xerosis (29 mm), while the n-hexane extract gave the lowest ZOI against S. aureus (MRSA) ATCC 33591 (8.20 mm). The water extract of C. perezi had high potential against C. xerosis with the highest AMI and PAI (1.53 and 153, respectively), while the same extract had the highest TAI against E. coli (81.43 mL/g). For fungi/yeast, the methanolic extract had the highest ZOI (29.70 mm) against S. cerevisiae and the lowest MIC/MFC (2.40 µg/mL) against the same pathogen. The n-Hexane extract gave the lowest ZOI (11.10 mm) against P. variotii and the highest MIC/MFC (31.60 µg/mL) against Penicillium sp. Atomic force microscopy (AFM) was used to analyse the disintegrating effect of the extracts (with the highest antimicrobial effect) on the cells of selected Gram-positive, Gram-negative and yeast species. The amino acid and fatty acid profiles and antimicrobial assessment showed that C. perezi has great nutritional importance, so the use of C. perezi as food is highly recommended for the Pakistani community.

Alternative protein sources for the human diet may help overcome the growing food pressure. Plants with abundant resources and high protein content are potential sources. In this article, graded proteins and isolated proteins from Corylus mandshurica Maxim kernels were extracted by the Osborne procedure and the alkali-solution and acid-isolation method, respectively, and the contents of the five proteins, and the differences in nutritional value and structural properties of the main proteins, were investigated. Amino acid analysis revealed that the total essential amino acids in the five proteins ranged from 249.58 to 324.52 mg/g. The essential amino acid profiles in the proteins were similar to those of FAO/WHO except for the alcohol-soluble protein. The essential amino acid indices ranged from 58.59 to 72.19 and the biological values ranged from 52.16 to 66.99, and the highest nutritional indices were found for the isolate and water-soluble protein, which were 41.68 and 55.78, respectively. The molecular weight pattern distribution of the protein isolates of the Corylus mandshurica Maxim kernel was more similar to that of the water-soluble proteins by SDS-PAGE. The β-sheet and α-helix were the main secondary structures in the two protein fractions. The fluorescence spectra showed that the maximum fluorescence intensity of the two proteins and their λmax were also somewhat different. From the perspective of microscopic morphology, the two proteins are mainly compact and irregular lamellar structures, but the surface of the water-soluble protein is more flat and regular. Both proteins have good solubility, and the water-soluble protein has higher solubility. In general, the protein isolates of the Corylus mandshurica Maxim kernel and the water-soluble protein showed their potential as plant protein resources.

Published studies have shown positive associations of branched chain and aromatic amino acids with type 2 diabetes mellitus (T2DM), and the findings remain consistent. However, the associations of other essential and semi-essential amino acids, i.e., methionine (Met), threonine (Thr), lysine (Lys), arginine (Arg) and histidine (His), with T2DM remain unknown. Obesity is an important independent risk factor for T2DM, and excessive amino acids can convert into glucose and lipids, which might underlie the associations of amino acids with obesity. Therefore, we aimed to estimate the associations between dietary intakes of these 5 amino acids and T2DM risk, as well as the mediation effects of obesity on these associations, in a Chinese population.
A total of 10,920 participants (57,293 person-years) were included, and dietary intakes of 5 amino acids were investigated using 24-h dietary recalls. Anthropometric obesity indices were measured at both baseline and the follow-up endpoints. Associations of amino acids with T2DM were estimated using COX regression models, hazard ratios (HRs) and 95% confidence intervals (95% CIs) were shown. The mediation effects of obesity indices were analyzed, and the proportion of the mediation effect was estimated.
Higher intakes of the 5 amino acids were associated with increasing T2DM risk, while significant HRs were only shown in men after adjustments. No interaction by gender was found. Regression analyses using quintiles of amino acids intakes showed that T2DM risk was positively associated with amino acids intakes only when comparing participants with the highest intake levels of amino acids to those with the lowest intake levels. Adjusted correlation coefficients between amino acid intakes and obesity indices measured at follow-up endpoints were significantly positive. Mediation analyses showed that mediation effects of obesity indices existed on associations between amino acids intakes and T2DM risk, and the mediation effect of waist circumference remained strongest for each amino acid.
We found positive associations of dietary intakes of Met, Thr, Lys, Arg and His with increasing T2DM risk in general Chinese residents, on which the mediation effect of obesity existed. These findings could be helpful for developing more constructive guidance in the primary prevention of T2DM based on dietary interventions.

Amino acids are an essential group of compounds involved in protein synthesis and various metabolic and immune reactions in the human body. Chinese jujubes (Ziziphus jujuba Mill.) are an important fruit and medicinal plant which are native to China and have been introduced into around 50 countries. However, systematic research on the composition and content diversity of amino acids in the jujube is still lacking. In this experiment, the amino acid composition and the contents of the dominant amino acids in the fruit of 161 cultivars of jujube were determined by HPLC. Of the twenty-one kinds of amino acids detected, a total of fourteen kinds of amino acids were detected, of which eight kinds of amino acids were relatively high, including five essential amino acids (threonine, valine, isoleucine, leucine, and phenylalanine) and three nonessential amino acids (glycine, alanine, and proline). However, the contents of the remaining six amino acids were relatively low (aspartic acid, glutamic acid, histidine, serine, arginine, and tryptophan). Therefore, the eight primary amino acids were used as the index to evaluate the amino acids of 161 jujube varieties. Proline accounts for 56.8% of the total amino acid content among the eight amino acids. The total content of the eight primary amino acids in most jujube varieties was 1-1.5 g/100 g, and the highest content of \'Zaoqiangmalianzao\' was 2.356 g/100 g. The average content of proline was 6.01-14.84 times that of the other seven amino acids. According to the WHO/FAO revised model spectrum of ideal essential amino acids for humans, 19 cultivars met the E/T (essential amino acids/total amino acids) standard, and their values ranged from 35% to 45%; 12 cultivars meet E/NE (non-essential amino acids) ≥ 60%. All cultivars reached the requirement of BC (branched-chain amino acids)/E ≥ 40% with 15 cultivars over 68%. One hundred and fifty-seven cultivars reach the standard of BC/A (aromatic amino acids) ≈ 3.0~3.5. The amino acid ratio coefficient analysis showed that phenylalanine was the first limiting amino acid of all the jujube cultivars. The SRC (the score of amino acid ratio coefficient) values of 134 cultivars were between 50% and 70%, with 12 cultivars over 70%, indicating that jujube fruits are of high nutritional value in terms of amino acids. Based on the principal component analysis and comprehensive ranking of amino acid nutritional value, the top five cultivars were screened from the 161 ones tested, i.e., \'Tengzhouchanghongzao\', \'Xinzhengxiaoyuanzao\', \'Hanguowudeng\', \'Xuputiansuanzao\', and \'Lichengxiaozao\'. This study established, firstly, a complete basic data analysis of amino acid content in jujube fruit which could be used to select germplasm resources suitable for developing functional amino acid food, and provide theoretical support for the high value utilization of amino acids in jujubes.

Age-induced osteoporosis is a global problem. Essential amino acids (EAAs) work as an energy source and a molecular pathway modulator in bone, but their functions have not been systematically reviewed in aging bone. This study aimed to discuss the contribution of EAAs on aging bone from in vitro, in vivo, and human investigations. In aged people with osteoporosis, serum EAAs were detected changing up and down, without a well-established conclusion. The supply of EAAs in aged people either rescued or did not affect bone mineral density (BMD) and bone volume. In most signaling studies, EAAs were proven to increase bone mass. Lysine, threonine, methionine, tryptophan, and isoleucine can increase osteoblast proliferation, activation, and differentiation, and decrease osteoclast activity. Oxidized L-tryptophan promotes bone marrow stem cells (BMSCs) differentiating into osteoblasts. However, the oxidation product of tryptophan called kynurenine increases osteoclast activity, and enhances the differentiation of adipocytes from BMSCs. Taken together, in terms of bone minerals and volume, more views consider EAAs to have a positive effect on aging bone, but the function of EAAs in bone metabolism has not been fully demonstrated and more studies are needed in this area in the future.

Acid rain threatens crop yield and nutritional quality, and Ca2+ can regulate plant responses to abiotic stresses. To improve the yield and nutritional quality of crops under acid rain stress, we applied exogenous Ca2+ to regulate nitrogen assimilation in rice seedlings under simulated acid rain stress (pH 4.5 or 3.0), taking yield and nutritional quality of rice as evaluation criteria. We found that Ca2+ (5 mM) maintained the total nitrogen content of rice at the seedling and booting stages to alleviate the inhibitory effect of simulated acid rain on rice yield. Meanwhile, Ca2+ improved the activity of glutamate synthase to eliminate the disruption of glutamine synthetase/glutamate synthase balance under simulated acid rain. It decreased the efficiency of nitrogen assimilation, thereby reducing the inhibition of essential amino acid content in rice. The mitigation effect on simulated acid rain at pH 4.5 was better than that of simulated acid rain at pH 3.0. Overall, Ca2+ may reduce the negative effect of acid rain on the yield and nutritional quality of crops.

Temperate honey bees (Apis mellifera) are challenged by low temperatures and abrupt dietary shifts associated with behavioral changes during winter. Case studies have revealed drastic turnover in the gut microbiota of winter bees, highlighted by the seasonal dominance of a non-core bacterium Bartonella. However, neither biological consequence nor underlying mechanism of this microbial turnover is clear. In particular, we ask whether such changes in gut profile are related to winter dietary shift and possibly beneficial to host and associated gut microbiome? Here, we integrated evidences from genomics, metagenomics, and metabolomics in three honey bee subspecies maintained at the same locality of northern China to profile both diversity and functional variations in gut bacteria across seasons. Our results showed that winter dominance of Bartonella was shared in all tested honey bee lineages. This seasonal change was likely a consequence of winter dietary shifts characterized by greatly reduced pollen consumption and accumulation of metabolic waste due to restricted excretion. Bartonella showed expanded genomic capacity in utilizing more diverse energy substrates, such as converting metabolic wastes lactate and ethanol into pyruvate, an energy source for self-utilization and possibly also for host and other symbionts. Furthermore, Bartonella was the only bacterium capable of both producing and secreting tryptophan and phenylalanine, whose metabolic products were detected in bee guts, even though all gut bacteria lacked relevant digestion enzymes. These results thus suggested a possible mechanism where the gut bacteria might benefit the host by supplementing them with essential amino acids lacking in a protein shortage diet. IMPORTANCE The abilities to survive winter and to adapt to major food changes are key traits that have enabled successful range expansion of the honey bees from the tropic to temperate climate. Our results highlighted a new possibility that gut bacteria may have played an important role in host survival of the severe winter condition. The non-core bacterium Bartonella is not only more adaptive to the winter diet but is also equipped with the capacity to provide the host with essential nutrients and important metabolic substrates. This overall host-bacterium profile is probably favored by natural selection, resulting in a consistent winter gut strategy across varied honey bee lineages. Conversely, when the hosts start to forage again, core bacteria maintained at low abundance during winter returned to their typical dominant status, thus completing the annual gut turnover. Our study suggests a new hypothesis where seasonal gut variations may improve the fitness of the honey bee, allowing them to explore more diverse climates.