Explore the vast range of titles available.

Key messageDuring abiotic stress low abundant amino acids are not synthesized but they accumulate due to increased protein turnover under conditions inducing carbohydrate starvation (dehydration, salt stress, darkness) and are degraded.Metabolic adaptation is crucial for abiotic stress resistance in plants, and accumulation of specific amino acids as well as secondary metabolites derived from amino acid metabolism has been implicated in increased tolerance to adverse environmental conditions. The role of proline, which is synthesized during Arabidopsis stress response to act as a compatible osmolyte, has been well established. However, conclusions drawn about potential functions of other amino acids such as leucine, valine, and isoleucine are not entirely consistent. This study reevaluates published datasets with a special emphasis on changes in the free amino acid pool and transcriptional regulation of the associated anabolic and catabolic pathways. In order to gain a comprehensive overview about the general direction of amino acid metabolism under abiotic stress conditions a complete map of all currently known enzymatic steps involved in amino acid synthesis and degradation was assembled including also the initial steps leading to the synthesis of secondary metabolites. Microarray datasets and amino acid profiles of Arabidopsis plants exposed to dehydration, high salinity, extended darkness, cold, and heat were systematically analyzed to identify trends in fluxes of amino acid metabolism. Some high abundant amino acids such as proline, arginine, asparagine, glutamine, and GABA are synthesized during abiotic stress to act as compatible osmolytes, precursors for secondary metabolites, or storage forms of organic nitrogen. In contrast, most of the low abundant amino acids are not synthesized but they accumulate due to increased protein turnover under conditions inducing carbohydrate starvation (dehydration, salt stress, extended darkness) and are degraded.

This study was aimed to investigate the effect of new production system of local Kurdish slow-growing broilers with special emphasis on organic technique. A total of 360 one-day-old chicks mixed local slow-growing broiler genotype were distributed randomly into six treatments: (T1) control, feeding ad libitum commercial diet (indoor), (T2) feeding ad libitum organic (indoor), (T3) feeding commercial % 75+ pasture, (T4) feeding organic % 75+ pasture, (T5) feeding commercial ad libitum + pasture, and (T6) feeding organic ad libitum + pasture. Each treatment consists of 60 birds with three replicates per treatment, 20 birds replicate. The results indicated that organic group treatment (T6) that fed ad libitum feed and pasture had the highest body weight and weight gain. Meanwhile it had the lowest feed intake and better FCR. Fatty acids contents between treatments found to have significant differences for both organic and commercial feed. Significant differences were found when compared treatments to each other. Raising slow-growing chickens under different system and feeding organic feed at a different level have had a potential effect on their performances and profile of fatty acids, and amino acids of their meat. It was concluded that feeding chicken organic feed ad libitum and allowing to access to the pasture performed better than all other treatment groups. Significant differences were found among treatments for sensory evaluation. Organic treatments and commercial treatments under same condition were not found any significant differences.

Six types of nut-based bars with the addition of edible insect flour were obtained. Flours made from three different insects (Tenebrio molitor L., Acheta domesticus L., Alphitobius diaperinus P.) were used at two different additive levels (15% and 30%) in relation to the weight of the nuts. The addition of insect flour significantly increased protein content and the insoluble fraction of dietary fiber. The largest amount of these compounds was found in bars with 30% cricket flour, 15.51 g/100 g and 6.04 g/100 g, respectively, in comparison to standard bars, 10.78 g/100 g and 3.14 g/100 g, respectively. The greatest consumer acceptance was found in relation to bars with buffalo worm flour. The overall acceptance of these bars was 6.26–6.28 points compared to 6.48 for standard bars. Bars and raw materials were characterized by the high biological value of the protein. Cis linoleic acid dominated among unsaturated fatty acids. The percentage of this compound was in the range of 69.56%, for bars with a 30% addition of buffalo worm flour, to 73.88%, for bars with 15% cricket flour. Instrumental analysis of taste and smell compounds showed the presence of compounds such as 3-methylbutanoic acid, hexanal, and 2,3-pentanedione.

Insects are one of the most promising alternatives that can ease the expected global shortage of proteins. Determination of the nutritional value of edible insects in various instars is, therefore, crucial. Herein, we determined the content of basic nutrients and amino acid profile of larvae and pupae of Alphitobius diaperinus. The pupae contained significantly more protein and less fat than larvae. Unlike the protein quantity, no significant differences were found in the profile of essential amino acids. The essential amino acid index, describing the quality of protein, was similar regardless of the instar and comparable to the index for other insects and soybean meal. Additionally, we provide the first note on chitin content in A. diaperinus, present at a very low level in the pupae. The harvest of A. diaperinus in the pupal stage may provide high quality insect protein with a low chitin level.

Honeybee products, as multicomponent substances, have been a focus of great interest. The present work aimed to perform the nutritional and chemical profiling and biochemical characterization of bee pollen (BP), bee bread (BB), and royal jelly (RJ) and study their applications in the fortification of functional fermented dairy products. Their effects on starter cultures and the physicochemical and sensorial quality of products were monitored. A molecular networking analysis identified a total of 46 compounds in the three bee products that could be potential medicines, including flavonoids, fatty acids, and peptides. BB showed the highest protein and sugar contents (22.57 and 26.78 g/100 g), which cover 45.14 and 53.56% of their daily values (DVs), with considerable amounts of the essential amino acids threonine and lysine (59.50 and 42.03%). BP, BB, and RJ can be considered sources of iron, as 100 g can cover 141, 198.5, and 94.94% of DV%, respectively. BP was revealed to have the highest phenolic and flavonoid contents (105.68 and 43.91 µg/g) and showed a synergetic effect when mixed with RJ, resulting in increased antioxidant activity, while BB showed a synergetic effect when mixed with RJ in terms of both antioxidant and proteolytic powers (IC50 7.54, 11.55, 12.15, 12.50, and 12.65 cP compared to the control (10.55 cP)), reflecting their organoleptic properties and highlighting these health-oriented products as promising natural products for human health care.

Nitric oxide (NO) is a well-accepted signaling molecule that has regulatory effects on plants under various stresses. Salinity is a major issue that adversely affects plant growth and productivity. The current study was carried out to investigate changes in the growth, biochemical parameters, and yield of wheat plants in response to NO donors, namely sodium nitroprusside (SNP) (2.5 and 5.0 mM) and arginine (10 and 20 mM), under two salinity levels (1.2 mM and 85.5 mM NaCl). Salinity stress significantly decreased the lengths and weights of plant parts (shoot, tiller, and root) and reduced the flag leaf area, photosynthetic pigments, indole acetic acid (IAA), and yield and its components. Moreover, salt stress induced a significant accumulation of some osmoprotectants (total soluble sugars (TSS) and amino acids, especially proline) and triggered the accumulation of hydrogen peroxide (H2O2) and lipid peroxidation in wheat leaves. In contrast, arginine and SNP treatments significantly mitigated the negative impacts of salinity on growth and productivity via enhancing photosynthetic pigments, nitrate reductase, phenolic compounds, IAA, TSS, free amino acids, and proline. In addition, SNP and arginine potentially reduced oxidative damage by decreasing H2O2 and lipid peroxidation through the induction of antioxidant enzymes. The individual amino acid composition of wheat grains under the interactive effect of salinity and NO sources has been scarcely documented until now. In this study, the NO sources restrained the reduction in essential amino acids (isoleucine and lysine) of wheat grains under salinity stress and further stimulated the contents of non-essential and total aromatic amino acids. Interestingly, the applied protectants recovered the decrease in arginine and serine induced by salinity stress. Thus, SNP or arginine at the levels of 5.0 and 20 mM, respectively, had a profound effect on modulating the salt stress of wheat throughout the life cycle.

Euglena gracilis is one of the few permitted edible microalgae. Considering consumer acceptance, E. gracilis grown heterotrophically with yellow appearances have wider food industrial applications such as producing meat analogs than green cells. However, there is much room to improve the protein content of heterotrophic culture cells. In this study, the effects of nitrogen sources, temperature, initial pH, and C/N ratios on the protein production of E. gracilis were evaluated under heterotrophic cultivation. These results indicated that ammonium sulfate was the optimal nitrogen source for protein production. The protein content of E. gracilis cultured by ammonium sulfate increased by 113% and 44.7% compared with that cultured by yeast extract and monosodium glutamate, respectively. The manipulation of the low C/N ratio further improved E. gracilis protein content to 66.10% (w/w), which was 1.6-fold of that in the C/N = 25 group. Additionally, amino acid analysis revealed that the nitrogen-to-protein conversion factor (NTP) could be affected by nitrogen sources. A superior essential amino acid index (EAAI) of 1.62 and a balanced amino acid profile further confirmed the high nutritional value of E. gracilis protein fed by ammonium sulfate. This study highlighted the vast potency of heterotrophic cultured E. gracilis as an alternative dietary protein source.

Putrescine (Put), gibberellic acid (GA3), and salicylic acid (SA) are involved in improving fruit growth and development. This is the first study investigating the effect of 1 mM Put, 100 mg L -1 GA3, and 100 mg L -1 SA on Phoenix dactylifera , cv. Zaghloul fruits. The experiment was conducted in a completely randomized block design during two successive seasons and five treatments [control (distilled water spray), Put, Put + GA3, Put + SA, and Put + GA3 + SA] were sprayed at the Hababouk (cell division) stage and Kimri [unripe green (cell elongation)] stage. Our results showed that all treatments significantly improved the yield and quality of ‘Zaghloul’ fruit by increasing the dry matter, crude fiber, ash, total soluble solids, (reducing, non-reducing, and total soluble) sugars, carbohydrate, protein, nitrogen, phosphorus, potassium, calcium, magnesium, sodium, zinc, iron, and manganese content as well as the peroxidase and catalase activity. Compared with the control treatment, exogenous applications also enhanced the amino acid (glutamic acid, aspartic acid, proline, glycine, alanine, arginine, cysteine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, serine, threonine, tyrosine, valine) acquisition and phytohormone (indole-3-acetic acid, cytokinins, GA3, SA) content, while decreasing the percentage of moisture, total acidity, total phenols, and tannins. The novel evidence indicates that among all treatments, application of diamine (Put), in combination with phytohormones (GA3 and SA), has the greatest effect on improving ‘Zaghloul’ fruit yield by up-regulating the nutrient acquisition, sugar accumulation, amino acid profile, antioxidant response, and phytohormone performance. These findings support the use of Put in conjunction with GA3 and SA to improve fruit yield and quality.

Amino acids not only play a vital role in the synthesis of biological molecules such as proteins in cancer malignant cells, they are also essential metabolites for immune cell activation and antitumor effects in the tumor microenvironment. The abnormal changes in amino acid metabolism are closely related to the occurrence and development of tumors and immunity. Intestinal microorganisms play an essential role in amino acid metabolism, and tryptophan and its intestinal microbial metabolites are typical representatives. However, it is known that the cyclic amino acid profile is affected by specific cancer types, so relevant studies mainly focus on one type of cancer and rarely study different cancer forms at the same time. The objective of this study was to examine the PFAA profile of five cancer patients and the characteristics of tryptophan intestinal microbial metabolites to determine whether there are general amino acid changes across tumors. Plasma samples were collected from esophageal (n = 53), lung (n = 73), colorectal (n = 94), gastric (n = 55), breast cancer (n = 25), and healthy control (HC) (n = 139) subjects. PFAA profile and tryptophan metabolites were measured, and their perioperative changes were examined using high-performance liquid chromatography. Univariate analysis revealed significant differences between cancer patients and HC. Furthermore, multivariate analysis discriminated cancer patients from HC. Regression diagnosis models were established for each cancer group using differential amino acids from univariate analysis. Receiver-operating characteristic analysis was applied to evaluate these diagnosis models. Finally, GABA, arginine, tryptophan, taurine, glutamic acid, and melatonin showed common alterations across all types of cancer patients. Metabolic pathway analysis shows that the most significant enrichment pathways were tryptophan, arginine, and proline metabolism. This study provides evidence that common alterations of the metabolites mentioned above suggest their role in the pathogenesis of each cancer patient. It was suggested that multivariate models based on PFAA profiles and tryptophan metabolites might be applicable in the screening of cancer patients.

Meat represents an important protein source, even in developing countries, but its production is scarcely sustainable, and its excessive consumption poses health issues. An increasing number of Western consumers would replace, at least partially, meat with alternative protein sources. This review aims at: (i) depicting nutritional, functional, sensory traits, and critical issues of single-cell proteins (SCP), filamentous fungi, microalgae, vegetables (alone or mixed with milk), and insects and (ii) displaying how fermentation could improve their quality, to facilitate their use as food items/ingredients/supplements. Production of SCP (yeasts, filamentous fungi, microalgae) does not need arable land and potable water and can run continuously, also using wastes and byproducts. Some filamentous fungi are also consumed as edible mushrooms, and others are involved in the fermentation of traditional vegetable-based foods. Cereals, pseudocereals, and legumes may be combined to offer an almost complete amino acid profile. Fermentation of such vegetables, even in combination with milk-based products (e.g., tarhana), could increase nutrient concentrations, including essential amino acids, and improve sensory traits. Different insects could be used, as such or, to increase their acceptability, as ingredient of foods (e.g., pasta). However, insects as a protein source face with safety concerns, cultural constraints, and a lack of international regulatory framework.