Essential Amino Acids Research Articles

Ultrasonication assisted enzymatic hydrolysis for generation of pulses protein hydrolysate having antioxidant and ACE-inhibitory activity

The main objective of this work was to investigate the impact of ultrasonication assisted enzymatic treatment on the physicochemical and bioactive properties of broad bean (BBP), lentil bean (LBP), and mung bean (MBP) protein isolates. The protein was extracted using alkaline acid precipitation method, ultrasonicated at a frequency of 20 kHz, temperature 20–30 °C and then hydrolysed using alcalase enzyme (1 % w/w, pH 8.5, 30 min, 55 οC). The generated hydrolysates were characterized by degree of hydrolysis (DH), SDS, FTIR, surface hydrophobicity, amino acid composition, antioxidant and antihypertensive properties. Results showed that the degree of hydrolysis was found to increase in ultrasonicated protein hydrolysate (18.9 to 40.71 %) in comparison to non- ultrasonicated protein hydrolysate (11 to 16.3 %). SDS-PAGE results showed significant changes in protein molecular weight profiles (100–11kDa) in comparison to their natives. However, no substantial change was found in ultrasonicated and non-ultrasonicated protein hydrolysates. The FTIR spectrum showed structural alterations in ultrasonicated and non-ultrasonicated protein hydrolysates, suggesting modifications in secondary structure such as amide A, amide I and amide II regions. The essential amino acid content varied in the range of 60.09 mg/g to 73.77 mg/g and 28.73 to 50.26 mg/g in case of ultrasonicated and non-ultrasonicated protein hydrolysates, and non-essential content varied in the range of 49.42 to 65.93 mg/g and 43.12 to 47.12 mg/g. Both antioxidant and antihypertensive activities were found to increase significantly in ultrasonicated and non-ultrasonicated protein hydrolysates in comparison to their native counterparts, highlighting their potential as functional ingredients for management of hypertension. It was concluded that ultrasonication assisted enzymatic hydrolysis is an efficient approach for production of bioactive pulse protein hydrolysates with enhanced nutracutical properties, thus offering promising avenues for their utilization in the food industry and beyond.

Fasting time after feeding affects the evaluation of metabolic response in abalone Haliotis discus hannai to nutrients using dietary methionine as an example

As one of the essential amino acid, methionine (Met) is the initiating amino acid for proteins synthesis, and it can also act as a molecular signal regulating various metabolic processes. Meanwhile, the postprandial metabolic responses varied greatly among different species, nutrients and fasting time. In the present study, postprandial metabolic responses of abalone Haliotis discus hannai fed with different levels of dietary methionine (0.46%, 1.19% and 2.07%, respectively) for 84 days were investigated. Compared with the group with 0.46% of dietary methionine, 2.07% of dietary methionine significantly increased the concentration of glucose in CFH at 0 h, 12 h, 24 h, 36 h, 60 h and 84 h, while the concentrations of ammonia were significantly decreased by 2.07% of dietary methionine at each time point after feeding (P < 0.05). The 1.19% of dietary methionine significantly increased the activity of trypsin at 0 h, 24 h 60 h and 84 h after feeding (P < 0.05). The phosphorylation levels of protein kinase B (AKT), mechanistic target of rapamycin (mTOR) and ribosomal s6 protein (S6) peaked at 12 h and then dropped to base level at 36–84 h. Compared with the group with 0.46% of dietary methionine, 1.19% of dietary methionine significantly increased the phosphorylation levels of AKT at 12 h and 24 h, and extended the phosphorylation time of AKT (P < 0.05). And the phosphorylation level of mTOR was significantly increased by 1.19% of dietary methionine at 12 h, 24 h and 36 h after feeding (P < 0.05). Significant activation or repression of the mRNA levels related to glucose and lipid metabolism were observed at 12–24 h after feeding, and most of which were remain stable at 36–84 h (P < 0.05). The expressions of genes related of insulin signaling pathway (phosphoinositide 3-kinase and protein kinase B), glycolysis (hexokinase) and transport of lipid (fatty acid transport protein) were significantly increased by 1.19% of dietary methionine, while the key gene of gluconeogenesis (glucose-6-phosphatase) were decreased. In summary, 1.19% of dietary methionine could enhance digestive and absorptive capacity, protein synthesis, glucose metabolism and fatty acid transportation of abalone. Take long-term feeding trial with dietary methionine as an example and combine the results of data analysis, it is suggested to analyze the protein level of mTOR signaling pathway within 36 h after feeding, assess the biochemical parameters in CFH and the mRNA levels of nutrient metabolism related genes within 36–84 h, and detect the activities of digestive and absorptive enzymes within 60–84 h.

The Association of the Essential Amino Acids Lysine, Methionine, and Threonine with Clinical Outcomes in Patients at Nutritional Risk: Secondary Analysis of a Randomized Clinical Trial.

Lysine, methionine, and threonine are essential amino acids with vital functions for muscle and connective tissue health, metabolic balance, and the immune system. During illness, the demand for these amino acids typically increases, which puts patients at risk for deficiencies with harmful clinical consequences. In a secondary analysis of the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), which compared individualized nutritional support to usual care nutrition in patients at nutritional risk, we investigated the prognostic impact of the lysine, methionine, and threonine metabolism. We had complete clinical and amino acid data in 237 patients, 58 of whom reached the primary endpoint of death at 30 days. In a model adjusted for comorbidities, sex, nutritional risk, and trial intervention, low plasma methionine levels were associated with 30-day mortality (adjusted HR 1.98 [95% CI 1.16 to 3.36], p = 0.01) and with a decline in functional status (adjusted OR 2.06 [95% CI 1.06 to 4.01], p = 0.03). The results for lysine and threonine did not show statistically significant differences regarding clinical outcomes. These findings suggest that low levels of methionine may be critical during hospitalization among patients at nutritional risk. Further studies should investigate the effect of supplementation of methionine in this patient group to improve outcomes.

Utilizing Supercritical CO2 for Bee Brood Oil Extraction and Analysis of Its Chemical Properties.

To obtain oil from bee brood, which was dried using a tray drying method, this study used the supercritical CO2 extraction method. Extraction occurred at temperatures between 40-60 °C and low pressures of 180-220 bar for 1.5 h, with a high pressure of 600 bar for 1 h. The study investigated both the yield and chemical properties of the extracted bee brood oils. Supercritical CO2 extraction of tray-dried bee brood at 600 bar pressure demonstrated higher oil extraction efficiency compared to lower pressures (180-220 bar). At temperatures of 40-60 °C, total phenolic compounds increased while total flavonoids decreased. The extracted oil exhibited antioxidant activity, primarily due to quercetin. Despite decreased acid, iodine, and saponification values, peroxide value slightly increased but remained below 12 meqO2/kg of oil. The make-up of the fatty acids changed. At 600 bar, palmitic and oleic acids were the most common, while myristic, linoleic, and docosadienoic acids decreased. At 600 bar, eicosadienoic acid was absent. The defatted bee brood retained significant essential and non-essential amino acids, indicating its potential for further development as a protein source.

Creation of novel animal protein substitutes with potato protein and gellan gum: Control of food texture, color, and shape

It is challenging to accurately simulate the desirable sensory attributes of animal-derived foods (like meat, seafood, egg, or cheese) using plant-derived ingredients. As a result, many omnivores are reluctant to incorporate plant-based foods into their diet. In this study, our aim was to develop a new category of plant-based foods known as novel animal protein substitutes (NAPS), which are not designed to mimic the properties of animal-derived foods. Instead, they are designed to have appearances, textures, flavors, and nutritional profiles that consumers find desirable. In this study, we showed that NAPS with different textures, colors, and shapes could be formulated from potato protein (PP) and high acyl or low acyl gellan gum (HA-GG or LA-GG). In addition to their functional attributes, the PP provided a source of essential amino acids, whereas the gellan gum contributed to the overall dietary fiber content. Texture analysis showed that the elastic modulus and fracture properties of NAPS could be modulated by controlling the biopolymer composition of PP/HA-GG or PP/LA-GG hydrogels. Colorimetry showed that the color and appearance of NAPS could be manipulated by adding different types and amounts of natural pigments. In addition, the impact of food matrix effects on the thermal stability of the natural pigments was examined. Our results show that nutritionally enhanced plant-based foods with a wide range of physicochemical properties can be created from plant proteins and dietary fibers, which opens the opportunity of creating a new protein-rich food category to replace animal-derived foods. In the future, however, it will be important to establish whether this kind of product will be accepted by consumers, thereby increasing the diversity of plant-based dietary options in the market.

Effect of standardized ileal digestible arginine:lysine on growth performance of 6- to 13-kg nursery pigs.

A total of 480 newly weaned pigs (PIC 337×1050; Genus, Hendersonville, TN) with an initial body weight (BW) of 6.20 ± 0.61kg were used in a dose-response study to investigate the impact of increasing standardized ileal digestible (SID) Arg:Lys on nursery pig growth performance. At weaning, pigs were placed into 48 pens with 5 barrows and 5 gilts per pen. Pens were randomly assigned to 1 of 6 dietary treatments. The experimental diets were formulated with increasing SID Arg:Lys, achieved by substituting corn starch, glycine, and l-alanine with l-arginine, resulting in SID Arg:Lys ranging from 45% to 145%. Diets were sublimiting in SID Lys and exceeded all other essential amino acid requirements. The experimental diets were fed across two feeding phases from days 0 to 10 and 10 to 27, with adjustments made to account for the Lys requirement of the pigs. All pens were placed on a common diet for the remaining 14 d of the study to evaluate carryover effects. Pigs and feeders were weighed at the start and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed according to a linear regression model, which included the linear and quadratic effects of SID Arg:Lys and initial BW. Pen was the experimental unit, and results were considered significant at P ≤ 0.05 and a tendency at 0.50 < P ≤ 0.10. From days 0 to 27, Arg:Lys tended to have a quadratic effect on ADFI (P = 0.058), where 97.00 ± 7.631% SID Arg:Lys maximized feed intake. Similarly, Arg:Lys had a quadratic impact on ADG (P = 0.046), where ADG was maximized at a SID Arg:Lys of 95.65 ± 7.165. Correspondingly, Arg:Lys had a quadratic effect on pig BW on day 27 (P = 0.014). These effects were carried through the end of the study, where Arg:Lys quadratically impacted days 0 to 41 ADFI (P = 0.006), ADG (P = 0.077), and day 41 BW (P = 0.028). There was no evidence of an effect of SID Arg:Lys on G:F throughout the study (P ≥ 0.315). In conclusion, SID Arg:Lys quadratically impacted ADFI and ADG in 6- to 13-kg nursery pigs, where ADFI was maximized at a SID Arg:Lys of 97.00% (95% CI [81.6%, 112.4%]), and ADG was maximized at a SID Arg:Lys of 95.65% (95% CI [81.2%, 110.1%]). Together, these data suggest that the SID Arg:Lys requirement of nursery pigs is at least 81%, based on the lower bounds of the 95% CI for maximum ADG and ADFI, and excessive Arg supplementation may negatively affect growth performance.

A metabolic constraint in the kynurenine pathway drives mucosal inflammation in IBD.

Inflammatory bowel disease (IBD) is associated with perturbed metabolism of the essential amino acid tryptophan (Trp). Whether increased degradation of Trp directly fuels mucosal inflammation or acts as a compensatory attempt to restore cellular energy levels via de-novo nicotinamide adenine dinucleotide (NAD + ) synthesis is not understood. Employing a systems medicine approach on longitudinal IBD therapy intervention cohorts and targeted screening in preclinical IBD models, we discover that steady increases in Trp levels upon therapy success coincide with a rewiring of metabolic processes within the kynurenine pathway (KP). In detail, we identify that Trp catabolism in IBD is metabolically constrained at the level of quinolinate phosphorybosyltransferase (QPRT), leading to accumulation of quinolinic acid (Quin) and a decrease of NAD + . We further demonstrate that Trp degradation along the KP occurs locally in the inflamed intestinal mucosa and critically depends on janus kinase / signal transducers and activators of transcription (JAK/STAT) signalling. Subsequently, knockdown of QPRT in-vitro induces NAD + depletion and a pro-inflammatory state, which can largely be rescued by bypassing QPRT via other NAD + precursors. We hence propose a model of impaired de-novo NAD + synthesis from Trp in IBD. These findings point towards the replenishment of NAD + precursors as a novel therapeutic pathway in IBD.

Antioxidant and Anti-Inflammatory Capacities of Three Dry Bean Varieties after Cooking and In Vitro Gastrointestinal Digestion.

The present study delved into the chemical composition, antioxidant, and anti-inflammatory properties of three dry edible beans: Black (BL), Great Northern (GN), and Pinto (PN). The beans were soaked, cooked, and subjected to in vitro gastrointestinal (GI) digestion. BL bean exhibited significantly higher gastric (42%) and intestinal (8%) digestion rates. Comparative assessment of soluble GI-digested fractions (<3 kDa) revealed that the GN bean exhibited the highest abundance of dipeptides (P < 0.05). The BL bean fraction displayed a 4-fold increase in tripeptides (P < 0.05). Both BL and PN bean fractions are high in essential free amino acids, flavonols, and derivatives of hydroxybenzoic acid when compared to the GN bean. All the beans exhibited the ability to mitigate TNF-α-induced pro-inflammatory signaling; however, the BL bean fraction was the most effective at lowering AAPH-induced oxidative stress in HT-29 cells, followed by the GN bean (P < 0.05). In contrast, a low antioxidant effect was observed with PN beans.

Evaluation of biological activity and amino acid profile of protein from Thai edible insects

Insects are one of the sources of protein for future foods. In some cultures, insects have been used as a component of traditional medicine. Moreover, some proteins from insects have also shown biological activities related to human health, such as non-communication disease treatment. In this study, the protein content, amino acid profile, and inhibitory activity against a-glucosidase, a-amylase, acetylcholinesterase, and tyrosinase of soluble protein from six species of Thai edible insects were investigated. The protein from six Thai edible insects, including Gryllus bimaculatus De Geer (Sample 1), Omphisa fuscidentalis (Sample 2), Bombyx mori L. (Sample 3), Brachytrupes portentosus (Lichtenstein 1796) (Sample 4), Acheta domesticus L. (Sample 5), and Patanga succincta (Linnaeus) (Sample 6), was extracted and evaluated for its content and biological activity. The results indicated that sample 1 yielded the highest protein content of 84.23±5.15 g/100 g which is more than the protein content of meat and dairy products. A total of eight essential amino acid contents (EAA) were found in all six edible Thai insects. The highest total EAA was obtained from Sample 2 with 37.21±1.82 g/100 g, higher than the criteria established by FAO/WHO/UNU.1985. Sample 3 yielded the highest inhibition percentage of soluble protein from edible insects against α-glucosidase. The same was true for Sample 4 for α-amylase, Sample 1 for acetylcholinesterase, and Sample 2 for tyrosinase. These results indicated the quality and functional properties of protein from six species of Thai edible insects, which may be helpful in their future exploration and application

Branched-Chain Amino Acids, Alanine, and Thyroid Function: A Cross-Sectional, Nuclear Magnetic Resonance (NMR)-Based Approach from ELSA-Brasil.

The association of thyroid function with essential and non-essential amino acids is understudied, despite their common metabolic roles. Thus, our aim was to evaluate the association of thyroid function with the levels of branched-chain amino acids (BCAAs-leucine, isoleucine, and valine) and of alanine in the general population. We utilized data from the São Paulo research center of ELSA-Brasil, a longitudinal population-based cohort study. Thyroid parameters included thyroid stimulating hormone (TSH), free T4 and free T3 levels, and the FT4:FT3 ratio. BCAAs and alanine were analyzed on a fully automated NMR platform. The current analysis included euthyroid participants and participants with subclinical hyperthyroidism and hypothyroidism. We used Pearson's coefficient to quantify the correlation between thyroid-related parameters and amino acids. Linear regression models were performed to analyze whether thyroid parameters were associated with BCAAs and alanine levels. We included 4098 participants (51.3 ± 9.0 years old, 51.5% women) in this study. In the most adjusted model, higher levels of TSH were associated with higher levels of alanine, FT4 levels were inversely associated with isoleucine levels, FT3 levels were statistically significant and positively associated with valine and leucine, and the T3:T4 ratio was positively associated with all amino acids. We observed that subclinical hypothyroidism was positively associated with isoleucine and alanine levels in all models, even after full adjustment. Our findings highlight the association of subclinical hypothyroidism and thyroid-related parameters (including TSH, free T4, free T3, and FT4:FT3 ratio) with BCAAs and alanine. Further studies are needed to explore the mechanisms underlying this association. These insights contribute to our understanding of the influence of thyroid-related parameters on BCAA and alanine metabolism.

Biological features and quality comprehensive analysis of twelve germplasm resources of the genus Allium from Tibet.

Allium is important vegetables and seasonings in China, Tibet is rich in unique resources of the genus Allium, but lacks development and utilization. We compared the biological features and comprehensively evaluating the quality of twelve germplasm resources of the genus Allium collected from Tibet. The results revealed that nine germplasm resources were bolting and bloom normally except for SC015, SC019, and SC048, all twelve germplasm resources were able to vegetative growth. The individual differences in moisture, soluble sugar, and protein content among the twelve germplasm resources were relatively small, with pyruvic acid content ranging from 0.11 to 1.12 mg/g and a large variation coefficient. A total of 8 categories and 97 volatile compounds were detected in twelve germplasm resources, the majority possessed the highest proportions of aldehydes and organosulfur compounds, but there were certain differences between the different Allium species. Additionally, 11 to 16 types of free amino acids were present in all germplasm resources, proline exhibited the highest content. The total content of essential and non-essential amino acids in SC009 was the highest. Carbon (C) accounted for the largest proportion of all elements, and the contents of other mineral elements varied greatly among the different plants. In conclusion, combined with biological performance and comprehensive evaluation of quality, SC009 is the excellent germplasm resource suitable for growth and capable of reproduction with good quality. These results improved the exploitation and utilization of the genus Allium in Tibet, as well as provided germplasm resources for high-quality breeding of the genus Allium.

Modification of the Protein Amino Acid Content in Hen Eggs as a Consequence of Different Concentrations of Lupine and Soy in Feed.

The effect of the diet modification (soybean and lupine addition) on the content of protein and amino acids (AA) in eggs was studied. Both the sampling day and the diet influenced the total protein content. In albumen, the lowest protein content (10.6%) was noted after administering a diet containing 25% lupine; in the same egg the yolk contained the most proteins (16.7%). In the content of nonessential AA (NAA) in egg yolks, differences were noted only for cysteine, with its the highest content in the yolks of the control group. The stable content of essential yolk amino acids (EAA) was observed only for isoleucine, leucine, tryptophan and phenylalanine. The highest contents of EAA and NAA were recorded in the yolks of the control group (~47 and ~53 g/100 g of protein, respectively) and in the group with 25% additions of lupine (~42 and ~51 g/100 g of protein, respectively). AA with constant content in the tested albumens were methionine, tryptophan and alanine. The highest content of EAA (>~42 g/100 g of protein) and NAA (>~62 g/100 g of protein) were determined in albumen of eggs determined in the group with at least 20% additions of lupine. The highest content of EAA for humans delivered eggs from groups 4-6 (with the addition of soy into the diet ≤5%). The protein sources used in the hen diet significantly influenced the content of protein and individual AA in the produced eggs.

Investigating Cellulose Binding of Peptides Derived from Carbohydrate Binding Module 1.

Carbohydrate-binding modules (CBM) have emerged as useful tools for a wide range of tasks, including the use as purification tags or for cellulose fiber modification. For this purpose, the CBM needs to be attached to a target protein leading to large constructs. We investigated if short peptides from the carbohydrate binding site of CBMs can bind in a similar way as native, full-length CBMs to nanocrystalline cellulose (NCC) or cotton linter paper. We designed our cellulose-binding peptides to be less hydrophobic and shorter than those previously reported. Starting from the binding site of Cel7A-CBM1, we incorporated the essential amino acids involved in cellulose binding into our peptides. These peptides, as well as control peptides with scrambled sequences or a lack of essential amino acids, bound to cellulose with similar affinity as CBM regardless of their secondary structure, sequence, or hydrophobicity. This unspecific mode of cellulose binding displayed by the presented peptides may be exploited to functionalize cellulose-based biomaterials by means of peptide-conjugates.

Intraspecific and interspecific resource partitioning between bumblebee workers and males related to nectar quantity and quality.

Bumblebees are important pollinators for many natural and agricultural systems in temperate regions. Interspecific and intraspecific variation in floral resource preferences have been proposed to influence bumblebee community structure. In particular, sexual dimorphism is a major source of intraspecific niche variation. Although interspecific resource partitioning is well studied, few studies have explored the intraspecific dynamics between workers and males. Here, we report a study on a total of 11528 workers and 2220 males of 14 bumblebee species recorded over 5years in the Hengduan Mountains of Southwest China. We first compared the potential for interspecific and intraspecific competition between workers and males using visitation records and resource partitioning indices (overlap index). We then evaluated the influence of nectar traits on flower preference, including nectar volume and the levels of hexose, sucrose and 10 essential amino acids (EAAs). We found that the niche overlap between intraspecific workers and males was higher than that between different species, and temporal overlap alone did not strongly determine diet overlap. Males of most species preferred flowers with high levels of EAAs and hexose, whereas workers of some species preferred flowers with high nectar volume and sucrose levels. This study suggests that there is floral resource partitioning among bumblebee species, and between workers and males, which may play a key role in alleviating interspecific and intraspecific competition. These findings also provide a useful guide for which kinds of plants might be most valuable for bumblebees, especially the understudied males, in this biodiversity hotspot.

Impact of Cricket and Caterpillar Meal Supplementation on the Nutritional Profile and Consumer Acceptability of Cookies

The quality of cookies produced from wheat flour, cricket, and caterpillar meal blends was evaluated. This was done to examine the effect of adding edible cricket and caterpillar meals on the nutritional and sensory quality of wheat-based cookies. Edible crickets and caterpillars were purchased from local farmers in Benue state, de-gutted, washed, oven-dried, sorted, milled, and sieved to produce their respective meals. The meals were mixed in wheat flour: edible insects ratios of 95:5, 90:10, 85:15 and 80:20 for Cricket and Caterpillar meal blends, respectively. However, samples 100:0 were not mixed and contained 100% wheat flour. The samples were subjected to functional analysis of proximate composition, mineral, vitamin, amino acid profile, physical properties analysis, and sensory attributes evaluation. The result generated from the study was subjected to analysis of variance (ANOVA) and the Duncan multiple range test (DMRT) was used for mean separation at the probability level of significance of 5%. While the protein, fat, ash, crude fibre, and moisture content of the cookies increased with increasing amount of edible insect meal incorporated into the formulation, the carbohydrate content of the cookies decreased significantly (p&lt;0.05). All minerals evaluated in the study (Ca, Zn, K, P, Na, Mg, and Fe) increased with the increase in the amount of edible insect meals in the formulations. An increase in vitamin content was also observed in the cookies, but this increase was insignificant (p&gt;0.05). There was a significant increase in all essential and non-essential amino acid content of the cookies as the level of cricket/caterpillar meal in the formulation increased. The addition of up to 20% of edible cricket/caterpillar meals to wheat flour increased all sensory attributes of the cookies. Cookies fortified with caterpillar meal were found to be more nutritious than those fortified with cricket meal. In general, samples 85:15(85% wheat flour + 15% cricket meal) and 85:15(85% wheat flour + 15% caterpillar meal) contained high nutritional content and recorded the best sensory attributes and therefore were selected as the best blends for a wheat flour+cricket meal and wheat flour+caterpillar meal blends for cookies production.

Impact of Dietary Variations on Kuruma Shrimp (Penaeus japonicus) Assessed through Individual-Based Rearing and Insights into Individual Differences.

This study developed an individual-rearing method to compare the effects of live feed (sandworms Perinereis aibuhitensis), formulated pellet diets, and a mixture of live feed and formula feed on the Kuruma shrimp Penaeus japonicus, aiming to minimize the influence of non-dietary factors on the growth of P. japonicus, like cannibalism. Results indicated that live feed, with its higher protein, essential amino acids, and fatty acid content, led to significantly better growth and feeding performance in P. japonicus (p < 0.05) compared to pellet diets. A mixed diet resulted in a lower average daily protein intake yet maintained a growth and feeding performance comparable to live feed. The intestinal microbiota of shrimp, dominated by Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria, showed significant shifts with diet changes. Specifically, formulated feed increased the relative abundance of Vibrio and Photobacterium while decreasing Shimia and Rhodobacterales (p < 0.05), and feeding live food resulted in a more complex and stable bacterial network. Notably, individual variances in growth and feeding were observed among shrimps, with some on formulated diets showing growth comparable to those on live feed. Each shrimp's final weight, specific growth rate, protein efficiency rate, and average daily food intake positively correlated with its initial body weight (p < 0.05), and daily intake varied cyclically with the molting cycle. These findings suggest that individual-rearing is an effective approach for detailed feed evaluation and monitoring in P. japonicus, contributing to improved feed selection, development, and feeding strategies.

Effect of ultrasound and marination on functional and sensory properties, protein profiles and bioaccessibility of amino acids in turkey meat

SummaryThis study investigates the impact of ultrasound treatment and marination on turkey meat proteins, focusing on functional and sensory properties and protein hydrolysis. Three different treatments, marination (M), ultrasound (US) and a combination of ultrasound and marination (USM), were applied to turkey meat. The USM caused the highest water‐holding capacity, increased tenderness and improved the general acceptability of turkey meat. SEM images of raw samples showed that US and M changed the structure of muscle fibres, exhibiting more cavities and irregular, broken and separated fibres. Cooking changed the muscle fibres of the sample, forming several cavities and separate fibres. SDS‐PAGE profiles showed that different treatments affected protein solubility during gastric digestion. Ultrasound treatment caused the loss of some essential amino acids in the supernatant of intestinal digests, including lysine, leucine and tyrosine. In vitro bioaccessibility of leucine, threonine, lysine, valine and isoleucine was the highest in the untreated sample.

The Impact of Drying Methods on the Quality of Blanched Yellow Mealworm (Tenebrio molitor L.) Larvae.

The growing world population necessitates the implementation of appropriate processing technologies for edible insects. The objective of this study was to examine the impact of distinct drying techniques, including convective drying at 70 °C (70CD) and 90 °C (90CD) and freeze-drying (FD), on the drying kinetics, physical characteristics (water activity, color), chemical characteristics (chemical composition, amino acid profile, oil properties, total polyphenol content and antioxidant activity, mineral composition, FTIR), and presence of hazards (allergens, microorganisms) of blanched yellow mealworm larvae. The freeze-drying process results in greater lightness and reduced moisture content and water activity. The study demonstrated that the freeze-dried insects exhibited lower contents of protein and essential amino acids as compared to the convective-dried insects. The lowest content of total polyphenols was found in the freeze-dried yellow mealworm larvae; however, the highest antioxidant activity was determined for those insects. Although the oil isolated from the freeze-dried insects exhibited the lowest acid and peroxide values, it proved to have the lowest PUFA content and oxidative stability. All the samples met the microbiological criteria for dried insects. The results of the study demonstrate that a high temperature during the CD method does not result in the anticipated undesirable changes. It appears that freeze-drying is not the optimal method for preserving the nutritional value of insects, particularly with regard to the quality of protein and oil.

Different amino acid compositions and food quality of particulate organic matter driven by two major phytoplankton groups in the Ross Sea

Understanding the amino acid (AA) composition of phytoplankton-derived particulate organic matter (POM) is crucial for unraveling phytoplankton physiology and assessing food quality. This study investigated AA compositions and food quality of POM associated with two phytoplankton groups in the Ross Sea polynya. The Phaeocystis antarctica (P. antarctica)-predominant group, with P. antarctica overwhelmingly contributing to its composition, demonstrated a fresh state and heightened physiological activity. In contrast, the P. antarctica and diatoms-mixed group exhibited superior essential amino acids (EAAs) contributions and a higher EAA index (EAAI), indicating enhanced food quality. Dissimilarity Index values provided nuanced insights into degradation stages not captured by other indices. Despite lower physiological activity, diatoms in the mixed group stood out as crucial sources of high-quality nutrition for higher trophic levels in the Ross Sea polynya. The observed variations in AA compositions not only reflected the phytoplankton community structure but also provided insights into their physiological conditions. Given the ongoing climate-induced environmental changes potentially influencing phytoplankton communities, this study underscores the potential impacts on the intricate food web dynamics in the Ross Sea polynya. The assessment of AA composition emerged as a valuable tool for understanding the ecological implications for higher trophic levels in this polar region.

Physicochemical property characterization, amino acid profiling and sensory evaluation of plant-based ice cream incorporated with soy, pea and milk proteins

This study examined the effects of incorporating milk protein concentrate (MPC), pea or soy proteins isolates (PPI and SPI) on the physicochemical, sensorial properties, and amino acid composition of ice creams containing 7% protein, in comparison to dairy ice cream as a reference. As protein ingredients, PPI exhibited higher water and oil holding capacity but lower surface hydrophobicity than SPI and MPC. Viscosity of the mixes were proportional to the firmness of ice cream, and both were highest with use of PPI. MPC ice cream had most similar physical and sensory properties to reference. PPI and SPI ice cream mixes showed higher extent of fat coalescence than MPC and reference. PPI and SPI conferred structural stability to ice cream with lower melting rate and better shape retention, and ability to delay ice recrystallization during temperature flocculation as compared with SMP and MPC. Confocal laser scanning microscope images indicated that higher extent of protein aggregation and more air cells were found in PPI ice cream. Sensory and amino acid profile results revealed that PPI and SPI ice creams were inferior in taste, texture, and essential amino acids like methionine. This study offers insights for the development of high protein frozen desserts.