Balanced Amino Acid Profile Research Articles

Nutritional, Techno-Functional and Structural Properties of Black Soldier Fly (Hermetia illucens) Larvae Flours and Protein Concentrates.

Due to their protein content and balanced amino acid profile, edible insects have been described as an excellent alternative protein source to combat malnutrition. As the global population continues to grow, edible insects such as the black soldier fly larvae (BSFL) may contribute to food security. The effect of different protein extraction methods, i.e., alkaline solution and acid precipitation (BSFL-PC1) and extraction with an alkali (BSFL-PC2), on the nutritional, techno-functional, and structural properties of BSFL flours and protein concentrates were studied. The highest protein content (73.35%) was obtained under alkaline and acid precipitation extraction (BSFL-PC1). The sum of essential amino acids significantly increased (p < 0.05) from 24.98% to 38.20% due to the defatting process during extraction. Protein solubility was significantly higher in protein concentrates (85–97%) than flours (30–35%) at pH 2. The emulsion capacity (EC) was significantly higher (p < 0.05) in the protein concentrates (BSFL-PC1 and BSFL-PC2) compared to the freeze-dried and defatted BSFL flours, while the emulsion stability (ES) was significantly (p < 0.05) higher in BSFL-PC1 (100%) compared with BSFL-PC2 (49.8%). No significant differences (p > 0.05) were observed in foaming stability (FS) between freeze-dried and defatted BSFL flours. Fourier transform infrared spectroscopy (FT-IR) analysis revealed distinct structural differences between BSFL flours and protein concentrates. This was supported by surface morphology through scanning electron microscopy (SEM) images, which showed that the protein extraction method influenced the structural properties of the protein concentrates. Therefore, based on the nutritional and techno-functional properties, BSFL flour fractions and protein concentrates show promise as novel functional ingredients for use in food applications.

Complete Replacement of Fishmeal With Plant Protein Ingredients in Gibel Carp (Carassius auratus gibelio) Diets by Supplementation With Essential Amino Acids Without Negative Impact on Growth Performance and Muscle Growth-Related Biomarkers

This study was conducted to investigate the effects of substitution of dietary fishmeal (FM) by compound plant protein supplemented with essential amino acids on growth performance, plasma physiology, and muscle growth-related genes of gibel carp (Carassius auratus gibelio). Four diets with equal digestible protein were prepared, where 30FM (control feed) contained 30% FM and land animal protein as a protein source, 10FM contained 10% FM, PMAa contained full plant meal (PM) supplemented with crystalline amino acid, and PM contained full PM feed. There was no significant difference in the specific growth rate (SGR) with 30FM, 10FM, and PMAa diets (p &amp;gt; 0.05); however, the SGR of PM group was the lowest with significant difference (p &amp;lt; 0.05). Feed efficiency of the PM group was the lowest with significant difference (p &amp;lt; 0.05). The whole-body crude protein content of fish in PMAa group was significantly higher than that in each group with additional FM (p &amp;lt; 0.05). There were no significant differences in plasma total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C), and free amino acid profile of 30FM, 10FM, and PMAa groups (p &amp;gt; 0.05); however, they were significantly higher than that in PM group (p &amp;lt; 0.05). The expression of key genes in the TOR signaling pathway (tor, s6k1, 4e-bp2, and eif4e), autophagy (ulk1 and atg13), and ubiquitin–proteasome (trim63 and znrf2) system of the PMAa group was similar to that of the FM group (p &amp;gt; 0.05), indicating that the muscle growth-related biomarker genes were positively regulated by the appropriate dietary amino acid composition at the transcriptional level. These results suggest that FM in gibel carp diet can be totally replaced by PM without negative impact on growth performance and muscle growth-related biomarkers at the transcriptional level, which provided the requirement of digestible protein and balanced amino acid profile is satisfied.

Utilization of underutilized grains in regional foods for improved health and nutritional status of the rural Punjabi women

Millets have great potential due to their high nutritional content, gluten free, and low glycemic index properties. Due to their high dietary fiber content, proteins with balanced amino acid profile, many essential minerals, some vitamins, and antioxidants, these can be considered as ‘Nutri Cereals’. However, due to the changing lifestyle, they are now considered as ‘Forgotten grains’ especially in the Punjabi diets. Due to increasing incidence of diabetes among rural women of Punjab, there is a need to develop foods that mimic the regional diets and can be conveniently adopted by people. The present study was undertaken to modify the commonly consumed traditional recipes of Punjab into the low glycemic index foods and investigate their effect on pre diabetic rural women. The modified foods i.e. dalia, missa parantha and chapati showed higher overall acceptance when compared to traditional preparations. These foods products had higher protein(12-17g/100g) and dietary fibre(12-15g/100g) content. The modified products had low glycemic index i.e. 39, 44 and 41 for dalia, missa parantha and chapati, respectively and with a low glycemic load. The dietary intervention on pre-diabetic rural women improved the nutritional profile (p<0.05) showing a positive effect of the modified foods on the blood profile of the subjects.

The Influence of Germinated Hull-less Barley Sordough Fermentation Conditions on the Microbiota Development

Abstract Sourdough plays an important role in quality assurance, especially during developing wholegrain wheat bread products. The value of barley and hull-less barley grains is determined by the low lipid and high carbohydrate (starch and resistant starch) content, balanced amino acid profile, dietary fibre and phenolic compounds. During germination (24 h) the amount of sugar, amino acids and vitamins increase in the grains. Therefore, it could be optimal environment for microbiota growth in sourdough. The goal of the research was to find optimal technological parameters and to study microorganism growth dynamic during the fermentation of sourdough with germinated hull-less barley. The study was performed using three steps of fermentation, with different temperature and time parameters. At each step pH, dynamics of lactic acid bacteria (LAB), yeast-like fungi and total plate count (TPC) growth were determined using standard methods. The results of the study showed that the optimal fermentation conditions for the first stage are 48 h and 26 ± 1 °C, for the second stage 8 h and 26 ± 1 °C and for the third stage 20 h and 28 ± 1 °C. During fermentation of the sourdough, the pH 3.91 is reached, LAB 8.8 log10 CFU g−1, and the yeast-like fungi 8.7 log10 CFU g−1 was determined. Obtained data show that more than 80 bacteria and 50 microscopic fungal species were detected in hull-less barley flour, but after germination their diversity decreased and in the germinated hull-less barley sourdoughs dominated species were Pediococcus pentosaceus.

Nutritional Characteristics Assessment of Sunflower Seeds, Oil and Cake. Perspective of Using Sunflower Oilcakes as a Functional Ingredient.

Ample amounts of by-products are generated from the oil industry. Among them, sunflower oilcakes have the potential to be used for human consumption, thus achieving the concept of sustainability and circular economy. The study assessed the nutritional composition of sunflower seeds, cold-pressed oil and the remaining press-cakes with the aim of its valorization as a food ingredient. Sunflower oil contains principally oleic (19.81%) and linoleic (64.35%) acids, which cannot be synthetized by humans and need to be assimilated through a diet. Sunflower seeds are very nutritive (33.85% proteins and 65.42% lipids and 18 mineral elements). Due to the rich content of lipids, they are principally used as a source of vegetable oil. Compared to seeds, sunflower oilcakes are richer in fibers (31.88% and 12.64% for samples in form of pellets and cake, respectively) and proteins (20.15% and 21.60%), with a balanced amino acids profile. The remaining oil (15.77% and 14.16%) is abundant in unsaturated fatty acids (95.59% and 92.12%). The comparison between the three products showed the presence of valuable components that makes them suitable for healthy diets with an adequate intake of nutrients and other bioactive compounds with benefic effects.

Characterization of nutritional and functional properties of Lima bean flour (Phaseolus Lunatus L.)

Lima beans (Phaseolus Lunatus L.) are underutilized crops with an excellent profile. Processing to flour to enhance the starch and protein content, reducing anti-nutritional components and the same time diversifies their use as ingredients by altering their functional properties. The study aims to characterize nutritional, amino acids, anti-nutritional, pasting and functional properties of Lima bean flour from Indonesia’s cultivated plant. The results showed that the Lima bean flour has a high carbohydrate concentration, moderate protein concentration, and low fat concentration. This flour has a balanced amino acid profile, rich in essential amino acids, highlighting them as a source of good quality protein for the food formulation of protein-enriched. The Lima bean flour contained 10.36 mg/g phytic acid, lower in phenolic content (0.63 mg/g) and concentration of HCN (8.83 mg/kg). The functional properties of the Lima bean flour swelling power, solubility, water absorption capacities, and oil absorption capacities were 6.88 g/g, 18.68%, 1.93 g/g, and 1.56 g/g respectively. Pasting properties of Lima bean flour exhibited peak, breakdown, final, and setback viscosity in 1172 cP, 83 cP, 2377 cP, 1288 cP respectively, and temperature pasting was high in 870C. The study may provide useful information to consumers and food manufacturers that Lima bean flour is significant potential used to enhance the nutritional value of cereal-based foods.

From Farm to Fork: Crickets as Alternative Source of Protein, Minerals, and Vitamins.

Globally, there is growing interest to integrate cricket-based ingredients (flour) into food products to combat food and nutrition insecurity. However, there is lack of information on in-depth nutrient profile of the two cricket species (Scapsipedus icipe and Gryllus bimaculatus), which are the most widely consumed in Africa. Here we determined the nutrient composition of two cricket species and compared them with published records of key animal and plant sources. Our results revealed that the crude protein contents of S. icipe and G. bimaculatus were similar (56.8 and 56.9%, respectively) and comparable to those of animal protein sources. Both cricket species had balanced amino acid profiles that are superior to that of animal and plant sources, except for histidine and cysteine. The protein digestibility of S. icipe and G. bimaculatus ranged between 80 and 88%, which is comparable to that of common plant foods but slightly lower than that of animal proteins. The iron, Zinc, and potassium contents were considerably higher in both cricket species compared to that of plant and animal sources. The calcium contents of both crickets (S. icipe and G. bimaculatus) was superior to that of plant and animal origin except for kidney beans and eggs, respectively. Riboflavin, thiamine, and folic acid concentrations of S. icipe and G. bimaculatus were superior to that of the conventional sources. Vitamin A levels were significantly higher in S. icipe compared to G. bimaculatus. This implies that S. icipe and G. bimaculatus can adequately contribute to our daily required nutrient intake. Thus, integrating cricket flours into ready-to-eat food products would address some of the most pressing nutritional deficiency challenges that many developing countries have to grapple with, particularly high risk to serious health problems such as anemia, poor pregnancy outcomes, hypertension, increased risk of morbidity and mortality, stunted growth and impaired physical and cognitive development. We conclude that edible crickets present unique opportunities for improving food and nutritional insecurity status of both resource-poor and Western populations.

Spirulina platensis meal inclusion effects on broilers fed a reduced protein diet

Apart from soybean meal, alternative sources of protein are a long-term concern facing commercial broiler producers. These alternative protein sources must be rich in protein, have a balanced amino acid profile, be highly digestible, be nutritionally safe for the bird, and ideally contain some other intrinsic value. Spirulina platensis is a microalgae that is growing in popularity due to its high protein level, health benefits, and environmental impact. Two experiments (in female and male Ross 708 broilers) were conducted to determine the effect of Spirulina inclusion in reduced crude protein diets on broiler growth, carcass yields, breast fillet color, breast myopathy, and footpad quality. The results showed that lowering crude protein impaired carcass yield in both experiments, while hindering growth performance more in male birds than female birds. Spirulina inclusion at 10% in a reduced protein diet improved footpad score in male broilers and increased meat and skin pigmentation in all birds. The inclusion of Spirulina into a commercial setting will always be driven by costs, but this study aids in expanding fundamental research to make that possible.

Wholegrains: a review on the amino acid profile, mineral content, physicochemical, bioactive composition and health benefits

SummaryWholegrains are a rich source of phytochemicals, dietary fibre, complex carbohydrate, proteins, minerals, lipids and vitamins that may have the tendency to increase heath beyond the simple provision of nutrition and energy. They are highly nutritive due to their balanced amino acid profile and other macro‐ and micronutrient composition. It is considered well‐balanced diet having functional characteristics that have shown to possess medicinal benefits. The inverse relation between consumption of wholegrains and the reduced risk of chronic diseases and metabolic syndromes are reported in several studies. The consumption of wholegrains is on the rise due to the growing health‐conscious populace and health‐promoting components support the dietary consumption of wholegrains and their products. Accordingly, the conclusive evaluation of wholegrains and the human intervention studies conducted for the whole grain intake, and the inference that the wholegrains, functional properties and the health outcomes associated with wholegrains are discussed.

Effect of hydrothermal treatment on physical properties of amaranth, an underutilized pseudocereal

Rice, wheat and maize are the only three grains used globally by majority of people. This makes the cropping systems highly vulnerable to the detrimental effects of climate change. Expansion of crop sources by integrating ‘psudocereals’ appears to be a promising strategy to decrease the implications of climate change on the food security. Amaranth, an underutilized pseudocereal, has gained much attention these days because of its balanced amino acid and micronutrient profiles. However, effect of processing treatments on the quality attributes of amaranth is rather scanty. Attempts were made in the present investigation to evaluate the effect of hydrothermal treatment (HT) on physical and structural attributes of amaranth grains and its flour. During HT, amaranth grains were steeped in water at 70 °C for 3 h followed by steaming for 3, 6 and 9 min. The treated grains were dried and converted into flour. The HT had a great impact on the physical, rheological, textural and micro-structural attributes. Up to 6 min of HT led to an increase of density, porosity, water holding capacity and swelling index of the grain.

Alternative Proteins as a Source of Bioactive Peptides: The Edible Snail and Generation of Hydrolysates Containing Peptides with Bioactive Potential for Use as Functional Foods.

Members of the Phylum Mollusca include shellfish such as oysters and squid but also the edible garden snail known as Helix aspersa. This snail species is consumed as a delicacy in countries including France (where they are known as petit-gris), southern Spain (where they are known as Bobe), Nigeria, Greece, Portugal and Italy but is not a traditional food in many other countries. However, it is considered an excellent protein source with a balanced amino acid profile and an environmentally friendly, sustainable protein source. The aim of this work was to develop a different dietary form of snail protein by generating protein hydrolysate ingredients from the edible snail using enzyme technology. A second aim was to assess the bioactive peptide content and potential health benefits of these hydrolysates. H. aspersa hydrolysates were made using the enzyme Alcalase® and the nutritional profile of these hydrolysates was determined. In addition, the bioactive peptide content of developed hydrolysates was identified using mass spectrometry. The potential heart health benefits of developed snail hydrolysates were measured in vitro using the Angiotensin-I-converting Enzyme (ACE-1; EC 3.4.15.1) inhibition assay, and the ACE-1 inhibitory drug Captopril© was used as a positive control. The generated H. aspersa hydrolysates were found to inhibit ACE-1 by 95.60% (±0.011) when assayed at a concentration of 1 mg/mL (n = 9) compared to the positive control Captopril© which inhibited ACE-1 by 96.53% (±0.0156) when assayed at a concentration of 0.005 mg/mL (n = 3). A total of 113 unique peptide sequences were identified following MS analysis with peptides identified ranging from 628.35 Da (peptide GGGLVGGI—protein accession number sp|P54334|XKDO_BACSU) to 2343.14 Da (peptide GPAGVPGLPGAKGDHGFPGSSGRRGD—protein accession number sp|Q7SIB2|CO4A1_BOVIN) in size using the BIOPEP-UWM database.

Microbial products in terms of isolates, whole-cell biomass, and live organisms as aquafeed ingredients: production, nutritional values, and market potential—a review

Utilizing microbial products could be considered a novel approach to sustain the present growth of the aquafeed sector due to dwindling availability and high cost of fishmeal. Various microbial products in terms of isolates, whole-cell biomass, and live organisms are mainly derived from algae, bacteria, fungi, and yeast through the process of fermentation. They have a balanced amino acid profile and contain several minerals and vitamins. However, essential amino acid index (EAAI) of fungal-based microbial meal was comparatively lower (0.57–0.67) than the other three microbes (0.77–0.90). Microbes were deployed in the production of microbial products ranked as algae > fungus/yeast > bacteria based on their nucleic acid content. The global production of microbial products was valued at US$5.3 billion in 2017 and is predicted to increase by 8.6% in 2018–2023. They could substitute fishmeal by 25–50% in feeds for aquatic species. Notwithstanding, they act as a potential growth promoter, a viable immunostimulant and can control infectious diseases in various aquatic species. The present review reiterates the utilization of microbial products in ameliorating the issues related to the global aquafeed industry, in particular fishmeal demand. However, newer approaches need to be established with regard to fermentation technology and genetic engineering to overcome the present limitations to make them an economical one.

Texture, sensory properties and functionality of extruded snacks from pulses and pseudocereal proteins.

The protein-rich fractions of pulses and pseudocereals exhibit a well-balanced amino acid profile, particularly when combined in different portions, and are therefore high-value ingredients for the production of extruded snacks. However, the impact of a combination of pulses and pseudocereals on the physical and sensory qualities of extruded snacks has not been investigated up to now. Native or preconditioned protein isolates and concentrates from pulses - as single ingredients or in combination with protein-rich flours of pseudocereals - were analyzed regarding their thermal and functional properties in relation to extrusion characteristics. Low moisture extrusion cooking was used to investigate the impact of protein source (lentil, lupin, faba bean), pseudocereal source (quinoa, amaranth, buckwheat) and protein content (30%, 50%, 70%) on sectional expansion, specific hardness, density and sensory properties of the snacks. With increasing protein content from 30% to 50%, the sectional expansion decreased and the density and specific hardness of the extrudates increased, which could be counteracted by preconditioning of the protein-rich ingredients. Lupin protein-based extrudates exhibited satisfactory texture and sensory properties. Extruded mixtures of pulses and pseudocereals (70% protein) exhibited a smaller sectional expansion compared to pulses as single ingredients (30%, 50%), regardless of pseudocereal type. However, the texture and sensory properties of the extruded blends were satisfactory. We show for the first time that protein-rich fractions of pulses and pseudocereals can be processed into expanded snacks with favorable texture and nutritional properties such as increased protein contents (70%) and balanced amino acid profiles. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Quinoa (Chenopodium quinoa Willd.): Exploring a Superfood from Andean Indigenous Cultures with Potential to Reduce Cardiovascular Disease (CVD) Risk Markers.

The pseudo-cereal quinoa has attracted worldwide attention in recent years, due to it being considered a functional food. This stress-tolerant crop has historically been used by Andean cultures as a staple food. Nowadays, the consumption of quinoa in high-income countries is increasing due to it being associated with numerous health benefits, namely related to cardiovascular health. We have carried out an extensive review on quinoa, including its main uses, applications, and components (nutrients, antinutrients, and bioactives) and their relationship with biological activities and cardiovascular health. Key findings and Conclusions: Quinoa possesses numerous activities, including protection against cardiovascular, metabolic, and degenerative diseases, improvement of the immune system, reduction of symptoms associated with post-menopause, and promotion of muscle mass increase. Some of the quinoa's activities are due to its balanced amino acid profile, high fiber content, presence of phosphorus, iron, potassium, magnesium, vitamin E, and B vitamins. A plethora of bioactives can also be found in quinoa, such as phytosterols, saponins, phenolics, bioactive peptides, and phytoecdysteroids. More research is needed to better understand the mechanisms of action involved in the biological/therapeutic action of some quinoa components, namely those related to the potential to reduce cardiovascular disease (CVD) risk markers. The knowledge of factors that affect quinoa variability, such as processing conditions, is also of great importance for being able to obtain more benefits from this crop.

Potential of black soldier fly (Hermetia illucens) as alternative protein source in salmonid feeds - A review

The current constant pressure on fishmeal production for aquaculture feeds stresses the need to search for alternative sources of protein. A possible protein ingredient is insect meal, being more cost effective than fishmeal and soybean meal. Black soldier fly (Hermetia illucens) larvae meal is used in many studies with positive results regarding the bioproductive performances of salmonids. The balanced amino acid profile is comparable with the one of soybean meal. The crude protein and amino acid digestibility is high and similar to that of fishmeal. For rainbow trout (Oncorhynchus mykiss), the protein biological value of the larvae is qualitatively lower than that of fishmeal. Atlantic salmon fed with experimental diets with larvae meal showed high bioproductive performances and a better protein biological value compared with salmon fed with a standard fishmeal diet. However, the nutritional quality and chemical composition of the larvae can be drastically improved through the feeding media, which make it a very interesting candidate as a substitute for fishmeal. The aim of this review is to present the current stage of H. illucens use in salmonid feeds, detailing the chemical composition and protein quality. Furthermore, the effect of larvae meal based diets on salmonids is presented.

Combining high-protein ingredients from pseudocereals and legumes for the development of fresh high-protein hybrid pasta: enhanced nutritional profile.

The fortification of wheat-based staple foods, such as pasta, with pseudocereal and legume flours has received growing research interest in recent years. While it is associated with many challenges regarding technological and sensory quality of the products, it promises a substantial improvement of the nutritional value of pasta. However, investigations of the nutritional quality of fortified pasta often focus on the carbohydrate/starch fraction, and information on changes in protein quality is relatively scarce. This study evaluates the nutritional profile of a high-protein hybrid pasta (HPHP) formulation in which a combination of three high-protein ingredients (HPIs) from buckwheat, faba bean and lupin is used to partially replace wheat semolina. The formulation's macronutrient composition, protein quality and the content of antinutritional compounds are assessed in comparison to regular wheat pasta. The HPHP formulation represents a more favourable macronutrient profile compared to regular wheat pasta, particularly in relation to the isocaloric replacement of wheat starch by non-wheat protein. Furthermore, a more balanced amino acid profile, improved N utilisation and increased protein efficiency ratio (in vivo) were determined for HPHP, which conclusively suggests a substantially enhanced protein quality. The cooking process was shown to significantly reduce levels of vicine/convicine and trypsin inhibitor activity originating from HPIs. The small remaining levels seem not to adversely affect HPHP's nutritional quality. This significant upgrade of pasta's nutritional value identifies HPHP, and similar hybrid formulations, as a healthy food choice and valuable alternative to regular wheat pasta, specifically for a protein supply of adequate quality in mostly plant-based diets. © 2020 Society of Chemical Industry.

Nutritional quality of protein concentrates from Moringa Oleifera leaves and in vitro digestibility

The nutritional value and digestibility of leaf proteins is still a major issue. Therefore, the goal of this work was to optimize the production of a protein concentrate (PC) from Moringa Oleifera defatted leaves (MODL) by enzymatic extraction using Viscozyme L and evaluate its nutritional quality and digestibility. Protein extraction conditions were screened using a factorial design. Enzyme/Substrate ratio and pH had no significant effect, whereas, the significant variables, temperature (°C), enzyme concentration and incubation time (h) were optimized by central composite design (CCD). PC contained 55.7% of proteins with a balanced amino acid profile when compared with MODL and higher content of essential amino acids (EAAs) (488.6–402.9 mg/g of protein respectively). Improvement on protein digestibility was observed for MODL compared to PC (64.75–99.86% respectively) and higher protein digestibility corrected amino acid score (PDCAAS) (62.10–91.41% respectively). PC meets FAO protein quality expectations.

Development of tef [Eragrostis tef(Zucc.) Trotter] based gluten‐free tarhana

The aim of this study was to prepare gluten-free tarhana by using different rates (20:40:40, 40:30:30, 60:20:20, 80:10:10, and 100:0:0%) tef flour (TF), corn flour, and potato starch instead of wheat flour and to determine the effects of tef flour addition levels on the some physical, chemical, nutritional, and sensory properties of tarhana samples. The use of tef flour in tarhana formulation increased the ash, protein, and fat contents of the tarhana samples, and also significantly (p < .05) affected their total phenolic content, antioxidant activity, and phytic acid contents. Increasing amount of tef flour in tarhana formulations were resulted in higher oil absorption, foaming capacity, foaming stability, and lower viscosity and water absorption values. Incorporation of tef flour showed slight influence on the sensorial quality of the tarhana samples. The results obtained showed that the tef flour can be used to develop a new gluten-free tarhana formulation. Practical applications Tef (Eragrostis tef Zucc.), due to its gluten-free composition, is an important grain for the daily diet of celiac patients, who should abstain from gluten-containing foods in their lifetime. Besides, it is a rich nutritional source in terms of a balanced amino acid profile, polyphenols, and phytochemicals. In this study, tef flour (TF), corn flour, and potato starch were used at different rates (20:40:40, 40:30:30, 60:20:20, 80:10:10, and 100:0:0%) for developing a new gluten-free tarhana formulation, and especially tef flour effects on physical, chemical, nutritional, and sensory properties of tarhana were evaluated. The addition of tef flour in particular increased the chemical and nutritional properties of tarhana.

Short-Term Supplementation of Dietary Arginine and Citrulline Modulates Gilthead Seabream (Sparus aurata) Immune Status.

Several amino acids (AA) are known to regulate key metabolic pathways that are crucial for immune responses. In particular, arginine (ARG) appears to have important roles regarding immune modulation since it is required for macrophage responses and lymphocyte development. Moreover, citrulline (CIT) is a precursor of arginine, and it was reported as an alternative to ARG for improving macrophage function in mammals. The present study aimed to explore the effects of dietary ARG and CIT supplementation on the gilthead seabream (Sparus aurata) immune status. Triplicate groups of fish (23.1 ± 0.4 g) were either fed a control diet (CTRL) with a balanced AA profile, or the CTRL diet supplemented with graded levels of ARG or CIT (i.e., 0.5 and 1% of feed; ARG1, CIT1, ARG2, and CIT2, respectively). After 2 and 4 weeks of feeding, fish were euthanized and blood was collected for blood smears, plasma for humoral immune parameters and shotgun proteomics, and head-kidney tissue for the measurement of health-related transcripts. A total of 94 proteins were identified in the plasma of all treatments. Among them, components of the complement system, apolipoproteins, as well as some glycoproteins were found to be highly abundant. After performing a PLS of the expressed proteins, differences between the two sampling points were observed. In this regard, component 1 (61%) was correlated with the effect of sampling time, whereas component 2 (18%) seemed associated to individual variability within diet. Gilthead seabream fed ARG2 and CIT2 at 4 weeks were more distant than fish fed all dietary treatments at 2 weeks and fish fed the CTRL diet at 4 weeks. Therefore, data suggest that the modulatory effects of AA supplementation at the proteome level were more effective after 4 weeks of feeding and at the higher inclusion level (i.e., 1% of feed). The bactericidal activity increased in fish fed the highest supplementation level of both AAs after 4 weeks. Peripheral monocyte numbers correlated positively with nitric oxide, which showed an increasing trend in a dose-dependent manner. The colony-stimulating factor 1 receptor tended to be up-regulated at the final sampling point regardless of dietary treatments. Data from this study point to an immunostimulatory effect of dietary ARG or CIT supplementation after 4 weeks of feeding in the gilthead seabream, particularly when supplemented at a 1% inclusion level.

Antioxidant Peptides from Dark Meat of Yellowfin Tuna (Thunnus albacares): Process Optimization and Characterization

Tuna dark meat is a major edible by-product obtained from tuna cannery which is currently under-utilized or opted for the preparation of low-end products. Effective utilization of this marine biomass to bioactive peptides is a promising option facilitating numerous food and nutraceutical applications. Process optimisation studies for the extraction of antioxidant peptides from cooked dark meat of Thunnus albacares using RSM, indicated a papain based hydrolytic condition of 0.98% E/S (w/w), 240 min hydrolysis time as desirable under a pre-optimized temperature and pH of 60 °C and 6.5, respectively. Further detailed characterization viz., nutritional profile, molecular weight, surface morphology, thermal and spectral characteristics, physico-chemical properties, thermal/pH stability and in-vitro digestibility studies of the optimized antioxidant peptide was performed. Nutritional evaluation indicated its abundance in protein with balanced aminoacid profile and explored its richness in glutamic acid, aspartic acid, lysine and leucine. Molecular weight pattern indicated a major distribution (45%) of peptides in the size range of < 3 kDa, 25% peptides between 10–30 kDa and 30% (3–10 kDa). Present study explores the application potential of tuna protein hydrolysate as a natural antioxidant in variety of food and nutraceutical systems.