Essential Amino Acid Profile Research Articles

Breathing New Life to Ancient Crops: Promoting the Ancient Philippine Grain "Kabog Millet" as an Alternative to Rice.

Consumption of underutilised ancient crops has huge benefits for our society. It improves food security by diversifying our staple foods and makes our agriculture more adaptable to climate change. The Philippines has a rich biodiversity and many plant species used as staple foods are native to the Philippines. An example of ancient Philippine crops is the kabog millet, an ecotype of Panicum miliaceum. There is a dearth of information about its uses and properties; hence, in this study, the nutritional quality of kabog millet was evaluated. The total starch, % amylose, ash, dietary fibre, proteins, essential amino acid profile, phenolic acids, carotenoids, tocopherols, and the antioxidant properties of its total phenolic acid extracts were compared to four types of rice (white, brown, red, and black) and a reference millet, purchased from local Swiss supermarkets. Our analyses showed that kabog millet has higher total dietary fibre, total protein, total phenolic acids, tocopherols, and carotenoids content than white rice. It also performed well in antioxidant assays. Our results indicate that kabog millet is a good alternative to rice. It is hoped that the results of this study will encourage consumers and farmers to diversify their food palette and address food insecurity.

Baseline plasma essential amino acids are associated with lower levels of fatigue after weight loss in morbidly obese adults

Rationale: Studies have reported that plasma Essential Amino Acids (EAAs) are elevated in obesity. Inline, a disproportionate number of obese patients suffer from mental illnesses with anxiety and depression. It remains unclear whether the response in psychological outcomes to weight loss programs is related to their baseline plasma EAA profile.

Assessment of black gram milling by-product as a potential source of nutrients.

The present study was carried out to classify and explore the nutrient distribution of black gram milling by-product, with an intention to find value-added applications. The by-product was classified into two fractions, i.e., fraction BRGA (By-product Rich in Germ and Aleurone) and husk and their nutritional profiles were compared to cotyledon and whole seed (naive and germinated). BRGA found to be the richest source of protein (31.38%), minerals (Mg, Na, Fe, Zn and Mn) with appreciable amount of soluble dietary fiber (3.13%). Husk was the richest source of total dietary fiber (79.62%). Furthermore, both by-products were endowed with valuable essential amino acid and fatty acid profiles when compared to cotyledon and whole seeds. Overall, the present study revealed that the black gram by-product is a promising food ingredient that can be processed to obtain fractionsrich in protein, fiber, essential fatty acids and minerals, fordeveloping specialty foods for target population.

Partially Defatted Hermetia illucens Larva Meal in Diet of Eurasian Perch (Perca fluviatilis) Juveniles.

Simple SummaryThe replacement of fishmeal by insect meal is a promising strategy to obtain more sustainable fish feeds, a major goal in aquaculture. Black soldier fly Hermetia illucens larva meal has a high crude protein and fat content, essential for omnivorous and carnivorous fish. We used partially defatted H. illucens larva meal as a substitute for 20%, 40% and 60% of the fishmeal in standard diets for Eurasian perch and measured its effect on growth performance, feed utilization, body indices, fish body composition and blood indices. We found no significant differences in survival, size heterogeneity, hematology indices; or in whole-body dry matter, crude protein and ether extract content. The 60% inclusion reduced final body weight, specific growth rate, feeding rate, protein efficiency ratio, condition factor and hepatosomatic index. The fish-in-fish-out index decreased proportionally with increased H. illucens meal inclusion. Partially defatted H. illucens larva meal seems to be a promising alternative to fishmeal for Eurasian perch nutrition at moderate inclusion level.Insect meal is gaining increased attention in aquafeed formulations due to high protein content and an essential amino acid profile similar to that of fishmeal. To investigate insect meal in feed for European perch Perca fluviatilis, a promising candidate for European intensive culture, we replaced standard fishmeal with partially defatted black soldier fly Hermetia illucens larva meal at rates of 0%, 20%, 40% and 60% (groups CON, H20, H40 and H60, respectively) and compared growth performance, somatic indices, hematological parameters, whole-body proximate composition and occurrence of spleen lipidosis. In addition, we assessed the economic and environmental sustainability of the tested feeds by calculating economic conversion ratio (ECR) and economic profit index (EPI). The tested groups did not differ in survival rate. Significant differences were documented in final body weight and specific growth rate, with the highest values in CON, H20 and H40. The proximate composition of fish whole-body at the end of the experiment did not differ in dry matter, crude protein or ether extract, while organic matter, ash and gross energy composition showed significant differences. The fatty acid content and n-3/n-6 ratio showed a decreasing trend with increasing H. illucens larva meal inclusion. No differences were found in hematological parameters among tested groups. The H. illucens larva meal inclusion significantly affected ECR and EPI, even at 20% inclusion level the cost of diets did not differ from the control fish meal based diet. Results suggested that 40% inclusion of H. illucens larva meal can be used successfully in standard diets for perch.

Amino Acid Profile and Protein Quality Assessment of Macroalgae Produced in an Integrated Multi-Trophic Aquaculture System.

Seaweeds are a recognized source of bioactive compounds and techno-functional ingredients. However, its protein fraction is still underexplored. The aim of this study was to determine the total and free amino acid profile and protein content of four seaweeds species (Porphyra dioica, Porphyra umbilicalis, Gracilaria vermiculophylla, and Ulva rigida) produced in an integrated multi-trophic aquaculture system, while assessing their protein quality. Samples were submitted to acid and alkaline hydrolysis (total amino acids) and to an aqueous extraction (free amino acids) followed by an automated online derivatization procedure, and analyzed by reverse phase-high performance liquid chromatography. Protein-, non-protein and total-nitrogen were quantified by the Kjeldahl method. Crude and true protein contents were estimated based on the nitrogen and amino acid composition. Protein quality was assessed based on the amino acids profile. Porphyra species presented the highest protein content compared to the remaining three seaweed species tested. All samples presented a complete profile of essential amino acids and a high quality protein profile, according to World Health Organization and Food and Agriculture Organization standards. Methionine and tryptophan were the first limiting amino acids in all species. Red species (Porphyra and Gracilaria) presented high levels of free alanine, glutamic, and aspartic acids. The results highlight the potential of using seaweeds as an alternative and sustainable source of protein and amino acids for human nutrition and industrial food processing.

Protein and amino acid composition of different quinoa (Chenopodium quinoa willd) cultivars grown under field conditions in Ethiopia, Kenya, Uganda, and Zambia

Protein-energy malnutrition (PEM) remains a public health concern in most developing nations. In Africa, PEM can be attributed to monotonous diets based on cereals, roots, and tubers, with little or no protein of animal origin. Diversifying cropping systems to include protein dense pseudo-cereals such as Quinoa (Chenopodium quinoa Willd.) could help provide more protein in the diet of vulnerable populations. Quinoa is a crop with potential for biodiversification because it has a high nutritional value; however, it is underutilized in Africa, and information about the nutritional quality of the grain grown in contrasting environments is limited. Within the framework of FAO’s commemoration of 2013 as the ‘The International Year of the Quinoa’ (IYQ), a Technical Cooperation Programme (TCP) project was developed with some African countries to assess the capacity of quinoa to adapt to different agro-ecological regions and the nutritional quality of the resulting grain. For this study, we evaluated the protein content and amino acidprofile of three genotypes of quinoa that had been grown under diverse altitudes, soil, and climate conditions in Ethiopia, Kenya, Uganda, and Zambia. The mean protein content (g/100g) of Kancolla, Titicaca and BBR varieties grown in Africa ranged from 14.33 ±0.20 to 17.61 ±0.55, 14.23 ±0.25 to 16.65 ±0.55, and 13.13 ±0.2 to 16.23 ±0.49, respectively. On the other hand, the protein content (g/100g) of Kancolla, Titicaca, and BBR seeds grown in Peru was 13.80 ±0.10, 17.43 ±0.31, and 17.07 ±0.11, respectively. The Kancolla variety [grown in Ethiopia and Kenya] had a significantly higher protein content than that obtained from Peru [P < 0.001]. Regarding the profile of essential amino acids, Quinoa is essentially richer in methionine than most cereals. Levels of methionine were lower in the seeds grown in Africa compared to those from Peru [P < 0.001]. In terms of environmental influences, the protein content was relatively higher in quinoa seeds grown in high-altitude areas, where soils have a low pH and high nitrogen content. We conclude that Quinoa can be introduced to Africa, especially to high altitudes and warm regions where the soil has a low pH and high nitrogen content. Thecrop would be ideal for diversifying local diets. Key words: Africa, Agro-ecology, Chenopodium quinoa, protein, amino acid content, biodiversity, diets

Animal, Plant, Collagen and Blended Dietary Proteins: Effects on Musculoskeletal Outcomes.

Dietary protein is critical for the maintenance of musculoskeletal health, where appropriate intake (i.e., source, dose, timing) can mitigate declines in muscle and bone mass and/or function. Animal-derived protein is a potent anabolic source due to rapid digestion and absorption kinetics stimulating robust increases in muscle protein synthesis and promoting bone accretion and maintenance. However, global concerns surrounding environmental sustainability has led to an increasing interest in plant- and collagen-derived protein as alternative or adjunct dietary sources. This is despite the lower anabolic profile of plant and collagen protein due to the inferior essential amino acid profile (e.g., lower leucine content) and subordinate digestibility (versus animal). This review evaluates the efficacy of animal-, plant- and collagen-derived proteins in isolation, and as protein blends, for augmenting muscle and bone metabolism and health in the context of ageing, exercise and energy restriction.

Ideal profile of essential amino acids for Nile tilapia ( Oreochromis niloticus ) in the finishing growth phase

This study aimed to estimate the ideal profile of essential amino acids (EAAs) for Nile tilapia (Oreochromis niloticus) in the finishing growth phase. A total of 264 fish (initial average weight of 625 g) were distributed among randomly arranged 33 fibre tanks of 1000-L water capacity each, connected to a water recirculation system. The 60-day experiment consisted of 11 treatments with three replicates each and fish were fed three times a day. The treatments consisted of a control diet (CD), 45% of which was composed of crystalline amino acids along with purified ingredients and the remaining 55% was contributed by the conventional ingredients meeting the nutritional requirements, and other 10 EAA-deficient test diets (DD) which were deficient from 33%–41% in each evaluated AA. The essential amino acid ratios were calculated from the relationship between body nitrogen retention and the amount of amino acid deleted from the test diet. This study found the following ideal profile of essential amino acids expressed in relation to lysine (100%); arginine (80.73%), phenylalanine (69.73%), histidine (34.15%), isoleucine (51.24%), leucine (66.01%), methionine (41.49%), threonine (88.96%), tryptophan (23.07%) and valine (72.63%).

Separating the Wheat from the Chaff: Nutritional Value of Plant Proteins and Their Potential Contribution to Human Health

The quality and nutritional value of dietary proteins are determined by the quantity, digestibility and bioavailability of essential amino acids (EAA), which play a critical role in human growth, longevity and metabolic health. Plant-source protein is often deficient in one or more EAAs (e.g., branched-chain amino acids, lysine, methionine and/or tryptophan) and, in its natural form, is less digestible than animal-source protein. Nevertheless, dietary intake of plant-source protein has been promoted because of its potential health benefits, lower cost of production and lower environmental impact compared to animal-source protein. Implementation of dietary strategies that improve both human and planetary health are of critical importance and subject to growing interest from researchers and consumers. Therefore, in this review we analyse current plant protein intake patterns and discuss possible countermeasures that can enhance plant protein nutrition, examples include: (1) combining different plant proteins with complementary EAA profiles; (2) identification and commercial cultivation of new and novel high-quality plant proteins; (3) industrial and domestic processing methods; and (4) genome-editing techniques.

Protein hydrolysates from Alphitobius diaperinus and Hermetia illucens larvae treated with commercial proteases

Insect proteins have been proposed as a promising alternative for feed and food formulations. In the present work protease-assisted extraction was studied as a way to separate and extract proteins from two different insect species: Alphitobius diaperinus (AD) and Hermetia illucens (HI). The proteolytic activity of seven enzymes (papain, pancreatin, dispase I, pepsin, protease from Bacillus licheniformis, bromelain and trypsin) was evaluated determining the protein extraction yield, the degree of hydrolysis (DH) and the released free amino acids (FAA). Both insects represent an interesting source of proteins, not only for their amount (more than 40% on dry matter) but also for the nutritional value, with essential amino acid profile exceeding the requirements proposed for human nutrition. Enzyme-assisted protein extraction, performed at laboratory scale, gave for HI an average yield of extraction of 71±8% and for AD 67±6%. Hydrolysates produced from HI gave a DH% ranging between 3 to 18%, whereas hydrolysates produced from AD yielded a DH% between 7 to 23%. The protein hydrolysates were composed by peptides and FAA (which accounted for more than 30% of the extracted protein fraction), which were released according to their abundance in initial protein. A moderate correlation between the DH% and the total amount of FAA was found, except for AD hydrolysed with trypsin and HI with papain. Based on these results, the production of hydrolysates was preliminary scaled up in a proof-of-concept experiment, focusing on the most promising insect-enzyme combination. The final product resulted to be rich in protein (60% on dry matter). This work support enzymatic hydrolysis as an effective method to extract and isolate proteins from insects, with minimal sample preparation, tailoring their composition, preserving the nutritional quality, decreasing the risk of allergic reactions and making them more accessible for their future use as feed/food supplements.

Impact of Fermentation and Phytase Treatment of Pea-Oat Protein Blend on Physicochemical, Sensory, and Nutritional Properties of Extruded Meat Analogs.

Plant materials that are used for the production of extruded meat analogs are often nutritionally incomplete and also contain antinutrients, thus there is a need to explore alternative plant proteins and pre-treatments. This study demonstrates application of phytase and fermentation to a pea-oat protein blend with a good essential amino acid profile and subsequent texturization using extrusion cooking. Enzymatic treatment reduced the content of antinutrient phytic acid by 32%. Extrusion also degraded phytic acid by up to 18%, but the effect depended on the material. Differences in physicochemical, sensorial, and textural properties between untreated and phytase-treated extruded meat analogs were small. In contrast, fermented material was more difficult to texturize due to degradation of macromolecules; physicochemical and textural properties of extrudates were markedly different; sensory analysis showed enhancement of flavor, but also detected an increase in some unwanted taste attributes (bitterness, cereal and off-taste). Phytic acid was not degraded by fermentation. Analysis of volatile compounds showed extrusion eliminated volatiles from the raw material but introduced Maillard reaction products. Overall, phytase treatment and fermentation demonstrated the potential for application in extruded meat analogs but also highlighted the necessity of optimization of process conditions.

Rubisco: A promising plant protein to enrich wheat-based food without impairing dough viscoelasticity and protein polymerisation

Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), a leaf protein, has an interesting amino acid profile and promising functional properties. Incorporated in wheat-based products, it would increase their protein content and improve their essential amino acid profile, particularly lysine. The impact of rubisco enrichment on wheat dough mechanical properties and protein-protein interactions was investigated using Dynamic Mechanical Thermal Analysis and Size-Exclusion chromatography, respectively. Experiments were also performed on gluten and pea protein enriched doughs as a comparison. Wheat doughs with increasing concentrations of rubisco, gluten or pea proteins (from 0 to 33% of total proteins) were prepared using a 2 g-mixograph at constant hydration. In contrast to pea proteins and gluten, rubisco does not reduce dough stiffening during heating, probably due to its own reactivity to temperature and to low competition with starch for water. Detailed analysis of protein interactions showed that rubisco is part of the gluten network formed during dough mixing through the establishment of weak and disulphide bonds. In addition, rubisco subunits form new covalent bonds during the heat treatment thereby increasing the concentration of SDS insoluble high molecular weight aggregates. These results suggest that rubisco actively participates in the formation of the dough protein network. The colocation of gluten and rubisco proteins on micrographs supports the hypothesis that they form a co-protein network.

Process effects on carinata Brassica carinata and camelina Camelina sativa seed meal compositions and diet palatability in Rainbow Trout Oncorhynchus mykiss

Inclusion levels of raw carinata Brassica carinata and camelina Camelina sativa seed meals in animal diets, especially monogastrics, is limited by antinutrients, mainly glucosinolates (GLS), sinapine and crude fiber. The effect of processing on these seed meals composition was assessed by first subjecting cold-pressed (CP) carinata and camelina seed meals to extrusion (EX), solvent extraction (SE) and aerobic conversion (AC), or sequential process combinations to determine which process(es) yielded improved chemical composition. The palatability of the processed meals was then conducted to determine the effects of processing on meal acceptability in fish. Carinata meals generally yielded more crude protein than camelina meals for a given process treatment. Similarly, the fiber contents of carinata meals were generally lower than observed for camelina meals. Largest protein increase was due to oil removal and AC, but not EX. Generally, AC increased the essential amino acids (EAA) of all meals. Although AC increased the crude fiber of all meals, it reduced the GLS of all meals by at least 70 %, with more reduction observed in camelina meals. Palatability of carinata and camelina meals was improved by SE. Extrusion improved the palatability of camelina and AC improved the palatability of carinata. Generally, AC meals were higher in protein and EAA, lower in soluble carbohydrate and GLS than unconverted meals and would be suitable for use in fish diets. Extrusion did not improve the composition or palatability of CPEXSEAC beyond CPSEAC. Generally, CPSEAC carinata would be preferred by feed manufacturers over CPSEAC camelina because of a better EAA profile, higher protein content and lower crude fiber. Reduction of crude fiber in CPSEAC carinata would likely improve the utilization of nutrients, increasing meal utilization in fish and /or monogastrics in general. Digestibility studies should be conducted to improve an understanding of the utilization of the different processed carinata and camelina meals in fish and/ or monogastrics, in addition to processing economics.

Optimal Dietary Protein Requirement for Juvenile Sesarmid Crab (Episesarma singaporense).

Simple SummaryEssential information on the major nutrients which could affect the survival and growth of early juvenile Episesarma singaporense crabs, especially their protein requirements, is still lacking. Therefore, the objective of this study was to determine the dietary protein requirement for early juvenile E. singaporense crabs. Growth performance, feed utilization, digestive enzyme activity, and muscle amino acid profiles were used as criteria for assessing the suitable treatment. Based on our investigations, desirable characteristics were achieved in the crabs fed with diet containing 45% protein. This level is similar to previous reports in other crab species, and could be employed in preparing artificial diets for this species.The optimal dietary protein requirement for sesarmid crabs (Episesarma singaporense) was investigated. Juvenile E. singaporense, individually reared in plastic glasses containing 250 mL sea water, were fed five fish meal-soybean meal-microbound diets variously containing dietary protein levels of 30%, 35%, 40%, 45% and 50% for six weeks. A completely randomized design was used in the experiment, comprising five treatments with 60 crabs in each. At the end of the experiment, a significant improvement in survival was observed in all treatments relative to the diet containing 30% dietary protein (p < 0.05) while the growth performance parameters did not differ across the five dietary groups. A significantly higher protein efficiency ratio was observed in the E. singaporense crabs receiving 45% dietary protein relative to the remaining treatments. The specific activities of the digestive enzymes, pepsin-like, trypsin, amylase, and lipase, and the amylase to trypsin ratio fluctuated across the five treatments, but that of chymotrypsin remained consistent, suggesting different nutritional responses to the various dietary protein levels. The crabs receiving the 45% protein diet had significantly higher in essential amino acid (EAA) profiles followed by the 40% protein diet, although some EAA values were only moderate. The pattern for the non-EAA (NEAA) was reversed, and the ΣEAA/ΣNEAA ratio was higher in the crabs receiving the 45% protein diets relative to the other treatments. Based on our investigations, the optimal dietary protein requirement achieving desirable characteristics of juvenile E. singaporense crabs was 45%. This finding would be a useful guideline in preparing artificial diets for the mariculture of this species.

Physicochemical properties and proximate composition of tamarillo (Solanum betaceum Cav.) fruits from New Zealand

This study reports physical parameters, proximate compositions, reducing sugar and amino acid contents in Amber, Laird’s Large and Mulligan tamarillos that were produced in New Zealand. Across all three cultivars, about 3 % of dietary fibre was present. Higher amounts of neutral side chains were observed in pectin from Laird’s Large compared to other cultivars and in pectin from pulps compared to peels. Among 22 detected amino acids, 2 essential amino acids and 5 non-essential amino acids were reported herein for the first time. The total amino acids content in peel and pulp of tamarillos ranged from 1192 to 1753 and 3455–6077 mg 100 g−1 dry weight, respectively. l-glutamic acid, γ-aminobutyric acid and l-aspartic acid dominated amino acid profile of tamarillo except for Amber peel. l-histidine and l-lysine dominated the essential amino acid profile of all tamarillo samples. Principal component analysis revealed a clear separation among soluble sugar and amino acid profiles of different cultivars and tissues of tamarillo.

Acute Effect of a Protein Supplement on Targeted Plasma Amino Acid Profile among Healthy Asian Indians: A Randomized Controlled Trial.

Background Indians have a poor protein intake in terms of quantity as well as quality because of their predominantly cereal-based diet. However, there is limited information on circulatory amino acid levels in healthy Indians. Herein, we evaluated the acute effect of a protein supplement on the plasma levels of essential amino acids (EAAs) in healthy Indian adults, using targeted EAA analysis. Methods In this double-blind, randomized, crossover study, 20 healthy Indian adults were randomized to receive the test protein supplement (treatment arm, n = 10) or placebo (control arm, n = 10) with milk, after overnight fasting. After 7 days, the participants returned for the crossover treatment. Blood samples were collected at baseline and at 60 and 120 min after protein/placebo consumption. Plasma EAA levels were estimated using liquid chromatography-tandem mass spectrometry. Repeated measures ANOVA was performed to assess the effect of treatment on EAA levels. P values < 0.05 were considered statistically significant. Results At baseline, mean plasma levels did not differ significantly between the two arms for any of the EAAs. In the treatment arm, the mean levels of all EAAs increased significantly from baseline to 60 min (P < 0.01), with no significant change from 60 to 120 min. There was no significant change in amino acid levels in the control arm. The magnitude as well as percentage of increase from baseline to 60 min was significantly greater in the treatment arm than in the control arm for all EAAs. Conclusion Compared to placebo, protein supplement increased circulatory amino acid levels in healthy Indians. The observed increase in EAA levels and its role in conjunction with exercise in both healthy and diseased states need to be further evaluated. This is the first dataset exploring targeted EAA profiles and the effect of a protein supplement among healthy Indians. The clinical trial is registered with CTRI/2018/12/016777.

Preparation of Gluten-Free Corn Crackers Supplemented with Some Legume Flours

Defatted soybean and chickpea flours were incorporated at levels up to 40% into gluten-free corn crackers formulations with the aim of preparing crackers with enhanced nutritional profile. Supplementation with legume flours led to an increase in protein content up to more than a double as that of the control crackers, while the carbohydrate content was decreased. Moreover, amino acid profile was improved by the increase in essential amino acid profile, especially with lysine content which is the first limiting amino acid in cereals in the produced crackers which scored up to three times higher than the control ones. These results were accompanied, by its turn, by improved protein quality parameters such as Essential Amino Acid Index (EAAI), Biological Value (BV), Protein Efficiency Ratio (PER) and Chemical Score (CS). Sensory characteristics of defatted soybean flour-containing crackers were not significantly affected at the level of 20%, while crackers with chickpea flour scored lower than the control ones but were still highly acceptable by the panelists. How to cite this article: Kamel MAA, Aly MMH, Abd-El-Khalek MH. Preparation of Gluten-Free Corn Crackers Supplemented with Some Legume Flours. J Adv Res Food Sci Nutr 2020; 3(1): 42-49. DOI: https://doi.org/10.24321/2582.3892.202006

Dried aerobic heterotrophic bacteria from treatment of food and beverage effluents: Screening of correlations between operation parameters and microbial protein quality

Consortia of aerobic heterotrophic bacteria (AHB) have potential as sustainable microbial protein (MP) source in animal feed. A systematic screening of the nutritional value and safety of AHB biomass from full-scale activated sludge plants from 25 companies in the food sector was performed. The variable protein content (21–49%) was positively correlated with biomass-specific nitrogen loading rate and negatively with sludge retention time (SRT). Compared to the essential amino acid profile of soybean meal protein, AHB displayed an overall surplus of threonine and valine, and deficits in cysteine, histidine, lysine and phenylalanine. Histidine was positively correlated with bCOD/PO43− in the influent and valine, isoleucine and threonine with SRT. Most AHB samples were safe apropos heavy metals, polycyclic aromatic hydrocarbons and antibiotics. Some pesticides exceeded regulatory limits, necessitating mitigation. This work highlighted that the food sector can provide high-quality MP, while retrofitting existing activated sludge plants towards high-rate processes can increase AHB quality and productivity.

Agri-Food Side-Stream Inclusion in The Diet of Alphitobius Diaperinus. Part 2: Impact on Larvae Composition.

Insects are gaining interest as an alternative protein source for feed/food purposes. Although the lesser mealworm (LM) is commercially produced for human consumption, published data on its nutrient composition is scarce. This study reports on LM larvae reared on 18 different diets composed of side-streams to (1) determine the nutritional composition of the larvae and (2) study the effect of dietary changes on the larval nutrient composition. The LM larvae proved to be of good nutritional value with essential amino acids profiles comparable with that of beef and linoleic acid (C18:2) was the most dominant essential fatty acids in the larvae. The side-stream based diets varied on dry matter basis in protein (16–34%) and lipid content (2–19%). The nutrient content of the larvae reared on diets that supported good growth ranged between 37% and 49% of protein, 22% and 26% of lipid and 4% to 6% of chitin on dry matter basis. No significant correlations were identified between the larval protein or lipid content and that of the diet, but it was found between the diet nutrients and larval growth. Based on larval growth data and economic considerations, diets composed of wheat middlings with a 10–15% inclusion of rapeseed meal were identified as suitable feed for LM. Highest larval yields were obtained with diets containing 15–22% of proteins and 5–10% of lipids.

Determination of the optimum dietary essential amino acid profile for growing phase of Nile tilapia by deletion method

The present study aimed to determine the optimal ratios of essential amino acids (EAAs) for Nile tilapia (Oreochromis niloticus) juveniles (150–200 g) using the deletion method. A total of 880 Nile tilapia juveniles (158.78 ± 0.9 g) were randomly distributed among 44 tanks (20 fish per tank/replicate) of 1500-L capacity each. During the 53 days feeding trial, fish were fed with the respective diets and daily feed intake was regularly recorded. In order to prevent any feed wastage, the fish were hand-fed three times a day until apparent satiation. A balanced diet (BD) and other ten diets were formulated by the deletion method, where the BD diet was adjusted to result in a reduction of 45% of each tested EAA. A group of fish at the beginning and at the end of the experiment was euthanized for the determination of the carcass nitrogen (N) composition. Based on the results of the present study, the optimal balance of essential amino acids for Nile tilapia juveniles weighing 150 and 200 g (g 16 g−1 N) was estimated as, arginine 4.88, lysine 5.87, threonine 6.02, histidine 1.73, isoleucine 3.26, leucine 4.82, methionine 2.36, phenylalanine 3.66, valine 3.46 and tryptophan 0.87.