Amino Acid Score Research Articles

Impact of steaming and roasting heat‐treatment on physico‐chemical and functional properties of walnut kernel

AbstractIn this study, the effect of steaming and roasting treatment on the physicochemical and functional properties of walnut kernel at 95°C for different time (15, 20, and 30 min) was investigated. Steaming and roasting treatments significantly increased the enthalpy change for protein denaturation, in‐vitro digestibility, viscosity, storage modulus (G′) and loss modulus (G″) (p < 0.05), the order from high to low was steaming (7.11–8.69 J g−1; the gastric and intestinal digestion: 1.21%–17.83% and 1.51%–27.31%, respectively; 134.04–450.49 Pa s; 214.28–1047.14 and 61.72–196.09 Pa) > roasting (6.24–7.07 J g−1; the gastric and intestinal digestion: 1.26–15.42% and 1.21–22.37% a, respectively; 16.92–86.07 Pa s; 6.58–209.85 and 3.08–67.14) > untreated (4.53 J g−1; the gastric and intestinal digestion: 0.24%–4.18% and 1.00–7.58%, respectively; 17.06 Pa s; 5.78 and 1.79 Pa). All samples contained the essential amino acids, the amino acid score of samples by steaming was the highest. In addition, the protein of walnut kernel after heating treatment contained more α‐helix and random coil structures compared to the untreated sample, while β‐sheet and β‐turns structures decreased. Moreover, the thermal treatment could cause the changes of the water/oil holding capacity, foaming and emulsifying properties of walnut kernel flour. When there were differences between the results of steaming and roasting samples, it was concluded that the water played an important role in steaming. These results suggested that the thermal treatment as an effective approach could improve the physico‐chemical, structural and functional properties of walnut kernel and be potentially applied in the food processing.

Pea protein globulins: Does their relative ratio matter?

The relatively low abundance of 11S legumin in pea protein, coupled with the wide diversity in 7S vicilin to 11S legumin ratio among pea protein ingredients, are assumed contributors to inferior and inconsistent properties relative to soy protein. To improve the performance of pea protein ingredients in food applications, optimum protein profile must be identified. Therefore, this work followed a holistic approach to determine the impact of 7S/11S ratio on pea protein structure, functionality, and nutritional quality. Vicilin- and legumin-rich fractions were isolated and combined in different proportions to produce samples of varying 7S/11S ratios. For the first time, pea protein isolate was also enriched with 11S legumin to evaluate the impact of 11S abundance on functionality within an unfractionated protein matrix. The low abundance of 11S in pea protein did not seem to be the cause of inferior properties. In fact, 7S vicilin had 6-fold higher gel strength and 5-fold higher emulsification capacity, but significantly lower nutritional quality, than 11S legumin. Despite having significantly higher sulfur-containing amino acids, high protein polymerization in 11S legumin contributed to relatively low functionality. Further, fractionation induced unique changes to amino acid composition, resulting in significantly lower amino acid scores for isolated 7S vicilin and 11S legumin relative to pea protein isolate. Accordingly, 11S legumin enrichment of pea protein isolate did not improve functionality or nutritional quality. Nevertheless, this work contributed foundational knowledge that will provide direction for future studies aiming at devising strategies to improve the quality and consistency of pea protein ingredients.

Production of chickpea protein hydrolysate at laboratory and pilot plant scales: Optimization using principal component analysis based on antioxidant activities

Chickpeas are a nutrient-rich source with optimal and high essential amino acid score. To evaluate its potential as a functional food ingredient, 36 chickpea protein hydrolysates were produced at the lab-scale using food-grade enzymes. Parameters including yields, protein content, hydrolysis degree, and antioxidant activities were employed to identify the most favourable conditions for scaling up production to a pilot plant level using a principal component analysis. The selected hydrolysate demonstrated commendable traits: a substantial content of essential amino acids and proteins at 67.71%, notable protein (73.12%) and weight (72.00%) yields, coupled with exceptional solubility exceeding 80%, and a noteworthy digestibility of 89.50%. Upon transition to pilot plant proportions, the hydrolysate retained its attenuated protein profile while exhibiting heightened antioxidant activities. Derived chickpea protein hydrolysates offer promise for innovative foods applications, impacting health and chronic disease prevention.

Extraction, optimization, and functional quality evaluation of carotenoproteins from shrimp processing side streams through enzymatic process.

The study aimed to develop an effective and eco-friendly enzymatic process to extract carotenoproteins from shrimp waste. The optimization of enzymatic hydrolysis conditions to maximize the degree of deproteinization (DDP) of carotenoprotein from shrimp head waste (SHW) and shrimp shell waste (SSW) was conducted separately using the Box-Behnken design of response surface methodology (RSM). To achieve a maximum DDP of 92.32% for SSW and 96.72% for SHW, the optimal hydrolysis conditions were determined as follows: temperature (SSW: 53.13°C; SHW: 45.90°C), pH (SSW: 7.13; SHW: 6.78), time (SSW: 90min; SHW: 61.18min), and enzyme/substrate ratio (SSW: 2g/100g; SHW: 1.18g/100g). The carotenoprotein effluent obtained was subjected to spray drying and subsequently assessed for color, nutritional, and functional characteristics. The carotenoprotein from shrimp shell (CpSS) contained a higher essential amino acid score than carotenoprotein from shrimp head (CpSH). CpSS had a higher whiteness index of 82.05, while CpSH had 64.04. Both CpSS and CpSH showed good functional properties viz solubility, emulsion, and foaming properties. The maximum solubility of CpSH and CpSS was determined to be 92.94% and 96.48% at pH 10.0, respectively. The highest emulsion capacity (CpSH: 81.33%, CpSS: 70.13%) and stability (CpSH: 57.06%, CpSS: 63.05%) were observed at 3% carotenoprotein concentration. Similarly, the highest values of foaming capacity (CpSH: 27.66%, CpSS: 105.5%) and stability (CpSH: 23.83%, CpSS: 105.33%) were also found at the same 3% carotenoprotein concentration. In conclusion, the carotenoproteins obtained from shrimp waste showed favorable attributes in terms of color, amino acid composition, and functional properties. These findings strongly suggest the potential applicability of CpSS and CpSH as valuable resources in various domains. CpSS, with its higher whiteness index, greater amino acid content, and superior functional characteristics, may find suitability as functional ingredients in human food products. Conversely, CpSH could be considered for incorporation into animal feed formulations.

Nutritional quality, glycemic index and glycemic load of two similar traditional diets consumed in Northeast, Nigeria

Glycemic index (GI) and glycemic load (GL) have been implicated in the development and progression of chronic non communicable diseases (NCDs) and WHO has recommended dietary approach in its management. This study was conducted to assess the nutritional composition of two varieties of Danwaken; fulawa and dawa which are traditional diets consumed in Bauchi and Gombe states with a view to ascertaining its GI in the management of chronic NCDs. Proximate, amino and fatty acids compositions of the Danwake varieties were analyzed using standard procedures. Eighty volunteers were recruited from Bauchi and Gombe metropolitan areas and feed with 50 g of test and reference foods (white bread) and GI was determined by trapezoid method. Danwaken fulawa had a significantly higher moisture and carbohydrate content (p<0.05) and lower protein content compared to Danwaken dawa. Total amino acids and essential amino acids in Danwaken dawa (912, 367 mg/g protein) were higher than Danwaken fulawa (854, 294 mg/g protein) respectively, with higher limiting amino acid score compared with WHO/FAO/UNU requirements except lysine. Both diets had no essential fatty acids with high GI and GL, although Danwaken fulawa had a higher GL value which was significantly different (p<0.05).

Comparative assessment of beef characteristics from young bulls of different breeds and the influence of storage conditions on meat quality indicators

Comparative assessment results for quality indicators of meat samples obtained from Black Pied, Simmental and Aberdeen Angus young bulls and the influence of different temperature conditions on the quality of vacuum-packed beef during refrigerated storage are presented. The general chemical composition, physicochemical properties, and biological value of the samples based on the content of nonessential and essential amino acids were determined, as well as the protein quality index (PQI) and amino acid score. Analysis of the general chemical composition revealed higher moisture and protein content and the lowest fat content in Black Pied beef compared to other breeds. The amino acid composition of the protein showed a higher content of essential amino acids and the highest PQI value in Simmental beef. According to the calculation results, higher amino acid scores for lysine (149.1% and 129.1%) and tryptophane (200.0% and 240.0%) were noted in meat from Simmental and Aberdeen Angus young bulls, respectively. For the process of storing vacuum-packed meat in a cooled (at a temperature of 2.0 ± 0.5 °C) and superchilled state (minus 2.0 ± 0.5 °C) at a relative air humidity of 85%, a comparative analysis of changes in free amino acids and dynamics of hydrolytic and oxidative spoil- age of meat samples from various breeds was conducted. After 21 days of storage in a superchilled state, the content of free amino acids in Black Pied, Simmental and Aberdeen Angus beef was lower by 13.1% (P > 0.05), 24.1% (P ≤ 0.05) and 17.0% (P ≤ 0.01) compared to storage in a cooled state, respectively. For all studied samples stored in a cooled state, the acid number values were 40% to 41% (P ≤ 0.01) higher than in a superchilled state and peroxide number values were 20% to 23% (P ≤ 0.05) higher than in a superchilled state. It has been established that lowering the storage temperature of vacuum-packed beef helps to better preserve quality and ensure safety for meat from all breeds studied.

The animal protein hydrolysate attenuates sarcopenia via the muscle-gut axis in aged mice

Age-related muscle loss and dysfunction, sarcopenia, is a common condition that results in poor quality of life in the elderly. Protein supplementation is a potential strategy for preventing sarcopenia and increasing muscle synthesis, but the effectiveness of protein type and level in improving sarcopenia is not well understood. In this study, we compared animal protein hydrolysate (APH), which has a high protein digestibility-corrected amino acid score (PDCAAS) and low molecular weight, with casein as a control group to investigate the effects and mechanisms of sarcopenia improvement, with a particular focus on the gut-muscle axis. APH supplementation improved age-related declines in muscle mass, grip strength, hind leg thickness, muscle protein level, muscle fiber size, and myokine levels, compared to the control group. In particular, levels of plasma cortisol, muscle lipids, and muscle collagen were markedly reduced by APH supplements in the aged mice. Furthermore, APH efficiently recovered the concentration of total SCFAs including acetic, propionic, and isovaleric acids decreased in aged mice. Finally, APH induced changes in gut microbiota and increased production of SCFAs, which were positively correlated with muscle protein level and negatively correlated with pro-inflammatory cytokines. In conclusion, APH can help to inhibit age-related sarcopenia by increasing muscle synthesis, inhibiting muscle breakdown, and potentially modulating the gut-muscle axis.

Impact of cooking on the protein quality of Russet potatoes.

Despite being low in crude protein, on a fresh weight basis, given their overall contribution to the North American diet, potatoes contribute approximately 2%-4% of the population's protein intake. However, the quality of the protein remains ill-defined. To that end, Russet potatoes were secured and subjected to various cooking conditions (raw [control], boiled, baked, microwaved, and fried [3, 6, and 9 min]) to determine the impact of cooking method on protein quality, as determined by amino acid score (AAS) and indices of in vivo true fecal protein digestibility (TFPD%; rodent bioassay) and in vitro protein digestibility (pH-drop, pH-Stat, and simulated gastrointestinal digestion both static and dynamic). The AAS of raw Russet potatoes was 0.67 ± 0.01, with histidine being the limiting AA. Frying led to a significant reduction in the AAS, however, other cooking methods yielded similar results to the raw control. The TFPD% of raw potato was low (40.5% ± 3.9%) and was significantly enhanced to over 80% with all cooking methods. Similar patterns were observed with all in vitro measures, however, all methods yielded higher values for the raw control samples. Final protein digestibility-corrected AAS (PDCAAS; product of AAS and TFPD%) values ranged from 0.27 (raw) to a high of 0.57 (boiled), with cooked values being comparable to other plant-based protein sources, including grains, and some nuts and pulses. In vitro PDCAAS values followed similar trends. This study defined the protein quality of cooked Russet potatoes and provides data for use in defining the quality of total protein consumed in the North American diet.

Milk Thistle (Silybum marianum (L.) Gaertner) Endosperm as an Alternative Protein Source for a Sustainable Food System (SFS)—Pilot Studies

Milk thistle is a plant that perfectly meets the needs of sustainable agriculture. Despite their high protein content, the seeds and endosperm of S. marianum have not been considered as raw food material so far. Therefore, the work aimed to characterize milk thistle endosperm in terms of its possible use in producing novel food. The nutritional and energy value of the raw material, profile of amino acids), fatty acids, and health quality indices of lipids were characterized. The main components of milk thistle endosperm (MTE) were protein (>20% dry matter (DM)), fat (>39% DM), and fiber (>31% DM). MTE protein is characterized by a high content of sulfur, aromatic amino acids, and tryptophan, comparing the FAO/WHO patterns. The PDCAA S (Protein Digestibility Corrected Amino Acid Score) value for lysine is low but can be higher in combination with other proteins. Milk thistle fat is dominated by unsaturated fatty acids, constituting about 80% of total fatty acids, of which over 56% are polyunsaturated fatty acids. Low values of atherogenicity and thrombogenicity indices of MTE fat testify to its potentially beneficial properties towards the cardiovascular system.

Сезонные изменения биологической ценности белков молока ослиц киргизской породы

Due to its protein component, donkey’s milk is a multifunctional product with a wide range of beneficial physiological properties. It is known for its antioxidant, anti-inflammatory, rejuvenating, antimicrobial, and antitumor effects. However, the milk of Kyrgyz donkeys has not received proper scientific attention in this respect. This study analyzed the seasonal amino acid profile and biological value of milk obtained from Kyrgyz donkeys.
 The donkeys belonged to the Kyrgyz breed and inhabited the highlands of the Chui Region, Republic of Kyrgyzstan. The sampling took place in April, July, and September. The amino acid composition of milk proteins was determined by capillary electrophoresis. The biological value of proteins was assessed by amino acid score, index of essential amino acids (Auxerre index), utility ratio of essential amino acids, and utility ratio of amino acid composition.
 The analysis revealed 18 amino acids, including eight essential ones. The total content of amino acids in the spring samples was 1840.07 mg/100 g. In the summer samples, this value peaked at 2037 mg/100 g; in autumn, it dropped to 1264.35 mg/100 g. The changes could be explained by the seasonal differences in the diet. The ratio of essential to non-essential amino acids approached 1:1. The milk also proved to contain arginine, which is an essential amino acid for a juvenile organism. In the spring samples, its content was 2.5 times as big as in the autumn ones. Leucine and isoleucine were responsible for 1/3 of the essential amino acids (322.60 ± 19.35 mg/100 g). The summer samples demonstrated the maximal content of some other essential amino acids, except for valine and tryptophan, which appeared to be the limiting essential amino acids for donkey’s milk in the autumn period. Total essential amino acids in the spring, summer, and autumn samples amounted to 54.24, 59.26, and 34.77 g/100 g, respectively, which exceeded the value for the reference protein (27.46 g/100 g).
 Kyrgyz donkey’s milk proteins were of high biological value, regardless of the season, which means that donkey’s milk can become part of new functional products.

Compositional characterization of starch, proteins and lipids of long bean, dwarf long bean, mung bean and French bean seed flours

Four underutilized legumes comprised of mung bean, long bean, dwarf long bean and French bean were investigated for their total starch, dietary fibre, amylose, amylopectin and resistant contents along with proteins and lipids profiles employing standard methods in order to explore appropriate end uses. Results showed significant variations (p<0.05) in the fat, protein, moisture, ash, total dietary fibre, carbohydrate, starch, amylose and amylopectin contents of all the four legume seeds Flours. Mung bean, long bean, dwarf long bean, and French bean showed carbohydrates contents of 55.24, 49.63, 48.12 and 45.56 g/100 g, respectively. Dwarf long bean, long bean and mung bean recorded total starch of 38.39, 49.78 and 57.68 g/100 g, respectively. Whereas French bean had the highest total dietary fibre of 16.91 g/100 g and dwarf long bean the highest amylopectin (86.67 g/100 g), both dwarf long bean and long bean recorded insoluble dietary fibre and soluble dietary fibre in the range of 7.25 to 14.58 g/100 g and 0.05 to 1.25 g/100 g, respectively, however, all the seed flours showed higher content of insoluble dietary fibre than soluble dietary fibre. Significant differences (p<0.05) observed in the total starch, resistant starch and non-resistant starch content of all the 4 samples. Non-resistant starch was the predominant constituents of the total of all the seed flours with mung bean showing the highest value (54.16 g/100 g) followed by long bean, dwarf long bean and French bean with 48.74, 37.73 and 16.88 g/100 g, respectively. Though the beans had low amylose contents, their amino acids score and patterns surpassed the FAO reference proteins and their saturated and unsaturated fatty acids ratio falls within FAO allowed limits. This study highlights the hidden potentials of these non-conventional legumes as sources of quality proteins, functional foods, healthy fats and dietary fibres.

Nutritional characterization of quality protein maize (QPM) (Zea mays L.) protein concentrates

Maize is considered a staple food for the population; however, its protein contribution to the development of individuals is limited by its low quality. Quality protein maize varieties (QPM) have been developed to remedy this. The protein quality presents in protein concentrates obtained from two QPM varieties was evaluated: Sac Beh (SB) and Chichen Itza (ChI), which were compared with a traditional variety (Blanco Uxmal, BU) as a control. All were evaluated with non-nixtamalization (NN) and nixtamalization (N). Amino acid profile, in vitro digestibility, calculated protein digestibility-corrected amino acid score (PDCAAS), calculated protein efficiency ratio (c-PER), and biological value (BV) were determined. The extraction process of the QPM concentrates and nixtamalization had important effects on the essential amino acids Lys and Trp. In vitro digestibility showed significant differences (p < 0.05). The predominant limiting amino acid was tryptophan. The QPMs were closer to the requirements of the FAO/WHO standard, since they obtained chemical score values higher than 100% for His and Leu. PDCAAS values decreased in the amino acid tryptophan of SB and BU nixtamalized maize compared with the NN. PER7 and PER10 values were statistically higher (p < 0.05) in the QPMs compared to the BU control. The estimated biological value showed an imbalance in the concentration of essential amino acids. Lys and Trp in the QPM varieties were not sufficient evidence of increased biological value the proteins, due to the effect of the extraction processes and the alkaline heat treatment to which the maize grains were subjected.

Nutritional Evaluation of Green Mussel Perna viridis (Linnaeus, 1758) and Brown Mussel Modiolus modulaides (Röding, 1798) From Panay Island, Philippines

Mussels are considered a low-cost protein source in the Philippines. The green mussel Perna viridis (Linnaeus, 1758) is widely consumed, while the brown mussel Modiolus modulaides (Röding, 1798) is not yet fully utilised as human food but used as animal food or fermented for human consumption. This study aims to determine the nutritional value of these mussels in terms of their proximate composition, amino acid, fatty acid, and mineral components. Results revealed that the moisture content of M. modulaides was significantly higher (P &lt; 0.05) than P. viridis. In comparison, the crude protein content of P. viridis (11.39 %) was significantly higher (P &lt; 0.05) than M. modulaides (9.19 %), but they have similar amounts of lipids. There were 18 amino acids detected in the two species with significantly higher (P &lt; 0.05) total essential amino acids (EAA) and non-essential amino acids found in P. viridis. The most abundant EAA were leucine and lysine in P. viridis and M. modulaides. Results also revealed that the two mussel species are qualified for good quality protein claims with an essential amino acid index of &gt;0.9 and digestible indispensable amino acid scores of &gt;100 %. Palmitic and stearic acids were detected in both species, but eicosapentaenoic and docosahexaenoic acids were only detected in P. viridis. Sodium, potassium, iron, and calcium were also found in the two species. These results indicate that the two Philippine mussel species can be good sources of important amino acids, lipids and minerals for human and animal diets.

Red Algae Palmaria Palmata: Biological and Chemical-Technological Characteristics, Recommendations for Its Use as a Source of Nutrients in Human Nutrition

One of the ways to develop micronutrient balanced products may be to include P. palmata red algae in its formulation. The aim is to study the biochemical parameters of P. palmata growing in the White Sea, and to assess the prospects of its use in human nutrition. The thesis presents the biological and chemical-technological characteristics, as well as the results of the drying process of P. palmata growing in the coastal zone of the White Sea, Solovetsky Islands. Analysis of the chemical composition of P. palmata showed that the main components were carbohydrates (45.6–75%) including fiber – 3.6–7.7%, proteins – 7.04–22.62%, ash –18.03–31.74%. The research presents the macro- and microelement composition of P. palmata collected in 2022 in the White Sea. 1 gram of dry algae for iodine, chromium by 12–16% corresponds to the norms of physiological need. The amino acid score value for all essential amino acids is less than 100%, while the limiting amino acids are lysine and threonine. The difference coefficient of amino acid score is 7.6%, the biological value of P. palmata protein is 92%. The dried P. palmata yield from raw algae is 18–20%. Under favorable weather conditions, Palmaria layers are dried to 10–15% water content within 23–26 hours. Based on the results of studies on the safety indicators and chemical composition of P. palmata, the authors demonstrated its applicability in food formulations development as a source of biologically active substances, such as amino acids. Alcohol extracts obtained from P. palmata have antimicrobial activity against Proteus vulgaris and Pseudomonas aeruginosa. In this regard, alcohol extracts from P. palmata can probably be used as an antimicrobial agent in the process of food production.

The in vivo and in vitro protein quality of three hemp protein sources.

In this work, the protein quality of defatted hemp hearts and protein-enriched hemp fractions was determined. Protein quality was assessed using a rodent bioassay to evaluate growth and protein digestibility, while amino acid composition was determined via HPLC. A method for determining in vitro protein digestibility was compared to in vivo methodology and used to generate an in vitro protein quality score. The true protein digestibility of hemp protein 2, a hemp protein concentrate, was significantly lower than that of either defatted hemp hearts or hemp protein 1, a hemp protein concentrate (p < .05). While there was no relationship between the in vivo and in vitro measurements of protein digestibility (R 2 = .293, p = .459), there was a significant correlation between the protein digestibility-corrected amino acid score (PDCAAS) determined in vivo and in vitro PDCAAS (R 2 = .989, p = .005). The protein efficiency ratio of hemp protein 1 was significantly lower than that of either defatted hemp hearts or hemp protein 2 (p < .05). These data highlight the nutritional capacity of hemp protein sources while also demonstrating the relationship between in vivo and in vitro methods for determining protein quality.

In vitro determination of the protein quality of maize varieties cultivated in Malawi using the INFOGEST digestion method

There is an urgent need to alleviate protein deficiencies in low-income countries where cereal-based diets dominate. The objective of this study was to use the INFOGEST static digestion method and a recently established analytical workflow to determine the in vitro amino acid digestibility and protein quality of seven maize varieties grown in Malawi. Protein quality was measured using the in vitro digestible indispensable amino acid score (DIAAS). Amino acid digestibility was higher for the dehulled, low fibre, provitamin A maize flour (66%), compared to whole grain maize flours (51–61%), suggesting that the presence of fibre reduced digestibility (p < 0.05). Lysine was the limiting amino acid in all varieties, with the following DIAAS values for each variety; Provitamin A maize – 24, SC 719 – 32, Mtsikinya – 37, SC 167 – 39, Quality protein maize (QPM) – 40, Bantum – 40, SC 403 – 44. In addition to the variety of maize, protein quality was dependent on the level of processing and the agronomic practice applied with higher protein quality for the SC 403 variety in which zinc enriched fertilizer was applied. Comparing protein quality data with published in vivo data showed that DIAAS data were in closer agreement than amino acid digestibility data, which was slightly lower than published values, with mean in vitro amino acid digestibilities of 56–70% compared to a mean in vivo value of 77%. Overall, the in vitro method was able to correctly predict both the direction and magnitude of response. The INFOGEST digestion method coupled with the new analytical workflow will therefore be useful in the screening of high protein cereal crops and subsequent development of cereal-based foods with high protein quality.

Effects of Cooking Processes on Protein Nutritional Values and Volatile Flavor Substances of Silver Carp (Hypophthalmichthys molitrix).

Silver carp (Hypophthalmichthys molitrix) is normally cooked at a high temperature. In order to explore the effects of cooking methods on the protein nutritional values and volatile flavor substances of silver carp meat, the meat was fried, roasted and steamed, and its contents were determined in relation to moisture, protein, fat, ash, amino acids and volatile flavor substances. The results show that the moisture content of cooked silver carp can be ranked as follows: raw > steamed > roasted > fried. The protein content order of the four samples can be ranked: fried > roasted > raw > steamed. The ash and the fat contents of the four samples showed similar significant (p < 0.05) differences, in the order of fried > roasted > steamed > raw. The contents of all the amino acids in the fried meat were significantly (p < 0.05) higher than the contents in others, and the frying, roasting and steaming processes improved the umami taste (supported by the increased content of glutamate and aspartate) and the protein nutritional value (supported by the amino acid score, essential amino acid index and protein efficiency ratio) of the silver carp meat. A total of 51 compounds were detected in the fried, roasted and steamed meat. Frying and roasting reduced the fishy flavor of this meat. The odor activity value (OAV) indicated that methanethiol, 1-octen-3-ol and 2-heptanone were the key flavor chemicals in raw meat. Hexanal, propionaldehyde, octanal, nonanal, decanal, 1-octen-3-ol and 2-heptanone were key to the flavor of fried meat. Pentanal, decanal, methyl mercap-tan and 1-octen-3-ol contributed greatly to the overall flavor of the roasted meat. Nonanal, methylmercaptan and 1-octene-3-ol had strong effects on the flavor of the steamed silver carp meat.

Impact of growth conditions on the nitrogen, protein, colour and amino acid profiles of the cultured macroalga, Palmaria palmata

The impact of growth conditions on the nitrogen, protein, colour and amino acid profiles of Palmaria palmata (from 2 locations) were investigated. Laboratory cultures of P. palmata were grown over a period of 18 days with and without nutrient addition, i.e., with culture medium (F/2) and urea (0.05 or 0.10 g L−1). The total nitrogen (TN) content of cultured P. palmata originating from longlines harvested from Cork increased with the addition of culture medium (F/2) and urea (0.05 g L−1) in comparison to the initial sample (4.15 ± 0.05 vs 1.73 ± 0.03%) while biomass from Galway increased with addition of culture medium (F/2) and urea (0.10 g L−1) in comparison to the initial sample (3.72 ± 0.05 vs 2.43 ± 0.06%). The protein nitrogen (PN) and non-protein nitrogen (NPN) of cultured P. palmata originating from Galway also increased when grown with the addition of nutrients. Nutrient enrichment during growth influenced the colour characteristics (lightness L*, redness a*, yellowness b* and colour difference ΔE) and the electrophoretic protein profile. Correlations between TN and ΔE (r = 0.945) for Cork originated sample, PN and ΔE (r =-0.944) and NPN and ΔE (r = 0.734) for Galway originated sample were observed. In-gel digestion followed by UPLC-MS/MS demonstrated that RuBiSCo, phycoerythrin and allophycocyanin expression in P. palmata was enhanced with nutrient addition. Amino acid profile and score analysis showed variation as a function of nutrient addition. Overall, nutrient inclusion in the growth medium provides a strategy for the enhanced production of high-quality protein by P. palmata.

Impact of extraction conditions and seed variety on the characteristics of pennycress (Thlaspi arvense) protein: a structure and function approach

AbstractAs the consumer demand for plant proteins continues to grow, the food industry is seeking novel and sustainable protein sources to incorporate in various food products. Pennycress (Thlaspi arvense), a sustainable cover crop, produces oilseeds high in protein, warranting investigation. Accordingly, protein extraction from pennycress was evaluated under various extraction conditions, using alkaline extraction and salt solubilization coupled with ultrafiltration. Given the superior color and functionality of the salt extracted pennycress protein isolate (PcPI), its production was scaled‐up about two hundred folds in a pilot plant. Furthermore, a new pennycress accession bred to have zero erucic acid (0EA) was evaluated to determine the impact of seed variety on protein characteristics. Structural and functional characterization was performed on PcPI and compared to native (nSPI) and commercial (cSPI) soy protein isolates. Salt extracted PcPI had comparable gel strength to cSPI, three times higher solubility under acidic conditions, and ~1.5 times better emulsification capacity. PcPI extracted from 0EA was mildly different in structure and functionality from that extracted from wildtype pennycress, with the slight variation attributed to genetic variance. Finally, the protein digestibility‐corrected amino acid score (PDCAAS) of the salt extracted PcPI, calculated in vivo (0.72) and in vitro (0.87), was superior or comparable to other plant protein sources. This research provided, for the first time, a comprehensive evaluation of different protein extraction protocols to produce a functional PcPI that can compete with soy protein for various food applications, such as acidic beverages, meat and dairy products, and emulsified systems.

Biological value of the meat protein of Edilbaev lambs when enriching diets with es-sential microelements

The article presents the results of studying the quality and usefulness of the protein in meat products obtained from lambs of the Edilbaev breed. The experiment involved one control and three experimental groups of animals, the diet of which was enriched with essential microelements in the form of feed additives "Yoddar-Zn" and "DAFS-25". The results of the research showed that in the rams of the experimental group, which were fed in combination with the main diet supplements Ioddar-Zn and DAFS-25, the maximum amino acid score and protein-quality index were noted, which indicates a high biological value of meat. According to the coefficients of utility and comparable redundancy, it is assumed that in the meat of rams from the control group, amino acids are better balanced and can be more rationally used by the human body. Among the experimental groups of young sheep, the meat of the experimental group, where two feed additives were used at once, had the best rationality.