Protein Digestibility-corrected Amino Acid Score Research Articles

Fourier‐transform mid‐infrared spectroscopy for in vitro protein digestibility measurement of pulse crops

AbstractThe standard method of estimating in vitro protein digestibility, the protein digestibility corrected amino acid score (PDCAAS) assay, does not support the expected workflow of a pulse breeding program. This is mainly due to its low‐throughput design and long processing time (∼16–24 h) per sample. Fourier‐transform mid‐infrared (FT‐MIR) spectroscopy has been developed as a high‐throughput phenotyping tool to estimate protein digestibility in pulses. The mid‐infrared region representing the amide I band (1756.81–1586.27 cm−1) was utilized to perform chemometric modeling with partial least squares regression (PLSR) to estimate in vitro protein digestibility in dry pea (Pisum sativum L.), lentil (Lens culinaris Medik.), and chickpea (Cicer arietinum L.) flours. The root mean square error of predictions of the developed PLSR models for dry pea, lentil, and chickpea were 0.00039, 0.00024, and 0.00017, respectively. Phenotyping with the FT‐MIR approach is more rapid than with the PDCAAS assay and estimates protein digestibility from the flour of a single seed in a shorter time (∼1–2 min). The FT‐MIR approach is robust as the spectroscopic data are consistent and chemically fingerprint this nutritional trait. Accordingly, FT‐MIR can resolve the phenotypic bottleneck of pulse breeding related to in vitro protein digestibility measurements by enabling a high‐throughput phenotyping workflow.

Low protein digestibility-corrected amino acid score and net nitrogen-to-protein conversion factor value of edible insects

The amount of chitin, a nitrogen-containing dietary fiber, in edible insects can mislead the exact nitrogen-to-protein conversion factor (NPF) and true protein content. We determined the amino acid score (AAS), protein digestibility-corrected AAS (PDCAAS), chitin content, and net NPF of five edible insects. Additionally, the effect of the amino acid composition of migratory locust on rat growth were investigated. The AAS of the insects were ranged from 63 to 94. The chitin contents were ranged from 1.6 g/100 g to 10.7 g/100 g. The PDCAAS, calculated by AAS and gut-intestinal digestibility, ranged from 44 to 81, which was lower than casein (97). The net NPF ranged from 4.93 to 5.76, which were lower than the conventional value. Dietary migratory locust, whose PDCAAS was the lowest, decreased growth and altered lipid metabolism. Therefore, a lower PDCAAS and overestimation of net NPF of insects can affect the true protein calculations and growth.

In vivo protein quality of pistachios (Pistacia vera L.)

Pistachios (Pistacia vera L.), similar to other nuts, fall under the protein foods category, according to the current U.S. Dietary Guidelines and Canada’s Food Guide. When substantiating claims for protein content of pistachios, protein quality data must be available to support these claims. In North America, the Protein Digestibility-Corrected Amino Acid Score (PDCAAS) is used for this purpose, however, Canada requires that this value be used to calculate a Protein Efficiency Ratio (PER). PER can be used for estimating protein quality. The current investigation aimed to offer current assessments of PER and PDCAAS, through the utilization of established in vivo rodent bioassays, for pistachio samples (raw, dry-roasted, and oil-roasted). Amino acid scores established lysine as the most limiting amino acid, with values of 0.933, 1.073, and 1.058 for raw, dry-roasted and oil-roasted pistachios, respectively. PDCAAS values ranged from 83 to 94%, being highest for dry-roasted pistachios. The measured PER values (corrected to casein = 2.50) were 2.53, 2.48, and 2.58 for the raw, dry-roasted, and oil-roasted pistachios, respectively, and were not significantly different from casein. These data support the position that pistachios can be labeled as “good sources of protein” in the U. S. and Canada.

Simultaneous biogas upgrading and single cell protein production using hydrogen oxidizing bacteria

CO2, a primary byproduct of anaerobic digestion, significantly reduces the calorific value of biogas, necessitating its enhancement through biogas upgrading to increase the CH4 content. The hydrogen oxidizing bacteria (HOB) Cupriavidus necator H16 demonstrates potential as a candidate for biological biogas upgrading due to its efficient CO2 capture and biosynthesis capabilities. Results indicated that in batch experiments, the concentration of CH4 could be elevated from 57.09 % to 98.46 % within 72 h by HOB, with a maximum CO2 assimilation efficiency of 27 mL/(L·h), meeting the requirements for biomethane. In bioreactor scale-up experiments, the CH4 concentration was increased to 94.22 % within 96 h. Beyond biogas upgrading, HOB also produces biomass usable as single cell protein (SCP), with its protein content varying between 43.75–70.83 % depending on the gas supply ratio. A total of 17 amino acids were identified, including eight essential amino acids. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) indicated that the essential amino acid content in the HOB-based protein was well-balanced, closely approximating the quality of fishmeal and pork. A techno-economic analysis revealed that the net revenue from the anaerobic digestion process could be enhanced by 48.49 % using HOB-based biogas upgrading. In contrast, biogas upgrading processes based on hydrogenotrophic methanogens (HM) resulted in a 57 % reduction in net revenue. This study establishes a carbon flow pathway from organic solid waste to biomethane and utilizable protein sources, facilitating sustainable nutrient recovery. This approach not only enhances economic benefits but also reduces carbon emissions associated with the anaerobic digestion process.

Effect of fortifying sorghum and wheat with Longhorn grasshopper (Ruspolia differens) powder on nutritional composition and consumer acceptability of biscuits.

This study aimed at improving the nutrient composition and protein quality of biscuits made from sorghum and wheat through fortification with Longhorn Ruspolia differens powder (RDP) for use as a supplementary food targeting children vulnerable to protein-energy malnutrition (PEM). Ten biscuit formulations were prepared by replacing a part of wheat and sorghum-wheat flours with 5, 15, 20, and 40% RDP. To establish the nutrient content of biscuits, proximate and mineral compositions were determined. The amino acid composition, reactive lysine and invitro protein digestibility were determined for protein quality. Compositing wheat or wheat-sorghum biscuits with RDP increased the protein, fat, ash, and crude fiber by percentages as high as 118, 37, 133, and 573%, respectively. Mineral content increased with, iron, zinc, and potassium as high as 161, 219, and 169%, respectively. The lysine, reactive lysine and invitro protein digestibility of the fortified biscuits increased significantly, relative to the 100% cereal biscuits. Fortification with RDP significantly improved the amino acid content of the biscuits but had a marginal effect on improvement of the lysine score and did not meet the reference pattern for children aged 3-10 years. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) of wheat-sorghum and wheat biscuits improved by 6% to 47% and 2% to 33%, respectively, compared to the control biscuits. The fortified biscuits were liked by the consumers. The RDP-fortified biscuits have the potential to alleviate PME in developing countries.

A promising Artemisia capillaris Thunb. Leaf proteins with high nutrition, applicable function and excellent antioxidant activity

The nutritional and functional properties of leaf proteins is a decisive factor for their use in food. This work was aimed to extract defatted Artemisia capillaris Thunb. (ACD) leaf proteins (ACLP), and assess ACLP nutritional quality, functional properties and in vitro antioxidant activity, as well characterize the structure. ACLP had a balanced amino acid profile and high bioavailability (protein digestibility corrected amino acid score (PDCAAS) 99.29 %). Solubility, foaming capacity and emulsifying ability of ACLP correlated positively with pH. Water and oil holding capacity were increased with temperature. Gel electrophoresis shown the protein molecular size was mainly ∼25 kDa, and random coil was the mainly secondary structure while β-sheet was dominant regular conformation as indicated by circular dichroism (CD). ACLP performed in vitro antioxidant activity which was better after digestion. All data implied ACLP met the WHO/FAO protein quality expectations and had application potential in food.

Estimating In Vitro Protein Digestion and Protein Digestibility Corrected Amino Acid Score of Chicken Breasts Affected by White Striping and Wooden Breast Abnormalities.

An understanding regarding impacts of growth-related myopathies, i.e., white striping (WS) and wooden breast (WB), on the quality of dietary protein from cooked chicken breast is still limited. This study aimed at comparing protein content and in vitro protein digestion and estimating the in vitro protein digestibility corrected amino acid score (PDCAAS) of cooked chicken meat exhibiting different abnormality levels (i.e., normal, WS, and WS + WB). The results show that the WS + WB samples exhibited lower protein content, greater cooking loss, and greater lipid oxidation than those of normal samples (p < 0.05). No differences in protein carbonyls or the myofibril fragmentation index were found (p ≥ 0.05). Cooked samples were hydrolyzed in vitro using digestive enzyme mixtures that subsequently mimicked the enzymatic reactions in oral, gastric, and intestinal routes. The WS + WB samples exhibited greater values of free NH2 and degree of hydrolysis than the others at all digestion phases (p < 0.05), suggesting a greater proteolytic susceptibility. The in vitro PDCAAS of the WS + WB samples was greater than that of the other samples for pre-school children, school children, and adults (p < 0.05). Overall, the findings suggest that the cooked chicken breast with the WS + WB condition might provide greater protein digestibility and availability than WS and normal chicken breasts.

Options for substantiating protein content claims for conventional foods.

In Canada and the United States, front-of-package protein content claims require data to support the quality of the protein. In general, protein quality reflects the product of the amino acid composition of the food protein relative to human amino acid requirements and a measure of digestibility. The currently accepted method in both jurisdictions is the protein digestibility-corrected amino acid score (PDCAAS) that requires the measurement of true fecal protein (nitrogen) digestibility. The latter must be measured in vivo using a rat model. This requirement for animal testing is inconsistent with international efforts to reduce the usage of animals in testing for regulatory purposes. The current commentary positions four options to remove the need to use animal testing for determining protein quality, when considering protein content claim substantiation. These options include (i) a focus on protein quantity alone; (ii) the use of the amino acid score alone, with no correction for digestibility; (iii) the use of a fixed digestibility coefficient to estimate protein quality; and (iv) the use of in vitro methods to measure protein and/or amino acid digestibility. The relative merits and deficiencies of the options are positioned with the goal of encouraging dialogue within the regulatory agencies to move towards alternative approaches for substantiating protein content claims on foods, including those derived from plant-based sources.

Effect of full fat and defatted insect meals in breadmaking quality

Fat content and type of lipids in edible insect meals could affect bread quality when used to partially substitute wheat in bread formulations. This study evaluated the effect of Acheta domesticus (AD) and Tenebrio molitor (TM) meals in breadmaking. Full fat (FF), partially-(PD), and complete-defatted (DF) TM and AD meals were used to replace 10% (w/w) of wheat flour in bread formulations, resulting in 6 composite flours (FFAD/PDAD/DFAD/FFTM/PDTM/DFTM) and a 100% wheat control. Dough thermomechanical properties, breadmaking parameters, proximal composition, texture profile analysis, and Protein Digestibility-Corrected Amino Acid scores (PDCAAS) were assayed. Defatting insect meals increased water absorption of composite flours by 7 (TM) and 3% (AD) and TM fat increased the mixolab dough stability by 2.4 min. FFTM showed the highest bread volume (843 cm3) and lowest density (0.19 g/cm3) among composite loaves. The protein content of insect-supplemented bread increased up to 34% compared to the control. FFTM bread had the lowest hardness values through storage at room temperature. Defatted AD and TM had higher PDCAAS compared to the control. These findings indicated that TM fat contributes to breadmaking quality and DFAD increased the PDCAAS value, making it a nutritious alternative to partially substitute wheat in bread formulations.

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.

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.

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.

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.

Plant Proteins: Methods of Quality Assessment and the Human Health Benefits of Pulses.

As countries increase their standard of living and individual income levels rise, there is a concomitant increase in the demand for animal-based protein. However, there are alternative sources. One of the alternatives available is that of increased direct human consumption of plant proteins. The quality of a dietary protein is an important consideration when discussing the merits of one protein source over another. The three most commonly used methods to express protein quality are the protein efficiency ratio (PER), a weight gain measurement; protein digestibility-corrected amino acid score (PDCAAS); and the digestible indispensable amino acid score (DIAAS). The possibility that alterations in the quality and quantity of protein in the diet could generate specific health outcomes is one being actively researched. Plant-based proteins may have additional beneficial properties for human health when compared to animal protein sources, including reductions in risk factors for cardiovascular disease and contributions to increased satiety. In this paper, the methods for the determination of protein quality and the potential beneficial qualities of plant proteins to human health will be described.

Determination of Indispensable Amino Acid Digestibility of the Red Kidney Bean in Humans Using a Dual Stable Isotope Tracer Method

BackgroundProtein quality of the red kidney bean (RKB), a common source of dietary protein, has been assessed using the protein digestibility-corrected amino acid score (PDCAAS) determined in animal models using mainly oro-fecal digestibility. More recently, the FAO recommended to use digestible indispensable amino acid score (DIAAS) instead of PDCAAS but highlighted insufficient data on true ileal indispensable amino acid (IAA) digestibility of proteins because amino acids are absorbed in the ileum. ObjectivesUsing a recently developed dual stable isotope tracer method, we aimed to measure each IAA digestibility as representation of true ileal digestibility of the RKB, Phaseolus vulgaris, in humans consuming a typical Jamaican meal. MethodsRKB-IAAs were intrinsically labeled by adding 2H2O to the plants. Uniformly labeled-[13C]-spirulina (standard protein) was added to a meal prepared with the labeled RKB and fed to 10 healthy adults (5 males, 5 females) in a nonrandomized trial as primed/intermittent doses to achieve a steady state IAA enrichment in plasma. Enrichment of 2H- and 13C-labeled IAA in plasma and the bean was measured by mass spectrometry. Each IAA digestibility (except tryptophan and histidine) was calculated as the ratio of plasma 2H-IAA to meal 2H-IAA divided by the ratio of plasma 13C-IAA to meal 13C-IAA adjusted for loss of 2H-atom during transamination and digestibility of spirulina. ResultsAdequate IAA labeling (>1000 ppm 2H excess) and plasma plateau isotopic enrichment were achieved. Mean RKB-IAA digestibility (%) was 79.4 ± 0.5, ranging from 69.0 ± 1.2 (threonine) to 85.7 ± 1.7 (lysine). ConclusionThe dual stable isotope tracer digestibility data are similar to published oro-fecal digestibility supporting substantial nitrogen exchange in the colon. The individual IAA digestibility is useful to derive DIAAS to replace PDCAAS. Using published RKB-IAA composition, extrapolated DIAAS was 0.63 based on the lowest score for methionine. Clinical trial registrationhttps://register.clinicaltrials.gov; ID: NCT-04118517.

Solid-state fungal fermentation transforms low-quality plant-based foods into products with improved protein quality

To meet global protein demand sustainably in the future, we have to move to alternative, non-animal sources. A problem of many plant-derived foods is their low protein quality compared to animal-based proteins, in particular their deficiency in lysine. To improve the protein quality, plant proteins could be converted to fungal proteins using solid-state fungal fermentation (SSFF). In this project Rhizopus microsporus var. oligosporus and Aspergillus oryzae were used to ferment barley and rice, producing tempeh and koji, respectively. SSFF yielded products with 6–13% (dry weight basis) fungal biomass. Protein quality was defined by the parameters indispensable amino acid index (IAAI) and protein digestibility corrected amino acid score (PDCAAS). SSFF improved both parameters in all samples. Lysine was the limiting amino acid in unfermented barley and rice, with PDCAAS of 0.54 and 0.57, respectively. SSFF increased the PDCAAS of lysine by approximately 30% in barley koji, barley tempeh and rice koji and 10% in rice tempeh. These results demonstrate the use of SSFF to improve the protein quality of staple foods. Thereby, this fermentation method can aid in meeting protein demands sustainably in the future through plant-based diets.

Perspective: Developing a Nutrient-Based Framework for Protein Quality

The future of precision nutrition requires treating amino acids as essential nutrients. Currently, recognition of essential amino acid requirements is embedded within a generalized measure of protein quality known as the PDCAAS (Protein Digestibility-Corrected Amino Acid Score). Calculating the PDCAAS includes the FAO/WHO/UNU amino acid score, which is based on the limiting amino acid in a food, that is, the single amino acid with the lowest concentration compared to the reference standard. That “limiting” amino acid score is then multiplied by a bioavailability factor to obtain the PDCAAS, which ranks proteins from 0.0 (poor quality) to 1.0 (high quality). However, the PDCAAS has multiple limitations: it only allows for direct protein quality comparison between 2 proteins, and it is not scalable, transparent, or additive. We therefore propose that shifting the protein quality evaluation paradigm from the current generalized perspective to a precision nutrition focus treating amino acids as unique, metabolically active nutrients will be valuable for multiple areas of science and public health. We report the development and validation of the Essential Amino Acid 9 (EAA-9) score, an innovative, nutrient-based protein quality scoring framework. EAA-9 scores can be used to ensure that dietary recommendations for each essential amino acid are met. The EAA-9 scoring framework also offers the advantages of being additive and, perhaps most importantly, allows for personalization of essential amino acid needs based on age or metabolic conditions. Comparisons of the EAA-9 score with PDCAAS demonstrated the validity of the EAA-9 framework, and practical applications demonstrated that the EAA-9 framework is a powerful tool for precision nutrition applications.

Physical and Chemical Characterization and Bioavailability Evaluation In Vivo of Amaranth Protein Concentrate.

Special attention is being paid to the study of amaranth proteins. They are characterized by a high biological value that significantly exceeds those of grain crops. The production of protein concentrate from amaranth flour includes preliminary enzymatic hydrolysis, extraction of the resulting mixture, protein precipitation, microfiltration, and freeze-drying. In our study, the obtained amaranth protein concentrate was limited by valine, with an amino acid score of 74%. The true digestibility of the amaranth protein concentrate determined in vivo was 97.6 ± 0.3%, which was significantly lower than that of casein (99.3 ± 0.2%). The protein digestibility-corrected amino acid score value of the concentrate was 72.2%. The obtained concentrate was a rich source of selenium, copper, magnesium, manganese, and iron. Ferulic acid was the only polyphenolic compound found in the amaranth protein concentrate, but its content was significantly greater compared to the original flour. Saponins were not removed completely during the process of obtaining the amaranth protein concentrate. We identified 15 saponins in the concentrate, mainly of the bidesmoside type, the sapogenins of which are related derivatives of oleanolic acid. Thus, the developed amaranth protein concentrate can be used as an ingredient in functional food products, with a high biological value.

Evaluation of a low-resource soy protein production method and its products.

One key approach to achieve zero hunger in Sub-Saharan Africa (SSA) is to develop sustainable, affordable, and green technologies to process nutritious food products from locally available sources. Soybeans are an inexpensive source of high-quality protein that may help reduce undernutrition, but it is underutilized for human consumption. This research evaluated the feasibility of a low-cost method developed initially at the United States Department of Agriculture to produce soy protein concentrate (SPC) from mechanically pressed soy cake and thus create a more valuable ingredient to improve protein intake in SSA. The method was initially tested in the bench scale to assess process parameters. Raw ingredients comprised defatted soy flour (DSF), defatted toasted soy flour (DTSF), low-fat soy flour 1 (LFSF1; 8% oil), and LFSF2 (13% oil). Flours were mixed with water (1:10 w/v) at two temperatures (22 or 60°C) for two durations (30 or 60 min). After centrifugation, supernatants were decanted, and pellets were dried at 60°C for 2.5 h. Larger batches (350 g) of LFSF1 were used to examine the scalability of this method. At this level, protein, oil, crude fiber, ash, and phytic acid contents were measured. Thiobarbituric acid reactive substances (TBARS), hexanal concentration and peroxide value were measured in SPC and oil to evaluate oxidative status. Amino acid profiles, in vitro protein digestibility, and protein digestibility corrected amino acid score (PDCAAS) were determined to assess protein quality. Bench scale results showed accumulation of protein (1.5-fold higher) and reduction of oxidative markers and phytic acid to almost half their initial values. Similarly, the large-scale production trials showed high batch-to-batch replicability and 1.3-fold protein increase from initial material (48%). The SPC also showed reductions in peroxide value (53%), TBARS (75%), and hexanal (32%) from the starting material. SPC's in vitro protein digestibility was higher than the starting material. The proposed low-resource method results in an SPC with improved nutritional quality, higher oxidative stability, and lower antinutrient content, which enhances its use in food-to-food fortification for human consumption and is thus amenable to address protein quantity and quality gaps among vulnerable populations in SSA.

How different amino acid scoring patterns recommended by FAO/WHO can affect the nutritional quality and protein claims of lentils

AbstractAs a nutritious pulse and protein source, lentils play an important role in the plant‐based protein market. Pulses' nutritional quality is influenced by their protein content and amino acid composition. Recommended scoring patterns by FAO/WHO can estimate protein quality for dietary assessment, but different guidelines for protein content in food labeling exist in North America. This study determined the in vitro protein digestibility (IVPD) and amino acid score (AAS) for the protein quality assessment of lentils. The impact of different recommended amino acid scoring patterns by FAO/WHO (1991, 2013) on AAS and AAS corrected for in vitro protein digestibility (AAS‐IVPDC) were evaluated. The impact of AAS‐IVPDC for determining protein content claims for lentils using USA standards was also evaluated. Sulfur AA and tryptophan were the most limiting amino acids. From this work, estimates of lentil protein quality vary with different recommended amino acid scoring patterns. IVPD in lentils was 82.6%, while mean AAS‐IVPDC values ranged from 37.5% to 64.0%. Regarding the protein content claims, if considering a similar interpretation to the protein digestibility–corrected amino acid score (PDCAAS) system (i.e., corrected content is ≥ 5.0 g per RACC), all lentil samples were considered a “good source of protein.” However, if considering a similar interpretation to digestible indispensable amino acid score (DIAAS) system (i.e., corrected content is ≥ 5.0 g per RACC and a claim threshold of 75%), no samples met these protein claims due to the arbitrary cut‐off. The criteria set for making protein content claims should be revised.