Balanced Amino Acid Composition Research Articles

Comparison between isoelectric precipitation and ultrafiltration processes to obtain Amaranth mantegazzianus protein concentrates at pilot plant scale

The aim of this study was to compare protein yield, protein concentration and physicochemical characteristics of Amaranth mantegazzianus protein concentrates (APC) obtained at pilot-scale by a conventional process (CP) (alkaline extraction and isoelectric precipitation) and two alternative processes (AP): (1) acid pre-treatment process combined with isoelectric precipitation and (2) acid pre-treatment process combined with ultrafiltration. Although AP resulted in higher protein concentration, protein yield was lower than in CP. SDS–PAGE and size-exclusion chromatography showed high molecular weight fractions only for isoelectric precipitation concentrates (obtained by CP and AP). The amino acids concentration, especially phenylalanine, isoleucine and methionine, increased in all protein concentrates respect to the amaranth flour. Particularly, the product obtained by ultrafiltration was rich in phenylalanine and lysine, and presented no limiting amino acid with respect to the recommendation of the Food and Agriculture Organization of the United Nations (FAO).In conclusion, process (2) improved protein concentration and nutritional quality (balanced amino acid composition) of A. mantegazzianus protein concentrates respect to CP and process (1), suggesting that the ultrafiltration process is a viable alternative to conventional process and a promising method for obtaining protein concentrates.

EFFECTS OF BUCKWHEAT (FAGOPYRUM ESCULENTUMMOENCH) MILLING PRODUCTS, TRANSGLUTAMINASE AND SODIUM STEAROYL-2-LACTYLATE ON BREAD PROPERTIES

ABSTRACT Buckwheat milling products (white flour, whole flour and bran) were replaced with wheat flour at a 20% ratio and was used in bread making with and without the additives of sodium stearoyl-2-lactylate (SSL), transglutaminase (TG) and SSL + TG combination. An experiment was conducted according to (4 × 4) × 2 factorial design. Rheological properties of doughs and the physical, chemical and sensory properties of breads were determined. Buckwheat milling products (BMP) decreased stability of the doughs, but SSL and SSL + TG combination showed positive effect on the dough stability. The synergistic effect of TG+SSL combination on resistance of the dough was observed. All BMP reduced bread volume and the lightness (L) values of crust and crumb. SSL + TG combination improved bread volume, 72nd hours crumb softness, the crust and crumb lightness. Especially, buckwheat bran addition increased ash, protein, fiber, fat and mineral contents of the breads. The bread containing white buckwheat flour or whole buckwheat flour showed similar or superior sensory bread properties compared with the control prepared with wheat flour. To take into account handling properties of dough and technological, nutritional and sensory properties of breads, the best combination were found as whole buckwheat flour and SSL + TG usage. PRACTICAL APPLICATIONS Buckwheat is an important raw material in functional food production with balanced amino acid composition, high contents of vitamins, minerals, polyunsaturated essential fatty acids, sterols, flavanoids and fagopyratol. Some functional components of buckwheat have health benefits like reducing high blood pressure, lowering cholesterol, controlling blood sugar and preventing cancer risk. In this research transglutaminase (TG) and sodium stearoyl-2-lactylate (SSL) were used to overcome the quality losses and to improve technological and sensory properties of breads prepared with BMP. The bread-making process was applied successfully with aiding TG and SSL.

Overexpression of a modified protein from amaranth seed in Escherichia coli and effect of environmental conditions on the protein expression

Amaranth seeds are considered as an excellent complementary source of food protein due to their balanced amino acid composition. Amarantin acidic subunit has the potential as a functional and nutraceutical protein, and it is structurally a good candidate for modification. The aim of this work was to improve its functionality, then the primary structure was modified into the third variable region of 11S globulins, by inserting antihypertensive peptides: four Val-Tyr in tandem and Arg-Ile-Pro-Pro in the C-terminal region. Modified protein was expressed in Escherichia coli Origami (DE3) and was purified. The culture conditions, including the culture media, temperature, agitation speed and air flow were tested in order to obtain an increased expression levels of the modified protein. A 2(3) factorial design was used for evaluate the effect of environmental conditions on modified protein production. The results indicated that the yield of modified protein could be increased by up 3-fold in bioreactor as compared with flask. In addition, the temperature, the agitation speed and the oxygen were significant factors on the expression of the antihypertensive protein. The maximum production was 99 mg protein-L(-1). The hydrolyzed protein showed a high inhibitory activity of the angiotensin converting enzyme (IC50=0.047 mg mL(-1)).

Nutritional Characteristics of Seed Proteins in 28 Vicia Species (Fabaceae) from Southern Spain

The study of local plants could provide useful data for the possible development of future crops with good nutritional and functional properties. The nutritional characteristics of the seed proteins of 28 Vicia species (31 taxa) (Fabaceae) from Spain were studied. Protein contents in studied Vicia ranged from 20.1% in V. articulata to 32% in V. pyrenaica. V. altissima, which is only deficient in Trp, showed the most balanced amino acid composition, while the remaining taxa were limiting in Met, Cys, and Trp. In vitro protein digestibility (IVPD) ranged from 78% in V. incana to 86.3% in V. hirsuta. In addition to the amino acid composition and IVPD, other nutritional parameters, such as amino acid score, biological value, protein efficiency ratio, or protein digestibility corrected amino acid score, were studied. Results confirm the interest of studying wild populations of cultivated and non cultivated Vicia species as potentially interesting sources of seeds with good nutritional characteristics.

Characterization of the proteins fractions extracted from leaves of Amaranthus dubius (Amaranthus spp.)

Amaranth is an ancient plant belonging to the Amaranthaceae family, which is believed to have originated in Central and South America. The high nutritional quality of the amaranth seed protein is one of the main factors that has attracted the attention of the researchers. However, till date, the protein profile of the leaves of the most researched varieties has not been well studied. Moreover, the nutritional profile of Amaranthus dubius remains unknown. Therefore, it would be interesting to study it. Protein from A. dubius leaves has a high nutritional value due to its balanced amino acid composition. The concentrations of albumins, globulins, prolamins and glutelins are 73.42, 6.60, 6.47 and 6.11%, respectively. It was found that the best agent for extraction of globulins was Na2HPO4 and for glutelins, it was NaOH. The highest amino acid content was found in the albumins fraction and the lowest one in the glutelins fraction. The chemical score of the essential amino acids from proteins of the leaves of A. dubius flour was 92.83%; the flour has only one limiting essential amino acid: Leucine (Leu). The leaves of A. dubius can be used as complement dietary for rice, wheat and corn proteins. Key words: Amaranth, amino acids, protein content, protein fractions.

The spectrum of low molecular weight alpha-amylase/protease inhibitor genes expressed in the US bread wheat cultivar Butte 86

BackgroundWheat grains accumulate a variety of low molecular weight proteins that are inhibitors of alpha-amylases and proteases and play an important protective role in the grain. These proteins have more balanced amino acid compositions than the major wheat gluten proteins and contribute important reserves for both seedling growth and human nutrition. The alpha-amylase/protease inhibitors also are of interest because they cause IgE-mediated occupational and food allergies and thereby impact human health.ResultsThe complement of genes encoding alpha-amylase/protease inhibitors expressed in the US bread wheat Butte 86 was characterized by analysis of expressed sequence tags (ESTs). Coding sequences for 19 distinct proteins were identified. These included two monomeric (WMAI), four dimeric (WDAI), and six tetrameric (WTAI) inhibitors of exogenous alpha-amylases, two inhibitors of endogenous alpha-amylases (WASI), four putative trypsin inhibitors (CMx and WTI), and one putative chymotrypsin inhibitor (WCI). A number of the encoded proteins were identical or very similar to proteins in the NCBI database. Sequences not reported previously included variants of WTAI-CM3, three CMx inhibitors and WTI. Within the WDAI group, two different genes encoded the same mature protein. Based on numbers of ESTs, transcripts for WTAI-CM3 Bu-1, WMAI Bu-1 and WTAI-CM16 Bu-1 were most abundant in Butte 86 developing grain. Coding sequences for 16 of the inhibitors were unequivocally associated with specific proteins identified by tandem mass spectrometry (MS/MS) in a previous proteomic analysis of milled white flour from Butte 86. Proteins corresponding to WDAI Bu-1/Bu-2, WMAI Bu-1 and the WTAI subunits CM2 Bu-1, CM3 Bu-1 and CM16 Bu-1 were accumulated to the highest levels in flour.ConclusionsInformation on the spectrum of alpha-amylase/protease inhibitor genes and proteins expressed in a single wheat cultivar is central to understanding the importance of these proteins in both plant defense mechanisms and human allergies and facilitates both breeding and biotechnology approaches for manipulating the composition of these proteins in plants.

Optimizing amino acid composition of CHO cell culture media for a fusion protein production

The amino acid composition of CHO cell culture media for manufacturing an antibody fusion protein (B1) was optimized using data obtained through metabolic flux analysis. The metabolic flux analysis was performed using the metabolic rates derived from two semi-steady states of continuous culture. The amino acid composition was the same for media used in both the fed-batch and continuous cultures, which made the modification of amino acid composition suggested by the metabolic flux analysis applicable to the fed-batch culture. The flux analysis indicated that methionine, tryptophan, asparagine and serine were limiting, while alanine, arginine, glutamine and glycine were in excess at the semi-steady states. Based on this result, the limiting amino acids were increased while those in excess were reduced to obtain balanced amino acid composition in both the batch and feed media. The fed-batch cell cultures using the modified media generated less lactate and ammonia, and more significantly, increased peak cell densities by 55% and B1 protein titer by 27% without any impact on final sialic acid content, a quality attribute of the B1 protein.

Contrasting effects of nitrogen limitation and amino acid imbalance on carbon and nitrogen turnover in three species of Collembola

Abstract Soil animal detritivores play an important role in facilitating decomposition processes but little information is available on how the quality of dietary resources affects their stoichiometry of carbon (C) nitrogen (N) and phosphorus (P), and turnover of C and N. This study investigated how a fungal diet, Fusarium culmorum , with a low N content and imbalanced amino acid (AA) composition affected the physiology of three soil-dwelling collembolans ( Folsomia candida , Protaphorura fimata and Proisotoma minuta ) in comparison to a control diet, Saccharomyces cerevisiae, with a high N content and balanced AA composition. We compared the elemental composition of animals, their growth rates and tissue replacement of C and N. We also measured the individual AA δ 13 C to investigate the extent that Collembola may rely on endogenous sources to compensate for scarcity of essential AAs. The results showed that animal's N content tracked closely the composition of their diets, decreasing from around 10 to 7% N from the high to low N diet. They also had a significant increase of C and a decrease of P. P. fimata was less affected than F. candida and P. minuta . The total incorporation of C and N in the animals due to growth and tissue replacement decreased from 11–17 to 6–12% DM d −1 on the high and low N diet respectively with P. fimata experiencing the smallest change. Essential AAs δ 13 C did not always match perfectly between Collembola species and their diets; particularly on the low N diet. Isotope patterns of AAs indicate that bacteria may have been the alternative source of essential AAs. While the results of this study cannot be extrapolated directly to the dynamics of Collembola populations in the field, they serve to demonstrate their flexibility in adapting physiologically to the temporal and spatial patchiness of the soil environment.

MICROBIAL PRODUCTION OF LYSINE USING WHEY PERMEATE AND MOLASSES

Lysine is nutritionally essential for humans and animals. It cannot be synthesized biologically in body. Children and growing animals have a high requirement of lysine, since it is needed for bone formation. Therefore, it must be added to food and feed supplement to improve the protein quality. In addition, lysine has some pharmaceutical applications in the formulation of diets with balanced amino acid composition. Chemical, enzymatic and biotechnological processes have been used to synthesize lysine. However, biotechnological methods (fermentation) seem to be the most economical and practicable means of producing lysine. In the present study, production of lysine by Brevibacterium linens PTCC 1603 from whey and molasses medium, in the purpose of using agricultural by-products as low-cost sources for production of value-added products, was investigated. Whey medium was prepared by hydrolyzing of lactose with HCl and molasses medium was prepared by addition of some chemicals to it. The production of lysine was examined qualitatively and quantitatively using ascending thin layer chromatography (TLC) and spectrophotometry. Results showed that lysine concentration in both media was increased significantly by the time. The highest concentration of lysine produced from whey and molasses media were 11.8 and 10.5 g.L-1, respectively. Increasing lysine concentration resulted in pH increment in molasses medium, while the pH of whey medium was decreased. After 6 days of fermentation, the amount of lysine in whey medium was significantly higher than in molasses medium. Keywords: Lysine, Fermentation, Brevibacterium linens, Whey, Molasses

Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolysate on its bioactive properties

Numerous studies have demonstrated that in vitro controlled enzymatic hydrolysis of fish and shellfish proteins leads to bioactive peptides. Ultrafiltration (UF) and/or nanofiltration (NF) can be used to refine hydrolysates and also to fractionate them in order to obtain a peptide population enriched in selected sizes. This study was designed to highlight the impact of controlled UF and NF on the stability of biological activities of an industrial fish protein hydrolysate (FPH) and to understand whether fractionation could improve its content in bioactive peptides. The starting fish protein hydrolysate exhibited a balanced amino acid composition, a reproducible molecular weight (MW) profile, and a low sodium chloride content, allowing the study of its biological activity. Successive fractionation on UF and NF membranes allowed concentration of peptides of selected sizes, without, however, carrying out sharp separations, some MW classes being found in several fractions. Peptides containing Pro, Hyp, Asp and Glu were concentrated in the UF and NF retentates compared to the unfractionated hydrolysate and UF permeate, respectively. Gastrin/cholecystokinin-like peptides were present in the starting FPH, UF and NF fractions, but fractionation did not increase their concentration. In contrast, quantification of calcitonin gene-related peptide (CGRP)-like peptides demonstrated an increase in CGRP-like activities in the UF permeate, relative to the starting FPH. The starting hydrolysate also showed a potent antioxidant and radical scavenging activity, and a moderate angiotensin-converting enzyme (ACE)-1 inhibitory activity, which were not increased by UF and NF fractionation. Fractionation of an FPH using membrane separation, with a molecular weight cut-off adapted to the peptide composition, may provide an effective means to concentrate CGRP-like peptides and peptides enriched in selected amino acids. The peptide size distribution observed after UF and NF fractionation demonstrates that it is misleading to characterize the fractions obtained by membrane filtration according to the MW cut-off of the membrane only, as is currently done in the literature.

Use of canola oil in fish feeds

In the world and our country, rapidly growing population has reached problem causal dimen-sions especially in terms of food requirements in society. Marine products have been main-taining the importance and the place in our diets from the past to present. Nowadays, the de-mand for aquaculture is increasing because of the depletion of natural stocks and the excessive hunting. Therefore, the rapid development of fish farming causes an increase for the demand to fish meal and fish oil, the basic contents of aquaculture feeds. Fish meal is an indispensable protein source due to high level of protein and balanced amino acid composition contents. Fish oil is an excellent source of oil in terms of A‰Â· -3 fatty acids contents for fish feeds. Fish oil leads to significant increase in the feed production cost since it is used not only in fish feed but also in land-based livestock feed and human consumption. In this case, while global amount of fish oil has decreased, the usage of fish oil has increased. The amount of fish oil to be used in aquafeed industry is estimated to reach almost 80 to 90 % of global fish oil production (0.96 million tonnes) by 2010. It is important to find alternative oil sources which are healthy and can met the fatty acid requirements of fish for the establishment of a sustaina-ble and economic aquafeed industry in terms of decreasing the cost of sector and contri-bute to national economy. Therefore, several studies done on fish nutrition have covered the substituting other alternative vegetable oil sources (corn, sunflower, linseed etc.) that are easy to produce, economic and rich in Essential Fatty Acids in recent years. These in-vestigations showed that plant oils, rich for fatty acids and not affecting fish growth and the whole body fatty acid composition negatively in freshwater and marine fish species, are alternatives to fish oil and partial or total replacement of dietary fish oil with these oil have successfully presented. For this purpose, in this study, the potential use of canola oil, which is intensively produced and much cheaper than fish oil in Turkey, as an alternative to fish oil will be evaluated comparing with the other studies where the other vegetable oil sources have been tested so far in fish diets.

Comparison of gender differences in biochemical composition and nutritional value of various edible parts of the blue swimmer crab

The nutritional value of various edible parts of the blue swimmer crab ( Portunus pelagicus) was evaluated, and gender differences in terms of edible yield, proximate composition, amino acids, lipid classes and fatty acid content were compared. The results showed that females (44.3%) had a higher edible yield than males (35.9%) ( P < 0.05). Although higher protein and lipid contents were detected in the meat and gonad of females, the males contained higher docosahexaenoic acid (DHA) ( P < 0.05). Significant differences in fatty acid composition were also found among various edible parts and between genders ( P < 0.05). For example, the meat was shown to have higher total highly unsaturated fatty acids (HUFA) (36–39%) than the hepatopancreas (16–18%) or gonads (16–24%). A balanced amino acid composition was found in both meat and gonads. The results obtained from the present study indicate that the meat and ovaries of the blue swimmer crab are one of the healthiest seafoods, and they are also suitable for making processed products.

Characterization and ACE‐Inhibitory Activity of Amaranth Proteins

Amaranth seeds have been considered as an excellent alternative or complementary source of food protein due to their balanced amino acid composition. However, their potential as a source of bioactive peptides has not been explored. The present study is aimed at characterizing and evaluating the activity of the angiotensin converting enzyme inhibitor of the amaranth protein concentrate and of hydrolysates produced with Alcalase. The protein concentrate, after simulated gastrointestinal digestion, showed lower angiotensin converting enzyme-inhibitory activity (IC(50) of 0.439 +/- 0.018 mg protein/mL and 0.475 +/- 0.021 mg protein/mL, for untreated and heat treated protein concentrate, respectively) than the hydrolysates produced with Alcalase, before and after simulated gastrointestinal digestion (IC(50) 0.118 +/- 0.009, 0.123 +/- 0.007, 0.137 +/- 0.002, and 0.176 +/- 0.014 mg protein/mL, respectively). The simulated gastrointestinal digestion (pepsin-pancreatin) did not significantly alter the angiotensin-converting enzyme inhibiting activity of the Alcalase hydrolysates, suggesting that the peptides of the hydrolysates were resistant to gastrointestinal hydrolysis. These results highlight the angiotensin converting enzyme-inhibitory potential of amaranth proteins, which is an indication of their health-promoting potential.

Analytical nutritional characteristics of seed proteins in six wild Lupinus species from Southern Spain

Abstract The nutritional characteristics of seed proteins of Spanish wild populations of Lupinus angustifolius , L. cosentinii , L. gredensis , L. hispanicus , L. luteus and L. micranthus have been studied. Protein contents in this genus ranged from 23.8% in L. gredensis to 33.6% in L. luteus . On the one hand, L. cosentinii showed the most balanced amino acid composition, being only deficient in lysine. On the other hand, L. gredensis showed the worst amino acid composition. The in vitro protein digestibility (IVPD) was high in all species examined, ranging from 82.3% in L. gredensis to 89.0% in L. cosentinii . In addition to the amino acid composition and IVPD, other nutritional parameters, such as amino acid score, calculated biological value, predicted protein efficiency ratio or protein digestibility corrected amino acid score, were studied. These data yielded L. luteus , L. hispanicus and L. cosentinii as the species with seed proteins with the best nutritional properties, similar to those observed in other legumes with recognised high quality proteins, such as soybean. Results confirm the importance of studying wild populations of cultivated and non-cultivated Lupinus species as sources of seeds with good nutritional characteristics.

Suppression of C-Hordein Synthesis in Barley by Antisense Constructs Results in a More Balanced Amino Acid Composition

Barley has for feeding purposes a shortage of essential amino acids, especially lysine, threonine, and methionine, and an excess of proline and glutamine. In the present study, we have introduced into barley an antisense construct against C-hordeins, the storage protein with the lowest nutritional quality. SDS-PAGE and reverse phase HPLC revealed a relative reduction in the amounts of C-hordeins and relative increases in the content of the other storage proteins. The five different lines analyzed had lower amounts of proline, glutamic acid/glutamine, and phenylalanine (up to 12%, 6%, and 9% reductions), while the lysine, threonine, and methionine content was increased with up to 16%, 13% and 11%. It is concluded that antisense mediated suppression of C-hordein synthesis may be a promising approach for improving the nutritional value of barley as a feed crop while at the same time reducing the environmental nitrogen load.

Caracterización proteica de las semillas de once especies de amaranto

The protein profile and the amino acid composition of eleven amaranth species have been studied. The following species were taken into account: A. viridis, A. powellii, A.muricatus, A. deflexus, A. graecizans, A. blitoides, A. retroflexus, A. blitum, A. albus, A. cruentus and A. hypochondriacus . Seed samples were obtained from wild populations located in the southwest of Spain. The protein profile was studied by gel filtration chromatography and denaturing electrophoresis. Profiles were similar in all taxa, with small variations in the molecular weights and amounts of the main seed proteins. Thus, after gel filtration chromatography six main fractions of around 300 kDa, 180 kDa, 120 kDa, between 40 and 50 kDa, 20 and 30 kDa and below 10 kDa were observed. On the other hand, the electrophoretic analysis showed peptides grouped into three main fractions, between 50 and 64 kDa, 33 and 37 kDa and 18 and 25 kda. The most balanced amino acid compositions were observed in the wild taxa A. muricatus, A. blitum and A. powellii showed the most equilibrated amino acid composition. A. hypochondriacus and A. graecizans showed the most deficient amino acid composition with limitations in five essential amino acids. These results show the potential of wild amaranthus taxa for their introduction as crops or their use in the improvement by hybridization mechanisms of other crops such as A. hypochondriacus.

Biomass production of yeast isolate from salad oil manufacturing wastewater

Conversion of oil-rich salad oil manufacturing wastewater (SOMW) into protein source for animal feed through biomass production of yeast isolate was investigated in this study. Five species of yeasts, including Rhodotorula rubra, Candida tropicalis, C. utilis, C. boidinii, Trichosporon cutaneum, were isolated from SOMW following enrichment culture. Of them, C. utilis was chosen as the sole biomass producer in the study due to its greatest oil uptake rate, 0.96 kg oil kg −1 biomass d −1, and highest specific growth rate, 0.25 h −1. The cells of C. utilis contained 26% protein, 9% crude lipid, 55% carbohydrate and balanced amino acid compositions. The initial N:C ratio in SOMW drastically influenced oil reduction efficiency, biomass production and protein content of C. utilis, and therefore a range between 1:6 and 1:8 was recommended in consideration of these three factors simultaneously.

Amino acids composition of Teucrium nutlet proteins and their systematic significance.

Plant species are considered as a good source of dietary proteins, although the nutritional quality of proteins depends on their amino acid composition. In this work the protein content and amino acid composition of nutlets of 21 Teucrium taxa (Lamiaceae) from Spain were analysed and their nutritional quality was compared with the minimum values established by the Food and Agriculture Organization of the United Nations (FAO). In addition, the amino acid composition was evaluated as a chemical character to clarify the taxonomic complexity in this genus. Amino acid content of nutlets was determined after derivatization with diethyl ethoxymethylenemalonate by high-performance liquid chromatography. Previously, nutlets samples were hydrolysed and incubated in an oven at 110 degrees C for 24 h. The protein content was variable, ranging from 6.4 % in T. dunense to 43.8 % in T. algarbiense. According to the FAO values all taxa contain satisfactory amounts of leucine, threonine and valine and are deficient in lysine. The similarity analysis of Teucrium taxa using amino acid composition data did not clearly reflect the infrageneric classification of this genus. Annual species, such as T. spinosum, T. aristatum and T. resupinatum showed a better balanced amino acid composition. The dendrogram partly matched with the karyological complexity of Teucrium. No correlation between amino acid composition and habitat has been observed, showing that Teucrium nutlet amino acid composition may not be strongly influenced by the environment.

Brassica carinata protein isolates: chemical composition, protein characterization and improvement of functional properties by protein hydrolysis

Brassica carinata defatted flour has been used to prepare protein isolates by alkaline extraction and precipitation at low pH. Different extraction parameters have been tested, and the chemical composition and functional properties of the resulting isolates have been analyzed. All the isolates had a protein content above 90% and a well balanced amino acid composition according to FAO standards except for a low content of lysine. The extraction process reduced antinutritional components by more than 90%. Solubility, water and fat adsorption, emulsifying and foaming properties of the original flour and the isolates have been compared. In addition, hydrolysis of B. carinata protein during extraction using the endoprotease preparation Alcalase was performed, and functional properties of hydrolysates with low and high degrees of hydrolysis were studied and compared with those of the original isolates.

Comparative nutritive value of various staple foods*

A population successful in an ecological niche must have a dietary pattern that provides the minimum requirements of all 40–45 essential nutrients, in addition to the energy sources—carbohydrates, fat, and protein. Cereal production and its contribution to diets in developing countries exceed that of legumes and roots, tubers, plantains and bananas. Legumes are highest in protein and is rich in lysine but deficient in cystine and methionine. Cereals are intermediate in protein content; their protein is rich in cystine and methionine but deficient in lysine. Thus cereal‐legume diets have a better amino acid balance than either diet alone, as shown by the high protein quality of most composite diets. Storage proteins are prolamin and glutelin in cereal endosperm, but globulin in legume cotyledon, occurring as prolamin protein body (PB) in cereals and globulin PB in legumes. Glutelin PB occurs in rice endosperm. Roots, tubers, plantains and bananas are high in moisture, hence, poor in protein content and other nutrients and have a poor postharvest shelf life. Potato protein has a balanced amino acid composition. Antinutrition factors for protein include protease (trypsin) inhibitor, tannins, and phytate. Digestible energy correlates with true protein digestibility and increases with processing. Starch occurs as partially crystalline storage granules. The amylose content of starch correlates negatively with gly‐cemic index and positively with resistant starch, a component of soluble dietary fiber. In some cases, starch gelatinization temperature correlates negatively with glycémie index and positively with resistant starch. Antinutrition factors for starch include amylase inhibitor, tannins, and phytate. Flatulence factors include galactose‐containing oligosaccha‐rides, which are particularly high in legumes. Soluble cc‐glucans of oat and barley have hypocholesterolemic activity. Legumes are generally energy‐dense due to their high fat content, particularly peanut and soybean. The unsaponifiable matter of rice oil has hypocholesterolemic activity. Some varieties of root crops have cy‐anogenic glycosides that release HCN on hydrolysis, causing death to consumers. Others have saponins and tannins that contribute to a bitter taste. Staple foods are a major source of vitamins and minerals due to the large amount consumed. Breeding efforts in the 1960s and 1970s attempted to improve the protein content and limiting amino acid (lysine content in cereals and cystine and methionine in legumes) in staple foods, both of which require more energy to produce. CGIAR recently launched a project to increase the micronutrient density of selected crops, particularly vitamin A, iron, and zinc, although mineral absorption from a vegetable source is poor. The low phytate mutant of cereals may improve protein digestibility, glycémie index, and mineral absorption. Rice mutant lacking li‐poxygenase 3 and a lower polyunsaturated fatty acid content may reduce fat rancidity and maintain the essential fatty acid level of food during storage, as in soybean. The adoption of GATT‐WTO in most countries, the accompanying emphasis on value‐added food products, and the popularization of functional foods and nutraceuticals in developed countries will have an impact on the properties and nutritive value of food products in developing countries in the 2000s.