Balance Of Essential Amino Acids Research Articles

Nutritional balance of essential amino acids and carbohydrates of the adult worker honeybee depends on age

Dietary sources of essential amino acids (EAAs) are used for growth, somatic maintenance and reproduction. Eusocial insect workers such as honeybees are sterile, and unlike other animals, their nutritional needs should be largely dictated by somatic demands that arise from their role within the colony. Here, we investigated the extent to which the dietary requirements of adult worker honeybees for EAAs and carbohydrates are affected by behavioural caste using the Geometric Framework for nutrition. The nutritional optimum, or intake target (IT), was determined by confining cohorts of 20 young bees or foragers to liquid diets composed of specific proportions of EAAs and sucrose. The IT of young, queenless bees shifted from a proportion of EAAs-to-carbohydrates (EAA:C) of 1:50 towards 1:75 over a 2-week period, accompanied by a reduced lifespan on diets high in EAAs. Foragers required a diet high in carbohydrates (1:250) and also had low survival on diets high in EAA. Workers exposed to queen mandibular pheromone lived longer on diets high in EAA, even when those diets contained 5× their dietary requirements. Our data show that worker honeybees prioritize their intake of carbohydrates over dietary EAAs, even when overeating EAAs to obtain sufficient carbohydrates results in a shorter lifespan. Thus, our data demonstrate that even when young bees are not nursing brood and foragers are not flying, their nutritional needs shift towards a diet largely composed of carbohydrates when they make the transition from within-hive duties to foraging.Electronic supplementary materialThe online version of this article (doi:10.1007/s00726-014-1706-2) contains supplementary material, which is available to authorized users.

Potential of crab meal as a protein substitute for fish meal in diets for mudfish Heterobranchus longifilis juveniles

A study aimed at evaluating the suitability of crab meal as a potential substitute for dietary fishmeal protein for mudfish (Heterobranchus longifilis ) juvenile was carried out. Fishmeal (FM) and crab meal (CM) protein sources were used separately to prepare diets containing 30, 35 and 40% crude protein (CP). The diets were fed to fish at 5% body weight for 70 days in plastic aquaria. Crab meal at 30% CP level showed a performance of approximately 56.6% (percent weight gain), 50% (specific growth rate, protein efficiency ratio and apparent net protein utilization) of FM containing diet of 30% CP but was similar in fish condition, 0.62 ± 0.005 and 0.66 ± 0.005 for CM and FM diets. Fish survival was 100% for all experimental diets. The feed conversion ratio was appreciable, 4.50 ±1.38 for CM compared to 2.60 ± 0.65 and 1.94 ± 0.65 for 30% and 35% protein fishmeal diets. Inadequate essential amino acid balance and digestibility could be responsible for the reduced performance of crab meal compared to fishmeal. Crab meal has potentials and future trails on partial replacement of FM could reveal improved performance on H. longifilis .

EFFECT OF SOAKING PRE-TREATMENTS ON NUTRITIONAL COMPOSITION AND FUNCTIONAL PROPERTIES OF BAMBARA GROUNDNUT (VIGNA SUBTERRANEA) FLOUR

Bambara groundnut (Vigna subterranean) is one of the underutilised legumes in Nigeria. The protein content of the seeds is high with a good balance of essential amino acids, especially lysine and methionine. Bambara groundnut is a particularly hardy crop, being extremely drought resistant, and can be grown under extreme climatic conditions; hence, it is a promising crop against global climatic changes. However, the legume contains certain anti-nutrients which hinder the efficient utilisation, absorption or digestion of nutrients and thus reduce their bioavailability and their nutritional qualities. This study investigated the effect of soaking pretreatments on the nutritional composition and functional properties of flour from black and cream Bambara groundnut with a view to provide information that will enhance the end use of the legume. Soaking the seeds in hot water for 4 h resulted in the highest reduction in the tannin, phytate, trypsin inhibitor, oxalate and heamagglutinin contents of the flour compared to 24 h soaking in cold water and 3 h soaking in hot water. Soaking does not have significant (P>0.05) effect on the proximate composition of the flours, irrespective of cultivar. Moisture, ash, fat, protein and crude fibre contents ranged from 9.9-11.5%, 2.7-3.1%, 7.6-9.4, 18.4-19.7% and from 1.1-2.3%, respectively. The mineral composition of the flour was significantly (P<0.05) affected by the soaking treatment. Soaking in hot water resulted in a greater reduction in mineral content than soaking in cold water. Water absorption capacity ranged from 69.6-90.8% while dispersibility ranged from 70.5-75.5%. Swelling power and solubility ranged from 4.9-5.9 and from 22.7-31.9%, respectively. Emulsion stability, foaming capacity and foaming stability of the flours ranged from 59.8-78.5%, 10.0-18.0 foam volume/ml and from 50-66%, respectively. The study concludes that soaking pretreatment led to significant reduction in the anti-nutritional factors and mineral content (copper, manganese and zinc) of Bambara groundnut flour.

CRUZAS SIMPLES Y DOBLES EN QUINUA (Chenopodium quinoa Willd.) USANDO MARCADORES MOLECULARES Y MAYORES DISTANCIAS GENÉTICAS

Quinoa (Chenopodium quinoa Willd.) considered by FAO as nutraceutical and orthomolecular food for humanity is reaching global significance for its high protein content and ideal balance of essential amino acids. The research seeks to improve the desired characteristics of quinoa by means of, simple and double crosses and the use of molecular genetics to determine the genetic distances between parents to shorten and facilitate the hybridization of the species; utilizing initially two environments (Puno and Arequipa) for self breeding and selection; it is proposed to develop new varieties by conventional breeding for different agro-climatic conditions of Peru; demonstrate the utility of genetic markers to predict segregation variance in segregating populations of quinoa. Eight parents of quinoa (INIA Salcedo, Huariponcho, Choclito, Chullpi, Pasankalla, Negra kollana, Kancolla, Pandela rosada) were used to determine the value of genetic similarity and genetic distances at the Hohenheim University-Germany, using the GBS methodology. Following the methodology described for quinoa, 28 single crosses (September 2011 to April 2012) were performed, obtaining F1 seeds. The F1 more distant of single crosses and the closer ones were crossed, getting six double crosses, then self-pollinated in Puno and Arequipa to shorten the time, currently being in the S2 of double crosses and S4 of single crosses.

Isolation and Characterization of Proteins from Chia Seeds (Salvia hispanica L.)

Chia ( Salvia hispanica L.) is a plant that produces seeds rich in some nutraceutical compounds with high protein content, but little is known about them; for this reason the aim of this study was to characterize the seed storage proteins. Protein fractions were extracted from chia seed flour. The main protein fraction corresponded to globulins (52%). Sedimentation coefficient studies showed that the globulin fraction contains mostly 11S and 7S proteins. The molecular sizes of all the reduced fractions were about 15-50 kDa. Electrophoretic experiments under native conditions exhibited four bands of globulins in the range of 104-628 kDa. The denaturation temperatures of crude albumins, globulins, prolamins, and glutelins were 103, 105, 85.6, and 91 °C, respectively; albumins and globulins had relatively good thermal stability. Selected globulin peptides by mass spectrometry showed homology to sesame proteins. A good balance of essential amino acids was found in the seed flour and globulins, especially of methionine+cysteine.

Genetic diversity and comparison of physicochemical and nutritional characteristics of six quinoa (Chenopodium quinoa willd.) genotypes cultivated in Chile

The present study was focused on the analysis of agronomical, nutritional, physicochemical, and antioxidant properties of six genetically different quinoa (Chenopodium quinoa Willd) genotypes cultivated in three distinctive geographical zones of Chile. Ancovinto and Cancosa genotypes from the northern Altiplano (19 ºS), Cáhuil and Faro from the central region (34 ºS), and Regalona and Villarica from the southern region (39 ºS) are representative of high genetic differentiation among the pooled samples, in particular between Altiplano and the central-southern groups. A Common-Garden Assay at 30 ºS showed significant differences among seed origins in all morphometric parameters and also in yields. Altiplano genotypes had larger panicule length but no seed production. A significant influence of the different quinoa genotypes on chemical composition and functional properties was also observed. Protein concentration ranged from 11.13 to 16.18 g.100 g-1 d.m., while total dietary fiber content ranged from 8.07-12.08 g.100 g-1 d.m., and both were the highest in Villarrica ecotype. An adequate balance of essential amino acids was also observed. Sucrose was the predominant sugar in all genotypes. Antioxidant activity was high in all genotypes, and it was highest in Faro genotype (79.58% inhibition).

Differential utilization of biochemical components during larval development of the spider crab Maja brachydactyla (Decapoda: Majidae)

Changes in lipid class, fatty acid, fat-soluble vitamins, amino acid and minerals were studied during larval development of Maja brachydactyla Balss, 1922 in order to provide information of its ontogeny and evaluate possible dietary deficiencies and constraints. Four different batches were analyzed from hatching to metamorphosis using enriched Artemia as food. Cultured larvae were in a good nutritional condition as confirmed by the continuous lipid accumulation throughout ontogeny. A regulation of polyunsaturated fatty acids (PUFA) occurred during development in order to maintain adequate basal levels of ω-3 fatty acids (likely through a retro conversion of C20 and C22 into C18 PUFA). Variations in the tocopherol levels indicated its possible role in PUFA protection against oxidation. Essential amino acid balance during development was not correlated with the Artemia feeding regime, but rather reflected inherent variations of the own species ontogeny. Larval requirements in essential minerals were fully supplied by the enriched Artemia.

Tryptic amaranth glutelin digests induce endothelial nitric oxide production through inhibition of ACE: Antihypertensive role of amaranth peptides

Amaranth seed proteins have a better balance of essential amino acids than cereals and legumes. In addition, the tryptic hydrolysis of amaranth proteins generates, among other peptides, angiotensin converting enzyme (ACE) inhibitory (ACEi) peptides. ACE converts angiotensin I (Ang I) into Ang II, but is also responsible for the degradation of bradykinin (BK). In contrast to Ang II, BK stimulates vasodilation modulated through endothelial nitric oxide (NO) production. The aim of the present study was to characterize the ACEi activity of amaranth trypsin-digested glutelins (TDGs) and their ability to induce endothelial NO production. An IC 50 value of 200 μg ml −1 was measured for TDG inhibition of ACE. TDGs stimulated endothelial NO production in coronary endothelial cells (CEC) by 52% compared to control. The effects of TDGs were comparable to those of BK and Captopril, both used as positive controls of NO production. Consistent with these effects, TDGs induced, in a dose-dependent manner, endothelial NO-dependent vasodilation in isolated rat aortic rings. These results suggest that TDGs induce endothelial NO production and consequent vasodilation through their ACEi activity. Amaranth TDGs have a high potential as a nutraceutical food in prevention of cardiovascular diseases. Further molecular, cellular and physiological studies are currently under way and the results may contribute to a better understanding and control of cardiovascular disorders.

Nutritional and therapeutic properties of camel and human milks

Camel and human milk samples (twenty individuals’ samples each) were analysed for fat, total protein (casein, whey protein), lactose, minerals as well as vitamins; B1, B2, niacin and C. Meanwhile, amino and fatty acid compositions and, antimicrobial factors namely; lysozyme (LZ), lactoferrin (LF) and total immunoglobulins (Igs) were determined. Results indicated that camel milk contained higher fat, protein (especially casein), ash, Ca, Mg, P, K, Na, Fe, and Cu but lower in whey protein, lactose and Zn than human milk. Vitamins C and niacin were higher in camel milk than human milk. Camel milk proteins contained satisfactory balance of essential amino acids. The ratio of essential to non-essential amino acids was 0.93 and 1.07 in camel and human milk proteins, respectively. Camel milk was characterized by higher ratio of Igs but lower in both LZ and LF than human milk. General pattern of camel milk fatty acids indicated that short chain fatty acids (C4 –C12) were present in very small amount, but higher than in human milk fat. On the contrary the concentration of C14:0, C16:1 and C18:0are relatively high in camel’s milk fat as compared to human milk fat. Appreciable amounts of essential fatty acids were present in camel milk. It can be concluded that camel milk can be considered as a good food of high nutritive and therapeutic applications. Meanwhile, the high content of antimicrobial agents in camel milk may explain its potential as an antiviral activity specially against diarrhea-causing viruses. Key words: Human milk composition, camel milk composition, nutrition, lysozme, lactoferin, immunoglobulins, gel electrophoresis.

Positive net movements of amino acids in the hindlimb after overnight food deprivation contribute to sustaining the elevated anabolism of neonatal pigs

During the neonatal period, high protein breakdown rate is a metabolic process inherent to elevated rates of protein accretion in skeletal muscle. To determine the relationship between hindlimb net movements of essential and nonessential amino acids in the regulation of hindlimb protein breakdown during an overnight fasting-feeding cycle, we infused overnight-food-deprived 10- and 28-day-old piglets with [1-(13)C]phenylalanine and [ring-(2)H(4)]tyrosine over 7 h (during 3 h of fasting and then during 4 h of feeding). Extraction rates for aspartate and glutamate after an overnight fast were 15% and 51% in the 10-day-old compared with 6% and 25% in the 28-day-old (P < 0.05) piglets, suggesting an altered requirement for precursors of amino acids to shuttle nitrogen to the liver as early life progresses. This occurred simultaneously with marginal positive hindlimb net balance of essential amino acids after an overnight fast, with negative net release of many nonessential amino acids, such as alanine, asparagine, glutamine, glycine, and proline. This suggests that newborn muscle does not undergo significant protein mobilization after a short period of fasting in support of an elevated rate of protein accretion. Furthermore, tyrosine efflux from hindlimb breakdown between overnight fasting and feeding periods was not different in the 10-day-old piglets, for which tyrosine was limiting, but when tyrosine supply balanced requirements in the 28-day-old piglet, hindlimb efflux was increased (P = 0.01). The results of the present study indicate that proteolysis and net movements of amino acids are coordinated mechanisms that sustain the elevated rate of net protein accretion during overnight feeding-fasting cycles in the neonate.

Amaranth ( Amaranthus hypochondriacus) as an alternative crop for sustainable food production: Phenolic acids and flavonoids with potential impact on its nutraceutical quality

The demand for food is increasing, not only to meet food security for growing populations, but also to provide more nutritious food, rich in good quality proteins and nutraceutical compounds. The amaranth ( Amaranthus hypochondriacus) plant, in addition to its high nutritive and nutraceutical characteristics, has excellent agronomic features. The objective of the present study was to analyze some physical and proximal-nutritional properties of amaranth seeds obtained from different varieties grown in arid zones and characterize their phenolic acids and flavonoids. Two commercial (Tulyehualco and Nutrisol) and two new (DGETA and Gabriela) varieties of A. hypochondriacus were grown at the Mexican Highlands zone. Tulyehualco and DGETA varieties had higher seed yield of 1475 and 1422 kg ha −1, respectively, comparable to corn and soybean production in agricultural areas. Gabriela had the highest protein content of 17.3%, but all varieties had an adequate balance of essential amino acids. Polyphenols as rutin (4.0–10.2 μg g −1 flour) and nicotiflorin (7.2–4.8 μg g −1 flour) were detected. Amaranth can be cultivated in arid zones where commercial crops cannot be grown; the seeds besides their well known nutritive characteristics could be a source of phenolic compounds of high antioxidant properties.

Role of Resistant Starches Particularly Rice Containing Resistant Starches in Type 2 Diabetes

Non-insulin-dependent or type 2 diabetes mellitus is on the rise in India particularly in the affluent urban and rural population. The exact cause is unknown. Malnutrition, defective intake of essential fatty acids and reduced intake of fibres are found in Indian diet, particularly rural Indian diet and the dietary factors may be one of the causes leading to increased incidence of the disease. Dietary fibers reduce blood glucose and cholesterol levels. Resistant starches behave as dietary fiber. As rice is the staple food in Indian villages, to increase the fibre consumption, a special variety of rice is processed which contains more of resistant starch. The high protein efficiency ratio (PER) in rice is presumably due to the balance of essential amino acids in rice protein. This high resistant starch containing rice was fed to diabetic patients for three months and effects observed. Results showed that total cholesterol, fasting blood sugar, low-density lipoprotein cholesterol were reduced while other parameters showed no significant changes.

Assessment of the protein quality of fourteen soybean [Glycine max (L.) Merr.] cultivars using amino acid analysis and two-dimensional electrophoresis

The protein quality of commercial soybeans varieties can be determined from their total protein content, their amino acid composition and from the ratio of glycinin to β-conglycinin, the major seed storage protein components. In this study 14 commercial soybean cultivars were assessed. There were significant differences in storage protein composition (P < 0.05) and in their valine, proline and phenylalanine contents (P < 0.01 to P < 0.001). Mean protein values among these varieties ranged from 29.8% to 36.1%. The total amino acid nitrogen (AAN) ranged from 89.6 to 95.1 g AA/16 g of nitrogen, corresponding to nitrogen values from 16.5 to 17.9 g AAN/100 g protein. All varieties contained a good balance of essential amino acids (EAA9), limited only in methionine. Two-dimensional gel electrophoretic (2-DE) separations, led to the establishment of high-resolution proteome reference maps, enabling polypeptide chain identification and calculation of the ratio of the constituent glycinin and β-conglycinin storage proteins of soybean. This method enables the assessment of the genetic variability of the soybean cultivars, which can then be correlated with their protein quality and food processing properties. These three methods can be used as very effective tools for assisting plant breeders in their selection of high quality soybean varieties.

Protein quality and identification of the storage protein subunits of tofu and null soybean genotypes, using amino acid analysis, one- and two-dimensional gel electrophoresis, and tandem mass spectrometry

The protein quality of 11 null and 2 tofu soybean genotypes were determined from their total protein content, their amino acid composition, and their glycinin and β-conglycinin contents. There were highly significant differences (P < 0.001) in their total storage proteins, and amino acid contents. Total protein among these genotypes ranged from 33 to 37%, with arginine being the third highest amino acid (7.4–10.9 g/100 g protein) followed by glutamic and aspartic acids. Methionine accounted for only 1.6–2.4 g/ 100 g of protein. All genotypes contained a good balance of essential amino acids (EAA9), ranging from 43.5 to 47.3% of the total protein, limited only in methionine and possibly threonine and valine. Two-dimensional gel electrophoretic (2-DE) reference maps, using narrow range immobilized pH gradient (IPG) strips, revealed unique differences in the proteome, and subunit expression of glycinin and β-conglycinin, among these null genotypes, which can then be correlated with their protein quality. Out of a total of 111 basic (pH 6–11), and 223 acidic (pH 4–7) protein spots separated by 2-DE, 41 soybean storage protein spots were excised, and identified by liquid chromatography on-line with electro spray LCQ DecaXP tandem quadrupole time-of-flight mass spectrometry (LC/MS/MS). These methods will enable accurate evaluation of protein quality in soybeans, based on their protein digestibility-corrected amino acid score, assessment of the genetic variability of soybean genotypes, and serve as very effective tools for assisting plant breeders in their selection of high quality soybean varieties.

Replacement of fish meal by meat and bone meal in diets for large yellow croaker, Pseudosciaena crocea

A growth experiment was conducted to investigate the effects of replacement of fish meal (FM) by meat and bone meal (MBM) in diets on the growth and body composition of large yellow croaker ( Pseudosciaena crocea). Six isonitrogenous (43% crude protein) and isoenergetic (20 kJ g − 1 ) diets replacing 0, 15, 30, 45, 60 and 75% FM protein by MBM protein were formulated. Each diet was randomly allocated to triplicate groups of fish in sea floating cages (1.0 × 1.0 × 1.5 m), and each cage was stocked with 180 fish (initial average weight of 1.88 ± 0.02 g). Fish were fed twice daily (05:00 and 17:30) to apparent satiation for 8 weeks. The water temperature ranged from 26.5 to 32.5 °C, salinity from 32 to 36‰, and dissolved oxygen content was approximately 7 mg l − 1 during the experimental period. Survival decreased with increasing dietary MBM and the survival in the fish fed the diet with 75% protein from MBM was significantly lower than other groups ( P < 0.05). There were no significant differences in specific growth rate (SGR) among the fish fed the diets with 0 (the control group), 15, 30 and 45% protein from MBM. However, SGR in the fish fed the diets with 60 and 75% protein from MBM were significantly lower than other groups ( P < 0.05). No significant differences in feeding rate were observed among dietary treatments. The digestibility experiment showed that the apparent digestibility coefficients (ADC) of dry matter, protein, lipid and energy of MBM were significantly lower compared with those of FM ( P < 0.05). Essential amino acid index was found to be correlated positively with SGR in the present study, suggesting that essential amino acid balance was important. Body composition analysis showed that the carcass protein and essential amino acids were not significantly affected by dietary MBM. The lipid and n-3 highly unsaturated fatty acid (n-3 HUFA) in fish muscle, however, significantly decreased with increasing dietary MBM. These results showed that 45% of FM protein could be replaced by MBM protein in diets of large yellow croaker without significantly reducing growth. It was suggested that the reduced growth with higher MBM was due to lower digestibility and imbalance of essential amino acids.

Influence of dietary digestible energy content on growth, protein and energy utilization and body composition of growth hormone transgenic and non-transgenic coho salmon ( Oncorhynchus kisutch)

Triplicate groups of size (mean initial weight, 12.9 g)- and age (1.5 years old)-matched growth hormone transgenic (T; construct OnMTGH1) and non-transgenic (NT) pre-smolt coho salmon held in running, 8–11 °C well water on a natural photocycle, were each fed to satiation twice daily one of four dry diets for 84 days. The diets had similar ratios of digestible protein to available energy (21–23 MJ/kg dry diet), identical essential amino acid balance, and supplemental vitamin and mineral levels, but different digestible energy (DE) content (i.e., 15, 17, 19 or 21 MJ/kg dry weight) by varying α-cellulose, anchovy oil and pre-gelatinized wheat starch concentrations. The intent was to determine whether the two genotypes of fish differed with respect to their abilities to ingest food to satisfy their daily energy needs. Moreover, for T fish, which characteristically have high and unregulated growth hormone production, we were interested to determine whether the physical distention of the stomach and other aspects of their digestive physiology would allow similar available protein and energy intake and, consequently, fish growth across a wide range of dietary DE content. All diets supported excellent growth in T coho, but only diets with ≥ 17 MJ DE/kg supported growth in NT coho. Specific growth rates (SGR) in weight of both coho genotypes were directly related to dietary DE but were uninfluenced when DE was ≥ 17 MJ/kg. Values for SGR for T coho fed diets with 17–21 MJ DE/kg were 6–13-fold higher than those of NT counterparts. Dry feed and gross energy intakes were directly related to dietary DE in NT coho, whereas the opposite was true in T coho when the values were expressed on a body weight basis. Values for feed efficiency were positively correlated with dietary DE in both genotypes and significantly elevated by each DE increment in T fish. Gross energy and available (digestible) energy utilization values were uninfluenced by dietary treatment in T fish. Percentages for gross (PPD) and available protein deposited were unaffected by diet treatment in T fish, but PPD in NT coho was significantly depressed in fish fed the diet with lowest DE. In T coho, apparent digestibility coefficients for gross energy and organic matter were directly related to dietary DE, whereas the opposite trend was found for protein digestibility. Terminal percentages of body lipid content were directly related to dietary DE content in T salmon.

Biological evaluation of mechanically deboned chicken meat protein quality

Mechanically deboned chicken meat (MDCM) is a meat product obtained by crushing tissues after meat removal and is largely used in meat products. Protein quality of flour prepared from defatted MDCM and from fresh chicken breast meat (FCBM) was chemically and biologically evaluated by rat growth and nitrogen balance studies. Proximate chemical composition, on a dry basis, of MDCM and FCBM showed protein contents of 90.5% and 82.2%, lipid contents of 3.0% and 13.2% and ash contents of 6.1% and 4.2%, respectively. There was a relatively good balance of essential amino acids in both samples although lysine was in low concentration in MDCM being a limiting amino acid. Feeding of flour diets resulted in high protein efficiency ratio, a high net protein utilization and high nitrogen balance, thus showing a high biological value and also high true digestibility and, consistently, NPU for both samples is similar to casein.

Effect of fermented/germinated cowpea flour addition on the rheological and baking properties of wheat flour

There is a growing interest in fortifying wheat flour with high lysine material, such as cowpea flour, to improve the essential amino acid balance of baked food products. The use of cowpeas as a food source has not been utilised fully, especially in developed countries. In this research, wheat flour in a standard bread formulation was partially replaced with cowpea flour, germinated cowpea flour and fermented cowpea flour at levels of 5%, 10%, 15% and 20% (wt/wt). Composite flours were analysed for ash, protein, gluten contents and α-amylase activity as well as colour, farinograph and extensograph characteristics. Bread baked from composite flours was analysed for loaf volume and weight, texture, crumb-grain structure and colour. Increasing levels of cowpea flour in the blends resulted in changed flour characteristics such as ash and protein contents and colour. It also changed farinograph and extensograph characteristics, mainly by increased water absorption. Incorporation of cowpea flour exerted a certain volume depressing effect on the bread and gave a compact structure at higher substitution levels. Overall acceptable results were obtained based on characteristics of control bread.

Lupin Flours as Additives: Dough Mixing, Breadmaking, Emulsifying, and Foaming

ABSTRACTThe nutritional quality of various food products could be improved by supplementation with grain legumes to increase protein content and to improve the balance of essential amino acids. The lupin grain is a good candidate for this role, given its yield potential in a range of climatic environments and soil types. To establish the practicality of extending the use of lupins as food additives, the functional properties of various species and cultivars of lupin were studied for their effect as additives to baked products and their ability to provide foaming and emulsifying properties. Of the two lupin species that are commonly cultivated commercially, Lupinus albus showed the greater potential as a bread additive; loaf height and structure were maintained when lupin flour was substituted for wheat flour at levels up to 5%. This level of substitution offered the advantage of reducing mixing time. The detrimental effects at higher substitution levels appeared to be associated with the nonprotein components of the lupin flour. L. albus showed better functionality than L. angustifolius in emulsifying attributes, although L. angustifolius showed greater potential as a foaming agent. Defatting the lupin flour may be necessary to show these properties to best advantage. Certain cultivars (within each species) showed preferable performance, indicating the potential for plant breeding to provide germplasm better suited to uses as food additives.

Strategies for further development of aquatic feeds

: To date, aquatic feeds have depended heavily on fishmeal and fish oil as their source of protein and lipid. However, the feed industry is encountering shortfalls in the availability of these ingredients because of a decline in the number of fish captured in the wild and the increased human demand for some of the species currently being used for fishmeal and oil production. Therefore, efforts are now being directed in different parts of the world to finding alternative quality ingredients, which ideally are less expensive and readily available for use in practical diets. The data accrued have shown that a large proportion of both fishmeal and fish oil can be replaced by other protein and lipid sources. However, it is emphasized that an optimal essential amino acid balance be maintained and that the n-3 highly unsaturated fatty acid requirement be satisfied when combining economical protein and lipid ingredients. Newly developed feeds should aim at being nutrient-dense in order to reduce the output of solid, P and N waste. This can be done through improving nutrient availability, optimizing the digestible protein to energy balance of the diet, and replacing dietary fishmeal with alternate ingredients. These diets should also be effective for maintaining good health and improving disease resistance in fish through enhancement of immune responses. A wholesome approach to culturing fish would be to use appropriate feeding standards that are aimed not only at improving economic returns but also at developing a lasting cohabitation of sustainable aquaculture and a cleaner environment. Furthermore, in the 2lst century aquaculture would still retain its place as a prominent source of food protein, signifying that fish feed research remains a forceful area in discovering better feeds for the industry.