Some Antinutritional Factors in Moringa peregrina (Al-Yassar or Al-Ban) and Soybean Products

Moringa peregrina and soybean defatted flours, protein concentrates, and isolates were assayed for trypsin (TIA) and α-amylase (AIA) inhibitor activities, phytic acid, tannin and chlorogenic acid contents, and in vitro protein digestibility (IVPD). TIA in M. peregrina defatted flour (MDF) was lower (P < 0.05) but more heat resistant than in soybean. AIA in MDF was lower than in soybean and inhibited pancreatic amylase more than bacterial amylase. Some M.peregrina products were higher in phytic acid but lower in chlorogenic acid than soybean. Tannin was low in all samples. IVPD was slightly lower for M.peregrina than for soybean.     

Preparation and characterization of a protein hydrolysate from an oilseed flour mixture

A novel protein hydrolysate was prepared from the mixture of oilseed flours (soybean, sesame and peanut) and determined physicochemical & functional properties along with comparison of individual oilseed flour hydrolysate of soybean. Mixed flour obtained from oilseed flours viz. soybean, sesame and peanut by using calculated amounts in the ratio of 1.1:1.7:0.7, respectively was used as a starting raw material having balanced amino acid profile. Protein hydrolysates were prepared from mixed flour and soybean flour by a double enzyme treatment method to a level of 40% degree of hydrolysis. The dried protein hydrolysate prepared from the mixed flour had 72% crude protein. This protein was characterized by gel filtration chromatography and SDS-PAGE. Comparison of the amino acid profile of the protein hydrolysate from mixed flours and soyabean flours showed a significant increase in the former one with respect to amino acid contents usually deficient of single oilseed flour hydrolysate. The product is creamish yellow in colour and had a solubility of >90% over a wide pH range of 2–10. The mixed flour protein hydrolysate showed better functional attributes such as foaming, as compared to that from soybean flour alone.     

In vitro digestibility of protein and amino acids in protein mixtures

Six protein sources, casein, field peas, peanut meal, wheat flour, rapeseed and soya bean concentrate and their blends (ratio 1:1) were subjected to in vitro enzymic digestion. Wheat flour had the lowest in vitro digestibility (30% in 6 h) while the other sources had similar digestibilities (40%). Basic and aromatic amino acids were the most readily liberated from these protein sources. Some protein combinations, such as a rapeseed/field pea blend, gave in vitro digestibilities higher than calculated from individual proteins. The type of response observed could not be predicted from either nitrogen digestibility or amino acid composition of the individual sources. The digestibility of some amino acids was modified and this could be due to varying affinity of digestive enzymes for the protein.     

Sensory evaluation and in vitro protein digestibility of mung bean as affected by cooking time

Heat treatment is particularly important in the preparation of mung bean for consumption, from the point of view not only of acceptability but also of improvement on protein digestibility. Sensory evaluation of cooked mung bean in terms of taste, colour, aroma and texture has an organoleptic panel indicated that there was no significant difference (P < 0.05) between mung bean cooked for 25, 30, 35, 40 and 45 min. An in vitro protein digestibility assay was used to examine the effect of cooking time on protein digestibility. The applied non-linear mathematical model indicated a high correlation coefficient between experimental and predicted data (R² ≥ 0.999). A maximum improvement in in vitro protein digestibility (IVPD) of 4.83% was obtained by cooking for 38.6 min. No remarkable changes in most amino acids were found between raw and cooked samples except that tryptophan was decreased by 4.69% and a 10.29% loss of threonine occurred with the optimum cooking time. © 1999 Society of Chemical Industry     

Germination‐Assisted Enzymatic Hydrolysis Can Improve the Quality of Soybean Protein

This study aimed to investigate the effects of combined germination and Alcalase hydrolysis on the quality of soybean protein. Protein profiles, water solubility, foaming and emulsifying properties, thixotropic properties, and in vitro protein digestibility (IVPD) were tested, the chemical score (CS), essential amino acid index (EAAI), and protein efficiency ratio (PER) of soybean protein were also defined. The combined treatment of germination and Alcalase hydrolysis remarkably improved the solubility, emulsification activity index, emulsion stability index, and foaming capacity of soybean protein. Notably, a decrease in foaming stability was detected. The electrophoretic profile showed a weak breakdown of soybean protein during germination. However, a strong breakdown of protein was observed after the hydrolysis with Alcalase. The combined treatment also decreased the CS and EAAI of soybean protein, but only by 18%. Meanwhile, the IVPD and PER of soybean protein were significantly improved. Moreover, the protein of the germinated and hydrolyzed soybean flour demonstrated better swallowing properties. These findings indicated that the combined treatment of germination and enzymatic hydrolysis can improve the quality of soybean protein.     

The effect of cooking on proteins from acha (Digitaria exilis) and durum wheat

The effect of cooking on proteins from acha and durum wheat was assessed from an analysis of protein extractability, gel electrophoretic profiles, in-vitro protein digestibility (IVPD) and the amino acid compositions of wholemeal flour and residue proteins. Heating wholemeal flour samples at 100–140°C (t = 10–40 min) resulted in 0–30% and 45–55% decreases in acha and durum protein solubility, respectively. In general, high molecular weight (30–70 k Da) protein subunits were more susceptible to heat damage. For both cereals, sodium dodecyl sulphate (SDS; 10 g litre^?1) and/or dithiothrcitol (DTT; 10 mM ) increased protein solubility in unheated and heated samples. The IVPD index was 90–91% and was not significantly altered by cooking (100–120°C, t = 40 min). Cooking at extreme temperatures (140°C, t = 40 min) reduced the IVPD by 8% (P = 0.05). Osborne fractionation resulted in a durum or acha residue level of 7.8% or 55.2%. Treatment with solvent containing propanol, SDS and/or DTT at room temperature followed by SDS-polyacrylamide gel electrophoresis of non-solubilised proteins showed that the glutelin fraction of acha, with the exception of a 65 kDa subunit, was insoluble owing to strong inter-subunit hydrophobic and disulphide interactions. Wholemeal acha flour and residue protein showed a significantly greater level of hydrophobic and sulphur amino acids as well as glutamine which is associated with H-bonding. The possibility that cereal protein solubility is also dependent on protein-carbohydrate links is discussed.     

Intermediate moisture meat product: biological evaluation of charqui meat protein quality

Charqui is a typical salted and dry Brazilian meat product. A harsh condition for salting and drying during charqui processing could eventually damage its biological value. Therefore protein quality of raw and cooked charqui meat flours was chemically and biologically evaluated by rat growth and nitrogen balance studies. Proximate chemical compositions of desalted raw and cooked charqui flour samples showed protein content of 74.2 and 81.1%, respectively and lipid contents of 20.06 and 13.52%, respectively. There was a good balance of essential amino acids in both samples. Feeding of flour diets prepared from exhaustively desalted and dried cooked and raw charqui samples resulted in high protein efficiency ratios, in high net protein utilisations and high nitrogen balances thus showing a high biological value and also high true digestibility, with NPU similar to casein.     

Effect of fermentation on biochemical and sensory characteristics of millet flour supplemented with whey protein

Pearl millet like other cereals shows qualitative and quantitative deficiency in protein. The main objective of this study was to obtain the food of high nutritive value with high protein content and biological value by supplementing pearl millet, with whey protein. Two levels of whey protein were considered (20% and 25% protein content). Supplemented samples and control were fermented in the presence of starter for 14 h according to the traditional method utilised in Sudan. The pH, crude protein, in vitro protein digestibility (IVPD) and protein fractions of the fermented and supplemented pearl millet were determined at 2‐ h intervals. Supplementation of whey protein resulted in significant increase in protein content compared to the control, i.e. 14.8%, 23.9% and 28.7% for Ashana control (AC), Ashana plus whey protein (20% protein content) (AW₁) and Ashana plus whey protein (25% protein content) (AW₂), respectively. Fermentation was found to cause a highly significant (P ≤ 0.05) improvement in IVPD for AC, AW₁ and AW_2. The major protein fraction in the whey protein supplemented doughs was the globulin. This would indicate an improvement in the nutritional quality of pearl millet. Sensory evaluation revealed higher acceptability for whey protein supplemented formulas compared to control.     

Protein contents, physical and sensory properties of Nigerian snack foods (cake, chin-chin and puff-puff) prepared from cowpea – wheat flour blends

Some Nigerian snack foods, particularly cake, chin‐chin and puff‐puff, were prepared from blends of cowpea and wheat flours. The snack foods were evaluated for their protein content, physical and sensory characteristics. The latter included colour, flavor, texture and overall acceptability. All the snack foods showed higher protein content when compared with the 100% wheat flour based snack foods. The protein content increased with the increasing levels of cowpea flour in the blend. The physical properties of the supplemented snack foods were not adversely affected by supplementation with cowpea. Similarly, at all levels of cowpea supplementation, the sensory characteristics of the snack foods did not differ significantly (P > 0.05) from those of the 100% wheat flour based snack foods.     

Proximate composition and digestibility of fermented and extruded uji from maize-finger millet blend

The proximate composition, amino acid profile and in vitro starch and protein digestibilities of raw; fermented; fermented and cooked; unfermented and extruded; and fermented and extruded maize-finger millet blend was studied. Aspartic acid, glycine, cystine, methionine, tyrosine and lysine increased after fermentation, while contents of all other amino acids showed no significant changes. Greater losses of amino acids occurred when the fermented blend was extruded than when cooked. Fermentation improved protein and starch digestibilities, whereas cooking or extruding the fermented blend reduced the digestibilities. Extruding the unfermented blend increased protein and starch digestibilities and reduced nitrogen solubility index by 50%. Raw flour had 0.41 g/100 g water-soluble starch which declined to 0.05 g/100 g on fermentation but increased to 20-34 g/100 g after extrusion.     

Organoleptic and nutritional evaluation of wheat breads supplemented with soybean and barley flour

Supplementations of soy (full fat and defatted) and barley flours to wheat flours at 5, 10, 15 and 20% levels were carried out to test the effects on organoleptic and nutritional evaluation of the supplemented bread. Additions of 15% barley flour, 10% soy flour (full fat and defatted), 15% barley plus full fat soy flour and 15% barley plus defatted soy flour to wheat flour produced acceptable breads. However, substitution of soy (full fat and defatted) and barley flours to wheat flour separately and in combinations at 20% levels did not produce organoleptically acceptable bread. Various nutritional parameters, such as protein, fat, total lysine, protein digestibility (in vitro), sugars, starch digestibility (in vitro), total and available minerals, antinutrients, dietary fibre and β-glucan were determined in supplemented and control bread. Increasing the level of substitution from 5 to 10% of full fat and defatted soy flour to wheat flour significantly (P<0.05) increased protein (from 12.1 to 13.7 and 12.4 to 13.8%), lysine (from 2.74 to 3.02 and 2.76–3.05 mg/100 g protein) and total calcium (from 70.2 to 81.4 and 71.9–81.8 mg/100 g) contents. However, there was also an increase in phytic acid (238–260 and 233–253 mg/100 g), polyphenol (324–331 and 321–329 mg/100 g) and trypsin inhibitor activity (193–204 and 193–198 TIU/g). When barley flour was substituted separately, and in combinations, with full fat and defatted soy flour up to 15%, this significantly increased the contents of protein, total lysine, dietary fibre and β-glucan. It may be concluded that breads supplemented with barley and defatted soy flour, up to a 15% level, are organoleptically and nutritionally acceptable.     

Semolina supplementation with processed lupin and pigeon pea flours improve protein quality of pasta

The objective of this work was to study the effect of processing (alcoholic extraction, fermentation and germination) on protein quality of lupin (Lupinus angustifolius L. var. Troll and Emir) and pigeon pea (Cajanus cajan L. var. Aroito) flours. Second, the effect of semolina supplementation with the processed legume flours on protein quality of pasta was also evaluated. For protein quality evaluation amino acid composition and chemical score (CS) were determined in raw and processed legume flours as well as cooked semolina pasta supplemented and non-supplemented with processed legumes. Alcoholic extraction did not cause important changes in the amino acid profile of lupin seeds. Certainly, sulphur amino acid content of ethanol extracted lupin flours was reduced but levels remained similar to those usually found in other legumes. However, fermentation and germination of pigeon pea seeds improved some essential amino acids and slight changes in CS indexes were observed. Moreover, semolina supplementation with processed lupin and pigeon pea flours improved protein quality of pasta as a result of higher CS and EAA levels compared to the control cooked semolina pasta. Therefore, ethanol extracted lupin, as well as fermented and germinated pigeon pea seeds are suitable protein sources for formulating new pasta products.     

Effect of lipoxygenase activity in defatted soybean flour on the gelling properties of soybean protein isolate

Soybean lipoxygenase was inactivated to different degrees by dry heating of defatted soybean flour for 0, 5, 10, 15, 20 and 25 min and soy protein isolates were prepared thereof by isoelectric precipitation of the water extract of the defatted soybean flour. The fluorescence emission intensity at 420 nm of the chloroform–methanol extract of soy protein isolates, which was indicator of the existence of peroxidized lipid, varied in parallel with the lipoxygenase residual activity in defatted soybean flours. The dispersion of soy protein isolate showed an increasing turbidity with the increase of lipoxygenase residual activity in the starting defatted soybean flour, suggesting an elevated tendency to form insoluble aggregates during the preparation of soy protein isolate. Small deformation rheological test revealed that the gelling times were shorter for those soy protein isolates derived from low lipoxygenase activity defatted soybean flours than that of high lipoxygenase activity. Frequency sweep showed that G′ of soy protein isolate derived from low lipoxygenase defatted soybean flour was independent of oscillation frequency in contrast to that of derived from non dry-heated defatted soybean flour, the latter showed a marked frequency dependence. Large deformation test revealed that the gel hardness increased about 10 times after dry heating of defatted soybean flour for 20 min. As the increase of the lipoxygenase residual activity, the gel permeability increased markedly, suggesting that soy protein isolate from high lipoxygenase defatted soybean flour produced coarser textured gel, which corresponded well with the results of scanning electron microscopy.     

Comparative study of the emulsifying and foaming properties of defatted coriander (Coriandrum sativum) seed flour and protein concentrate

Emulsifying and foaming properties were determined for coriander protein products (defatted flour and protein concentrate) at pH 4.0, 7.0 and 9.0 and the results compared with those obtained for defatted soybean flour. Mean oil droplet size and interfacial protein concentration was smallest for emulsions (∼17% oil, v/v) stabilized by the coriander protein concentrate, when compared to the coriander and soybean flours. Polypeptide composition of the interfacial protein membrane of the emulsions was different from the polypeptide composition present in the respective coriander flour and protein concentrate. In contrast, soybean flour-stabilized emulsions contained similar polypeptide composition to that of the flour. Soybean flour formed the greatest amount of foams at pH 4.0, 7.0 and 9.0 followed by the coriander flour, which had greater amounts of foam at pH 4.0 and 5.0. The foam stability of both the coriander flour and protein concentrate were significantly (P⩽0.05) less than those of the soybean flour. It was concluded that the reduced level of non-protein components in the coriander protein concentrate favoured increased surface activity at the oil–water interface but not at the air–water interface.     

Chemical,biological and sensory evaluation of pasta products supplemented with α‐galactoside‐free lupin flours

α‐Galactoside‐free lupin flour has been used to supplement durum wheat semolina flour in order to increase the nutritive value of pasta products. Supplemented pasta products had a shorter cooking time, higher cooking water absorption, cooking loss and protein loss in water than control pasta prepared with only semolina. Sensory evaluation of cooked pastas showed that products supplemented with 80 g kg^?1 of α‐galactoside‐free Lupinus angustifolius var. Emir flour or with 100 g kg^?1 of α‐galactoside‐free Lupinus angustifolius var. Troll flour showed the same acceptability by panellists as the semolina pasta. These levels of supplementation were selected for further studies. The cooked α‐galactoside‐free lupin/semolina pastas showed higher amounts of protein, dietary fibre, calcium, phosphorus, magnesium, zinc and antioxidant capacity than control pasta and a reasonable level of vitamin B₁, vitamin B₂ and vitamin E. Biological assessment of cooked pastas indicated that the true protein digestibility did not change after the fortification of semolina but protein efficiency ratio increased sharply in the pasta supplemented with α‐galactoside‐free lupin flours (2.07 and 1.92 for Emir and Troll lupin varieties, respectively) in comparison with the control pasta (1.11). It is concluded that the α‐galactoside‐free lupin flours are an adequate ingredient to improve the nutritional quality of pasta products without adding flatulent oligosaccharides. Copyright © 2006 Society of Chemical Industry     

Soy Supplementation of a Maize Based Kenyan Food (Ugali)

The effects of soy-supplementation of maize meal on the nutritive value of Kenyan Ugali was determined by consideration of amino acids, available lysine, minerals, phytate, oligosaccharides, protein and in vitro protein digestibility. Supplementation at 10%, 20%, and 30% of soy flour resulted in (a) increased protein ranging from 12.6% to 19.6% (b) increased chemical score ranging from 74 to 87; (c) increase in available lysine of Ugali ranging from 2.61 to 5.11 g/ 16gN and, (d) increases in minerals, phytate, and oligosaccharides. The supplementation did not affect adversely the in vitro protein digestibility of Ugali prepared from the maize-soy blends. Supplementation up to 20% had no apparent effect on the taste preference of Ugali. The overall nutritional value of Ugali could be improved substantially by supplementation of the maize meal with 20-30% soy flour.     

PROCESSING AND ACCEPTABILITY OF FRIED CASSAVA BALLS ("AKARA-AKPU") SUPPLEMENTED WITH MELON AND SOYBEAN FLOURS

The processing and acceptability of fried cassava balls (“Akara‐akpu”) supplemented with melon and soybean flours were studied. Cassava flour, defatted soybean flour and cassava mash were produced. Some functional and chemical properties of the flours were determined. Akara‐akpu prepared from 100% cassava mash served as control; 100% cassava flour, 80% cassava flour + 20% defatted soybean and 70% cassava flour + 30% defatted melon flour were prepared. Akara‐akpu balls were subjected to chemical and physical analyses. Akara‐akpu prepared from composite flour blends had higher protein, fat, ash and energy value than Akara‐akpu from 100% cassava mash. The cyanide content and degree of starch gelatinization of Akara‐akpu prepared from 100% cassava mash (control) were higher than Akara‐akpu prepared from cassava mash plus composite flour blends. There was a significant difference (P ≤ 0.05) in weight and yield between Akara‐akpu prepared from 100% cassava mash (control) and cassava mash plus composite flour blends. There was no significant difference (P ≤ 0.05) in volume between Akara‐akpu made from control sample and those cassava plus composite flour blends.     

Modelling the effect of peanut and cowpea flour supplementation on quality of Chinese-type noodles

Chinese-type noodles were prepared from wheat flour fortified with 7–21% defatted peanut and 4–12% cowpea flours. A full factorial 4X4 design was used. Fifteen supplemented Chinese-type noodle formulae and a control sample were analysed for protein content and physical and sensory qualities. The protein content of noodles was increased as the level of peanut/cowpea flours increased. Colour and cutting force of supplemented noodles were affected negatively by cowpea and peanut flours, respectively. Sensory scores for firmness and yellowness of supplemented Chinese-type noodles were decreased as the level of peanut/cowpea flours increased. Computer-generated response surface and contour plot interpretations revealed that up to 15% peanut flour and 8% cowpea flour supplementation will produce acceptable supplemented Chinese noodles with high protein content (21%).     

Gluten-free quinoa noodles: effects of intermediate moisture extrusion and soy protein isolates supplement on cooking quality and in vitro digestibility

Quinoa is considered as a superior gluten-free material due to its balanced composition of amino acids in protein and abundant nutrients. However, the processing behaviour of quinoa flour is limited by protein functional properties. In this study, twin-screw extrusion was used for the production of gluten-free quinoa noodles (GFQNs). Moisture was found to be closely related to the cooking quality and texture characteristics of extruded noodles by regulating the formation of starch gel. With this in concern, the moisture dose was optimised as 30%. Then, soy protein isolate (SPI) was supplemented into quinoa flour to improve the texture and cooking quality of GFQNs while decrease its in vitro starch digestibility. It was found that SPI could significantly reduce the cooking loss of GFQNs from 16.65% to 11.82% while increase the hardness of the noodles from 6.35 N to 7.99 N, and form a more porous structure as observed by SEM. Furthermore, the addition of SPI also delayed the in vitro hydrolysis rate of quinoa-based noodles, as shown by the significant decrease in rapid digestible starch around 8%. Therefore, quinoa–SPI mixture flour with the intermediate moisture extrusion showed prospective to develop low glycaemic index GFQNs.     

Amino acid profile,protein digestibility,thermal and functional properties of Conophor nut (Tetracarpidium conophorum) defatted flour,protein concentrate and isolates

Functional properties, amino acid compositions, in vitro protein digestibility, electrophoretic and thermal characteristics of conophor defatted flour (CDF), conophor protein concentrate (CPC), isoelectric protein isolate (CII) and neutral protein isolate (CNI) were evaluated. The isolates (CII and CNI) showed significantly lower (P < 0.05) water and oil absorption capacities, emulsifying and gelling capacities, but higher emulsion stability and foaming capacity. In vitro protein digestibility, enthalpy and denaturation temperature varied between 52.28% and 73.4%, 1.62–4.04 J g^?1 protein and 79.7–89.3 °C, respectively. The native proteins were comprised of subunits with molecular weights ranging between 15.3 and 129.3 kDa. The major amino acids in all the samples were aspartic acid, glutamic acid and arginine, whereas the percentages of essential amino acids in CDF, CPC, CII and CNI were 39.35%, 40.46%, 44.54% and 46.04%, respectively. Conophor protein products could be used as functional ingredients in food formulations and for enriching low quality protein diets.