Baboo M. Nair

Nutritional quality of the protein in quinoa (Chenopodium quinoa, Willd) seeds

The nutritional quality of protein in quinoa seeds has been determined by amino acid assay and by animal feeding experiments. The amino acid composition of the protein in raw quinoa and washed quinoa show similar pattern. The first limiting amino acids were the aromatic amino acids thyrosine + phenylalanine giving a chemical score of 86 for protein in raw quinoa and 85 for protein in washed quinoa. Threonine was the next limiting amino acid followed by lysine. The amount of lysine and sulfur amino acids (methionine + cystine) was relatively high. In general, the content of essential amino acids in quinoa is higher than in common cereals. The animal experiments showed NPU values of 75.7, BV of 82.6 and TD value of 91.7 for the protein in raw quinoa. Results of the in-vitro enzymatic methods showed that the digestibility of the protein in quinoa is comparable to that of other high quality food proteins. The corresponding experiments carried out with samples of guinoa seeds, which have been processed to remove the saponins, showed that, the saponins do not exert any negative effect on the nutritive quality of the protein.

Content of fat, vitamins and minerals in quinoa (Chenopodium quinoa, Willd) seeds

The seed of an important food crop, indigenous to the Andean region of Latin America, called quinoa (Chenopdium quinoa, Willd) is a good source of thiamin (0·4mg100 g), folic acid (78·1 mg100 g), and vitamin C (16·4 mg100 g). The seeds contain twice as much γ-tocopherol (5·3 mg100 g) as α-tocopherol (2·6 mg100 g) and larger amounts of calcium (874 mg/kg), phosphorus (5·3 g/kg), magnesium (2·6 mg100 g), iron (81 mg/kg), zinc (36 mg/kg), potassium (12 g/kg), and copper (10 mg/kg) than most of the common cereal grains. The amounts of mercury, lead, and cadmium found in these samples were low in relation to the values of tolerable intake for these elements. All values are expressed on a dry-weight basis. The fat content of raw quinoa seeds was 9·7% on a dry-weight basis with high amounts of oleic acid (24·8%) and linoleic acid (52·3%). The level of linolenic acid was 3·9%. The process of removing saponins from the seeds reduces the vitamin and mineral contents to some extent. The loss is significant (p < 0·001) in the case of potassium, and considerable also in the case of iron and manganese (p < 0·01).

Proximate composition, mineral and amino acid content of mature Canavalia gladiata seeds

Abstract The chemical composition and the nutritional quality of protein and carbohydrates of mature seeds of Canavalia gladiata (L.) were investigated. The whole and cotyledon flour of mature seeds contained; crude protein 26.8 and 29.2%; fat 2.8 and 3.1%; fibre 33.2 and 10.2%; ash 3.9 and 4.3%; carbohydrate 33.3 and 53.2% on dry matter basis respectively. The carbohydrate fractions have starch contents of 30.7 and 39.6% and 27.7 and 34.6 mg g−1 low molecular weight carbohydrates on dry matter basis. The energy content of whole seed and cotyledon flour was 11,082 and 14,923 kJ kg−1. Sucrose represents the highest fraction of low molecular weight carbohydrates with fructose being the lowest. The mineral analysis showed K, Mg, Ca, P and S to be present in high quantities. The essential amino acid profile compared well with FAO/WHO recommended pattern except for sulphur containing amino acids, cysteine and methionine. Therefore the chemical composition of the raw mature seeds of Canavalia gladiata (kernel) indicates the bean to be a good supplement to cereal-based diets.

Isolation, separation and characterization of water soluble non-starch polysaccharides from wheat and rye

Abstract The water holding capacity of the dough and the freshness of the bread made of rye and wheat are much dependent upon their content of non-starch polysaccharides (NSP), most of which are polymers of xylose and arabinose, i.e. pentosans. The yield of water soluble pentosans from rye flour (1.76%) was higher than that of wheat flour (0.59%), and the xylose to arabinose ratio of rye pentosans was 1:36 while it was 1:16 for wheat pentosans. The galactose content in wheat pentosans was 17% of the total monosaccharides. In rye pentosans the content of galactose was lower (3.5% of the total monosaccharides). The total content of monosaccharides in wheat pentosans (65%) was slightly lower than that in the rye pentosans (71.7%). The weight average molecular weight of rye pentosans (770 000) was higher than that of the wheat pentosans (255 000). The number average molecular weight of the pentosans from rye was 90 000 while the corresponding figure for wheat was 61 000. The rye pentosans showed a higher degree of polydispersity in solution than the wheat pentosans. The separation of the pentosans on a DEAE-Sephadex column resulted in five fractions. The first two fractions contained mainly arabinose and xylose and the protein content in these fractions was ~1%. The protein content of the fractions increased with the increased concentration of the borate. The Xyl: Ara ratio was 2:23 and 2:39 in fractions I and II of wheat and 1:63 and 2:32 in fractions I and II of rye. Galactose appeared in fractions IV and V in wheat and fractions IV, V-A and V-B in rye along with some arabinose which suggests the presence of arabinogalactans in these fractions.

Saponins, phytic acid, tannins and protease inhibitors in quinoa (Chenopodium quinoa, Willd) seeds

Abstract The seeds of quinoa ( Chenopodium quinoa , Willd), a food crop of the Andean region of Latin America, contain protein of good quality and high amounts of carbohydrates, fat, vitamins, and minerals. An industrial process for manufacturing infant food using quinoa as a basic raw material is being developed. The presence of antinutrients are of importance in this context, and this paper deals with saponins, phytic acid, tannins and protease inhibitors in quinoa seeds. The samples of quinoa analysed in this experiment contained two main types of saponins. The amount of saponin A (β- d -glucopyranosyl -[β- d -glucopyranosyl -(1 → 3)-α- l -arabino- pyranosyl -(1 → 3)]-3-β-23- dihydroxy -12- en -28- oate methyl ester ) was 0·7% of the dry weight and that of the saponin B (β- d -glucopyranosyl -[β- d -glucopyranosyl -(1 → 3)-α- l -arabino- pyranosyl -(1 → 3)]-3-β-23- dihydroxyolcan -12- en -28- oate was 0·2% of the dry weight. These were the major saponins found in the quinoa bran collected while polishing the seeds. After scrubbing and washing, the level of saponin-A remaining in the seeds decreased to 0·31% of the dry weight, and saponin-B was completely removed by this process. The content of phytic acid in the quinoa seeds was about 1% of the dry matter, and scrubbing and washing reduced the phytic acid content of the seeds by about 30%. Neither protease inhibitor nor tannins were detected in the quinoa seeds.

Properties of starch and dietary fibre in raw and processed quinoa (Chenopodium quinoa, Willd) seeds

We investigated certain properties of starch in raw and in heat-treated samples of quinoa, properties that are of importance to the nutritional quality of an infant food currently being developed. Scanning electron microscopy of the starch in raw seeds showed polygonal granules (0.6 to 2.0 µm diameter) to be present both singly and as spherical aggregates. Thermograms (DSC) of the flours showed one transition phase for gelatinisation of the starch and another for the amylose-lipid complex. The gelatinisation temperature of the starch was 67°C. Cooked samples manifested the highest degree of gelatinisation (97%), followed by the drum-dried (96%) and autoclaved (27%) samples. Separation of the starch on a SEPHAROSE CL-2B column showed the quinoa starch to be affected by the heat treatment, manifesting changes in the degree and extent of degradation. The amylograph viscosity of the quinoa flour showed no distinct peak for pasting, but the viscosity remained constant after gelatinisation. Cooking and autoclaving modified the viscosity of the paste. The drum-dried sample manifested a higher initial viscosity at 25°C. Thein vitro digestibility of raw quinoa starch determined by incubation for 60 min with α-amylase was 22%, while that of autoclaved, cooked and drum-dried samples was 32%, 45% and 73%, respectively. Saponins did not affect the digestibility of the starch, though they tended to increase the amylograph viscosity. The total dietary fibre content in the cooked sample (11.0%) was significantly lower than that in the autoclaved (13.2%), drum-dried (13.3%) or raw samples (13.3%), while the insoluble dietary fibre fraction in the samples did not change with heat treatment. However, as compared with that of raw quinoa, the soluble dietary fibre fraction was reduced significantly both by cooking (0.9%) and by autoclaving (1.0%).

Certain physical properties of water soluble non-starch polysaccharides from wheat, rye, triticale, barley and oats

The yield of water soluble non-starch polysaccharides (WSNSP) prepared from whole grains of wheat, rye, triticale, barley and oats was 0.6, 1.8, 0.7, 1.2 and 1.0% respectively of the dry matter. Th ...

Binding of mineral elements by some dietary fibre components - In vitro (II)

Abstract The binding of copper, cadmium and zinc ions to some soluble and gelforming types of dietary fibre (guar gum, low and high methoxylated pectin and sterculia gum) has been investigated potentiometrically. Considerable binding was found to low methoxylated pectin, but the binding to sterculia gum and high methoxylated pectin was less pronounced. The binding to guar gum was negligible. Thus, the formation of complexes seemed to be due to the proportion of free carboxyl groups. The amount of added metal bound to sterculia gum was proportional to the fibre concentration, whereas the pectins showed increased binding at higher fibre concentrations. This was possibly due to intermolecular interactions between the polymers and metal ions. The order of complex formation ability to the fibres investigated was different for different metals. To low methoxylated pectin the order Cu>Zn ⪢ Cd was observed.

The nutritional quality of an infant food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in undernourished children

An infant food product was manufactured by drum drying a pre-cooked slurry of quinoa (Chenopodium quinoa, Willd) flour. The chemical composition shows that the product is a potential source of valuable nutrients, like protein (16%), vitamin E (19 mg/kg), thiamine (0.7 mg/100 g), iron (70 mg/kg), zinc (48 mg/kg) and magnesium (1.8 g/kg), all the values expressed on dry basis, to pre-school children (of 5 years of age). The animal feeding experiments with rats showed a net protein utilisation (NPU) of 68, digestibility (TD) 95 and biological value (BV) 71. The level of insulin-like growth factor-1 (IGF-1) in the plasma of the children who consumed a supplementary portion of 2 × 100 g of the above infant food product showed an increase after a period of 15 days, while the plasma level of IGF-1 in the children of the control group as well as the reference group did not show any significant increase.

Effect of processing on the content of β-N-oxalyl-α, β-diaminopropionic acid (gb-ODAP) in grass pea (Lathyrus sativus) seeds and flour as determined by flow injection analysis

Abstract The effect of cooking, roasting, autoclaving and fermentation on the content of β-ODAP in the whole seeds and flour of grass pea (Lathyrus sativus) were studied at different levels of temperature, time, pH, degree of soaking and moisture content. The method of determination used was flow injection analysis, with immobilised glutamate oxidase and horseradish peroxidase. The whole seeds flour was found to contain about 922 mg 100g−1 β-ODAP in dry weight basis. The reduction of β-ODAP content, in samples which were cooked for 60min and roasted (150 °C for 60min) was 57% and 82%, respectively. The content of β-ODAP in dry seeds autoclaved for 30 min also showed a significant (p = 0.05) reduction by 39%, as compared to that of raw whole seeds. Similarly, by cooking of presoaked seeds the content of β-ODAP was reduced by up to 67%. Neither the back-slopped fermentation process nor the spontaneous fermentation were effective in reducing the content of β-ODAP. Whereas roasting and autoclaving of the milled samples caused significant (p = 0.05) reduction in the content of β-ODAP up to 30% and 50%, respectively, compared to that of raw whole seeds.