Shelf life of weaning foods developed from locally available food stuffs

Four weaning foods were formulated using locally available cereals and pulses such as wheat (Triticum aestivum), barley (Hordeum vulgare), green gram (Vigna radiata) and jaggery. Cereal, pulse and jaggery were used in the proportion of 70:30:25. Roasting and malting were two processing techniques used. The developed weaning foods were evaluated for their nutritional characteristics and shelf life. All the formulations had a nutrient composition within the range prescribed by the Indian Standard Institute (ISI) for processed weaning foods. Peroxide value and fat acidity of weaning foods increased with increase in storage period. Malting of weaning foods resulted in higher increase of peroxide value and fat acidity as compared to roasted ones during the period of storage. All the blends were found to be acceptable up to 60 days of storage. The results, indicated that weaning foods developed from locally available less inexpensive foods may be used as good supplements for infants.     

Improvement in HCl-extractability of minerals in home made weaning foods

Three weaning foods were formulated from locally available cereals and pulses such as rice (Oryza sativa), kangini (Setaria italica), sanwak (Echinochloa frumentacea), green gram (Vigna radiata) and jaggery. Cereals and pulses were mixed in the proportion of 7:3. Nutrient composition of developed weaning foods was within range prescribed by Indian Standard Institute and was found to be acceptable. Roasting was the processing technique employed in developing weaning foods which resulted in significant increase in HC1-extractable minerals, an index of their bioavailability to humans. The higher HC1-extractability of the minerals may be ascribed to the decreased phytic acid in the processed home made weaning foods.     

Protein quality of weaning foods based on locally available cereal and pulse combination

Locally available cereals and pulses such as rice (Oryza sativa), kangini (Setaria italica), sanwak (Echinochloa frumentacea), green gram (Vigna radiata) and jaggery were used to formulate three weaning foods. Cereal, pulse and jaggery were mixed in the ratio of 70:30:25. Roasting was the main processing technique used in the formulation of these weaning foods. The developed weaning foods had 5.06 to 5.68 g moisture, 10.28 to 13.71 g protein, 2.91 to 3.77 g ash, 1.08 to 1.87 g fat, 14.42 to 14.98 mg iron, 1.03 to 1.27 g crude fibre, and 357 to 374 Kcal. The weaning foods had a nutrient composition within the range prescribed by the Indian Standard Institute for processed weaning foods. The study indicated that the weaning foods obtained from locally available food stuffs have the potential of being produced locally, adaptable for household consumption and can be good substitute for commercial formulae.     

Relationship between dietary fiber levels and protein digestibility in selected foods as determined in rats

Samples of 15 food products and feces obtained by feeding them to rats were analysed for dietary fiber fractions. The food products were added as the sole source of protein in 8% protein diets, making up 8.8–51.6% of the diets. Diets were supplemented with 0.54–5.00% purified cellulose to make them more comparable in total fiber. Fiber analyses of food products revealed that the protein sources provided 0.06–7.27% total dietary fiber. The true protein digestibility in rats was negatively correlated with the total food fiber level (r=–0.69,P<0.01) or with the food cellulose level (r=–0.82,P<0.01) but it was positively correlated (r=+0.81,P<0.01) with the purified cellulose level. No relationship was found between protein digestibility and fiber fermentability. Results indicate that several food fiber fractions and possibly associated substances influenced protein digestibility. Purified cellulose did not have the same physiological behavior as food cellulose from the viewpoint of protein digestibility and fiber fermentability.     

Digestibility of proteins and starch (in vitro) of amphidiploids (black gram×mung bean) as affected by domestic processing and cooking

The effects of different domestic processing and cooking methods on starch digestibility (in vitro) and protein digestibility (in vitro) of four strains of amphidiploids (black gram×mung bean) were investigated. An increase of 35 to 48% and 22 to 25% was observed in starch digestibility and protein digestibility, respectively, when the seed of amphidiploids were soaked for 18 h. Cooking (both of unsoaked and soaked seeds) and germination improved significantly the starch digestibility and protein digestibility of all the varieties.     

Nutritional quality of germinated cowpea flour (Vigna unguiculata) and its application in home prepared powdered weaning foods

Amino acid profiles, protein digestibility corrected aminoacid scores (PDCAAS), chemical scores, essential amino acid indexes, andcalculated biological values of control-cowpea flour (CCF), germinated cowpeaflour (GCF) prepared from cowpeas germinated at 25 ^°C for either24 h or 48 h and weaning foods prepared from cowpea flours weredetermined. Locally available rice, cowpea flour, banana-pumpkin slurry,and skim milk powder and sucrose in the ratio 35:35:15:15:5 were used to formulateweaning food containing not less than 15% protein. The ingredients werecooked into a slurry and oven-dried to produce flakes. The nutritional andsensory qualities of the weaning products were evaluated. Germination hadlittle effect on the amino acid profile of cowpeas. In vitro proteinquality and starch digestibility were improved in germinated cowpea flour. The PDCAAS of 24 h germinated cowpea flour (GCF) weaning food washigher (55.49%) than CCF-weaning food (46.74%). Vitamin A activityin 24 h GCF weaning food was higher than in CCF-weaning food. Invitro starch digestibilities of 24 h GCF and 48 h GCF-weaning foods werehigher than that of CCF weaning food. The 24 h GCF-weaning food which hada higher overall acceptability score by sensory panelist than 48 h GCFand CCF-weaning food is recommended for household consumption.     

The nutritive value of amaranth grain (Amaranthus caudatus)

Digestibility of dietary fibre (DF) and energy of three pale-seeded and one darkseeded variety ofAmaranthus caudatus were studied in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 8% of DF and the black seeds about twice as much. The soluble DF fraction made up 33–44% of the total DF (TDF) fraction in the pale-seeded varieties, but only 18% in the black seeds. The monomer sugar composition of the DF was very similar in all products. However, the black seeds were very high in lignin, and DF of the black-seeded products were more resistant to digestion than that of the pale-coloured products. In the pale amaranth products digestible energy (DE) varied between 86 and 91%. In the dark-seeded products DE was lower, and there was a significant negative correlation (r=–0.92) between DE and TDF. Processing of pale seeds had only minor effects on TDF and DE, but increased the proportion of soluble DF and the digestibility of DF in one variety. The food intake tended to be lower in rats fed raw pale seeds compared with those consuming processed products, indicating the presence of heat-labile factors reducing palatability.In conclusion, the pale seeds had a lower content of DF than most cereal grains and the DF was more easily digested. As a source of energy, amaranth grains seem to be comparable to other cereals.     

Influence of phytate on in vitro digestibility of casein under physiological conditions

The phytic acid content of four different varieties of beans under different processing conditions was estimated. It was highest in red kidney (1.86–2.13%) slightly lower in pigeon (1.86–2.03%), white (1.80–1.96%) and black eyed beans (1.15–1.64%). There was no significant change in phytic acid content of beans after soaking at 25°C for 22 hours. However, both soaking and cooking revealed 26–37% loss of phytic acid in all four varieties of beans.The rate of in vitro casein digestibility with and without phytic acid at concentrations found in legumes was determined at pH 8 and 37°C using multienzyme technique. Addition of 5 mg Na-phytate reduced the casein digestibility up to 20% compared to the control. However, only 25% reduction of casein digestibility was observed in the presence of 25 mg of Na-phytate. Higher concentration of Na-phytate had no significant effect on the rate of casein digestibility. Data strongly suggest the formation of protein phytate complex at alkaline pH of small intestine.Part of this work was presented at the XIII International Congress of Nutrition in Brighton, UK in August 1985.     

Nutritional and Antinutritional Characteristics of Seven South Indian Wild Legumes

Seeds from seven species of wild legumes of the South India were analyzed for proximate composition, mineral profiles, amino acid profiles of total seed protein, in vitro protein digestibility, and certain antinutritional factors to assess their potential as alternative sources of protein crops. The major findings of the study were as follows: crude protein ranged from 20.3 to 35.0%, crude lipid 3.1–9.6%, crude fiber 5.9–12.1%, ash 2.7–5.1%, and carbohydrates 49.2–61.8%. Minerals viz., sodium, potassium, calcium, magnesium, phosphorus, iron, copper, zinc, and manganese occurred in the range 42.9–135.9, 556.2–1639.5, 304.5–572.2, 174.9–686.7, 98.4–947.8, 3.6–16.4, 0.2–1.2, 2.0–30.0, and 1.0–3.9 mg/100 g seed flour, respectively. Profiles of amino acids of total seed proteins detected in the present study revealed that levels of valine, phenylalanine, tyrosine, isoleucine, and histidine of all the seven wild legume seed samples, threonine of Canavalia ensiformis and C. gladiata, leucine of Mucuna pruriens var. pruriens, and lysine of Cassia floribunda and C. obtusifolia were found to be higher than FAO/WHO (1991) requirement pattern. The in vitro protein digestibility of the legumes under study ranged from 63.39 to 83.32%. Antinutritional factors such as total free phenolics ranged from 0.41 to 5.96%, tannins from 0.04 to 0.60%, L-DOPA from 1.34 to 8.37% and trypsin inhibitor activity from 13.48 to 65.43 TIU/mg protein. The detected antinutritional factors probably have little nutritional significance if the seeds are properly processed.     

Chemical composition,in vitro protein digestibility andin vitro available iron of blue green alga,Nostoc commune

Blue-green alga,Nostoc commune, contained moderate amounts of protein and iron. Itsin vitro protein digestibility was 43–50%. The soluble and ionic iron from the alga was extractable to some extent at pH 1.5 but was not detectable at pH 8.0. The digestion by protease did not affect the iron detection. Heat processing at 100 and 120°C failed to increase the digestibility and the content of available iron. The dietary fiber in the alga may be responsible for low protein digestion and low iron availability.     

Optimization of the solid state fermentation process to obtain tempeh from hardened chickpeas (Cicer arietinum L.)

Solid state fermentation (SSF) represents a technological alternative for a great variety of cereals and legumes, orcombination of them, to improve their nutritional quality and to obtain edible products with palatable sensorial characteristics. The objective of this work was to find the best conditions of fermentation temperature and time to obtain tempeh from hardened chickpeas (Cicer arietinum L.) applying SSF. Response surface methodology(RSM) was applied over three response variables (phytic acid, in vitro protein digestibility and available lysine) to find best conditions of fermentation to carry out the process. A central composite experimental design with two factors [X₁ = temperature (31–36 ^°C) and X₂ = time (48–72 h)] in five levels (2 factorials,2 axial, I central) was used. Spores from Rhizopus stolonifer were suspended in distilled water (1 ×10⁶ spores/mL) and used as starter. According to regression models, minimum and maximum levels of the response variables were 1.24–2.66 mg phytic acid/g ofsample DM, 77.6–83.5% in vitro protein digestibility and2.18–4.63 g available lysine/16 g N. The superposition ofcontour plots of each one of the response variables allowedresearchers to find, graphically, the best conditions for the SSF process: 35.8 ^°C for 42.7 h.     

Nutritional evaluation of some commercial wheat varieties grown in Pakistan

The nutritive value of some commercial wheat varieties grown in Pakistan was measured chemically, including amino acid analysis, and biologically in N-balance experiments with growing rats. The protein content ranged from 13.2% in Punjab-83 to 16% in Barani-83. Lysine per 100g protein varied between 2.46 and 2.75%. The available carbohydrate ranged from 67.3 to 74.7%. Iron content was highest in Sonalika while the concentration of zinc and manganese was highest in Sarhad-82. The protein digestibility (TD), biological value (BV) and net protein utilisation (NPU) varied between 92–95%, 56–68% and 53–65% respectively. Level of wheat protein was negatively correlated with available carbohydrate (r=–0.93), lysine per unit protein (r=–0.67) and BV (r=–0.76). The lysine content (g/16gN) of commercial wheat varieties showed a positive correlation (r=+0.95) with the BV. The protein quality was lowered in varieties having higher content of protein.     

Evaluation of the selenium and chromium content of plant foods

In the present study the selenium and chromium content of different plant foods such as fruits, greens, flowers, vegetables, dried fruits, spices, condiments, cereals and pulses were analysed. The selenium values for cereals indehiscent vegetables, root vegetables, stem vegetables, pulses, fleshy vegetables, greens, fleshy fruits, condiment seeds, spices and dried fruits ranged between 24.2–32.16, 2.4–18.9, 2.8–21.5, 3.0–32, 48.7–92.5, 1.25–9.5, 3.0–8.2, 2.0–9.4, 6.2–66.2, 6.2–17.5 and 3.5–16.8 g/100 g respectively. The chromium values for the same ranged between 48.2–52.6, 31.0–45, 21.2–25.7, 23.7–62.8, 15.0–43.5, 20.4–65, 14.2–42.1, 14.25–46.7, 58.4–150 and 96–168 g/100 g respectively. Thus dried fruits have the highest chromium content and pulses the highest selenium content.     

Digestibility of protein and amino acids in selected foods as determined by a rat balance method

Values (%) for true digestibility of crude protein and individual amino acids in 20 selected foods were determined by the rat balance (fecal) method. The products were fed as the sole source of protein in diets containing 8% crude protein (N × 6.25). Lowest true protein digestibility values (79–84) were obtained for pinto beans, kidney beans and lentils; intermediate values (89–92) were obtained for chick peas, beef stew, skim milk (over heated), rolled oats, whole wheat cereal, and pea protein concentrate; and highest values (94–100) were obtained for sausage, macaroni-cheese, rice-wheat gluten cereal, skim milk, tuna, soy isolate, peanut butter, chicken frankfurters, beef salami, casein and casein + methionine. In animal foods, peanut butter and soy isolate, the differences between true digestibility of crude protein and most individual amino acids were less than 5%. However, the values for true digestibility of methionine and cystine were up to 44% lower than those of crude protein in pinto beans, kidney beans, lentils, chick peas and pea concentrate. In these legumes, digestibility of crude protein was not a good predictor of digestibility of the limiting amino acids.     

Effects of soaking in aqueous acidic and alkali solutions on removal of polyphenols and in vitro digestibility of cowpea

Mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) UPL Cp 3, were subjected to several soaking treatments to remove their polyphenols. Soaking in water at room temperature for 8 and 24 h resulted in 17% and 21% loss of assayable polyphenols, respectively. Dilute solutions of alkali (Na₂CO₃, NaHCO₃, NH₄OH and KOH) and acid (CH₃ COOH, HCl and H₂ SO₄) were more effective in removing polyphenols up to 88% than higher concentrations of alkali and acid solutions.Vinegar (0.005–0.65 M CH₃ COOH) decreased polyphenols from 55 to 62% with a 6 to 14% improvement in in vitro protein digestibility (IVPD). Commercial lime (65% CaO) removed polyphenols from seeds soaked for 8 to 24 h by 70% with 2 to 10% increase in in vitro protein digestibility. Ash removed 40 to 60% of the polyphenols after 8 and 24 h of soaking with an increase in IVPD of 7 to 13%. Total polyphenols were significantly correlated (+0.92**) with protein precipitable polyphenols (condensed tannins).     

Content of antinutrients and in vitro protein digestibility of the African yambean,pigeon and cowpea

The protein, trypsin inhibitor (TI), tannin, phytate, phytic acid phosphorus and in vitro protein digestibility (IVPD) of cultivars of the African yambean (Sphenostylis stenocarpa) — AYB, pigeon pea (Cajanus cajan) — PP and cowpea (Vigna unguiculata) — CP were determined. The protein content of CP (24–28.0%) was higher than those of PP (21–22.5%) and AYB (21–22.5%). The cream and speckled AYB contained more TI (30.9 and 25.3 mg/g) than PP (7.5–14.1 mg/g) and CP (9.8–20.5 mg/g). Apart from the white CP cultivar, they contained more tannin (1.24–1.42 mg/g) than PP (0.14–0.97 mg/g) and AYB (0.71–1.17 mg/g). Phytate was lowest in the AYB (6.30–7.49 mg/g) than PP (8.31–11.31 mg/g) and CP (8.40–9.92 mg/g). Phytic acid contributed 67–74% of the phosphorous in the AYB, 66–75% in PP and 54–59% in CP. The IVPD of the AYB (73.3±0.7%) was significantly lower (p<0.05) than those of PP (76.34±0.2%) and CP (77.8±0.4%). There was a significant negative correlation between TI and IVPD (r=–0.63,p<0.05). There was no significant correlation between IVPD and phytate and tannin contents. There was a positive correlation between protein content and IVPD (r=0.69**) for the legumes under study. These legumes may pose no serious problems to populations consuming them especially when heat treatment is applied before consumption.     

Development,acceptability and nutritional value of weaning mixtures

Low cost weaning mixtures were prepared by mixing (i) malted pearl millet (Penicitum typhidium L), roasted amaranth (Amaranthus sp.); roasted green gram (Vigna radiata); jaggery and (ii) malted barley (Dehusked barley); roasted amaranth grain; roasted green gram; jaggery in proportion 60204045 wt/wt and were nutritionally evaluated. Both the blends had a nutrient composition within the range prescribed by the Indian Standard Institute (ISI) for processed weaning foods. The processing of grains resulted in lower levels of phytic acid, polyphenols and saponins and higher in vitro protein digestibility than those of the raw grains used for preparing mixtures. Both the mixtures were acceptable to trained panelists and children.     

Relationship between amino acid scores and protein quality indices based on rat growth

Protein efficiency ratio (PER), relative PER (RPER), net protein ratio (NPR) and relative NPR (RNPR) values, and amino acid scores were calculated for 20 food products (casein, casein + Met, beef salami, skim milk, tuna, chicken frankfurters, sausage, heated skim milk, peanut butter, rolled oats, soy isolate, chick peas, pea concentrate, kidney beans, wheat cereal, pinto bean, lentils, rice-wheat gluten cereal, macaroni-cheese, and beef stew). In most cases, PER, RPER, NPR or RNPR ranked the products in the same order and positive correlations among the protein quality methods were highly significant (r=0.98–0.99). Amino acid scores (based on the first limiting amino acid, Lys-Met-Cys, Lys-Met-Cys-Trp or lys-Met-Cys-Trp-Thr) were positively correlated to the PER, RPER, NPR or RNPR data (r=0.61–0.75). Inclusion of the correction for true digestibility of protein improved the correlations between amino acid scores and the indices based on rat growth. The correlations were especially high between Lys-Met-Cys scores (corrected for true digestibility of protein) and PER, RPER, NPR or RNPR (r=0.86–0.91). Inclusion of the correction for true digestibility of individual amino acids did not result in further improvements of the correlations in most cases. It is concluded that adjusting amino acid scores for true digestibility of protein would be sufficient and further correction for digestibility of amino acids would be unnecessary in mixed diets.This paper was presented in part at the 71st annual FASAB meeting, Washington, DC, March 29–April 2, 1987.     

Effect of feeding some plant foods as source of dietary fibre on biological utilisation of diet in rats

Isoproteinous diets containing 1% cholesterol and 10% fibre derived from plant foods namely,peepalbanti (Ficus religiosa),barbanti (Ficus bengalensis),gullar (Ficus glomerata),teent (Capparis decidua) andkhejri beans (Prsopsis cineria) or pure cellulose, were fed to rats for 40 days. Effect of incorporation of these whole plant parts on feed intake, weight gain, feed efficiency ratio (FER), dry matter digestibility (DMD) and true protein digestibility (TPD) in weanling rats was studied. Their inclusion did not affect the weight gain significantly whereas all other parameters were influenced to a varying extent. Foods rich in lignin had relatively lower FER, DMD and TPD whereas cellulose and pectin rich foods had higher DMD and TPD.     

A preliminary study on the use of tempe-based formula as a weaning diet in Nigeria

Tempe, an Indonesian mold fermented food, was prepared from cowpeasand soybeans using the traditional oriental process with modifications whereappropriate. Four complementary foods were developed from whole maizemeal or dehydrated fermented maize (ogi) flour fortified with eithercowpea tempe or soybean tempe. Wholesomeness and potentials of thevanilla-flavored foods as weaning diets were determined. The nutrientcontent of all the developed products were within the range prescribed bythe FAO/WHO pattern for processed weaning foods. The products hadloose bulk densities between 0.40–0.55 g/ml and packed bulk densitiesbetween 0.68–0.75 g/ml; reconstitution indexes were between92.30–104.00 g/ml; viscosities were 34.2–65.0 CP at 70 ^°C and45.0–76.9 CP at 30 ^°C. Total plate counts ranged from 3.2 ×10³ – 4.3 × 10⁴cfu/g; coliforms staphylococcus, mold, andyeast were absent in some of the products. The results on sensoryattributes showed that tempe-based weaning diets were comparable withMameal, a commercial product. Maize and maize-fortified diets wereslightly higher in packed bulk density. Fortification reduced the viscosityof the diets and the values reduced with increasing temperature. Tempe-based weaning foods reconstituted easily in hot water, while cookingdestroyed most of the microorganisms present. Maize-based tempefortified foods were relatively inexpensive and have potential as weaningfoods.