Effect of heat processing on in vitro protein digestibility and some chemical properties of African breadfruit (Treculia africana Decne) seeds

The effects of dry heat (roasting) and moist heat (boiling) on in vitro protein digestibility, protein fractions and other chemical properties of African breadfruit (Treculia africana Decne) seed that affect their utilization as a source of human food were investigated. Chemical analyses showed that the crude protein and fat contents of the unprocessed (raw) seeds were 20.1% and 13.7%, respectively. The level of phytic acid in the raw seed (1.19 mg/g) was lower than the levels found in some commonly consumed pulses in Nigeria. Albumin and globulin protein fractions were found to be the major seed proteins of African breadfruit seed, constituting 67.8% of the total protein of the raw seed. There were no significant (p<0.05) differences between crude protein, ash and fat contents of the raw and heat processed samples. Boiling proved more effective than roasting for improving protein digestibility and for reducing the levels of trypsin inhibitor, phytic acid and polyphenols of the samples. The complete removal of these antinutrients, however, would require a more severe heat treatment of the seed, which in turn would profoundly reduce the nutritional value and availability of proteins, as demonstrated by the low values obtained for in vitro protein digestibility, protein fractions and protein extractability.     

Irradiation and germination effects on phytate,protein and amino acids of soybean

Influence of irradiation (0.05–0.20 kGy) and germination (24–120 hours) in distilled and tap water on phytate, protein and amino acids of soybean, was studied. Phytate values significantly decreased with increasing germination period and irradiation dose (P<0.01). Irradiation independently decreased the original phytate (212.0 mg/100 g) to a range value of 205.0–190.0 mg/100 g depending upon dose level. Germination of unirradiated seeds for 120 hours in distilled and tap water lowered the phytate to 55.0 and 94.9 mg/100 g (74.1 and 55.2% reduction) respectively. Maximum destruction of phytate to levels of 20.5 and 50.9 mg/100 g (90.3 and 76.0% reduction) occurred during germination of 0.20 kGy samples for 120 hours in distilled and tap water respectively. Total protein content significantly increased during germination (P<0.05) and the increase was more in tap than distilled water. Germination for 120 hours of untreated seeds in tap water increased the essential and decreased non-essential amino acids while in the 0.10 kGy sample, increases in both cases were observed.     

Cultivar and processing effects on the pasting characteristics,tannin content and protein quality and digestibility of cowpea (Vigna unguiculata)

Four popular West African local cultivars of cowpea (Vigna unguiculata), with distinctly different seed coat colors, were evaluated for their relative amylograph pasting characteristics, condensed tannin content, in vitro protein digestibility and Tetrahymena protein efficiency ratio (t-PER). The effects of roasting and dehulling on these properties were also determined. There were wide variations in the hot paste viscosity characteristics of the different cultivars studied. The raw cowpea flour samples exhibited maximum paste viscosities ranging between 260 Brabender Units (BU) for the Mottled cultivar and 460 BU for the cream-colored Blackeye cultivar. Cowpea cultivars with the greatest peak viscosities showed low stabilities to extended cooking. Roasting depressed paste viscosity properties of all the cowpea cultivars studied. Tannin concentrations were 0.3–6.9 and 7.2–116 mg CE/g flour from whole cowpea seeds and seed coats respectively, increasing with intensity of seed color. Although dehulling removed 98% of the tannin content of raw cowpeas, improvement in protein quality as a result of dehulling was observed for only the highly-pigmented Maroon-red variety. Roasting significantly improved digestibility and more than doubled the t-PER of all cowpea cultivars studied. Roasted cowpeas possess adequate nutritional and functional qualities as protein supplements in cereal-based weaning foods. However, it appears that dehulling is necessary to enhance the nutritional quality of the highly pigmented cultivars of cowpea.     

Agrobotanical traits and chemical composition of Cassia obtusifolia L.: A lesser-known legume of the Western Ghats region of South India

Four accessions of the lesser-known legume, Cassia obtusifolia L. (Sickle pod), collected from four different agroclimatic regions of Western Ghats, were evaluated for agrobotanical traits and chemical composition. Amongthe four accessions, the Keriparai accession had the highest values for plant height (cm), number of flowers per cluster, number of pods per cluster, pod length (cm), seeds per pod, seed weight (g) per pod and seed recovery percentage. Crude protein ranged from 18.56–22.93%, crude lipid was between 5.35–7.40%, crude fiber ranged from 6.83–9.45%, ash content ranged from 5.14–5.83% and carbohydrate varied from 57.00–60.69%. Globulins constituted the bulk of the seed protein as in most legumes. Mineral profiles, viz., sodium, potassium, calcium, magnesium, phosphorus, iron, copper, zinc and manganese ranged from 42.92–84.83, 758.05–1555.79, 559.92–791.72, 456.36–709.47, 629.13–947.79, 8.42–12.35, 0.93–2.06, 10.60–30.04 and 2.12–4.12 Mg/100 g seeds flour, respectively. Seed proteins of all accessions exhibited relatively high levels of non-essential and essential amino acids, with the exception of threonine. The in vitro protein digestibility of the legume ranged from 74.66 to 81.44%. Antinutritional substances such as total free phenolics ranged from 0.34–0.66%; tannins were between 0.47–0.60%, L-DOPA content ranged from 0.98–1.34%; trypsin inhibitor activity varied from 11.4–13.5 TIU/mg protein and chymotrypsin inhibitor activity ranged from 10.8–12.3 CIU/mg protein. Phytohemagglutinating activity also was assayed. Inconclusion, the accessions of C. obtusifolia, collected from Western Ghats, South India, could serve as a low-cost source of some important nutrients for humans. The antinutritional factors might have little nutritional significance, if the seeds are processed properly.     

Effect of domestic processing,cooking and germination on the trypsin inhibitor activity and tannin content of faba bean (Vicia faba)

The effects of domestic processing methods like soaking for 12 h dehulling, ordinary cooking of whole as well as dehulled seeds at 151bs/inch² pressure for 15 and 25 min, and germination for 24, 36 and 48 h were observed on trypsin inhibitor (TIA) and tannin content of two varieties of faba bean viz. VH-131 and WF. A non-significant reduction in TIA was observed on soaking and dehulling, while tannins showed a reduction of 42 and 51% on soaking in VH 131 and WF, respectively. Dehulled seeds showed a decline in tannin content by 70 to 73% in two varieties. There was a significant reduction in TIA (75–76 per cent) and tannin (76–81%) on cooking, while autoclaving for 25 min almost completely eliminated both of these stress factors. Germination of seeds for 48 h led to a reduction of 64–65% in TIA and 90–91% in tannins, which was more than germination for 24 and 36 h. Soaked seeds gave positive results of both these antinutrients.     

Effect of domestic processing on the cooking time,nutrients, antinutrients andin vitro Protein digestibility of the African yambean (Sphenostylis stenocarpa)

The effects of processing (soaking, dehulling, fermentation and heat treatment) on the cooking time, protien, mineral, tannin, phytate and in vitro protein digestibility (IVPD) of the african yambean (AYB) were examined. The cooking time ranged from 90–155 minutes. Soaking reduced cooking time by about 50 percent. Soaking for 12 hours was the most appropriate to reduce cooking time, tannin and phytate levels. It improved in vitro protein digestibility (IVPD). Prolonged soaking (24 hours) decreased calcium (Ca) and iron (Fe) values by 19 percent and 35 percent, respectively. Dehulling showed that Ca, Fe, magnesium (Mg) and zinc (Zn) were concentrated in the seed coat of the AYB. The seeds soaked and dehulled retained Mg and Zn. Dehulling reduced tannin but had no significant effect on phytate and the IVPD of the AYB except for seeds soaked for 12 hours before dehulling. Soaking for 24 hours before dehulling significantly increased crude protein content by 16 percent (p<0.05). Blanching and roasting increased the IVPD by 8–11 percent. Fermentation had no effect on the crude protein, Ca, Fe, Mg and Zn but significantly reduced phytate content of the AYB. Fermentation had no advantage over heat treatment with respect to improving the in vitro protein digestibility of the AYB.     

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.     

Nutrient composition and biological evaluation of mesta (Hibiscus sabdariffa) seeds

Two varieties of mesta (Hibiscus sabdariffa) seeds were analysed for their proximate composition. Their protein (18.8–22.3%), fat (19.1–22.8%) and dietary fiber (39.5–42.6%) contents were found to be high. The seeds were found to be a good source of minerals like phosphorus, magnesium and calcium. Their lysine and tryptophan contents were also high. Sulphur containing amino acids were limiting in this seed protein and the chemical score of mesta seed protein was 40 and 57 for AMV-2 and Bhimili-1 varieties respectively. Mesta seed oil is rich in unsaturated fatty acids (70%), of which linoleic acid constituted 44%. Weanling rats were fed with 10% mesta seed protein before and after cooking for 4 weeks. Food intake of animals receiving raw mesta seed diets was significantly lower than those receiving cooked mesta seed diets as well as the casein control diet. Protein and dry matter digestibilities of raw and cooked mesta seed diets were lower than that of casein control diet. Cooking improved the food intake, gain in body weight, dry matter and protein digestibility of mesta seed diets. PER and NPU of cooked mesta seed diets were significantly higher than the corresponding raw diets. These results indicate that cooked mesta seed protein is of relatively good quality.     

Nutrient changes and antinutrient contents of beniseed and beniseed soup during cooking using a Nigerian traditional method

Evaluations of the effect of prolong cooking on the nutrient and antinutrient composition ofbeniseed and beniseed soup were carried out in this study. Proximate, mineral, vitamin A and C and antinutrient compositions of raw beniseed (BS-R), beniseed boiled (BSB) for 15, 30, 45 and 60 min and beniseed soup (BSS) cooked for the same intervals of time were assessed. Results of the proximate composition analyses showed that raw and boiled beniseed had lower moisture content (5.39-5.51%) than beniseed soups (10.06-15.20%). Nitrogen-free extract (total carbohydrates), fats and phosphorus contents were improved in both the boiled beniseed and beniseed soup while calcium and potassium were increased in the boiled seeds and soup samples respectively. Moisture (in the raw and boiled beniseed), ash, magnesium, zinc, iron contents in both the seed and soup were unchanged in all the samples. Vitamins A and C levels of both boiled beniseed and beniseed soup samples were reduced with increase in cooking time. Beniseed soup had higher protein contents than both the raw and boiled beniseed which decreased with increase in cooking time. Beniseed samples provided good sources of energy (572.97-666.05 kcal/100 g). Except for phytate, the levels of antinutrients tested were lower in the raw and boiled beniseed than in the soup samples which decreased with increase in cooking time. The results are discussed with reference to the effect of prolonged cooking on the nutrient requirements of consumers.     

Nutritional assessment of seed proteins in rice bean [Vigna Umbellata (Thumb.) Ohwi and Ohashi

Seeds of three rice bean accessions had 17.26 to 21.42% protein, 3.46 to 4.03% fat, 61.09 to 64.73% carbohydrates 3.99 to 4.58% ash and 5.22 to 7.43% fiber (dry weight basis).The most limiting amino acids in the seed meal, albumin and globulin fractions, were methionine and cysteine with chemical scores of these fractions being 38% to 59%. The amino acid pattern of globulin and seed meal were similar.Thein vitro protein digestibility (IVPD) ranged from 82 to 86% for the seed meal, 86 to 88.5% for the albumin and 75.9 to 83.3% for the globulin. Relative nutritive values (RNV) of raw mature seed of two accessions were 22.6% and 42.4% and increased to 55.6% to 79.4% after boiling and roasting.Part of MS thesis of the senior author.     

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.     

Composition and functional properties of unprocessed and locally processed seeds from three underutilized food sources in Nigeria

Chemical and functional properties of unprocessed (raw) and locally processed seeds ofBrachystegia eurycoma, Detarium microcarpum andMucuna sloanei that affect their utilization as sources of human food were investigated. The seeds, which are underutilized food sources in Nigeria, were subjected to local processing methods which included roasting, boiling, dehulling/shelling, soaking and the changes in composition and functional properties were estimated. Chemical analyses showed that the crude protein contents of the raw seeds ranged from 12.2 to 23.2%; fat varied from 4.9 to 12.0%. The level of phytic acid in the raw seeds (192.4–215 mg/100 g) was observed to be lower than the levels found in some commonly consumed pulses in Nigeria. There were no significant differences (p>0.05) between crude protein contents and the least gelation concentrations of the raw and processed samples, but processing (roasting, boiling, dehulling and soaking) significantly (p=0.011) improved in vitro protein digestibility, water and fat absorption capacity and decreased the bulk density, nitrogen solubility and the phytic acid and polyphenol contents of the samples. Processed samples had high water (3.4–3.8 g/g) and fat (1.8–2.1 g/g) absorption capacities and hence may be useful as functional agents in fabricated foods such as bakery products and ground meat formulations.     

Chemical composition of the underutilized legume Cassia hirsuta L.

Seven accessions of the underutilized legume, Cassia hirsuta L., seeds collected from seven different agroclimatic regions of Tamil Nadu, India, were analyzed for proximate composition, total proteins, protein fractions, mineral profiles and selected antinutritional factors. Crude protein ranged from 15.52 to 20.74%, crude lipid 3.77–7.04%, crude fiber4.68–6.92%, ash 3.98–6.42% and carbohydrates 62.45–70.16%. Energyvalues of the seeds were 1549–1634 kJ/100 g (DM), which are comparable to those of other legumes. Data on seed protein fractions revealed thatglobulins constituted the bulk of the seed protein as in most legumes. Mineralcontents of the seeds showed greater variation. Potassium was the mostabundant mineral (1029–1786 mg/100 g), whereas manganese was low (2.1–2.2 mg/100 g). Antinutritional factors such as total free phenolics,tannins, L-DOPA and lectins were analyzed. The results of the studydemonstrated that the accessions of C. hirsuta seeds collectedfrom Tamil Nadu, India, could be good sources of some important nutrientsfor humans.     

Preparation and properties of flours and protein concentrates from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds

In vitro protein digestibility, chemical composition and selected functional properties of flours and protein concentrates prepared from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds were studied. Protein concentrates prepared by an alkaline extraction process had increased crude protein contents (61.5–70.8%) compared to flour samples (46.4–52.7%). The yields of protein concentrates ranged from 24.5% to 29.4% while values for protein recoveries varied between 64.8% and 65.2%. Protein concentrates also had increased foam volume and decreased foam stability (100% decrease over a 2 h period), compared to flour samples. Fermentation and germination were observed to significantly (p<0.05) lower polyphenol and phytic acid contents, but increased protein digestibility of fluted pumpkin seed flours and concentrates. Both raw flour and concentrate were significantly (p<0.05) higher in water absorption capacity than germinated or fermented flours and concentrates. Protein concentrates had comparatively better fat absorption properties than the flour samples. Hence protein concentrates may prove to have useful applications in ground meat formulations.     

Comparative studies on the storage proteins and anti-nutritional factors from seeds ofPsophocarpus tetragonolobus (L.) DC from five South-East Asian countries

The seeds of 27 varieties ofP. tetragonolobus from six regions of South-East Asia have been examined by polyacrylamide gel electrophoresis. No marked variations in the electrophoretic patterns were found which could be exploited by plant breeders to improve nutritional quality with respect to sulfur containing amino acids. The amino acid compositions of varieties from the different regions showed little variation. Seed extracts of all 27 varieties ofP. tetragonolobus showed trypsin and chymotrypsin inhibitory activities, and hemagglutinating activities. The levels of trypsin inhibitory activities showed some genotypic differences varying from 22.2 to 42.5 mg trypsin inbibited g^?1 of seed meal. As a group the varieties from Malaysia showed the lowest levels of trypsin inhibitor. The chymotrypsin inhibitory activity also showed a similar variation (30.1–47.6 mg chymotrypsin inhibited g^?1 of seed meal). Seed extracts agglutinated type O⁺ and B⁺ human and rabbit erythrocytes with little difference in activity between varieties. Autoclaving winged bean seed meal prior to protein extraction inactivated the anti-nutritional factors and resulted in considerable reduction of protein solubility.     

Screening soybean (grain and vegetable) genotypes for nutrients and anti-nutritional factors

Fifty six genotypes of grain-type soybean and 17 genotypes of vegetable-type soybean collections were analyzed for protein and oil content, trypsin inhibitor, and lipoxygenase activities. The protein and oil content ranged from 36.9 to 47.9% and from 13.3 to 23.0% for different accessions in grain- and vegetable-type soybeans, respectively. Trypsin inhibitor and lipoxygenase activities ranged from 22.0 to 47.0 trypsin inhibitor units/mg meal and from 482 to 6265 lipoxygenase units/min/mg meal for grain- and vegetable-type soybeans, respectively. Significant correlations (r=–0.62 and –0.52,P<0.05) were found between protein and oil, and between protein and trypsin inhibitor. A significant positive correlation (r=0.42,P<0.05) was also calculated for oil and lipoxygenase activity. Several genotypes of soybean and vegetable soybean (plant introductions 423905, 417330, 417223, 171451, 200506, 200523, 417124, 227687, 203402, 445842, 203399, 423852, 416771, FC31927, Avoyelles, and Sooty) showed good nutritional potential and may be useful in a breeding program to improve the nutritional quality of soybean. Screening for essential amino acids, fatty acids, and trace minerals for selected genotypes is underway.     

Chemical composition and nutritional value of Mexican varieties of chickpea (Cicer arietinum L.)

Chemical composition and protein quality of the main chickpea varieties cultivated in Mexico were determined. The raw and cooked chickpeas analyzed were: Surutato, Surutato 77, Sonora, Sonora 80, Porquero, Macarena, Breve Duro and a mixture of broken seeds used mainly for animal feeding. The chemical composition of the raw chickpea studied was very similar; the average values of the nutrients were: ash 3.1±0.2, fat 5.0±1.0, protein 19.5±1.2 and fiber 3.7±2.1. Cooking diminished only the ash content and the Porquero variety was the only one that had a high content of crude fiber (9.1%). There was not found agglutinating activity to rabbit RBC in any of the raw chickpeas studied and the trypsin inhibitor activity average was 11.8±2.4 TUI/mg sample. Cooking destroyed 57% of this activity. Digestibility was the same in the raw and in the cooked chickpea (78%). There were not found significant differences in the PER values of the raw and cooked seeds: 1.65–2.30 and 1.80 to 2.61 respectively. The Surutato and Breve Duro varieties were statistically similar to the casein PER (2.5). It could be recommended to use these two varieties mainly for infant feeding.     

Method for analysis of fatty acid distribution and oil content on a single Lesquerella fendleri seed

Lesquerella fendleri is a developing oilseed crop suitable for temperate growing regions in the US. The seed oil is rich in lesquerolic acid (57%) and could serve as a domestic source of hydroxy fatty acids. A method for the analysis of fatty acids and total oil content of a half or single lesquerella seed was developed. Lesquerella seeds are small with 1000 seed weights around 0.6 g (half seed mass of 200–500 μg). Conventional analytical balances provide mass accuracy to ±40 μg which fails to provide sufficient accuracy/precession (4–40% mass error) for the initial seed mass. A microbalance which measures to ±2 μg provided good reproducibility in initial seed weights but was not suitable for mass balance of the extracted oil. A normal phase HPLC coupled to an evaporative light scattering detector gave good response for oil in the mass range of 22 μg to 110 μg/mL. Therefore, micelle concentrations from single or half seed extractions could be determined with good reproducibility. This method was then evaluated on bulk seed that had been fractionated on a gravity table. Gravity table fractionation of L. fendleri seeds obtained from a large field plot provided seven fractions with increasing bulk density. These fractions were then analyzed in sets of 30 individual seeds and as an aggregate of 50 seeds. Oil content for individual seeds varied widely (15.6–44.2%) as did lesquerolic acid content (42.2–63.7%). The mean oil content increased (27–33%) with increasing bulk density (684–745 g/L). The mean lesquerolic acid content did not correlate with bulk density.     

In vitro availability of iron and zinc in white and coloured ragi (Eleusine coracana): role of tannin and phytate

White and brown ragi (Eleusine coracana) varieties were analysed for tannin, phytate phosphorus, total phosphorus, iron, ionisable iron, zinc and soluble zinc content. White ragi had no detectable tannin while in brown varieties it ranged from 351 to 2392 mg per 100 g. Germination brought about a progressive decrease in tannin and phytate phosphorus and an increase in ionisable ion and soluble zinc content of grain ragi. Both in raw and germinated grain, ionizable iron was significantly higher in white than in brown varieties. While ionisable iron was inversely correlated with the level of tannin and phytate phosphorus, soluble zinc was negatively correlated with phytate phosphorus. After extraction of tannin, ionisable iron of brown ragi rose by 85%. On the other hand, in white varieties, addition of tannin extracted from brown ragi, resulted in a 52–65% decrease in ionisable iron content. These studies indicated that poor iron availability in ragi as judged by its low ionisable iron content was due to the presence of tannin in the grain.     

Protein quality of raw and autoclaved cowpeas: Comparison between some insect resistant and susceptible varieties

A comparative study was conducted with four improved cowpea (2 pod bug resistant and 2 susceptible) varieties to assess the effect of autoclaving at 105°C under 15 psi for 30 min on their protein quality, as measured by the levels of some antinutritional factors and performance of rats fed the different cowpea diets. Also, the relationships between antinutrients in the cowpeas and protein quality indicators were examined. Results showed that autoclaving completely eliminated trypsin inhibitor, hemagglutinin and HCN, whereas it reduced significantly (p<0.01) the levels of phytic and tannic acids in the cowpeas. In both raw and autoclaved forms, the insect susceptible cowpeas were better (P<0.05) utilized than their resistant counterparts, a condition which was attributable to lower levels of antinutrients in the susceptible varieties. In the raw cowpeas, trypsin inhibitor, hemagglutinin and HCN were significant variables affecting cowpea protein utilization, while in autoclaved samples, tannic and phytic acids were important though nonsignificant (P>0.05) factors. It was concluded that autoclaving at the above temperature and time improved the protein quality of the insect susceptible more than the insect resistant cowpea varieties.