Perumal Siddhuraju

Studies on the antioxidant activity of Indian Laburnum (Cassia fistula L.): a preliminary assessment of crude extracts from stem bark, leaves, flowers and fruit pulp

Abstract The antioxidant properties of 90% ethanol extracts of leaves, and 90% methanol extracts of stem bark, pulp and flowers from Indian Laburnum ( Cassia fistula L.) were investigated. The antioxidant activity power was in the decreasing order of stem bark, leaves, flowers and pulp and was well correlated with the total polyphenolic content of the extracts. The reason for low antioxidant activity in the flower and pulp fractions could be the presence of some prooxidants, such as chrysophanol and reducing sugars which dominate the antioxidant compounds present in the extracts. Thus, the stem bark had more antioxidant activity in terms of reducing power, inhibition of peroxidation, O 2 −. and DPPH radical scavenging ability.

Evaluation of nutritional quality of moringa (Moringa oleifera Lam.) leaves as an alternative protein source for Nile tilapia (Oreochromis niloticus L.)

Abstract This study was conducted to evaluate the suitability of freeze-dried moringa leaf meal, Moringa oleifera, as an alternative protein source for Nile tilapia. Three experimental diets were formulated to contain moringa leaf meal at levels of 10%, 20% and 30% of the total dietary protein (Diets 2, 3 and 4, respectively) and one diet acting as a control (Diet 1) which included only fish meal and wheat meal as protein sources. All diets were isonitrogenous (35% crude protein) and isoenergetic (20 kJ g−1). A 7-week feeding trial was carried out on triplicate groups of seven fish (9–11 g) in 45-l aquaria connected to a recirculating system. The daily fish ration was calculated at 15-g feed per metabolic body weight (kg0.8) per day (about five times maintenance). No feed-related mortality was observed during the whole experimental period. Diets with higher inclusion levels of moringa leaves (Diets 3 and 4) significantly depressed growth performance of the fish (SGR: 2.0% in both groups) compared to Diets 1 and 2 (SGR: 2.7% and 2.4%, respectively). The relatively high total phenolics (0.7% and 1%), nonhaemolytic saponin (1.5% and 2.3%) and phytic acid (0.5% and 0.8%) in Diets 3 and 4, respectively, as well as NDF (3.8% and 5.7%) and ADF (3.0% and 4.5%) in the aforementioned diets may have contributed to the poorer growth performance in these groups. These results suggest that moringa leaf meal can be used to substitute up to 10% of dietary protein in Nile tilapia without significant reduction in growth.

THE EFFECT OF IONISING RADIATION ON ANTINUTRITIONAL FACTORS AND THE NUTRITIONAL VALUE OF PLANT MATERIALS WITH REFERENCE TO HUMAN AND ANIMAL FOOD

Abstract Although some plant materials contain substantial protein, carbohydrate and other nutrients, their bioavailability and utilisation by either humans or animals is relatively low, particularly in under-utilised/lesser-known/non-conventional crops. This is due to the presence of high proportions of various antinutrients. Moreover, the currently-adapted processing methods are relatively ineffective for complete inactivation/removal of such antinutrients. Ionising radiation treatment could serve as a possible additional processing method for inactivation or removal of certain antinutritional factors. This review therefore attempts to highlight the impact of gamma irradiation on the chemistry of various antinutrients, including non-starch polysaccharides (NSPs), and biological and nutritional qualities of foods and feeds. The potential effect of low irradiation dose levels of up to 10 kGy on the reduction of various antinutrients is also reviewed. This approach could open avenues for the possible utilisation of under-utilised and non-conventional crops and other agricultural residues as potential additional food and feed sources in the near future.

Preliminary nutritional evaluation of Mucuna seed meal (Mucuna pruriens var. utilis) in common carp (Cyprinus carpio L.): an assessment by growth performance and feed utilisation

Two feeding trials were conducted in a warmwater recirculating system to assess the potential nutritive value of mucuna seed meal as a dietary replacement for fish meal in practical diets of common carp. For experiment I and II, raw and autoclaved mucuna seed meals, respectively, were used in the diets to replace 10%, 20%, 30% and 40% of the total dietary protein and the performance of fish fed these diets was compared to fish fed a fish meal based control diet which contained 40% protein. All diets were prepared to be isonitrogenous and isoenergetic. For experiment I, each treatment had two replicates using five fish per aquarium with mean initial body weight of 11.65±0.23 g, whereas seven fish per replicate with mean initial body weight of 3.93±0.02 g were used for experiment II. Daily fish ration was fed five times their maintenance level [(3.2 g feed kg0.8/day)×5]. No fish died during the experimental phase I and II. The growth rate, feed conversion ratio, apparent net protein utilisation and energy retention of diets 1 and 2 in both experiments appeared to be similar and significantly higher than the other dietary groups in both experiments. The higher inclusion of raw and autoclaved mucuna meals in diets 3, 4 and 5, respectively, showed a significantly reduced growth performance when compared to diets 1 and 2. Fish fed diets containing higher levels (>13%) of raw mucuna meal had significantly higher carcass moisture, lower levels of protein (except in fish fed diet 3) and lipid contents. Even though fish were fed with autoclaved mucuna meal in experiment II, the higher inclusion rate of mucuna seed meal significantly reduced the growth parameters. However, no significant differences were observed regarding the whole body moisture, protein, ash and lipid contents among fish fed the control and diets 2, 3 and 4, except for the lipid content of fish fed diet 5. The lower growth performance of fish fed diets containing higher levels of both raw and autoclaved mucuna meal might be due to the presence of the higher levels of heat stable antinutrients coupled with non-starch polysaccharide fractions rather than the thermolabile antinutrients.

Rapid reversed-phase high performance liquid chromatographic method for the quantification of L-Dopa (L-3,4-dihydroxyphenylalanine), non-methylated and methylated tetrahydroisoquinoline compounds from Mucuna beans

A high-performance liquid chromatographic (HPLC) assay for the extraction and quantitative determination of L-Dopa, L-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline and 1-methyl-3-carboxy-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline in Mucuna pruriens var. utilis seeds has been developed. All the three compounds, L-Dopa, CDTHIQ and MCDTHIQ in the white variety of whole (4.96 g 100 g−1, 130.3 and 116.8 mg 100 g−1) and dehulled (5.21 g 100 g−1, 138.3 and 125.9 mg 100 g−1) seeds have been found to be significantly (P<0.05) higher than the black variety, respectively. The method makes use of a reversed-phase system with a C18-bonded column and yields quantitative recovery of all the three compounds, L-Dopa (101.8%), CDTHIQ (98.2%) and MCDTHIQ (94.5%). This procedure is superior to other analytical techniques currently available because of its simplicity with regard to sample preparation, the sensitivity and rapidity of the method.

Species/variety differences in biochemical composition and nutritional value of Indian tribal legumes of the genus Canavalia.

Seeds of the Indian tribal pulses Canavalia gladiata (red and brown varieties), C. ensiformis and C. virosa were analysed for their physical characters, proximate composition, minerals, amino acid composition, dietary fibre constituents, starch fractions, fatty acid profiles and various antinutritional and/or toxic factors. Among the different species/varieties of Canavalia, the brown variety of C. gladiata was found to have the highest amount of protein (35.0%). The essential amino acid profile of total seed proteins compared favourably with the FAO/WHO reference pattern established for pre-school children, except for a deficiency of sulphur containing amino acids in both varieties of C. gladiata and C. ensiformis, whereas high concentrations of cystine and methionine were detected in C. virosa. However, tryptophan in the red variety and lysine in the brown variety of C. gladiata seemed to be the second most limiting amino acids. Generally, these Canavalia seeds appear to be a good source of potassium, phosphorus and calcium. They contain low levels of sodium. Even though the samples contained a high proportion of total starch (31.8-36.9%), the percentage of digestible starch appeared to be much higher in C. ensiformis (70.6%) and C. virosa (71.8%) than in C. gladiata. The seed lipids of all the Canavalia samples investigated had a large proportion of unsaturated fatty acids (71-78%) with oleic acid as the major one (38.6-47.4%). All samples were rich in dietary fibre (17.5-23.6%), most of which was insoluble dietary fibre. The level of the toxic amino acid, canavanine, was found to be relatively low (27-42%) in C. gladiata and C. ensiformis compared to previous literature reports for the same species. The other antinutrients such as phenolics, tannins, condensed tannins, saponins, protease inhibitors, alpha-amylase inhibitor and haemagglutinating activity were also analysed and reported here. C. ensiformis seeds exhibited a relatively high level (69.0%) of in vitro protein digestibility compared to the red (67.2%) and brown (65.4%) varieties of C. gladiata and C. virosa (62.5%).