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Lotus (Nelumbo nucifera G.) is an edible aquatic perennial herb which is gaining importance because of its neutraceutical properties, richness in nutrients and bioactive substances. The objectives of the study were to evaluate the physicochemical properties, bioactive compounds and therapeutic potential of lotus rhizome for diabetes. The study also assessed the quality aspects of rhizome flour and standardised the lotus rhizome flour incorporated cookies.
The moisture content in fresh rhizome was 72.14 per cent. The carbohydrate, protein, fibre and fat content in 100 g of rhizome were 16.03 g, 2.60 g, 4.20 g and 0.10 g respectively. Lotus rhizome contained calcium (40 mg/100 g), phosphorus (58 mg/100 g) and potassium (450 mg/100 g). Anti-nutritional factors such as tannin was as low as 0.88 g/ 100 g and cyanogen was absent in the rhizomes.
The phytochemical constituents were assessed using LCMS/MS analysis. The compounds with antidiabetic properties identified in rhizomes were betulinic acid, rutin and isoquercetin. In silico molecular docking was performed with 23 diabetes targets and 16 phytocompounds. Five compounds 3-hydroxyamobarbital, p-hydroxyphenobarbital, tetrahydroxy-2, 6-dimethylanthroquinone, acetoin and fluoroacetate with best docking scores were subjected to Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) analysis. These compounds attained satisfactory scores for all the ADMET parameters except for hepatotoxicity.
The best treatment selected for preparation of lotus rhizome flour was blanching for 5 minutes followed by dipping in 1 % potassium metabisulphite for 30 minutes, drying and pulverizing. The selected rhizome flour was subjected to storage study for three months.
The pH of the freshly prepared rhizome flour was 5.0 which on storage increased to 6.0. Moisture content increased from 5.20 per cent to 6.02 per cent at


the end of storage period. During storage a gradual increase was observed in water holding capacity (5.89 g to 5.95 g water/ g flour) and oil absorption capacity (1.15 to 1.20 oil/ g flour). A decrease in bulk density (g/ml) of the flour, from an initial value of 0.28 to 0.22 was observed. The product recovery from fresh rhizome to rhizome flour was 21.24 g/100 g.
The nutritional properties of lotus rhizome flour were evaluated initially and at the end of storage. A gradual decrease in starch (50.11 to 49.65 per cent), protein (6.88 to 6.21 per cent) and fibre (9.80 to 9.60 per cent) content was observed during storage. Gradual decrease in fibre, fat, vitamin C, ash and in vitro digestibility of starch was noticed. A nonsignificant difference in mineral content and in vitro availability of minerals during storage was observed in the study. No considerable changes in sensory qualities of rhizome flour were observed after three months of storage. The presence of bacteria, fungi and yeast were detected during storage but was found to be within the permissible limits in lotus flour.
Cookies were prepared and evaluated organoleptically by incorporating lotus rhizome flour at different levels with whole wheat flour. Nutrient analysis revealed a carbohydrate content of 48.12 per cent, protein content of 10.03 per cent and fibre content of 2.44 per cent. The standardised cookies contained total phenols (138 mg/100 g) and total flavonoids (70.42 mg/100 g) with an antioxidant capacity of 50.27 per cent. The lotus rhizome flour based cookies can be included in the category of low glycemic index foods with the score of 50.51, indicating it to be suitable for diabetic patients.
The present study found that good quality flour and acceptable cookies could be prepared from lotus rhizomes. It is clear that lotus rhizome due to its nutritional profile and therapeutic properties have immense scope in the development of neutraceuticals.