Physical, physicochemical and anti-nutritional properties of Horse Chestnut (Aesculus indica) seed

Abstract

The aim of the study was to investigate the physical, physicochemical and anti-nutritional properties of Horse Chestnut (HCN) seed. The average length, width and thickness of the seeds were 4.70, 4.00 and 3.20 cm, respectively. Geometric and arithmetic mean diameter were 3.92 and 3.97 cm. Average sphericity and aspect ratio of the seeds were 83.40 and 85.11 %, respectively. The true density, bulk density, density ratio and porosity values of the seeds were 1072, 518 g/cm3, 48.32 and 51.68 %, respectively. The angle of repose for the seeds obtained on plywood, mild steel, stainless steel and galvanized sheet was 22.30°, 20.30°, 18.30° and 22.79° respectively. The coefficient of static friction of the seeds obtained on plywood, mild steel, stainless steel and galvanized sheet was 0.54, 0.52, 0.51 and 0.52, respectively. The average force required to break the seed was 328 N. The L * , a * , and b * color values of seed flour were found to be 92.07, 3.47 and 13.70 respectively. Proximate composition of the seed flour revealed 10.71 % moisture, 3.16 % ash, 6.34 % crude fibre, 3.27 % fat, 6.78 % protein, 69.74 % carbohydrate, 10.15 % sugar and 59.59 % starch and energy value of 327.51 cal/100 g. Anti-nutritional factors of the seed flour were determined in terms of oxalate, phytate, tannin and saponin. Pre-treatments including soaking and microwave heating showed significant reduction of anti-nutritional factors of the seed flour. Microwave heating at 2450 MHz for 2.5 min showed higher reduction of 95.45, 91.66, 68.15 and 87.20 % in oxalate, phytate, tannin and saponin content respectively. Knowledge of physical properties of HCN seeds can be useful in designing equipment for postharvest handling and processing operations. Pre-treatments for reduction of anti-nutritional components of the seeds can be helpful for utilization of HCN seed in different food formulations.