Vol. 7, Issue 9, Part C (2025)

Onion (Allium cepa L.) is an economically significant vegetable widely used as a spice and for its medicinal properties, containing numerous essential vitamins and minerals vital to the human diet. Despite progress in onion processing and storage, the diverse nature of onions cultivated in India urgently calls for a comprehensive database detailing their physical, frictional, and textural characteristics to enhance the accuracy and efficiency of post-harvest operations such as grading, sorting, and packaging. For this study, the popular onion variety Phule Swami, commonly grown in Maharashtra, India, was selected. Various physical, chemical, frictional, thermal, and textural properties of the onion bulbs were measured and analyzed.
The physical properties such as polar diameter (Dp), equatorial diameter (De), thickness (T), geometric mean diameter (Dgm), arithmetic mean diameter (Dam), shape index, sphericity, bulk density, true density, porosity, volume, surface area, eccentricity, projected area, dry matter, colour L*, colour a* and colour b* values were ranged from 43.23 to 65.23mm, 42.25 to 64.52 mm, 35.06 to 58.63mm, 40.01 to 62.72 mm, 40.18 to 62.79mm, 1.0 to 1.15, 0.89 to 0.97, 526.24 to 560.00 kg/m³, 1084.26 to 1129.00kg/m³, 50.39 to 51.47, 6580 to 7840 mm³, 1074.54 to 2162.82 mm², 0.02 to 0.05, 268.63 to 540.70mm², 13.39 to 13.68%, 56.45 to 57.28, 14.22 to 14.56 and 8.24to 8.32, respectively. The chemical properties such as moisture content, carbohydrate content, ash content, protein content, fat content, inhibition DPPH, anthocynin content, reducing sugars, pH, total soluble soilids, pyruvic acid, ascorbic acid, total phenol and total flavonoids were ranged from 82.56 to 83.40%, 9.71 to 10.64%, 3.2 to 3.6%, 3.26 to 3.46%, 0.12 to 0.16%, 52.25 to 54.24%, 8.40 to 8.60mg/100g, 3.50 to 3.80g/100g, 5.88 to 5.94, 12 to 13 Brix, 14.20 to 14.52 µmole/g, 13.89 to 13.94 mg/100g, 56.23 to 57.63 mg GAE/100g and 25.24 to 26.18 mg CE/100g, respectively. The thermal property such as thermal conductivity was 0.51W/mK and specific heat was ranged from 3.62 to 3.74kJ/kgK. The frictional properties such as coefficient of static friction and angle of repose (ф) were ranged from 0.46 to 0.48 and 37.22 to 37.39^o, respectively. The textural property i.e. firmness was ranged from 10.36 to10.68N.