Nutritional values of onion bulbs with some essential structural parameters for packaging process

Onions belong to the Allium genus that has been frequently used for human diet and the traditional medication due to the bioactive compounds. The main nutritional values, vita-mins, and amino acid compositions of onion bulbs (Yellow, Red, Green, Leek, and Baby onions) with some essential structural parameters for the packaging process were investigated. Physical and structural parameters with frictions were applied for the packaging process. The results reported that moisture content was the main component of onion bulbs (88.65%). Besides, they were rich in proteins (9.22–13.21 g/100 g infresh weight) (FW). Results reported that Red and Yellow varieties established the largest vitamin C and carotenoids contents (45.07 mg/100 g⁻¹ FW) and (1.44 µg/mL FW), respectively. The major amino acid was arginine which was highly found in Green variety (17.02 mg/g FW) and a relatively high amount of glutamic and aspartic acids as (9.88–14.89 mg/g FW) and (4.93–10.55 mg/g FW), respectively. Yellow variety established the largest width, thickness, surface area, aspect ratio, and sphericity. The highest static and kinetic frictions were established on steel (0.14–0.52) and (0.75–0.96), respectively. This study presents the nutritional evidence of onion varieties for the human diet besides the horticultural processing for packaging quality improvement.