Nutritional value and fiber content related to asparagus quality

Green asparagus spears from Hoop-Ka-Pong, Banglane, Bangkrui, Kuiburi and Sriracha were investigated for their sizes, total weight (30 cm in length), weight of edible portion (15 cm in length) and their chemical compositions. The result indicated that the diameter of asparagus spears with three different grade of A, B and C were 0.94-1.28 cm 0.74-0.93 cm and 0.50-0.73 cm, respectively. Fresh asparagus from Hoop-Ka-Pong had the biggest size while spears from Sriracha had the smallest size with low weight of edible portion. Production area revealed notable influence on the amount of moisture contents, protein and total soluble solid. Difference portion of asparagus spears showed various values of chemical constitutents. The tip portion (0-7.5 cm) of spears from Banglane and Hoop-Ka-Pong, (group I) had 3.5-4.0 percent protein which substantially greater than the lower portion (7.5-15.0 cm) with 1.6-1.8 percent protein. Protein contents of spears grown in Kuiburi, Bangkrui, Banglane and Sriracha, (group II), were 3.6-4.2 percent analyzed from the upper portion of 0-2.5 cm and 2.0-2.3 percent from 2.5-5.0 cm portion. Grade C spears contained more fiber content than grade B and grade A. The upper portion from the tip had more fiber content than the lower portion. Asparagus spears from group I, length of 0-7.5 cm and 7.5-15.0 cm from the tip had 0.69-0.87 percent and 0.92-1.35 percent fiber contents, respectively. However, in group II, the tip portion of 0-2.5 cm contained 0.74-1.22 percent fiber while the lower part 2.5-5.0 cm contained 0.64-1.50 percent. Grade A, B and C asparagus spears from Sriracha showed the greatest fiber content. Ash content was not affected among grades and production areas. Other minerals such as calcium, phosphorus and iron differed depending on length and production area. The tip portion of asparagus spears had greater amount of minerals than the lower portion. Amount of ascorbic acid in asparagus spears depended on production area, length from the tip and grade. Grade A asparagus spears had greatest ascorbic acid content.