Nutrient Composition of Canned Beets and Tomatoes Grown in a Subtropical Area

Abstract

AaSTRACTCanned whole tomatoes and beets were collected from three canning plants in the Rio Grande Valley of South Texas, 3 times during the canning period and stored for 1 yr. Nutrient analyses revealed that fat, fiber, protein, iron, riboflavin, niacin, carbohydrate and caloric values of the tomatoes and ash, fat, fiber, calcium, iron, protein, thiamine, riboflavin and niacin of the beets were not changed by canning plant procedures, time of harvest during the canning period, or during 1 yr of storage. Tomatoes canned in plant C were consistently higher in total dry solids than those canned in plants A and B. The total dry solids in beets decreased slightly in the late harvest. Vitamin C decreased in tomatoes from each canning plant during storage. The ash content of tomatoes canned in plant A was lower than ash in tomatoes from plants B and C. Vitamin A in tomatoes increased in late harvest but decreased during storage. Beets canned in plants A and B decreased in carbohydrate and caloric values during the canning period. Canning plant operators in this subtropical area might expect values for fat and Vitamin A in tomatoes and of fat, calcium, iron, thiamine and riboflavin in beets to differ from the corresponding values listed in USDA Handbook No. 8.

Antioxidant Activity of Processed Table Beets (Beta vulgaris var, conditiva) and Green Beans (Phaseolus vulgaris L.)

“…Treatment under a constant time of 30 min at various temperatures of 105, 115, and 125 °C showed similar results as the former treatment group. There was a significant reduction (p < 0.05) in vitamin C content (Table 1), which was consistent with previous results (31). Dehydroascorbic acid (DHAA) content of processed beets showed a small and significant decrease compared to the control (p < 0.05) (Table 1).…”

“…Thermal processing of beets showed a slight linear degradation of free vitamin C content (Table 1). Treatment under constant temperature of 115 °C at various time intervals of 15, 30, and 45 min showed a small but significant reduction of vitamin C as compared to the control (Table 1), which is consistent with previous results (31). Treatment under a constant time of 30 min at various temperatures of 105, 115, and 125 °C showed similar results as the former treatment group.…”

Nutritional comparison of fresh, frozen, and canned fruits and vegetables II. Vitamin A and carotenoids, vitamin E, minerals and fiber

“…The authors suggest the loss may be attributed to thermally induced hydrolysis of complex carbohydrates within the cell wall 12. Saldana et al reported no significant changes in crude fiber content after 1‐year storage of canned beets and tomatoes 20…”

“…Saldana et al found significantly different calcium levels in canned tomatoes due to variance in processing plant practices. The addition of a salt–calcium–acidulant tablet raised calcium levels up to 0.37 g kg −1 WW in canned tomatoes, whereas concentrations of only 0.07 g kg −1 WW were found in canned tomatoes not utilizing this practice 20. The USDA database reports an average of 0.31 g calcium kg −1 WW.…”