EFFECT OF COOKING ON THE NUTRITIVE VALUE OF FOODS Ⅱ. CHANGE OF THE ASCORBIC ACID CONTENT IN VEGETABLES
- VernacularTitle:烹调方法对于食物中营养素含量的影响——Ⅱ.蔬菜中抗坏血酸含量的变化
- Author:
Hsuching WANG
;
Chihping SHEN
- Publication Type:Journal Article
- From:
Acta Nutrimenta Sinica
1956;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
The change of the ascorbic acid content in several vegetables at the different steps in the cooking process was studied. Special attention was directed to washing before or after cutting the vegetable into pieces of different size.Large-scale and household cooking methods were compared. The effect of storing the cooked vegetable at different temperatures and for different lengths of . time was also investigated.The loss of the total and reduced ascorbic acid in spinach, colza, cabbage and celery cabbage was insignificant after washing either before or after cutting. The loss was also not appreciable when these vegetables were held for 2 and 6 hrs. after cutting into wedges. When potatoes and cabbage were cut into strips, there was no change in the total ascorbic acid but a slight decrease of the reduced form. A marked loss of total ascorbic acid was observed when potatoes strips and slices were soaked in water; the slices lost 11.2% and 12,.8% and the strips lost 22.6,% and 23.9% respectively by the end of 2 and 6 hrs. When potatoes were cut and kept in the air at room temperature for 2 and 6 hrs., there was no change in total ascorbic acid, but an increase of the reduced form was apparent. Such an increase should not be attributed to the so-called "traumatic formation"; some changes in the redox system of ascorbic acid is to be expected.A certain amount of ascorbic acid was lost when'spinach, garlic green, colza and celery cabbage were cooked either in large or in small quantities. The retention of the reduced ascorbic acid in the vegetables cooked in small quantit ies ranged 50.2-64.1.%, and that of the total ranged 72.6-75.7%. In case of the large-scale cooking, the retention of reduced and total ascorbic acid ranged 53.6-70.5% and 73.9 - 85.4% respectively. No loss of ascorbic acid was observed when the potatoes were steamed whole, but a large amount was lost when their strips were scrambled in a Chinese style.Cooked vegetables held at 60℃ for 2 and 4 hrs. lost a part of its ascorbic acid; the percentage of loss in the 2 hr. period was lower than that in the 4 hr.
