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W. C. Davis D. J. Le Tourneau Mary V. Zaehringer Helen H. Cunningham 《American Journal of Potato Research》1973,50(2):35-41
Thin slices of tissue from low (1.075–1.078 and high (1.092–1.094) specific gravity tubers were soaked in distilled water (100g/250ml) for 0, 1, 2, 3, 4, and 6 hours. Following the soak periods, the soak water and remaining tissues were separated and analyzed. Analyses of the soak water included pH, electrical conductivity, total solids, K, P and citric acid. The tissue analyses included total ash, alkalinity of ash, Ca, Mg, total N and phytate P. Other tissue samples were soaked the same periods of time and used to evaluate the amount of sloughing that occurred during cooking. All constituents studied diffused into the water during the soak periods. The greatest loss from the slices occurred in the first 2 to 3 hours and were similar for both specific gravity groups. After 6 hours the average amounts of material in the soak water were: total solids — 23%, P — 68%, phytate P —55%, K — 71%, total ash — 62%, total nitrogen — 56%, Ca — 35% and Mg —50%. Citric acid diffused into the soak water during the first 3 hours and the amount in the water then decreased. This apparent change may be due to metabolism of the acid. The sloughing of tissue decreased with the length of the soak period. The decrease in sloughing was highly correlated (P<1 %) with the length of the soak period, increases in electrical conductivity of the soak water, and with the leaching of all constituents measured. 相似文献
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All anions or cations were removed from potato extract and were replaced by a single, naturally occurring anion or cation in an effort to determine the relative effect of each on the sloughing of potato tissue. The treated extracts were used in cooking soaked potato tissue slices. In the anion series, citrate caused the greatest amount of sloughing. Other cooking media and treatments in decreasing order of effectiveness were untreated extract, malate, oxalate, chloride, and distilled water. In the cation series, sodium and potassium caused significantly more sloughing than the untreated extract. Magnesium and calcium firmed the potato tissue, resulting in less sloughing than that obtained with distilled water. 相似文献
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Reproducible, objective methods which conformed closely to visual appraisal were developed for measuring color differences in either cooked or raw potatoes. Experimental samples, selected from lots stored at various temperatures for different periods of time, differed in extent of graying and yellowing. Ricing was found to be preferable to mashing as a method of cooked sample preparation. A comparison of methods of sample presentation using the Gardner Color Difference Meter showed thin-layer measurement was most successful in separating cooked samples differing in amount of yellow pigment; deep-layer measurement was most successful in separating grayed samples. A simple method for measurement of color differences in raw tubers successfully separated the samples. All three methods of sample presentation were significantly correlated with visual ranking. 相似文献
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