Cooking parameters affect the sodium content of prepared pasta

Authors: BIANCHI, LAURIE - Virginia Tech; PHILLIPS, KATHERINE - Virginia Tech; MCGINTY, RYAN - Virginia Tech; Ahuja, Jaspreet; Pehrsson, Pamela

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2018
Publication Date: 7/27/2018
Citation: Bianchi, L.M., Phillips, K.M., Mcginty, R.C., Ahuja, J.K., Pehrsson, P.R. 2018. Cooking parameters affect the sodium content of prepared pasta. Food Chemistry. https://doi.org/10.1016/j.foodchem.2018.07.198.
DOI: https://doi.org/10.1016/j.foodchem.2018.07.198

Interpretive Summary: Pasta is a food to which salt is often added during preparation. It is in the top 12 foods contributing to sodium intake in the United States. There are limited reports on sodium in pasta cooked with different amounts of salt and none on quantitative uptake with home cooking conditions and varying pasta type, water to pasta ratio, amount of salt in the cooking water, and other factors that might differ within recommended and customary practices. Semolina spaghetti was cooked by a typical method [454 g (1 lb), 5.68 L (6 qt) water, 36 g (2 Tbsp) salt, al dente, no rinsing] and in a series of treatments involving systematic variation of the amount of salt, water to pasta ratio, cooking time, rinsing, pasta shape, and whole grain. Sodium was assayed by inductively coupled plasma spectroscopy-mass spectrometry after acid digestion, including certified reference materials and rigorous quality control. Sodium in a 140 g standard serving of pasta cooked in salted water by the range of treatments tested was 247 - 490 mg, and there was a linear relationship between salt concentration in cooking water and sodium in the cooked pasta. Rinsing reduced sodium by 34%. The equation can be used to obtain a more accurate estimate of the sodium content than the average food composition database value for “pasta cooked with salt”, for pasta cooked with known amounts of salt and water. This information could also be communicated to consumers as demonstrable and simple way to reduce sodium intake, by relating how much salt in pasta cooking water increases sodium, and that rinsing after cooking could reduce by 1/3 the sodium content of pasta cooked in salted water.

Technical Abstract: Reducing dietary sodium is recommended to decrease risk of hypertension and cardiovascular disease. Dry pasta is low in sodium, but culinary recommendations involed cooking in salted water, with varying amounts of salt, water, and other cooking parameters. However, food composition database values for sodium in cooked pasta do not reflect specific cooking methods. In this study the quantitative effect of different preparation variables on the sodium content of cooked dry pasta was evaluated. Semolina spaghetti (< 5 mg sodium/100g) was cooked by a typical home preparation method [454 g (1 lb), 5.68 L (6 qt) water, 36 g (2 Tbsp) salt, al dente, no rinsing] and in a series of treatments involving systematic variation of amount of salt, water:pasta ratio, cooking time, rinsing, pasta shape, whole grain. Sodium was assayed by inductively coupled plasma spectroscopy-mass spectrometry after acid digestion, including certified reference materials and rigorous quality control. Pasta cooked without salt had <5 mg sodium in a 140 g standard serving, and 247 - 490 mg/serving when cooked in salted water by the different variations tested. There was a linear relationship between salt concentration in the cooking water and sodium in the cooked pasta; doubling the concentration increased sodium by 243 mg/serving (>10% of a 2300 mg/day maximum recommended intake) relative to the reference method (247 mg/serving), independent of cooking time, pasta shape, grain, and cooking volume, all of which had no effect on sodium. Rinsing reduced sodium by 34%. The linear relationship between sodium concentration in the cooking water and in the cooked pasta, regardless of other cooking parameters, allows estimation of sodium in pasta prepared by different methods relative to data in food composition tables that are based on discrete conditions, and will allow more accurate estimation of dietary intake, given the nutritionally significant sodium content of pasta cooked in salted water.