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Review
. 2021 Feb;86(2):266-275.
doi: 10.1111/1750-3841.15579. Epub 2021 Jan 12.

Estimation of water intake from food moisture in the Japanese diet using a cooking-based conversion factor for water content

Megumi Murakami  1 , Keiko Mizuma  2 , Yumi Nakamura  3 , Reiji Watanabe  2
Affiliations
Review

Estimation of water intake from food moisture in the Japanese diet using a cooking-based conversion factor for water content

Megumi Murakami et al. J Food Sci. 2021 Feb.

Abstract

This study aimed to estimate the water intake of Japanese people from food moisture. For this purpose, we described a water conversion factor for cooking (WCFC) that focuses on how cooking changes the water content of complete dishes and not food ingredients, and investigated methods for calculating the water content of cooked dishes. In this study, we utilized 129 dishes commonly consumed by Japanese people. We measured the water content of the dishes before and after cooking and calculated the percentage of residual water after cooking. The dishes were divided into staple foods or side dishes, and categorized based on residual percentage in water content and cooking method. The percentage of residual water after cooking change in water content in each category was expressed in terms of the WCFC, which is the water content of the cooked dish relative to the uncooked dish. In total, there were 43 categories with a WCFC range of 0.40 to 1.33. Our results revealed that the water content of food is not simply changed by heating-based cooking methods, but by a complex combination of cooking operations. Furthermore, by fitting WCFC to a culinary structuralism theory, it can potentially be utilized for all cuisines and not just dishes in Japan. Additionally, we found that the water content of a day's worth of food calculated using WCFC and actual measurements barely differed, indicating that WCFC could potentially be used to estimate water intake from food moisture. PRACTICAL APPLICATION: This research can be used in nutrition surveys to estimate water intake from food moisture.

Keywords: Japanese people; fluid intake; water content in food; water conversion factor for cooking; water estimation method.

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References

REFERENCES

    1. Adachi, M., & Harigaya, J. (2008). Actual serving size Shokuiku Card. Japanese food guide spinning top. Tokyo: Gunyosha. [in Japanese]
    1. Association of Official Analytical Chemists. (2002). Official Methods of Analysis of AOAC INTERNATIONAL 17th edition Revision 1:934.01 (4.1.0), 930.15 (4.1.06). Washington, DC: AOAC International.
    1. Food Guide Study Meeting. (2005). Decided by Ministry of Health, Labour and Welfare and Ministry of Agriculture, Forestry and Fisheries: Japanese Food Guide Spinning Top-Food Guide (provisional name) Review Meeting Report - Dai-ichi Shuppan Henshu-bu, I-2 illustration of a Japanese Food Guide Spinning Top (pp. 6-8). Tokyo: Dai-ichi Shuppan. [in Japanese]
    1. Haussinger, D., Lang, F., & Gerok, W. (1994). Regulation of cell function by the cellular hydration state. American Journal of Physiology, 267, E343-E355. https://doi.org/10.1152/ajpendo.1994.267.3.E343
    1. Hishida, A., & Sasaki, S. (2015). Dietary Reference Intakes for Japanese 2015, II Detailed <Reference>Water (pp. 343-344). Tokyo: Dai-ichi Shuppan Publishing. [in Japanese]

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