Non-Destructive Quantification of Lipid and Water in Fresh Tuna Meat by a Single-Sided Nuclear Magnetic Resonance Scanner

A portable single-sided nuclear magnetic resonance (NMR) surface scanner was applied to the non-destructive quantification of lipid and water in meat block samples of farmed bluefin tuna (Thunnus thynnus). Proton NMR relaxation measurements of the fresh meat block samples were performed at room temperature in a laboratory. Totally, 34 tuna meat block samples were measured; the required measurement time was approximately 70 s for each sample. The results yielded estimation errors of 3.7 and 2.7 g/100 g for the lipid and water weight fractions, respectively. The investigation depth of the sensor was as deep as 3 cm, which enables the non-destructive quantification of the meat of the intact whole tuna beneath the thick scales, skin, and subcutaneous fat in markets and seafood factories.