Duck Fat

The 'typical' column is the raw duck fat analysed in Table 1 of Shin et al., Animal Bioscience 35(6):927-937 (2022) - a commercial rendered duck fat supplied by Taekyung Nongsan Co., Seoul, profiled by GC alongside beef fat, pork backfat and soybean oil. Its 27 acids: C8:0 0.01, C10:0 0.04, C12:0 0.12, C14:0 1.08, C15:0 0.09, C16:0 25.15, C17:0 0.17, C18:0 5.95, C20:0 0.09, C21:0 0.12 (SFA 32.81); C14:1 0.18, C16:1 3.52, C18:1n-9 cis 42.89, C18:1n-9 trans 1.42, C18:2n-6 cis 17.13, C18:2n-6 trans 0.01, C18:3n-6 0.09, C18:3n-3 0.98, CLA 0.07, C20:1 0.34, C20:2 0.01, C20:3n-6 0.11, C20:3n-3 0.02, C20:4n-6 0.02, C20:5n-3 0.31, C22:1n-9 0.05, C22:6n-3 0.07 (UFA 67.19). The keys recorded here total 97.4 %; the missing 2.6 % is C15:0, C17:0, C21:0, C14:1, elaidic acid, CLA and the C20/C22 long-chain polyunsaturates, none of which has a key in this schema. Elaidic acid (trans-C18:1, 1.42 %) is deliberately not folded into oleic - same molar mass, so it makes no difference to lye, but the two are different acids and merging them would misreport the profile. Min/max widen the record with USDA FoodData Central SR Legacy 'Duck, domesticated, meat and skin, raw' (fdcId 172408, NDB 05139): total lipid 39.34 g/100 g, fatty acids per 100 g of food 12:0 0.05, 14:0 0.25, 16:0 9.58, 18:0 3.20, 16:1 1.54, 18:1 16.73, 20:1 0.40, 18:2 4.69, 18:3 0.39, with SFA 13.22 + MUFA 18.69 + PUFA 5.08 = 36.99 g total. Dividing each by 36.99 renormalises them to percent of total fatty acids: lauric 0.14, myristic 0.68, palmitic 25.90, stearic 8.65, palmitoleic 4.16, oleic 45.23, gadoleic 1.08, linoleic 12.68, linolenic 1.05 (99.57 %). That arithmetic is stated so a reader can undo it; USDA publishes grams per 100 g of food, not percent of fatty acids, and the two are not the same number. USDA has no rendered 'Fat, duck' entry the way it has Fat, goose (04576), Fat, chicken (04542) and Fat, turkey (04575); meat-and-skin is the closest published lipid and its skin fraction is the fat that gets rendered. DIET MOVES THESE NUMBERS, so the range is the honest form. Linoleic acid is the clearest case: 12.7 % in the USDA bird against 17.1 % in the Korean commercial fat, which is a feeding difference, not a measurement error - poultry deposit dietary linoleic almost unchanged. A third open study, Kowalska et al., Scientific Reports 10:13465 (2020), fed Cherry Valley Pekin ducks soybean meal or yellow lupin and reported subcutaneous and abdominal fat at C16:0 46.2-47.1 %, C18:1 28.9-29.8 %, C18:2 8.0-8.5 %, which disagrees with both sources used here far too widely to be a diet effect; palmitic at 46 % is nearly double every other published duck-fat figure, so that study is recorded as an outlier and not used. Its finding that lupin feeding raised C18:3n-3 from 0.59-0.60 to 0.67-0.70 % is the kind of shift diet genuinely produces. NO SAPONIFICATION OR IODINE VALUE IS RECORDED. Neither Shin et al. nor USDA measured either, and the 192.05 mg KOH/g that circulates for duck fat traces to an LWT 2023 review that could not be opened in this session - the same review, and the same inaccessibility, that left chicken-fat.json's saponification value null. The recorded profile implies about 196 mg KOH/g by stoichiometry, which the calculator will derive and label as derived; that is consistent with the 192 figure but is not a substitute for a measurement. Melting point and unsaponifiable matter not sourced. INCI not verified (null).

This record is part of the open ingredient database (ODbL). Found an error or a better primary source? The dataset is on GitHub; corrections with a document link are welcome.