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1,3-Distearoyl-2-oleoyl-glycerol, 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol and 1-stearoyl-2-oleoyl-3-arachidoyl-glycerol are typical high-melting symmetrical monounsaturated triacylglycerols (Hm-SMT) found in cocoa butter improver (CBI). These triacylglycerols help to increase the hardness of chocolate products in tropical climates. In the present study, natural CBI products were produced from mango (Mangifera indica, Linn) kernel fat (MKF) by selective three-stage fractionation using acetone. The second stearin (fraction I) from the first precipitate of MKF by fractionation for 180 min at 15 °C contained 86.9% of Hm-SMT, and the third stearin (fraction II) obtained from fraction I by further fractionation for 180 min at 18 °C was enriched with 94.4% Hm-SMT. High percentages of such triacylglycerols in these products contributed to higher slip melting points (36.5–37.7 °C) than commercial cocoa butter and cocoa butter equivalent (26.7 and 27.9 °C). Also, their differential scanning calorimetry properties and solid fat content values were superior to those in traditional confectionery fats, indicating that the tailored stearins could be used as ideal CBI. In particular, the hard fat blends consisting of 55–70% cocoa butter (CB) and 30–45% fraction II were considered as the preferred heat-resistant chocolate ingredients. In addition, the mixture of the oleins (fraction III) was rich in diunsaturated and triunsaturated triacylglycerols and showed similar thermal properties to super palm oil, thus making it more suitable as special fat ingredients and modified fat sources.

11 China-specific mango varieties, i.e., Tainong, Xiangya, Okrong, Keitt, Chiin Hwang, Guifei, Yuexi, Biantao, Guixiang, Zihua and Guire, were selected from South China, and the kernels were separated from pulps and then dried to extract mango kernel fats (MKF). 5.65–11.14 % of the fats could be obtained from dried kernels using hexane extraction, and their iodine values, slip melting points, triacylglycerols, sn-2 fatty acids and micronutrients were analyzed. MKF were comprised predominantly of triacylglycerols reaching 85.09–92.72, and 78.28–84.37 % of oleic at the sn-2 position. 29.99–55.44 % of SOS, 11.17–23.34 % of SOO and 13.10–19.79 % of POS occupied the main percentages of triacylglycerols, indicating MKF have diversified application after fractionation. Certain variety characterized as moderate values mentioned above, therefore, was selected and then fractionated by two-stage processes to produce typical MKF fractions. The stearin (Fraction-II) fractionated from the first solid fraction (Fraction-I) with 68.09 % of SOS and 15.43 % of POS was more suitable as cocoa butter improver, while the olein (Fraction-III) produced from the first liquid fraction was rich in SOO (45.59 %), POO (11.37 %) and OOO (11.14 %), which are considered as ideal cooking oil or frying fat ingredients. In addition, high amounts of micronutrients, including sterol, tocopherol and squalene, were also found in MKF ranged from 3837 to 7085, 81 to 916, and 164 to 941 mg/kg among different varieties, respectively. In particular, squalene levels were higher compared with most of other vegetable oils.

Eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA) isomers (22:5n-6 and 22:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) derived from tuna oil were concentrated by three stages of urea fractionation at various crystallization temperatures and different fatty acid/urea ratios. Thereafter, polyunsaturated fatty acids concentrate containing comparatively enriched DPA levels was purified by argentated silica gel column chromatography. A product containing 22.2 ± 0.6 % EPA, 4.6 ± 0.0 % DPAn-6, 5.9 ± 0.1 % DPAn-3 and 42.3 ± 1.2 % DHA was obtained at 1:1.6 fatty acid/urea ratio (w/w) by crystallization at −8 °C for 16 h, −20 °C for 8 h, and −8 °C for 16 h. A DPA isomer concentrate containing 26.1 ± 0.5 % DPAn-6 and 22.3 ± 0.4 % DPAn-3 was achieved by argentated silica gel chromatography in the 6 % acetone/n-hexane solvent fraction (v/v), and the recovery of both fatty acids was 66.1 ± 3.2 and 70.7 ± 2.2 %, respectively. Furthermore, 91.9 ± 2.5 % EPA and 99.5 ± 2.1 % DHA with recoveries of 47.8 ± 2.0 and 56.7 ± 3.3 %, respectively, were obtained in various fractions.