Mango kernel fat (MKF)-based fats characterized as high levels of 1,3-distearoyl-2-oleoyl-glycerol (StOSt), including physical blend (PB), interesterified blend (IB) and its counterpart non-interesterified blend (Non-IB), were used to prepare "dark chocolates" by optimizing tempering process. High melting StOSt promoted thermal properties in PB-, IB- and Non-IB-chocolates compared to traditional cocoa butter (CB)-chocolate. The three MKF-based chocolates were solid at 32 degrees C and became runny at 37 degrees C and may avoid leaving waxiness in the mouth, whereas CB-chocolate completely lost its shape at 32 degrees C. Further bloom tests showed that CB-chocolate was covered with white-greyish haze within 15 days, Non-IB chocolate exhibited white-round-shaped stripe around 45 days, while only slight bloom was observed in PB and IB-chocolates after 60 day-storage. The significant improvements on heat and fat bloom stabilities of PB- and IB-chocolates were attributed to their optimal triacylglycerol compositions (StOSt = 55.7-60.9%, 1-palmitoyl-2-oleoyl-3-stearoylglycerol = 21.1-23.8%, and 1,3-dipalmitoyl-2-oleoylglycerol = 8.2-11.1%) and plate-like growth at 20 degrees C. The plate-like growth-crystals could prevent bloom from fat recrystallization and further transformation into beta(1) polymorph.