Lipid oxidation is a major pathway for the chemical deterioration of low-moisture foods. Little is known about how the physical properties of the fat used in crackers impact lipid oxidation kinetics. Fully hydrogenated soybean fat + interesterified soybean oil, fully hydrogenated soybean fat + sunflower oil, fully hydrogenated soybean oil, and soybean oil and interesterified fat alone were formulated to have varying solid fat content (SFC) at 55 °C but the same linoleic acid and tocopherol contents, so the fats had similar susceptibility to oxidation. A fluorescence probe showed that lipid mobility increased with decreasing SFC in both cracker doughs and fat blends, suggesting the probe could be used to monitor SFC directly in foods. Decreasing SFC decreased oxidation in crackers. Crackers made from interesterified fat (13.7% SFC) were more oxidatively stable (hexanal lag phase = 33 days) than crackers made from fat blends (hexanal lag phase = 24 days). These results suggest that blended fats result in regions of liquid oil high in unsaturated fatty acids within a food product prone to oxidation. Conversely, interesterified fats where unsaturated and saturated fatty acids are more evenly distributed on the triacylglycerols are more stable. Thus, interesterified fats could allow for the formulation of products higher in unsaturated fatty acids to improve nutritional profiles without sacrificing shelf life.

中文翻译：

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固体脂肪含量在低水分裂解系统氧化稳定性中的作用

脂质氧化是低水分食品化学变质的主要途径。关于饼干中使用的脂肪的物理特性如何影响脂质氧化动力学知之甚少。全氢化大豆脂肪+酯交换大豆油、全氢化大豆脂肪+向日葵油、全氢化大豆油以及单独的大豆油和酯交换脂肪被配制成在55°C下具有不同的固体脂肪含量（SFC），但相同的亚油酸和生育酚含量，因此脂肪具有相似的氧化敏感性。荧光探针显示，在饼干面团和脂肪混合物中，脂质流动性随着 SFC 的降低而增加，表明该探针可用于直接监测食品中的 SFC。减少 SFC 会减少饼干中的氧化。由酯交换脂肪制成的饼干 (13. 7% SFC）比脂肪混合物制成的饼干（己醛滞后期 = 24 天）更稳定（己醛滞后期 = 33 天）。这些结果表明，混合脂肪会导致食品中不饱和脂肪酸含量高的液体油区域易于氧化。相反，不饱和和饱和脂肪酸更均匀地分布在甘油三酯上的酯交换脂肪更稳定。因此，酯交换脂肪可用于配制不饱和脂肪酸含量更高的产品，以在不牺牲保质期的情况下改善营养状况。不饱和和饱和脂肪酸更均匀地分布在甘油三酯上的酯交换脂肪更稳定。因此，酯交换脂肪可用于配制不饱和脂肪酸含量更高的产品，以在不牺牲保质期的情况下改善营养状况。不饱和和饱和脂肪酸更均匀地分布在甘油三酯上的酯交换脂肪更稳定。因此，酯交换脂肪可用于配制不饱和脂肪酸含量更高的产品，以在不牺牲保质期的情况下改善营养状况。