Departamento de Alimentação e Nutrição, Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA, I.P.), Av. Padre Cruz, 1649-016 Lisboa, Portugal.
CCMM/DQB - Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Food Chem. 2014 Aug 1;156:37-41. doi: 10.1016/j.foodchem.2014.01.050. Epub 2014 Feb 2.
The effects of freezing and storage temperature on the mass fraction of α- and β-carotene, β-cryptoxanthin, lutein, lycopene and zeaxanthin in minimally processed fresh food products, were evaluated after sample preparation, extraction and saponification (only when strictly necessary). Effects of freezing and long-term stability were studied at two temperatures, -20 and -70°C, using high performance liquid chromatography (reversed phase columns, UV-Vis diode array detector) at time points during storage; measurement uncertainty was included in the evaluation. Stability of working standard solutions was also examined. Freezing did not affect the carotenoid mass fraction under the conditions studied. Carotenoids in orange, cherry, peach, apple, and kale were stable (except α-carotene and zeaxanthin in peach) for 13, 9.7, 5.7, 2.5 and 7.5months, respectively. For these food sample matrices, no significant difference between the freezing/storage at -20 and -70°C was observed. Standard solutions (0.05-5μg/mL) were stable for at least 6months at -70°C, except lycopene which at 0.05μg/mL was apparently stable only for six weeks.
研究了样品制备、提取和皂化后（仅在必要时），冷冻和储存温度对微加工新鲜食品中 α-和 β-胡萝卜素、β-隐黄质、叶黄素、番茄红素和玉米黄质的质量分数的影响。使用高效液相色谱法（反相柱，紫外-可见二极管阵列检测器），在储存期间的时间点上，在 -20 和 -70°C 两个温度下研究了冷冻和长期稳定性；评估中包括测量不确定度。还检查了工作标准溶液的稳定性。在研究的条件下，冷冻不会影响类胡萝卜素的质量分数。在橙子、樱桃、桃子、苹果和羽衣甘蓝中，除了桃子中的 α-胡萝卜素和玉米黄质外，类胡萝卜素在 13、9.7、5.7、2.5 和 7.5 个月时稳定。对于这些食品样品基质，在 -20 和 -70°C 下冷冻/储存没有观察到显著差异。标准溶液（0.05-5μg/mL）在 -70°C 下至少稳定 6 个月，除了番茄红素，在 0.05μg/mL 时仅稳定 6 周。
