On the effect of ultrasound-assisted atmospheric freeze-drying on the antioxidant properties of eggplant
On the effect of ultrasound-assisted atmospheric freeze-drying on the antioxidant properties of eggplant
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DOI：
10.1016/j.foodres.2018.01.022
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发表时间：
2018-04-01
影响因子：
8.1
通讯作者：
Carcel, Juan A.
中科院分区：
文献类型：
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作者：
Colucci, Domenico;Fissore, Davide;Carcel, Juan A.
常压冷冻干燥中使用的低工作温度允许热敏性产品的有效干燥，而不会损害其质量属性。当使用功率超声时，可以提高干燥速度，从而缩短工艺时间。然而，超声波也会影响产品质量。本研究的目的是评价不同干燥工艺变量，即空气温度和速度、超声功率和样品大小对茄子样品抗氧化性能的影响。为此，在不同的干燥温度（-5、-7.5、-10℃）、功率超声水平（0、25、50 W; 21.9 kHz）和空气速度（2.5 m s(-1)）下，使用不同的样品尺寸（8.8 mm和17.6 mm立方体面）进行了干燥实验。以抗坏血酸含量（Jagota和Dani法）、总酚含量（Folin-Ciocalteau法）和抗氧化能力（FRAP法）作为干燥样品的质量指标。风速、温度和样品体积的增加显著降低了干燥样品的抗氧化能力（p值< 0.05）。对于给定的样本量，超声波的应用，在测试的声功率水平下，对所考虑的抗氧化指标没有产生显着影响。当施加声功率时，干燥样品内部的温度测量显示出不可忽略的温升。
The low operating temperatures employed in atmospheric freeze-drying permits an effective drying of heat sensitive products, without any impairment of their quality attributes. When using power ultrasound, the drying rate can be increased, thus reducing the process duration. However, ultrasound can also affect the product quality. The aim of this study was to evaluate the effect of various drying process variables, namely air temperature and velocity, ultrasound power and sample size, on the antioxidant properties of eggplant (Solanum melongena L.) samples. For this reason, drying experiments were carried out at different drying temperatures (-5,-7.5,-10 degrees C), power ultrasound levels (0, 25, 50 W; 21.9 kHz) and air velocities (2, 5 m s(-1)) using different sample sizes (8.8 mm and 17.6 mm cube side). The ascorbic acid content (Jagota and Dani method), total phenolic content (Folin-Ciocalteau method), and the antioxidant capacity (FRAP method) of the dried products were considered as quality indicators of the dried samples. The increase in air velocity and temperature, as well as the sample size, significantly reduced the antioxidant potential of the dried samples (p-value < .05). For a given sample size, the application of ultrasound, at the acoustic power levels tested, did not produce significant effects on the antioxidant indicators considered. Temperature measurements inside the drying sample showed a non-negligible temperature rise when acoustic power was applied.