Departamento Economía Agroambiental, Escuela Politécnica Superior de Orihuela (EPSO), Universidad Miguel Hernández de Elche (UMH), Carretera de Beniel, km 3.2, 03312 Orihuela, Alicante, Spain.
Departamento Tecnología Agroalimentaria, Grupo Calidad y Seguridad Alimentaria, Escuela Politécnica Superior de Orihuela (EPSO), Universidad Miguel Hernández de Elche (UMH), Carretera de Beniel, km 3.2, 03312 Orihuela, Alicante, Spain.
Molecules. 2020 Aug 10;25(16):3643. doi: 10.3390/molecules25163643.
The effect of different drying techniques (freeze, convective, vacuum-microwave and combined drying) on the drying kinetics, the phytochemical compounds and sensory characteristics in loquat cultivar 'Algar' was studied. The convective drying resulted in the highest amount of total hydroxycinnamic acids (5077 mg/kg wet weight (ww)), with 3-caffeoyl quinic acid and 5-caffeoyl quinic acid being the greatest carotenoids. The highest values of total carotenoids were obtained by the freeze-drying technique (2601 mg/kg ww), followed by all convective treatments and vacuum-microwave at 360 W. The highest carotenoid was β-carotene. The ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (Ferric Ion Reducing Antioxidant Power) values ranged from 2.04 up to 3.27 mmol Trolox/100 g ww, and from 1.89 up to 2.29 mmol Trolox/100 g ww, respectively. As expected, the color difference of freeze-dried samples was the lowest (7.06), similar to combined drying conditions (9.63), whilst the highest value was found after convective drying (37.0). All treatments were sensory acceptable (no off-flavors). However, still, further research is needed to fully optimize these studied drying treatments because the freeze-dried sample still had higher carotenoid content and better instrumental color parameters. Although recently the impact of microwave drying has been studied, this is the first work comparing phytochemical composition of loquat fruit under the different drying methods mentioned above.
不同干燥技术（冷冻、对流、真空微波和组合干燥）对枇杷品种“阿尔加尔”干燥动力学、植物化学化合物和感官特性的影响。对流干燥导致总羟基肉桂酸含量最高（5077mg/kg 湿重（ww）），其中 3-咖啡酰奎宁酸和 5-咖啡酰奎宁酸是最大的类胡萝卜素。真空微波在 360W 下，冻干技术获得的总类胡萝卜素含量最高（2601mg/kg ww），其次是所有对流处理。最高的类胡萝卜素是β-胡萝卜素。ABTS（2,2'- 联氮-双（3-乙基苯并噻唑啉-6-磺酸））和 FRAP（铁离子还原抗氧化能力）值范围为 2.04 至 3.27mmol Trolox/100g ww 和 1.89 至 2.29mmol Trolox/100g ww。如预期的那样，冻干样品的色差最低（7.06），类似于组合干燥条件（9.63），而对流干燥后色差最高（37.0）。所有处理均具有感官可接受性（无异味）。然而，仍需要进一步研究以充分优化这些研究的干燥处理，因为冻干样品仍然具有更高的类胡萝卜素含量和更好的仪器颜色参数。尽管最近已经研究了微波干燥的影响，但这是第一项比较上述不同干燥方法下枇杷果实植物化学成分的工作。
