该研究评价了超声辅助五种小分子糖渗透处理后冻干油柑的理化特性及体外抗氧化活性。结果表明：相比对照组，经超声辅助渗糖处理的油柑水分损失率、固形物增加率升高；冻干油柑内部孔隙更加致密，硬度显著提高、脆度基本保持，复水性下降；低聚异麦芽糖处理组的吸湿率（18.25%）低于对照组（22.54%）；葡萄糖和麦芽糖处理组的冻干油柑色差ΔE小，分别为2.73和1.71，即颜色保留率高；低聚麦芽糖和蔗糖对冻干油柑的风味强化效果较好；蔗糖、葡萄糖和麦芽糖处理组的冻干油柑可滴定酸含量较低；与对照组玻璃化转变温度（Tg=43.66 ℃）相比，麦芽糖处理组的Tg 升高到45.53 ℃，其他处理组则显著降低了样品的Tg ；除木糖醇处理组（9.44 mg/g）外，不同超声渗糖处理组的总酚保留率均较高；蔗糖和低聚异麦芽糖渗透处理可有效保持冻干油柑的体外抗氧化能力。总的来说，超声辅助蔗糖和低异聚麦芽糖渗透处理的冻干油柑品质较好，其中低异聚麦芽糖可作为一种蔗糖替代品用于开发功能性冻干油柑。

The physicochemical properties and antioxidant activities of freeze-dried Phyllanthus emblica (FDP) obtained by ultrasound-assisted osmotic treatment with five types of small molecular sugars were evaluated. The results showed that the water loss rate and the solid content rate increased, and the internal pores became denser, with significantly increased hardness and maintained brittleness, but decreased rehydration rate compared with the control group. The hygroscopic rate of the isomalto-oligosaccharide treatment group (18.25%) was lower than that of the control group (22.54%). The ΔE of the glucose and maltose treatment groups was 2.73 and 1.71, respectively, indicating that they exhibited potent color protection. Isomalto-oligosaccharide and sucrose treatment had a flavor-strengthening effect on FDP. The sucrose, glucose, and maltose treatments reduced the titrable acid content of FDP. The glass transition temperature (Tg) of the maltose treatment group increased to 45.53 ℃, whereas the Tg of other treatment groups significantly decreased compared with the control group (43.66 ℃). Except for the xylitol treatment group (9.44 mg/g), the total phenol retention rate was high in the different treatment groups. The antioxidant capacity of FDP was maintained by sucrose and isomaltose osmosis. In conclusion, the quality and antioxidant activity levels of FDP treated using ultrasound-assisted sucrose and isomalto-oligosaccharide osmosis were higher than those of other treatments. Thus, isomalto-oligosaccharide emerges as a viable substitute for sucrose in the development of functional lyophilized P. emblica.

广东省科技计划项目（2022B0202160004）；广东省区域联合基金青年基金项目（2021A1515110660）；广东省驻镇帮镇扶村科技特派员项目（KTP20210380）