张彦军等

摘 要 通过研究4种不同工艺条件真空冷冻干燥梯度降温模式对菠萝蜜冻干片含水率、复水率、色泽、氨基酸含量和抗氧化性的影响，探索提供一种外形、颜色保持良好，复水性高、营养成分损失少且能够提高干燥效率的菠萝蜜果肉真空冷冻干燥方法。结果表明，随冻干温度的升高，菠萝蜜果肉冻干片的复水率由2.90%降为2.39%、氨基酸总量5.12%降为2.57%、DPPH自由基清除率随着干燥温度的升高而呈降低的趋势，然而随着温度的升高色差值△E*由18.86增加到27.13。通过对比发现工艺条件1是菠萝蜜果肉最佳冻干工艺，为-20 ℃冷库预冻24 h，真空度为20～60 Pa，冷肼温度（-40±2）℃，加热板温度50～40 ℃，干燥时间16 h。在最佳冻干条件下菠萝蜜果干具有最大的复水率2.90%，与新鲜菠萝蜜果肉相比具有最小的色差值18.86，氨基酸总含量最高为5.12%，具有最高的抗氧化能力。

关键词 菠萝蜜果肉；真空冷冻干燥；复水率；色差；抗氧化性

中图分类号 TS255 文献标识码 A

Optimization of Vacuum Freeze-drying Process of

Jackfruit （Artocarpus heterophyllus Lam.） Fruit

Pulp and Its Physicochemical Properties

ZHANG Yanjun1， ZHU Kexue1， HE Shuzhen1， TAN Lehe1*， FU Lili2

1 Spice and Beverage Research Institute，CATAS，Wanning， Hainan 571533， China

2 Institute of Tropical Bioscience and Biotechnology，CATAS，Haikou， Hainan 571101， China

Abstract In order to provide a vacuum freeze-drying method of jackfruit fruit pulp which can keep the color， good rehydration properties， low loss of nutrition and high efficiency of drying， it was investigated that four different process conditions of vacuum freeze-drying on the physicochemical properties including moisture content， rehydration rate， amounts of amino acids and antioxidant capacity. The results showed that with the temperature increased， the rehydration rate and amounts of amino acids decreased from 2.90%， 5.12% to 2.39%， 2.57%， respectively. The DPPH radical scavenging activity also decreased while the values of △E*increased from 18.86 to 27.13 with the temperature increased， indicating the optimum conditions of vacuum freeze-drying process of jackfruit fruit pulp （the process condition 1） were that fruit pulp samples were pre-freeze at -20 ℃ for 24 hours， then maintaining the vacuum pressure between 20-60 Pa， temperature of cold trap between -38 ℃ and -42 ℃， and heated plate temperature between 50 ℃ and 40 ℃ for 16 hours. Under these optimal conditions， freezing dried jackfruit pulp slice showed the biggest rehydration rate of 2.90%， the lowest chromatic aberration of 18.86， the highest amino acids amounts of 5.12% and antioxidation properties.

Key words Jackfruit fruit pulp；Vacuum freeze-drying；Rehydration rate；Chromatic aberration；Antioxidation

doi 10.3969/j.issn.1000-2561.2015.09.020

菠萝蜜（Artocarpus heterophyllus Lam.）为桑科木菠萝属常绿乔木，又称“木菠萝”、“树菠萝”，是集水果、木本粮食、药用及珍贵木材于一身的热带树种，享有“热带珍果”、“热带水果皇后”等美誉[1]。菠萝蜜原产于印度，目前在中国、泰国、缅甸、斯里兰卡和印度尼西亚等国家均有栽培[2]。菠萝蜜果肉肥厚柔软、口感酸甜、香味浓郁，且含有丰富的糖类化合物、蛋白质、氨基酸、多酚、脂肪酸、维生素、矿物质等营养成分，具有非常高的营养价值[3]；Chowdhury等[4]测定了孟加拉首都达卡市售菠萝蜜不同部位所含的总糖、游离脂肪酸含量；Baliga等[5]通过分析发现菠萝蜜果肉中含碳水化合物16.0%～25.4%，蛋白质1.2%～1.9%，脂肪0.1%～0.4%，矿物质0.87%～0.90%；……