Effects of Different High Temperature Heat Pump Drying Conditions on the Quality of Dried Longan

doi:10.7506/spkx1002-6630-201404007

Abstract

Abstract:

The effects of different drying temperatures and different air velocities of high temperature heat pump drying
(HTHPD) on general physicochemical properties, color, texture and active components of dried longan were investigated.
Results showed that dried longan exhibited increased total acid content and decreased rehydration rate as the drying
temperature increased. The pH value of dried longan decreased as the drying temperature increased at the same air velocity.
Generally, the color of dried longan became darker (yellow) depending on both drying temperature and air velocity. The
overall changes in springiness, resilience hardness, chewiness and cohesiveness of dried longan were not significant
under different drying conditions. Adhesiveness value became higher when the air velocity was lower. The content of free
phenolic compounds reached the highest level when the dyring temperature was 60 ℃, while the contents of bound phenolic
compounds and polysaccharides were independent of the drying conditions.

Key words: dried longan, high temperature heat pump drying, drying conditions, quality

CLC Number:

TS255.42

LIN Xian, DENG Cai-ling, XU Yu-juan, TANG Dao-bang, WU Ji-jun, CHEN Yu-long, ZHANG Yan. Effects of Different High Temperature Heat Pump Drying Conditions on the Quality of Dried Longan[J]. FOOD SCIENCE, 2014, 35(4): 30-34.

References

[1]潘学文,曾莲,李建光等.广东省龙眼产业现状与发展对策[J].广东农业科学,2009,(1):124-127

[2] 石骏.干制加工对龙眼品质及抗氧化活性的影响[D].华中农业大学,2011

[3] Hiia C L, Lawa C L and Suzannahb S. Drying kinetics of the individual layer of cocoa beans during heat pump drying[J].Journal of Food Engineering.,2012,108(2):276-282

[4]陈坤杰,李娟玲,张瑞合.热泵干燥技术的应用现状与展望[J].农业机械学报,2000,31(3):109-111

[5]石骏.廖森泰,张名位等. 干制加工对龙眼果肉多酚组成及抗氧化活性的影响[J].华南师范大学学报自然科学版,2011,:111-115

[6]Wolfe K, Wu X and Liu RH.Antioxidant activity of apple peels[J].Journal of Agricultural and Food,2003,51(3):609-614

[7]Zhong K and Wang Q.Optimization of ultrasonic extraction of polysaccharides from dried longan pulp using response surface methodology[J].Carbohydrate Polymers,2010,80(1):19-25

[8] 阚建全.食品化学[M].中国农业大学出版社,北京,2002:49-60

[9] 杨韦杰.荔枝热泵干燥及果干霉变控制技术研究[D].江西农业大学,2012

[10] 张绪坤.热泵干燥动力学分析及典型物料干燥性能研究[D].中国农业大学,2005

[11]Phoungchandang S.and Saentaweesuk SEffect of two stage, tray and heat pump assisted-dehumidified drying on drying characteristics and qualities of dried ginger[J].. Food and Bioproducts Processing,2011,89:429-437

[12]Yemi? O, Bakkalba?? E and Art?k N.Changes in pigment profile and surface colour of fig (Ficus carica L) during drying[J].. International Journal of Food Science & Technology,2012,47(8):1710-1719

[13]Soponronnarit S, Nathakaranakule A, Wetchacama S, et al.Fruit drying using heat pump[J].RERIC International Journal,1998,20(l):39-53

[14]Artnaseaw A, Theerakulpisut S and Benjapiyaporn C.Development of a vacuum heat pump dryer for drying chilli[J].Biosystems Engineering,2010,105:130-138

[15]Guiné RPF and Barroca MJ.Effect of drying treatments on texture and color of vegetables (pumpkin and green pepper)[J].Food and Bioproducts Processing,2012,90:58-63

[16]温靖,徐玉娟,肖更生等.不同品种龙眼果实加工特性比较研究[J].食品科学,2010,31(01):71-75

[17]姜松,王海鸥.TPA质构分析及测试条件对苹果TPA质构分析的影响[J].食品科学,2004,25(12):68-71

[18] 徐将,安凤平,赖彩如.过热蒸汽膨化干燥番茄及其理化品质[J].福建农林大学学报(自然科学版)[J].,2013,42(1):93-99

[19]Mrad ND, Boudhrioua N, Kechaou N,et al.Influence of air drying temperature on kinetics, physicochemical properties, total phenolic content and ascorbic acid of pears[J].Food and Bioproducts Processing,2012,90(3):433-441

[20] Yousif AN，Durance TD，Scaman DH et al.Headspace volatiles and physical characteristics of vacuum-microwave, air, and freeze-dried oregano (Lippia berlandieri Schauer) [J].Journal of Food Science,2006,65(6):926-930

[21] 阚建全.食品技术原理[M].中国农业大学出版社,北京,2002:251-256

[22]李忠虎,蔺海明和陈垣等.不同干燥方式对党参多糖含量的影响[J].甘肃农业大学学报,2007,42(3):64-67