荔枝果实干制加工的热烫和无硫护色工艺  

Technologies of Blanching and Sulfur-free Color-protecting in Litchi Fruit During Drying Processing

作　　者：高志强[1,2,3] 沈夏筠[2] 林育钊[2,3,4] 曾玲珍 林河通 GAO Zhiqiang;SHEN Xiajun;LIN Yuzhao;ZENG Lingzhen;LIN Hetong(College of Food Engineering,Zhangzhou Institute of Technology,Zhangzhou,Fujian 363000,China;College of Food Science,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China;Key Laboratory of Postharvest Biology of SubtropicalSpecial Agricultural Products(Fujian Agriculture and Forestry University),Fujian Provincial Universities,Fuzhou,Fujian 350002,China;Institute of Postharvest Technology of Agricultural Products,Fujian Agriculture and Forestry University,Fuzhou,Fujian350002,China)

机构地区：[1]漳州职业技术学院食品工程学院,福建漳州363000 [2]福建农林大学食品科学学院,福建福州350002 [3]亚热带特色农产品采后生物学(福建农林大学)福建省高校重点实验室,福建福州350002 [4]福建农林大学农产品产后技术研究所,福建福州350002

出　　处：《热带作物学报》2022年第3期614-621,共8页Chinese Journal of Tropical Crops

基　　金：农业农村部公益性行业荔枝科研专项(No.nyhyzx07-031);福建省科技计划项目(No.2018N2002);福建农林大学科技创新专项基金项目(No.CXZX2020115A)。

摘　　要：荔枝是我国南方一种重要的热带、亚热带水果,具有较高的营养价值和商业潜力。然而,在高温高湿季节,采后荔枝果实极易发生腐烂变质、果皮褐变、病原菌侵染等品质劣变现象。因此,荔枝果实除鲜食外,常被加工成不同的商业产品,特别是荔枝果干。干制荔枝由于干制加工时间较长,易发生果皮褐变,导致其外观色泽、产品质量和风味丧失,最终限制荔枝加工业的可持续发展。因此,有必要开发一种安全的、有效的干制加工工艺,以延缓干制荔枝果皮褐变,稳定荔枝果皮外观色泽,提高干制荔枝的产品品质。有研究报道,热烫和无硫护色液可以通过钝化多酚氧化酶活性,进而减缓园艺产品在干制加工过程中发生酶促褐变,从而提高产品质量。然而,未见关于利用安全护色技术延缓荔枝果实干制加工过程中果皮褐变发生和稳定其外观品质的研究报道。因此,为控制荔枝果实在热风干制过程中发生褐变,研究干制荔枝果实加工的热烫和无硫护色工艺。通过L9(34)正交试验设计,研究不同浸酸热烫(热烫温度、热烫时间和柠檬酸浓度)和不同无硫护色液(柠檬酸、氯化钠和抗坏血酸)对荔枝果皮多酚氧化酶活性的钝化作用,分析干制荔枝果实加工的最佳浸酸热烫和无硫护色工艺参数。结果表明:当热烫温度为95℃,热烫时间为3 min,柠檬酸浓度为0.3%时,荔枝果实的热烫效果最佳;当无硫护色液配比为0.2%柠檬酸+2.0%氯化钠+0.3%抗坏血酸时,对荔枝果实干制品的护色效果最好。因此,上述适宜工艺参数能有效控制荔枝果实干制过程中的果皮褐变,较好地保持荔枝果实干制产品的品质。Litchi fruit,with the high nutritive value and commercial potential,is an important tropical and subtropical fruit in south China.However,the harvested litchi fruit is prone to quality deterioration such as rot occurrence,pericarp browning and pathogen infection in high temperature and high humidity seasons.Thus,litchi fruit is often processed into different commercial products in addition to fresh-eating,especially dried litchi.Due to the long drying processing time,the dried litchi is highly susceptible to serious pericarp browning development,resulting in the loss of appearance color,product quality and fruit flavor of the dried litchi,and eventually limit the sustainable development of litchi processing industry.Therefore,it is necessary to develop a safe and effective drying processing technology for the dried litchi fruit to delay pericarp browning,stabilize appearance color and improve quality of the dried litchi fruit.Some studies reported that the technologies of blanching and sulfur-free color protection liquids could effectively control the occurrence of enzymatic browning during drying processing by inactivating the activity of polyphenol oxidase(PPO),and thus improve the product quality of the dried horticultural products.However,there are few reports on delaying pericarp browning development and maintaining appearance quality in the dried litchi during hot-air drying processing by using the safe color-protecting technology.Therefore,in this study,in order to control the pericarp browning of litchi fruit during hot-air drying,the technologies of blanching and sulfur-free color-protecting in litchi fruit during drying processing were studied.An L9(34)orthogonal experimental design was used to investigate the effects of different blanching conditions such as blanching temperature and blanching time with different concentration of citric acid,and different sulfur-free color protection liquids including citric acid,sodium chloride(NaCl)and ascorbic acid,on the in-activation of PPO in the pericarp of litc

关 键 词：荔枝 果实 干制 热烫 无硫护色 

分 类 号：TS255.36[轻工技术与工程—农产品加工及贮藏工程]