中国农业科学 ›› 2022, Vol. 55 ›› Issue (7): 1423-1432.doi: 10.3864/j.issn.0578-1752.2022.07.013

• 食品科学与工程 • 上一篇    下一篇

高能电子束辐照对马铃薯贮藏品质及芽眼细胞超微结构的影响

彭雪1(),高月霞1,张琳煊1,高志强2,任亚梅1()   

  1. 1西北农林科技大学食品科学与工程学院,陕西杨凌 712100
    2成都文理学院,成都 610401
  • 收稿日期:2021-07-01 接受日期:2021-09-09 出版日期:2022-04-01 发布日期:2022-04-18
  • 通讯作者: 任亚梅
  • 作者简介:彭雪,E-mail: 1601961692@qq.com
  • 基金资助:
    陕西省科技厅农业攻关项目(K3300219042)

Effects of High-Energy Electron Beam Irradiation on Potato Storage Quality and Bud Eye Cell Ultrastructure

PENG Xue1(),GAO YueXia1,ZHANG LinXuan1,GAO ZhiQiang2,REN YaMei1()   

  1. 1College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi
    2Chengdu College of Arts and Sciences, Chengdu 610401
  • Received:2021-07-01 Accepted:2021-09-09 Online:2022-04-01 Published:2022-04-18
  • Contact: YaMei REN

摘要:

【目的】明确不同剂量高能电子束辐照对马铃薯发芽和贮藏品质的影响,探究其抑制马铃薯发芽的机理。【方法】以‘紫花白'马铃薯为试材,以未经高能电子束辐照马铃薯为对照,分别采用0.3、0.4和0.5 kGy高能电子束对块茎进行辐照处理,然后用0.03 mm牛皮纸袋包装后敞口贮藏于(8±1)℃、相对湿度70%—75%的冷库中,贮藏过程中每周观察记录各组块茎的发芽情况,每25 d取样测定块茎的呼吸强度、失重率、腐烂率、硬度及淀粉、Vc、还原糖等营养物质含量的变化,借助体视显微镜和透射电子显微镜观察块茎芽体形态和芽眼处细胞超微结构的变化。【结果】马铃薯经不同剂量高能电子束辐照后,在(8±1)℃贮藏至200 d均未发芽,休眠期显著延长;高能电子束辐照一定程度上延缓了块茎贮藏过程中可溶性固形物、Vc和淀粉的下降速率,促进了块茎中还原糖的积累,对可溶性蛋白含量无显著影响,块茎贮藏至200 d时具有良好的风味、口感和色泽;抑制了块茎呼吸强度,有利于减缓其衰老进程;但辐照加速了块茎重量和硬度的下降,且随辐照剂量的增大而增强。电镜结果显示高能电子束辐照对块茎芽眼处细胞超微结构形成了损伤,细胞壁畸变、扭曲,发生质壁分离;细胞核外形无规则变化,核内容物降解;随贮藏时间的延长,内质网完全降解;淀粉粒数量明显减少,颗粒减小,但维持了线粒体结构的完整性和稳定性;同时辐照使块茎幼芽直接死亡,芽体随贮藏时间的延长而逐渐干枯。【结论】高能电子束辐照可完全使块茎在(8±1)℃冷藏7个月不发芽,对块茎营养品质无不利影响,有利于保持其良好感官和营养品质;推测高能电子束辐照抑芽与块茎呼吸强度受到抑制相关,减弱了其生理活性;同时,辐照对芽眼细胞结构形成了损伤,并直接使其幼芽死亡干枯。

关键词: 马铃薯, 高能电子束, 贮藏品质, 细胞超微结构

Abstract:

【Objective】The aim of this study was to clarify the effects of high energy electron beam (e-beam) irradiation on potato sprouting and storage quality, and to explore the mechanism of inhibiting sprout. 【Method】By using potato tubers Zihuabai as the raw material and the non-irradiation tubers as the control, the tubers were irradiated with e-beam at 0.3, 0.4 and 0.5 kGy, then, which were packed in 0.03 mm kraft paper bags and stored at (8±1)℃ with a relative humidity of 70%-75%. During storage, the sprouting of tubers was observed and recorded every week, and the respiratory, weight loss rate, decay rate, firmness and changes in the content of nutrients (such as starch, Vc, and reducing sugar) of the tubers were determined every 25 days after storage. Besides, the changes of tuber bud morphology and cell ultrastructure at the bud eye were observed with the stereo microscope and transmission electron microscope, respectively. 【Result】All tubers did not sprouting for 200 days by irradiating with e-beam at 0.3, 0.4 and 0.5 kGy at (8±1)℃, and the dormancy period was significantly prolonged. The reductions of soluble solid, Vc and starch in tubers irradiated with e-beam were lower than that in non-irradiated tubers after 150 days storage, and had no significant effect on the soluble protein content with e-beam irradiation. The accumulation of reducing sugars in the irradiated tubers slightly higher than that in control, and the flavor, taste and color of the tubers after 200 days storage were good. The respiration intensity was inhibited by e-beam irradiated, which was beneficial to slow down its senescence process. However, unfortunately, e-beam accelerated the weight loss and firmness decrease of tuber, and aggravated positively with the increase of irradiation dose. Electron microscopy results showed that the ultrastructure of the cell at the eye of the tuber bud was damaged by e-beam irradiation, and the cell wall was distorted and plasmolysis; the shape of the nucleus changes irregularly, and the nuclear content was degraded; the endoplasmic reticulum completely degraded with the prolong of storage time, and the number of starch granules was obviously reduced and shrunk, but the integrity and stability of the mitochondrial structure were maintained. At the same time, the irradiation caused the tuber shoots to die directly, and the buds gradually wither with the storage time extension. 【Conclusion】 e-beam irradiation could completely inhibit potato tubers sprouting at (8±1)℃ for 7 months, however, it had no adverse effect on the nutritional quality of tubers, which was beneficial to maintain their good sensory and nutritional quality. It was speculated that the suppression of buds by e-beam irradiation related to the respiratory was inhibited, and the physiological activity level was weaken. At the same time, the irradiation damaged the cell structure of the bud eye, and directly caused the buds to die and dry.

Key words: potato, high-energy electron beam, storage quality, cell ultrastructure