中国农业科学 ›› 2021, Vol. 54 ›› Issue (2): 379-391.doi: 10.3864/j.issn.0578-1752.2021.02.013

• 食品科学与工程 • 上一篇    下一篇

高温胁迫下糙米短期储藏气味指纹图谱变化规律的动态分析

刘强(),刘纪伟,田恬,严薇,刘兵,赵思琪,胡秋辉,丁超()   

  1. 南京财经大学食品科学与工程学院/江苏省现代粮食流通与安全协同创新中心/江苏高校粮油质量安全控制及深加工重点实验室,南京 210023
  • 收稿日期:2020-05-27 接受日期:2020-08-18 出版日期:2021-01-16 发布日期:2021-02-03
  • 通讯作者: 丁超
  • 作者简介:刘强,E-mail: qiangliu@nufe.edu.cn
  • 基金资助:
    战略性国际科技创新合作重点专项(2020YFE0200200);国家重点研发计划(SQ2019YFC160040);江苏省高校优势学科建设工程资助项目(PAPD)

Dynamic Analysis for the Characteristics of Flavor Fingerprints for Brown Rice in Short-Term Storage Under High Temperature Stress

LIU Qiang(),LIU JiWei,TIAN Tian,YAN Wei,LIU Bing,ZHAO SiQi,HU QiuHui,DING Chao()   

  1. College of Food Science and Engineering, Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and Safety/Jiangsu Key Laboratory of Quality Control and Further Processing of Cereals and Oil, Nanjing 210023
  • Received:2020-05-27 Accepted:2020-08-18 Online:2021-01-16 Published:2021-02-03
  • Contact: Chao DING

摘要:

【目的】探讨高温胁迫下短期储藏时间内糙米气味指纹图谱变化规律性,为糙米品质劣变的快速检测提供参考。【方法】以17.0%水分含量的新鲜糙米随机等分成6组进行储藏,采用顶空进样方式,分别结合气相色谱质谱联用技术(gas chromatography-mass spectrometry,GC-MS)和气相离子迁移谱技术(gas chromatography-ion mobility spectrometry,GC-IMS),对高温储藏环境(40℃、相对湿度70%)中0、5、10、15、20和25 d的糙米挥发性化学成分及GC-IMS指纹图谱进行对比分析,并结合动态主成分和统计学方法进行数据分析。【结果】GC-MS定量分析表明,在新鲜糙米顶空气体成分中共检测出42种挥发性成分(GC-MS匹配度>85%),主要由醛类、醇类、烃类组成,含量占比超过85%。高温短期储藏15 d后,正己醛含量从初始的(81.09±0.53)μg·kg-1显著上升至(185.18±15.71)μg·kg-1,储藏25 d时,又急剧下降至(12.89±0.72)μg·kg-1P<0.01)。部分物质如苯甲醇、1-辛烯-3-醇、苯乙烯等在储藏过程中被检出。结合GC-IMS方法,乙酸丙酯对应的气味挥发性色谱分离离子迁移信号随储藏时间延长而逐渐降低,可以作为糙米高温储藏期的重要标识物质。动态主成分降维处理后表明,基于GC-IMS气味指纹图谱可以区分不同储藏时间的糙米样品。与GC-MS相比,GC-IMS在糙米挥发性醇类、酮类等挥发性物质定性识别方面优势较为明显。【结论】GC-MS和GC-IMS技术结合气味指纹图谱的主成分分析可以对高温胁迫下短期储藏糙米的挥发特性进行有效的定性与定量分析,为高温环境下不同储藏阶段糙米样品的准确区分和糙米储藏新鲜度的判定提供技术参考。

关键词: 糙米, 气相色谱-质谱法(GC-MS), 气相离子迁移谱(GC-IMS), 挥发性有机物, 气味指纹图谱

Abstract:

【Objective】 Changes of flavor fingerprinting in brown rice during high temperature short-term storage were investigated to establish a novel non-destructive detection methods for quality prediction of brown rice.【Method】 The brown rice with moisture content of 17.0 % (wet basis) was stored for 0, 5, 10, 15, 20 and 25 days under 40℃ temperature with relative humidity of 70%. Brown rice flavor compounds were collected by using headspace solid phase extraction method and its fingerprinting characteristics determined via gas chromatography-mass spectrometry (GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS). Dynamic principal component analysis (dPCA) model based on GC-IMS datasets was constructed.【Result】 Total of 42 volatile organic compounds were identified and quantitated based on GC-MS datasets. Aldehydes, alcohols and esters were the major compounds in flavor of fresh brown rice. After high temperature 15 days of storage, the contents of hexanal increased (P < 0.05) to (185.18±15.71) μg·kg-1 from initial contents of (81.09±0.53) μg·kg-1, and then sharply decreased to (12.89±0.72) μg·kg-1 aat 25 days of storage. Volatile organic compounds, including benzyl alcohol, 1-octene-3-ol and styrene, were successfully identified during storage stage. Based on GC-IMS analysis, ethyl acetate could be selected as the potential volatile markers to evaluate the freshness of brown rice. Good discriminated results were obtained for classifying different storage period of brown rice under via dPCA algorithm based on GC-IMS datasets. GC-IMS could better qualitatively analyze the volatile alcohols and ketones compounds than GC-MS. 【Conclusion】 GC-MS and GC-IMS detection method with dPCA discrimination analysis could obtain reliable flavor fingerprinting, achieve outstanding evaluation performance, and provide technical support for qualitative and quantitative monitoring the freshness of brown rice during high temperature storage.

Key words: brown rice, gas chromatography-mass spectrometry (GC-MS), gas phase ion migration spectrum (GC-IMS), volatile organic compounds, flavor fingerprint