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小麦制粉产品稳定碳、氮同位素组成特征

2017-02-16刘宏艳郭波莉魏帅姜涛张森燊魏益民

中国农业科学 2017年3期
关键词:麦粉制粉麸皮

刘宏艳,郭波莉,魏帅,姜涛,张森燊,魏益民

(中国农业科学院农产品加工研究所/农业部农产品加工综合性重点实验室,北京 100193)

小麦制粉产品稳定碳、氮同位素组成特征

刘宏艳,郭波莉,魏帅,姜涛,张森燊,魏益民

(中国农业科学院农产品加工研究所/农业部农产品加工综合性重点实验室,北京 100193)

【目的】小麦制粉产品稳定同位素指纹相对于全粒粉是否存在分馏效应,这些产品能否用于小麦的产地溯源,以及利用稳定同位素是否能实现对小麦制粉产品来源地的鉴别还不清楚。系统分析全麦粉及各制粉产品中碳、氮同位素在地域间、基因型间的差异,揭示小麦制粉产品碳、氮同位素的组成特征及相关性,为小麦及其制品产地溯源提供理论与技术支撑。【方法】2014年将3个不同基因型小麦品种(邯6172、衡5229和周麦16),种植于河北石家庄赵县、陕西杨凌区和河南省新乡辉县。每个地域3个小区,每小区面积10 m2,试验田按照当地小麦品种区域试验管理。2015年收获期于3个地域共采集27份小麦样品,小麦籽粒粉碎制得全麦粉;同时将小麦籽粒加工制粉,得到面粉、次粉和麸皮。利用元素分析-同位素比率质谱仪(EA-IRMS)测定全麦粉及制粉产品(麸皮、次粉和面粉)中的稳定碳、氮同位素。结合单因素方差分析及Duncan多重比较分析解析碳、氮同位素在不同地域、不同基因型以及不同制粉产品间的差异,结合皮尔逊相关分析及线性回归分析,解析不同种类样品碳、氮同位素的相关性。【结果】不同地域来源全麦粉及制粉产品中碳、氮同位素均有显著差异(P<0.05),碳同位素在地域间变化趋势为杨凌>辉县>赵县,氮同位素在地域间变化趋势为辉县>赵县>杨凌;全麦粉、麸皮和面粉中碳同位素及各类产品中氮同位素在基因型间均无显著差异,次粉中碳同位素在邯6172和衡5229之间有显著差异;碳同位素在全麦粉和不同制粉产品间存在显著差异(P<0.05),面粉对13C略显富集,次粉和麸皮相对贫化13C,而氮同位素在四类产品间无显著差异;全麦粉和各制粉产品碳、氮同位素相互之间均呈极显著相关关系(P<0.01)。【结论】碳同位素在小麦不同制粉产品间有显著差异,氮同位素在小麦不同制粉产品间无显著差异,不同制粉产品与小麦全麦粉中碳、氮同位素呈极显著相关关系;全麦粉及制粉产品中碳、氮同位素具有显著的地域特征,可用于小麦及其制粉产品的产地溯源。

小麦;制粉;面粉;产地溯源;稳定碳同位素;稳定氮同位素

0 引言

【研究意义】小麦是国内外谷物贸易的重要粮食作物,然而,为获取经济利益,跨地域交易中优质小麦经常被伪劣小麦替代,对消费者以及合法的生产商均带来较大的负面影响[1]。小麦产地溯源技术的建立,可有效协助政府监管、保护消费者利益、保障粮食安全。稳定同位素是用于小麦产地溯源的有效指标,研究小麦及其制粉产品中稳定同位素的组成特征及其在地域间、基因型间的变化规律,有助于扩大稳定同位素溯源指纹技术的应用范围,可为小麦产地溯源及小麦产业链追溯提供理论和技术支撑。【前人研究进展】由于光合过程中羧化酶对同位素的分馏效应以及气孔的扩散分馏效应不同, C3植物、C4植物和CAM植物的13C有明显区别。一般C3植物的δ13C=-23‰—-38‰,C4植物的δ13C= -12‰—-14‰,CAM植物δ13C值界于C3和C4植物之间[2]。另一方面,影响植物碳同位素分馏的气候环境因素有温度、降水、压力、光照、大气压及大气中 CO2的碳同位素组成等[3]。因此,即使同一种植物,其体内碳同位素组成也因不同地域环境因素的差异而不同。目前,稳定碳同位素指纹溯源技术已被应用于谷物[4-6]、酒类[7-8]、果蔬[9-11]等植源性农产品的产地溯源中。动物通过食物链摄食不同种类不同配比的植物,使得碳同位素也在肉类[12-13]、奶类[14-16]、鱼类[17]等动物源性食品产地溯源中得以应用。植物中的氮取决于土壤中的氮池(硝酸盐和氨水),而土壤中氮同位素组成取决于地理和气候条件,并与农业施肥有关,其通过影响矿化、硝化、氮的吸收和反硝化等生物转化过程,进而影响氮同位素分馏效应和氮的流失程度[18-19]。目前,用于小麦产地溯源研究的样品主要是全麦粉,BRANCH等[20]测定了来自美国、加拿大和欧洲小麦全麦粉中矿物元素含量(Cd、Se)与稳定同位素组成(δ13C、δ15N、208Pb/206Pb、207Pb/206Pb和87Sr/86Sr),发现单独使用δ13C可完全区分3个不同地域来源的小麦样品。LUO等[21]测定来自澳大利亚、美国、加拿大以及中国江苏省和山东省的 35份全麦粉样品,发现 δ13C在不同地域间具有显著差异(P<0.05),利用δ13C、δ15N同位素绘制二维分布图,能够明显区分不同地域间样品。全麦粉是由小麦籽粒粉碎制成,其稳定同位素组成表征籽粒中各种成分同位素的权重。小麦的主要消费途径是制成面粉,该过程还产生麸皮和次粉两类制粉产品。前人研究表明,矿物元素溯源指纹在麸皮、次粉和面粉间具有显著差异[22],而稳定同位素在不同制粉产品间是否存在分馏效应,不同产品中碳、氮同位素在地域间以及基因型间的表现是否一致,均为未知。【本研究切入点】小麦制粉产品中稳定同位素能否表征地域特征、进而应用于小麦产地及其自身的产地判别还不清楚,全麦粉与制粉产品中碳、氮同位素之间相关性的研究还未见报道。【拟解决的关键问题】以小麦为模式植物,设计模型试验,解析不同地域、不同基因型和不同制粉产品中碳、氮同位素的差异特征,明确全麦粉与制粉产品中碳、氮同位素的关系,为小麦及制粉产品的产地溯源提供理论参考。

1 材料与方法

1.1 试验材料

2014年选择3种基因型小麦(邯6172、衡5229、周麦16),分别种植于河北省石家庄赵县、河南省新乡市辉县和陕西省杨凌区3个试验点。每个地域3个基因型小麦随机排列,每个小区面积 10 m2。试验田按照当地小麦基因型区域试验管理。2015年收获期在每个试验点每个小区随机选择3个点作为重复,每点收割1 m2,共采集小麦样品27份。样品信息见表1。

表1 各试验站地理位置、气象因子及田间措施Table 1 The geographic locations, climate factors and field management of each experiment field

1.2 试验方法

1.2.1 样品前处理 将收获后小麦进行晾晒,手工脱粒,然后将小麦籽粒运往实验室进行前处理。挑出小麦籽粒中的石子、杂草等杂物,用去离子水反复冲洗干净,38℃烘箱内约24 h烘干至恒重。烘干样品用植物粉碎机粉碎,过100目筛,得到全麦粉样品。

1.2.2 小麦制粉 称取300 g小麦籽粒样品,进行润麦。添加超纯水(Milli-Q,Millipore,USA),调整衡5229和周麦16小麦含水率到14.5%,调整邯6172小麦含水率到15%,润麦时间24 h。采用实验性制粉机(LRMM8040-3-D,中国无锡锡粮机械制造有限公司)配合粉筛(LFS-30,中国无锡锡粮机械制造有限公司)分离小麦麸皮、次粉与面粉。麸皮和次粉样品用植物粉碎机粉碎,过100目筛,烘干备用。

1.2.3 样品测定 称取5 mg样品放入锡箔杯中,通过自动进样器进入元素分析仪(vario PYRO cube,Elementar,Germany),通过燃烧与还原转化为纯净的CO2和N2气体,CO2再经过稀释器稀释,最后进入稳定同位素质谱仪(IsoPrime100,IsoPrime,UK)进行检测。具体的工作参数如下:

元素分析仪条件:燃烧炉温度为1 020℃,还原炉温度为600℃,载气He流量为230 mL·min-1。

质谱仪条件:分析过程中,每12个样品穿插一个实验室标样,IAEA600(δ13CPDB=(-27.771±0.043)‰,δ15Nair=(1.0±0.2)‰)对测定结果进行校正。

稳定同位素比率计算如下:

δ(‰)=(R样品/R标准-1)×1000

其中,R为重同位素与轻同位素丰度比,即13C/12C和15N/14N, δ13C的相对标准为V-PDB,δ15N的相对标准是空气中氮气。

测定时,δ13C和δ15N的连续测定精度<0.2‰。

1.3 数据处理及质量控制

用SPSS 18.0软件分别对数据进行单因素方差分析,Duncan多重比较分析,皮尔逊(Pearson)相关分析。

2 结果

2.1 小麦及制粉产品中碳、氮同位素在地域间的差异

通过对不同地域全麦粉及不同制粉产品中碳、氮同位素进行单因素方差分析,结果表明,全麦粉及制粉产品中碳同位素在赵县与辉县/杨凌间有显著差异,氮同位素在不同地域间有显著差异(P<0.05)(表2)。各类样品中碳同位素在不同地域间变化趋势一致,均为杨凌最高,赵县最低;各类样品中氮同位素在地域间变化趋势也一致,均为辉县>赵县>杨凌。小麦中氮同位素值与当地使用肥料的种类有一定关系,辉县施用复合肥(δ15N=(4.39±0.41)‰),杨凌施用尿素(δ15N=(-6.89±0.03)‰)和磷酸二铵(δ15N=(-3.34±0.07)‰),赵县施用尿素(δ15N=(-0.47±0.00)‰)和磷酸二铵(δ15N=(1.54±0.04)‰)。

表2 不同地域全麦粉及小麦制粉产品中的碳、氮同位素Table 2 δ13C, δ15N in wheat milling fractions among different regions

2.2 小麦及制粉产品中碳、氮同位素在基因型间的差异

通过对不同基因型的全麦粉及制粉产品中碳、氮同位素进行单因素方差分析,结果表明,全麦粉、麸皮和面粉中碳同位素在3种基因型间无显著差异,次粉中碳同位素在邯6172和衡5229之间有显著差异;全麦粉及其他制粉产品中氮同位素在不同基因型间均无显著差异(表3)。

2.3 小麦制粉产品间碳、氮同位素差异

图1表示全麦粉与制粉产品中碳、氮同位素分布,以及单因素方差分析多重比较结果。其中全麦粉碳同位素处于中间,平均值为-28.24‰,变幅为-28.90‰—-27.44‰,面粉碳同位素最高,平均值为-28.07‰,变幅为-28.71‰—-27.57‰,麸皮碳同位素最低,平均值为-29.02‰,变幅为-30.02‰—-28.54‰。全麦粉、次粉及麸皮中碳同位素存在显著差异,其中麸皮和次粉中碳同位素相对贫化。尽管全麦粉与面粉中碳同位素无显著差异,但面粉中碳同位素平均值高于全麦粉,略显富集。

表3 不同基因型全麦粉及制粉产品中的碳、氮同位素Table 3 δ13C, δ15N in wheat milling fractions among different genotypes

图1 小麦制粉产品中稳定碳(A)、氮(B)同位素组成Fig. 1 δ13C (A) and δ15N (B) of different milling fractions

氮同位素在不同制粉产品间无显著差异。全麦粉、麸皮、次粉及面粉的氮同位素变幅分别为-4.50‰—5.15‰、-4.20‰—4.79‰、-4.66‰—4.56‰及-3.92‰—5.10‰。

2.4 小麦及制粉产品碳、氮同位素的相关性

为了研究全麦粉与不同制粉产品中碳、氮同位素的关系,对数据采用皮尔逊相关分析(表4)。结果表明,全麦粉与不同制粉产品中碳、氮同位素均呈极显著正相关(P<0.01),3类制粉产品之间碳、氮同位素也呈极显著正相关(P<0.01)。

利用3类不同制粉产品与全麦粉碳、氮同位素进行线性回归分析(图 2),结果表明,麸皮、次粉及面粉的碳同位素与全麦粉碳同位素线性拟合均较好,3条拟合线近似平行,且所有次粉样品位于面粉与麸皮之间。3种制粉产品的氮同位素与全麦粉氮同位素拟合效果优于碳同位素,3条拟合线相互间隔较近,次粉与麸皮存在部分交叉,进一步说明不同制粉产品氮同位素差异较小。

表4 小麦及制粉产品中碳、氮同位素相关分析系数表Table 4 Correlation coefficient of δ13C and δ15N of different wheat milling fractions (n=27)

图2 小麦中碳(A)、氮(B)同位素与制粉产品的线性回归分析Fig. 2 Linear fittings of δ13C (A) and δ15N (B) between whole wheat flour and milling fractions

3 讨论

小麦作为C3植物,其叶片碳同位素组成可表示为 δ13Cplant=δ13Cair-a-(b-a)Ci/Ca[23],表明小麦碳同位素主要受大气CO2的δ13C值、叶片内外CO2分压比的影响。大气CO2的碳同位素值有随纬度升高而增大的趋势[24],而本研究中纬度最低的杨凌小麦体内碳同位素最高,因此其变异来源主要是叶片内外 CO2分压比。小麦碳同位素表现为随海拔升高而增大的趋势,该结果与前人研究一致[25-26],然而,海拔对植物δ13C的影响是多种环境因素综合作用的结果。海拔高度的变化引起降水量、光照、温度、大气压等环境因素的变化,从而改变叶片形态、生理特性及光合气体交换,最终影响植物δ13C值的大小。其中,碳同位素有随湿度的降低而增加,随光照的增强而增大的趋势[3],但以上趋势均未在本研究中显现,可能由于3个地点降水量、湿度和光照强度的变化较小,不足以引起碳同位素变化。因此,本研究中海拔升高主要引起CO2浓度和大气压的降低,导致植物的Ci/Ca值减小,从而导致小麦体内碳同位素的增加。

比较不同地域小麦及化肥中氮同位素组成可知,氮同位素在不同地域间的差异主要受到栽培措施的影响,且受肥料影响较大。一方面化肥的种类不同,氮同位素值不同[27-28]。辉县复合肥的氮同位素显著高于杨凌和赵县施用的尿素和磷酸二铵;即使同一种化肥,生产厂家不同,也具有不同的氮同位素值[29]。杨凌地区小麦施用的尿素和磷酸二铵中氮同位素值均低于赵县小麦施用的这两类化肥的氮同位素值。此外,在一定氮浓度内,有机氮肥输入越多,植物体内的氮同位素随之升高;无机氮肥输入越多,植物体内的氮同位素随之降低[29]。LIM等[30]研究不同氮肥处理对盆栽大白菜和菊花中氮同位素的影响,发现未施肥的白菜和菊花中氮同位素值均显著高于施用尿素处理。本研究中3个试验地点中杨凌施肥量最高,也可能是导致当地小麦体内氮同位素更为贫化的原因之一。

前人研究表明,小麦籽粒碳同位素受基因型影响显著[31-32],并与植物本身的抗旱性和水分利用效率有关[33]。而本研究中全麦粉、面粉及麸皮的碳同位素在不同基因型间无显著差异,可能由于所选的3个小麦品种间碳同位素本身差异较小所致。

在实际的制粉工艺中,麸皮、次粉和面粉中各组分含量因不同的润麦加水量、润麦时间、剥刮力度而略有不同。麦麸约占小麦籽粒的22%—25%,主要由果皮、种皮、糊粉层、少量胚和胚乳组成;次粉约占小麦籽粒的5%左右,其中胚乳高于麸皮而低于面粉,糊粉层的含量高于麸皮和面粉[34-35];面粉主要由胚乳磨制而成,富含淀粉。本研究结果表明,制粉产品相对全麦粉碳同位素产生不同程度的贫化或富集。其中,麸皮和次粉碳同位素相对贫化,可能是由于二者相对于面粉具有较多的纤维素和木质素;另一方面,面粉中碳同位素略显富集,主要由于面粉富含淀粉,前人研究表明淀粉中碳同位素高于木质素和纤维素中碳同位素值[36]。同一品种小麦次粉中的纤维素、木质素和淀粉含量位于麸皮和面粉之间[36],因此,其碳同位素值低于面粉但高于麸皮。

氮同位素在动物不同组织间存在分馏效应。其中,蛋白质含量较高、脂肪含量较低的肌肉组织中氮同位素值较高,而脂肪含量较高的肝脏和肠组织中氮同位素值较低[37-38]。本研究中各类样品中氮同位素无显著差异,可能是由于全麦粉与制粉产品中蛋白质和脂肪含量差异较小导致。

4 结论

小麦制粉产品与全麦粉中碳、氮同位素具有地域特征,且变化趋势一致;小麦制粉产品中碳同位素具有显著差异,氮同位素无显著差异;全麦粉与制粉产品碳、氮同位素之间呈极显著相关性。因此,碳、氮稳定同位素指纹可用于小麦及其制粉产品的产地溯源。今后可进一步研究小麦不同种类蛋白、脂肪等同位素组成特征及其用于小麦产地溯源的可行性。

[1] ZHAO H Y, GUO B L, WEI Y M, ZHANG B, SUN S M, ZHANG L, YAN J H. Determining the geographic origin of wheat using multielement analysis and multivariate statistics. Journal of Agricultural and Food Chemistry, 2011, 59:4397-4402.

[2] 郑永飞, 陈江峰. 稳定同位素地球化学. 北京: 科学出版社, 2000.

ZHENG Y F, CHEN J F. Stable Isotope Geochemistry. Beijing: Science Press, 2000. (in Chinese)

[3] 王国安. 中国北方草本植物及表土有机质碳同位素组成[D]. 北京:中国科学院地质与地球物理研究所, 2001.

WANG G A. Herbaceous plants and soil organic carbon isotope in northern China [D]. Beijing: Institute of Geology and Geophysics, Chinese Academy of Sciences, 2001. (in Chinese)

[4] BRESCIA M A, DI MARTINO G, GUILLOU C, RENIERO F, SACCO A, SERRA F. Determination of the geographical origin of durum wheat semolina samples on the basis of isotopic composition. Rapid Communications in Mass Spectrometry, 2002, 16: 2286-2290. (in Chinese)

[5] KAWASAKI A, ODA H, HIRATA T. Determination of strontium isotope ratio of brown rice for estimating its provenance. Soil Science and Plant Nutrition, 2002, 48(5): 635-640.

[6] ARIYAMA K, SHINOZAKI M, KAWASAKI A. Determination of the geographic origin of rice by chemometrics with strontium and lead isotope ratios and multielement concentrations. Journal of Agricultural and Food Chemistry, 2012, 60: 1628-1634.

[7] DI PAOLA-NARANJO R D, BARONI M V, PODIO N S,RUBINSTEIN H R, FABANI M P, BADINI R G, INGA M, OSTERA H A, CAGNONI M, GALLEGOS E, GAUTIER E, PERAL-GARCIA P, HOOGEWERFF J, WUNDERLIN D A. Fingerprints for main varieties of Argentinean wines: terroir differentiation by inorganic, organic, and stable isotopic analyses coupled to chemometrics. Journal of Agricultural and Food Chemistry, 2011, 59: 7854-7865.

[8] MARCHIONNI S, BRASCHI E, TOMMASINI S, BOLLATI A, CIFELLI F, MULINACCI N, MATTEI M, CONTICELLI S. High-precision87Sr/86Sr analyses in wines and their use as a geological fingerprint for tracing geographic provenance. Journal of Agricultural and Food Chemistry, 2013, 61: 6822-6831.

[9] LI G C, WU Z J, WANG Y H, DONG X C, LI B, HE W D, WANG S C, CUI J H. Identification of geographical origins of Schisandra fruits in China based on stable carbon isotope ratio analysis. European Food Research and Technology, 2011, 232: 797-802.

[10] RUMMEL S, HOELZL S, HORN P, ROSSMANN A, SCHLICHT C. The combination of stable isotope abundance ratios of H, C, N and S with87Sr/86Sr for geographical origin assignment of orange juices. Food Chemistry, 2010, 118: 890-900.

[11] LI Q, CHEN L, DING Q, LIN G. The stable isotope signatures of blackcurrant (Ribes nigrum L.) in main cultivation regions of China: implications for tracing geographic origin. European Food Research and Technology, 2013, 237: 109-116.

[12] GUO B L, WEI Y M, PAN J R, LI Y. Stable C and N isotope ratio analysis for regional geographical traceability of cattle in China. Food Chemistry, 2010, 118: 915-920.

[13] OSORIO M T, MOLONEY A P, SCHMIDT O, MONAHAN F J. Multielement isotope analysis of bovine muscle for determination of international geographical origin of meat. Journal of Agricultural and Food Chemistry, 2011, 59: 3285-3294.

[14] CRITTENDEN R G, ANDREW A S, LEFOURNOUR M, YOUNG M D, MIDDLETON H, STOCKMANN R. Determining the geographic origin of milk in Australasia using multi-element stable isotope ratio analysis. International Dairy Journal, 2007, 17: 421-428.

[15] SCAMPICCHIO M, MIMMO T, CAPICI C, HUCK C, INNOCENTE N, DRUSCH S, CESCO S. Identification of milk origin and process-induced changes in milk by stable isotope ratio mass spectrometry. Journal of Agricultural and Food Chemistry, 2012, 60: 11268-11273.

[16] EHTESHAM E, HAYMAN A R, MCCOMB K A, VAN HALE R, FREW R D. Correlation of geographical location with stable isotope values of hydrogen and carbon of fatty acids from New Zealand milk and bulk milk powder. Journal of Agricultural and Food Chemistry, 2013, 61: 8914-8923.

[17] TURCHINI G M, QUINN G P, JONES P L, PALMERI G, GOOLEY G. Traceablility and discrimination among differently farmed fish: A case study on Australian murray Cod. Journal of Agriculture and Food Chemistry, 2009, 57: 274-281.

[18] 郭波莉, 魏益民, 潘家荣. 同位素指纹分析技术在食品产地溯源中的应用进展. 农业工程学报, 2010, 23(3): 284-289.

GUO B L, WEI Y M, PAN J R. Progress in the application of isotopic fingerprint analysis to food origin traceability. Transactions of the CSAE, 2010, 23(3): 284-289. (in Chinese)

[19] KORNEXL B E, WERNER T, ROßMANN A, SCHMIDT H L. Measurement of stable isotope abundances in milk and milk ingredients - a possible tool for origin assignment and quality control. Zeitschrift für Lebensmittel-Untersuchung und-Forschung, 1997, 205: 19-24.

[20] BRANCH S, BURKE S, EVANS P, FAIRMAN B, WOLFF BRICHE C S J. A preliminary study in determining the geographical origin of wheat using isotope ratio inductively coupled plasma mass spectrometry with13C,15N mass spectrometry. Journal of Analytical Atomic Spectrometry, 2003, 18(18): 17-22.

[21] LUO D, DONG H, LUO H, XIAN Y, WAN J, GUO X, WU Y. The application of stable isotope ratio analysis to determine the geographical origin of wheat. Food Chemistry, 2015, 174: 197-201.

[22] TANG J, ZOU C, HE Z, SHI R, ORTIZ-MONASTERIO I, QU Y, ZHANG Y. Mineral element distributions in milling fractions of Chinese wheats. Journal of Cereal Science, 2008, 48(3): 821-828.

[23] FARQUHAR G D, O’LEARY M H, BERRY J A. On the relationship between carbon isotope discrimination and the intercellular carbon dioxide concentration in leaves. Australian Journal of Plant Physiology, 1982, 9: 121-137.

[24] VAUGHN B H, EVANS C U, WHITE J W C, STILL C J, MASARIE K A, TURNBULL J. Global network measurements of atmospheric trace gas isotopes//Isoscapes, Understanding Movement, Pattern, and Process on Earth Through Isotope Mapping. Amsterdam: Springer. 2009: 3-31.

[25] HOBSON K A, WASSENAAR L I, MILA B, LOVETTE I, DINGLE C, SMITH T B. Stable isotopes as indicators of altitudinal distributions and movement in an Ecuadorean hummingbird community. Oecologia, 2003, 136(2): 302-308.

[26] KORNER C, FARQUHAR G D, ROKSANDIC Z. A global survey of carbon isotope discrimination in plants from high altitude. Oecologia, 1988, 74: 623-632.

[27] VITORIA L, OTERO N, SOLER A, CANALS A. Fertilizer characterization: isotopic data (N, S, O, C, and Sr). Environmental Science & Technology, 2004, 38(12): 3254-3262.

[28] BATEMAN A S, KELLY S D. Fertilizer nitrogen isotope signatures. Isotopes in Environmental & Health Studies, 2007, 43(3): 237-247.

[29] BATEMAN A S, KELLY S D, JICKELLS T D. Nitrogen isotope relationships between crops and fertilizer implications for using nitrogen isotope analysis as an indicator of agricultural regime. Journal of Agricultural and Food Chemistry, 2005, 53: 5760-5765.

[30] LIM S S, CHOI W J, KWAK J H, JUNG J W, CHANG S X, KIM H Y, YOON K S, CHOI S M. Nitrogen and carbon isotope responses of Chinese cabbage and chrysanthemum to the application of liquid pig manure. Plant & Soil, 2007, 295(1): 67-77.

[31] LIU H Y, GUO B L, WEI Y M, WEI S, MA Y Y, ZHANG W. Effects of region, genotype, harvest year and their interactions on δ13C, δ15N and δD in wheat kernels. Food Chemistry, 2015, 171: 56-61.

[32] ARAUS J L, CABRERA-BOSQUET L, SERRET M D, BORT J, NIETO-TALADRIZ M T. Comparative performance of δ13C, δ18O and δ15N for phenotyping durum wheat adaptation to a dryland environment. Functional Plant Biology, 2013, 40: 595-608.

[33] 林植芳, 彭长连, 林桂珠. 大豆和小麦不同基因型的碳同位素分馏作用及水分利用效率. 作物学报, 2001, 27: 409-414.

LIN Z F, PENG C L, LIN G Z. Carbon isotope discrimination and water use efficiency in different soybean and wheat genotypes. Acta Agronomica Sinica, 2001, 27: 409-414. (in Chinese)

[34] 郑学玲, 李利民. 次粉及面粉淀粉的制备、分级与组成分析. 河南工业大学学报(自然科学版), 2008, 29(6): 9-12.

ZHENG X L, LI L M. The preparation, purification and composition analysis of wheat shorts and flour starches. Journal of Henan University of Technology (Natural Science Edition), 2008, 29(6): 9-12. (in Chinese)

[35] 陈薇, 郑学玲, 牛磊, 杨敬雨. 不同品种小麦麸皮、次粉组分分析研究. 粮油加工, 2007(6): 97-100.

CHEN W, ZHENG X L, NIU L, YANG J Y. Different varieties of wheat bran, wheat component analysis. Cereals and Oils Processing, 2007(6): 97-100. (in Chinese)

[36] BOWLING D R, PATAKI D E, RANDERSON J T. Carbon isotopes in terrestrial ecosystem pools and CO2fluxes. New Phytologist, 2008, 178: 24-40.

[37] BELTRÁN M, FERNÁNDEZ-BORRÁS J, MÉDALE F, PÉREZSÁNCHEZ J, KAUSHIK S, BLASCO J. Natural abundance of15N and13C in fish tissues and the use of stable isotopes as dietary protein tracers in rainbow trout and gilthead sea bream. Aquaculture Nutrition, 2009, 15(1): 9-18.

[38] GASTON T F, SUTHERS I M. Spatial varation in δ13C and δ15N of liver, muscle and bone in a rocky reef planktivorous fish: the relative contribution of sewage. Journal of Experimental Marine Biology and Ecology, 2004, 304: 17-33.

(责任编辑 赵伶俐)

Characteristics of Stable Carbon and Nitrogen Isotopic Ratios in Wheat Milling Fractions

LIU HongYan, GUO BoLi, WEI Shuai, JIANG Tao, ZHANG SenShen, WEI YiMin
(Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Comprehensive Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193)

【Objective】 It remains unclear for several points when identifying the geographical origin of wheat. Is there any fractionation for the stable isotopic fingerprints of milling fractions by comparing with whole wheat flour, and whether the stable isotopic fingerprints in milling fractions can be used for identifying the geographical origin of the milling fractions as well as the whole wheat flour? These problems need to be resolved. This study was conducted to reveal the characteristics and correlations of stable carbon (δ13C) and nitrogen (δ15N) isotopic ratios in different milling fractions by analyzing the difference in stable isotopic ratios among milling fractions, regions or genotypes, which could provide a theoretical and technical basis for geographicaltraceability of wheat and its milling fractions.【Method】 In 2014, three genotypes of wheat (Han 6172, Heng 5229 and Zhoumai 16) were grown in three regions of China which were Huixian (Henan Province), Yangling (Shaanxi Province) and Zhaoxian (Hebei Province). Three plots were conducted in each region, the typical size of plot was 10 m2, recommended local agricultural practices were adopted. Totally 27 wheat samples were collected from three regions in 2015, whole wheat flour were obtained by grinding, and flour, wheat shorts and bran were obtained by milling. δ13C and δ15N were measured for whole wheat flour and milling fractions (flour, wheat shorts and bran) by an element analysis-isotope ratio mass spectrometer. One-way analysis of variance combined with Duncan’s multiple comparison was employed to identify the significant differences among different regions, genotypes and milling fractions at isotopic levels, and Pearson correlation analysis and linear regression analysis were used to test the correlations of δ13C and δ15N among different categories of samples.【Result】Significant differences were observed among different regions in δ13C and δ15N in whole wheat flour and milling fractions, and the δ13C in wheat from three regions decreased in the following order: Huixian>Zhaoxian>Yangling. No significant difference was found between different genotypes in δ13C in whole wheat flour, bran and flour, and in δ15N in each category of wheat samples, significant differences were found in δ13C between wheat genotypes of Han 6172 and Heng 5229. Significant differences were also found in δ13C among different categories of wheat samples (P<0.05), δ13C was relatively enriched in flour and depleted in wheat shorts and bran, while no significant difference was found in δ15N among different categories of wheat samples. Significant correlations were found in δ13C and δ15N between different kinds of wheat samples (P<0.01). 【Conclusion】There were significant differences in δ13C among different wheat milling fractions, but no significant differences in δ15N among different wheat milling fractions. Significant correlations were observed between different categories of wheat samples in δ13C and δ15N. Both δ13C and δ15N of whole wheat flour and milling fractions were characterized by geographical features, which could be used for identifying the geographical origin of wheat and its milling products.

wheat; mill; flour; geographical origin; stable carbon isotope; stable nitrogen isotope

2016-07-01;接受日期:2016-09-22

国家自然科学基金(31371774)、国家小麦产业技术体系建设专项(CARS-03)

联系方式:刘宏艳,Tel:010-62815954;E-mail:lhy_cpu@126.com。通信作者魏益民,Tel:010-62815956;Fax:010-62895141;E-mail:weiyimin36 @hotmail.com

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