高效液相色谱串联质谱法检测马铃薯及马铃薯粉中α-茄碱和α-卡茄碱含量

建立了高效液相色谱-串联质谱同时测定马铃薯及马铃薯粉中α-茄碱与α-卡茄碱含量的方法。样品采用10%乙酸水溶液匀浆提取3 min,马铃薯粉提取液经Bond Elut C18 SPE柱净化后,采用C18色谱柱分离,液相色谱串联质谱仪检测。结果表明,α-茄碱和α-卡茄碱在0.01~1.00 μg/mL范围内线性关系良好,相关系数分别为0.9998和0.9997。马铃薯和马铃薯粉在低、中、高三个添加浓度范围内,回收率在90.0%~110%之间,相对标准偏差在1.6%~5.0%之间。马铃薯中α-茄碱和α-卡茄碱的定量限分别为0.80和0.42 μg/kg,马铃薯粉中α-茄碱和α-卡茄碱的定量限分别为25和14 μg/kg(S/N=10)。本方法简单快速,灵敏度高,重复性好,适用于马铃薯及马铃薯粉中的α-茄碱和α-卡茄碱检测。     

贮藏期影响不同品种马铃薯龙葵碱风险的主要环境因素

目的探究影响不同品种马铃薯在不同贮藏条件下龙葵碱含量的主要环境因素,探讨马铃薯贮藏过程中龙葵碱含量的变化规律。方法样品经乙酸-乙醇(1:10, V:V)混合溶剂提取后,用甲醇复溶并稀释后,采用高效液相色谱-三重四级杆串联质谱(highperformanceliquidchromatography-triplequadrupoletandemmass spectrometry, HPLC-QQQ-MS)测定马铃薯块茎中龙葵碱含量,通过正交试验研究8个品种的马铃薯块茎在不同贮藏温度(5、15、25℃)、相对湿度(55%、70%、85%)、贮藏时间(8、16、24 d)下龙葵碱含量的变化情况。结果结果表明影响大西洋、新大坪、荷兰15号、夏波蒂与陇薯3号龙葵碱的贮藏主要环境因素为相对湿度;威芋5号与冀张12号的主要环境因素为温度;青薯9号品种的贮藏主要环境因素为时间。结论建议针对不同品种马铃薯重点控制不同环境因素,保障龙葵碱含量安全,其中青薯9号不宜长期贮藏。     

HPLC—ELSD法同时测定马铃薯中α-茄碱和α-卡茄碱含量

建立高效液相色谱—蒸发光散射检测(HPLC—ELSD)同时测定马铃薯中α-茄碱和α-卡茄碱的方法,并对不同样品含量进行测定。结果表明:当ELSD漂移管温度98℃,雾化管温度30℃,载气压力6.90kPa时,以0.1%三氟乙酸水—乙腈为流动相,经梯度洗脱程度,α-茄碱和α-卡茄碱可获得良好分离,色谱峰柱效高。样品用质量100倍的1%甲酸甲醇为提取溶剂在70℃下提取90min,提取液直接注入色谱仪进行检测。α-茄碱标准品在0.196~9.800μg线性关系良好(R2=0.999 5),平均回收率为99.4%,并以该标准曲线同时计算样品中的α-茄碱和α-卡茄碱的含量。马铃薯植物的不同部位均含有生物碱,α-茄碱的含量为0.13~1.59mg/g,α-卡茄碱的含量为0.39~8.28 mg/g;两种生物碱总量为0.52~9.37mg/g,同一部位中α-卡茄碱的含量为α-茄碱的1.2~7.6倍。     

超高效液相色谱-串联质谱法测定马铃薯中α-茄碱和α-卡茄碱

目的 建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)测定马铃薯中α-茄碱和α-卡茄碱的含量。方法 样品经80%甲醇水(V:V, 含0.1%甲酸)溶液提取、稀释后在正离子模式下以电喷雾电离串联质谱进行测定, 外标法定量。结果 α-茄碱和α-卡茄碱在50~1000 μg/L范围内线性良好, 相关系数＞0.99, 方法检出限为20 μg/kg, 定量限为50 μg/kg。在3、5、10 mg/kg的添加水平下, α-茄碱和α-卡茄碱平均回收率在83.5%~96.0%之间, 相对标准偏差(relative standard deviation, RSD), (n=6)在2.97%~5.41%之间。结论 本方法快速、准确、灵敏, 可应用于马铃薯中α-茄碱和α-卡茄碱的同时检测。     

马铃薯糖苷生物碱的水解及其工业应用

马铃薯糖苷生物碱是马铃薯中重要的植物次级代谢产物,在马铃薯的自身防御过程中起到了重要的作用,但同时也给马铃薯产品的品质带来很大的负面影响。本文主要从马铃薯块茎中两种主要的糖苷生物碱α-卡茄碱和α-茄碱的毒性、对马铃薯产品的影响,去除糖苷生物碱的方法以及马铃薯糖苷生物碱水解的研究进展及意义等方面进行综述。本文着重阐述了马铃薯糖苷生物碱在高/低酸浓度下的水解机理、影响水解的因素以及糖苷生物碱对马铃薯浓缩蛋白所带来的影响。期望通过对马铃薯糖苷生物碱水解的综述引起人们对其应用更为广泛的关注,并对马铃薯废弃物的再利用起到指导作用。     

乙醇熏蒸对马铃薯绿变和α-茄碱含量的影响

研究不同浓度乙醇熏蒸处理对马铃薯绿变和α-茄碱含量的影响。结果表明:在光照条件下,马铃薯表皮绿变程度和α-茄碱含量随着贮藏时间的延长而增加;不同浓度乙醇熏蒸处理可有效控制马铃薯绿变并对α-茄碱具有降解作用,贮藏到12 d,马铃薯表皮叶绿素含量与α-茄碱含量明显低于对照,其中1 000μL/L乙醇熏蒸处理效果最佳。     

超高效液相色谱-三重四级杆串联质谱法测定土豆中α-茄碱与α-卡茄碱含量

建立了超高效液相色谱-三重四级杆串联质谱法测定土豆以及薯片中α-茄碱与α-卡茄碱含量的方法。方法 样品经5%乙酸溶液提取,Waters Oasis C₁₈ SPE柱(600 cc)净化后,采用Waters BEH HILIC 色谱柱(100 mm×2.1 mm,1.7 μm)分离。流动相为乙腈∶水(含10 mmol/L乙酸铵)=88∶12(V/V),流速0.3 ml/min。以waters Xevo TQ-S三重四级杆质谱仪在电喷雾正离子化(ESI+)及MRM模式下定量。结果 α-茄碱在0.5～500 ng/ml范围内呈线性相关。方法精密度良好(RSD<10%,n=6),回收率>80%,α-茄碱和α-卡茄碱定量限分别为0.7和0.35 μg/kg(S/N=10)。结论 本方法快速简单,重现性好,灵敏度高,适合于土豆和薯片中α-茄碱和α-卡茄碱的检测。     

马铃薯糖苷生物碱抗真菌活性构效关系研究

采用平板菌丝生长抑制法测定了马铃薯糖苷生物碱茄碱和查茄碱、其酸水解产物β1-查茄碱、β2-查茄碱、γ-查茄碱和β2-茄碱及其硫酸化产物6-O-硫酸查茄碱和6-O-双硫酸茄碱的抗真菌活性,分析了糖链组成和结构与其活性的关系结果表明,糖链的单糖组成、连接方式、连接顺序和单糖数目等对化合物的生物活性均有重要影响.     

异丁醇萃取-高效液相色谱法测定马铃薯中α-茄碱

目的建立异丁醇萃取和高效液相色谱法(HPLC)测定马铃薯中α-茄碱含量的新方法。方法马铃薯匀浆样品经5%乙酸溶液搅拌提取30 min,提取液调节p H至11.0后加入异丁醇进行萃取,萃取液加热浓缩,N2吹干。残渣经甲醇复溶,过0.45μm滤膜后进样,HPLC检测α-茄碱含量。流动相为乙腈-0.02 mol/L磷酸二氢钾溶液(22∶78,V/V),Discovery C18柱(150 mm×4.6 mm,5μm),柱温30℃,检测波长210 nm,进样量20μl。结果在0.02~1.00 mg/ml范围内,α-茄碱的峰面积和浓度的线性关系良好(r=0.999 7)。检测限和定量限分别为0.68和2.27μg/ml,方法检出限为1.38μg/g。样品在0.04、0.40和2.00 mg/g 3个添加水平下的加标回收率为98%~116%。方法精密度RSD为0.16%~1.79%。结论该方法具有快速、简便,准确度和精密度高等特点,适用于马铃薯中的α-茄碱含量的快速检测。     

马铃薯中α-茄碱提取工艺优化

为了获得马铃薯中α-茄碱的最佳提取工艺参数,对其提取温度、提取时间、超声波功率及料液比等参数进行研究,运用响应面Box Behnken中心组合试验设计对α-茄碱的提取工艺进行优化。结果表明:马铃薯中α-茄碱的最佳提取工艺参数为以体积比8:2的乙醇-乙酸混合溶液作提取溶剂,提取温度49℃,提取时间61 min,超声波功率152 W,料液比1:14(g/mL),该条件下α-茄碱提取量为7.715mg/g,RSD为1.74%(n=5),与理论预测值基本吻合,平均回收率为98.21%,RSD为1.33%(n=3),说明该方法的提取率和精密度高、稳定性好,合理可行。     

Glycoalkaloid Concentrations in Aerial Tubers of Potato ( Solanum tuberosumL)

The total glycoalkaloid concentrations in aerial and subterranean tubers of 14 potato genotypes were measured using high-performance liquid chromatography immediately after harvest. Post-harvest, aerial tubers from all genotypes were exposed to 144 h continuous fluorescent light; additionally three genotypes (cvs Home Guard, Kerrs Pink and Desiree) were subjected to mechanical wounding prior to glycoalkaloid analysis. Variations in glycoalkaloid concentrations between aerial tubers taken from a single genotype (cv Kerrs Pink) were determined by analysis of eight aerial tubers formed in the second leaf axil, selected from separate individual plants. Irrespective of genotype, total and individual glycoalkaloid concentrations were higher in aerial than in subterranean tubers. The highest glycoalkaloid concentrations were found in aerial tubers of cv Kerrs Pink (1343·0 mg kg⁻¹ FW) and lowest in cv Lindsey (301·0 mg kg⁻¹ FW). Ratios of α-chaconine: α-solanine in aerial tubers differed significantly ( P< 0·05) from those in subterranean tubers of cv Cara, Golden Wonder, Home Guard, Lindsey, Maris Piper, Record and 8859 indicating that exposure to light during aerial tuber growth enhanced the synthesis of one glycoalkaloid to a greater degree than the other. In all cultivars except cv Maris Piper, exposure of aerial tubers to 144 h continuous fluorescent light post-harvest increased total and individual glycoalkaloids compared with dark-treated controls. However, the ratios of α-chaconine: α-solanine in all genotypes except cv Golden Wonder (decreased α-chaconine: α-solanine, P< 0·05) were not significantly altered in comparison with dark controls, indicating that light exposure of aerial tubers post-harvest fails to enhance selectively synthesis of individual glycoalkaloids in the majority of cultivars. Regardless of cultivar, total glycoalkaloid, α-solanine and α-chaconine concentrations were higher in wounded than unwounded aerial tubers. Wounding stimulated synthesis of α-solanine more than α-chaconine ( P< 0·05) in cv Home Guard and Desiree. Glycoalkaloid concentrations in aerial tubers varied widely from a minimum of 1010 mg kg⁻¹ to a maximum of 2520 mg kg⁻¹ FW when harvested from individual plants of cv Kerrs Pink but selected from equivalent positions on the plant. Throughout the experiments large, non-significant increases in total and individual glycoalkaloid concentrations were recorded following light and wounding treatments. The scientific implications of aerial tuber formation are discussed.     

Glycoalkaloids (α-chaconine and α-solanine) contents of selected Pakistani potato cultivars and their dietary intake assessment

Glycoalkaloids (α-solanine and α-chaconine) are naturally occurring toxic compounds in potato tuber (Solanum tuberosum L.) that cause acute intoxication in humans after their consumption. Present research was conducted to evaluate α-chaconine, α-solanine, and total glycoalkaloids (TGAs) contents in the peel and flesh portions by high-performance liquid chromatography method in selected Pakistani potato cultivars. The α-solanine content varies 45.98 ± 1.63 to 2742.60 ± 92.97 mg/100 g of dry weight (DW) in peel and from 4.01 ± 0.14 to 2466.56 ± 87.21 mg/100 g of DW in flesh. Similarly, α-chaconine content varied from 4.42 ± 0.16 to 6818.40 ± 211.07 mg/100 g of DW in potato peel and from 3.94 ± 0.14 to 475.33 ± 16.81 mg/100 g DW in flesh portion. The TGA concentration varied from 177.20 ± 6.26 to 5449.90 ± 192.68 mg/100 g of DW in peel and from 3.08 ± 0.11 to 14.69 ± 0.52 mg/100 g of DW in flesh portion of all the potato cultivars tested. All the potato cultivars contained lower concentration of TGA than the limits recommended as safe, except 2 cultivars, that is FD8-3 (2539.18 ± 89.77 mg/100 g of DW) and Cardinal (506.16 ± 17.90 mg/kg). The dietary intake assessment of potato cultivars revealed that Cardinal, FD 35-36, FD 8-3, and FD 3-9 contained higher amount of TGA in whole potato, although FD 8-3 only possessed higher content of TGA (154.93 ± 7.75) in its flesh portion rendering it unfit for human consumption. Practical Application: This paper was based on the research conducted on toxic compounds present in all possible potato cultivars in Pakistan. Actually, we quantify the toxic compounds (glycoalkaloids) of potato cultivars through HPLC and their dietary assessment. This paper revealed safety assessment and their application in food industries especially potato processing.     

A simplified method for the determination of total glycoalkaloids in potato tubers

A simplified method for the determination of total glycoalkaloids (TGA) in potato tubers has been developed in which potato tissue is extracted with dilute sulphuric acid and the extract is hydrolysed directly. Analysis is completed in less than 4 h using very simple apparatus and reagents. A colorimetric procedure employing bromothymol blue is used for quantitation. A study of the hydrolysis of α-solanine and α-chaconine and the stability of solanidine and solanthrene under hydrolysis conditions, which was made in order to define optimum conditions for the method, showed that hydrolysis time and temperature are quite critical if reproducible aglycone recovery is to be obtained. The results obtained using the method for tubers of fourteen experimental samples with a wide range of TGA contents compare well with corresponding results obtained using a lengthier and more tedious literature method. Its simplicity makes it a suitable method for plant breeders to use to measure the TGA content of new cultivars of potatoes.     

Genetic and environmental effects on levels of glycoalkaloids in cultivars of potato (Solanum tuberosum L.)

Glycoalkaloids were assayed in fifty-five potato cultivars, fifty-four breeding lines and one other species (S. stolonifer). The total glycoalkaloid content ranged from 16·3 μg/g FW for Alpha to 317·0 μg/g FW for Berita, with most values lying between 35 and 65 μg/g. The α-solanine content, as a percentage of total glycoalkaloids, ranged from 28·3% for Avenir to 57·0% for H42, with the majority of values lying between 38% and 46% α-solanine. There was a highly significant correlation between high total glycoalkaloid content and per cent α-solanine (P < 1%). The presence of β₂-chaconine was also related in a highly significant way to high total glycoalkaloid content. Potatoes grown at Yanco (hot, dry, inland climate) contained more glycoalkaloids (～60%) than when grown at Glen Innes (cooler, high altitude climate). However, there was no significant difference between total and relative glycoalkaloid levels of cultivars grown at Glen Innes and Healesville (coastal, temperate climate). A significantly higher per cent α-solanine content, but not total glycoalkaloid content, was observed for potatoes grown in the second year at Glen Innes.     

The influence of thermal process of coloured potatoes on the content of glycoalkaloids in the potato products

Potato products made from potato varieties with coloured flesh (red and blue-fleshed potatoes) may be an interesting alternative to traditional products. The purpose of this study was to determine the influence of peeling, cooking and frying of red and blue-fleshed potato tubers on the content of glycoalkaloids (α-solanine and α-chaconine) in processed potato products. The material taken for the study consisted of seven coloured potato varieties. French fries and crisps were prepared from two potato variety: Rosalinde and Blue Congo. The content of total glycoalkaloids (TGA) in raw material before and after peeling, in cooked unpeeled and peeled potatoes and also in fried potato products have been determined by HPLC method.     

Direct analysis for the distribution of toxic glycoalkaloids in potato tuber tissue using matrix-assisted laser desorption/ionization mass spectrometric imaging

A simple and rapid analytical method for detection and spatial distribution of glycoalkaloids in potato tubers has been developed for the first time using matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI). For effective MALDI-MSI analysis, we have developed a uniform matrix coating method using 2,5-dihydroxybenzoic acid (2,5-DHB) as the preferred matrix which results in better sensitivity than 2,4,6-trihydroxyacetophenone (2,4,6-THAP) using MALDI-TOF. The relative concentrations of two major and two minor glycoalkaloids, α-chaconine and α-solanine, dehydrochaconine and dehydrosolanine, were clearly detected and distinguished in various parts of potato tuber and their relative amounts were directly compared. We also successfully showed the relative concentrations of glycoalkaloids that were accumulated by light exposure during storage using MALDI-MSI. Therefore, MALDI-MSI has been shown to be a useful technique for screening toxic and bioactive metabolites in foods and medicinal plants.     

Potato Glycoalkaloids: occurrence,biological activities and extraction for biovalorisation – a review

Potato tuber (Solanum tuberosum L.) is the fourth most important agricultural product after wheat, rice and maize. With a total production of 388 million in 2017, c.a. 70% of this total production is processed in developed countries, producing a large amount of potato peel waste (PPW) as by-product. Although PPW is considered as a zero-value by-product by the feed industry because it is too fibrous, for other recycling industries it is an inexpensive by-product due to its significant contents of some interesting nutrients particularly polyphenols and glycoalkaloids. In potato, and Solanum species in general, many glycoalkaloids, predominantly α-chaconine and α-solanine, have been chemically and structurally identified. However, further research is needed to expand the knowledge of the biological values of potato glycoalkaloids in order to develop a recycling process to extract these technologically and nutritionally interesting bioactive ingredients for different sectors, in particular, the agricultural, food and pharmaceutical ones, which are demanding natural, safe and eco-friendly ingredients.     

GLYCOALKALOID CONTENT OF NEWFOUNDLAND GROWN POTATO TUBERS AND POTATO WART TISSUE

Eight cultivars of potato tubers grown in Newfoundland were examined for total glycoalkaloids (TGA) at harvest and after 3, 6, 9 or 12 days exposure to 150 footcandles light. Freshly harvested tubers had TGA ranging from 0.9 to 15.4 mg/100 g of total tuber tissue. TGA increased as a result of long term light exposure in all cases; however, those cultivars surface-pigmented with red or blue anthocyanins were less responsive to light induction. TGA in light exposed tubers ranged from 52–71 mg/100 g for white cultivars, 26–46 mg/100 g for red varieties, and 23–40 mg/100 g for those pigmented with blue anthocyanins. Healthy tubers from plants afflicted with potato wart did not show abnormally high TGA; however, healthy cankers contained as high as 170 mg/100 g. Greening or decomposition of wart tissue was associated with a decline in TGA. Thin-layer chromatography revealed α-solanine and α-chanconine were the principal components in TGA extracts of both tubers and wart tissue.     

High levels of glycoalkaloids in the established swedish potato variety magnum bonum

In 1986, potentially toxic levels of the glycoalkaloids α-solanine and α-chaconine were unexpectedly found in tubers of the established Swedish consumer potato variety Magnum Bonum, leading to the imposition of a conditional sales ban on such potatoes. The combined amounts of α-solanine and α-chaconine in more than 300 commercial lots of Magnum Bonum potatoes analysed as a consequence of the ban ranged from 61 to 665 mg kg^?1 fresh weight with an average of 254 mg kg^?1. Sixty-six percent of the samples exceeded a temporary maximum residue limit of 200 mg kg^?1, 8% were above 400 mg kg^?1. Peeling did not significantly remove the glycoalkaloids in tubers with a high content. The occasional glycoalkaloid elevation was initially attributed to the unusually cold and rainy conditions during the late part of the season in 1986, but subsequent investigations have failed to confirm this hypothesis. Varietal characteristics are likely to have been involved since most other common Swedish varieties seemed to have had normal glycoalkaloid levels in 1986. There were no indications of serious or widespread adverse health effects in consumers due to the high glycoalkaloid levels, although there was circumstantial evidence that a few cases of temporary gastrointestinal disturbances were caused by consumption of Magnum Bonum potatoes with glycoalkaloid concentrations in the range 310–1000 mg kg^?1.