Paredi Gianluca, Raboni Samanta, Marchesani Francesco, Ordoudi Stella A, Tsimidou Maria Z, Mozzarelli Andrea
Department of Pharmacy, Interdepartment Center SITEIA.PARMA, University of Parma, Parma 43124, Italy.
Laboratory of Food Chemistry and Technology, School of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
Molecules. 2016 Jan 29;21(2):167. doi: 10.3390/molecules21020167.
Saffron is a spice comprised of the dried stigmas and styles of Crocus sativus L. flowers and, since it is very expensive, it is frequently adulterated. So far, proteomic tools have never been applied to characterize the proteome of saffron or identify possible cases of fraud. In this study, 1D-Gel Electrophoresis was carried out to characterize the protein profile of (i) fresh stigmas and styles of the plant; (ii) dried stigmas and styles from different geographical origins (Spanish, Italian, Greek and Iranian) that had been stored for various periods of time after their processing; and (iii) two common plant adulterants, dried petals of Carthamus tinctorius L. and dried fruits of Gardenia jasminoides Ellis. A selective protein extraction protocol was applied to avoid interference from colored saffron metabolites, such as crocins, during electrophoretic analyses of saffron. We succeeded in separating and assigning the molecular weights to more than 20 proteins. In spite of the unavailability of the genome of saffron, we were able to identify five proteins by Peptide Mass Fingerprinting: phosphoenolpyruvate carboxylase 3, heat shock cognate 70 KDa protein, crocetin glucosyltransferase 2, α-1,4-glucan-protein synthase and glyceraldehydes-3-phosphate dehydrogenase-2. Our findings indicate that (i) few bands are present in all saffron samples independently of origin and storage time, with amounts that significantly vary among samples and (ii) aging during saffron storage is associated with a reduction in the number of detectable bands, suggesting that proteases are still active. The protein pattern of saffron was quite distinct from those of two common adulterants, such as the dried petals of Carthamus tinctorius and the dried fruits of Gardenia jasminoides indicating that proteomic analyses could be exploited for detecting possible frauds.
藏红花是一种由番红花（Crocus sativus L.）花朵的干燥柱头和花柱组成的香料，由于其价格昂贵，经常被掺假。到目前为止，蛋白质组学工具从未被用于表征藏红花的蛋白质组或识别可能的掺假情况。在本研究中，进行了一维凝胶电泳以表征：（i）该植物新鲜柱头和花柱的蛋白质谱；（ii）来自不同地理来源（西班牙、意大利、希腊和伊朗）的干燥柱头和花柱，这些样品在加工后已储存了不同时间；以及（iii）两种常见的植物掺假物，即红花（Carthamus tinctorius L.）的干燥花瓣和栀子（Gardenia jasminoides Ellis）的干燥果实。应用了一种选择性蛋白质提取方案，以避免在藏红花的电泳分析过程中受到藏红花有色代谢物（如藏花素）的干扰。我们成功分离并确定了20多种蛋白质的分子量。尽管藏红花的基因组不可用，但我们能够通过肽质量指纹图谱鉴定出五种蛋白质：磷酸烯醇式丙酮酸羧化酶3、热休克同源70 kDa蛋白、藏红花素糖基转移酶2、α-1,4-葡聚糖-蛋白质合酶和甘油醛-3-磷酸脱氢酶-2。我们的研究结果表明：（i）所有藏红花样品中均存在少量条带，与产地和储存时间无关，但其含量在样品之间存在显著差异；（ii）藏红花储存过程中的老化与可检测条带数量的减少有关，这表明蛋白酶仍然具有活性。藏红花的蛋白质模式与两种常见掺假物（如红花的干燥花瓣和栀子的干燥果实）的蛋白质模式截然不同，这表明蛋白质组学分析可用于检测可能的掺假情况。
