Bong Jessie, Middleditch Martin, Stephens Jonathan M, Loomes Kerry M
School of Biological Sciences and Institute for Innovation in Biotechnology, University of Auckland, Auckland 1010, New Zealand.
Mass Spectrometry Facility, Faculty of Science, University of Auckland, Auckland 1010, New Zealand.
Foods. 2023 May 12;12(10):1968. doi: 10.3390/foods12101968.
New Zealand mānuka () honey is a premium food product. Unfortunately, its high demand has led to "not true to label" marketed mānuka honey. Robust methods are therefore required to determine authenticity. We previously identified three unique nectar-derived proteins in mānuka honey, detected as twelve tryptic peptide markers, and hypothesized these could be used to determine authenticity. We invoked a targeted proteomic approach based on parallel reaction-monitoring (PRM) to selectively monitor relative abundance of these peptides in sixteen mānuka and twenty six non-mānuka honey samples of various floral origin. We included six tryptic peptide markers derived from three bee-derived major royal jelly proteins as potential internal standards. The twelve mānuka-specific tryptic peptide markers were present in all mānuka honeys with minor regional variation. By comparison, they had negligible presence in non-mānuka honeys. Bee-derived peptides were detected in all honeys with similar relative abundance but with sufficient variation precluding their utility as internal standards. Mānuka honeys displayed an inverse relationship between total protein content and the ratio between nectar- to bee-derived peptide abundance. This trend reveals an association between protein content on possible nectar processing time by bees. Overall, these findings demonstrate the first successful application of peptide profiling as an alternative and potentially more robust approach for mānuka honey authentication.
新西兰麦卢卡蜂蜜是一种优质食品。不幸的是，其高需求导致了市场上出现“名不副实”的麦卢卡蜂蜜。因此，需要可靠的方法来确定其真伪。我们之前在麦卢卡蜂蜜中鉴定出三种独特的源自花蜜的蛋白质，检测为12种胰蛋白酶肽标记物，并推测这些标记物可用于确定蜂蜜的真伪。我们采用了基于平行反应监测（PRM）的靶向蛋白质组学方法，以选择性监测这些肽在16个不同花蜜来源的麦卢卡蜂蜜和26个非麦卢卡蜂蜜样品中的相对丰度。我们纳入了六种源自三种蜜蜂主要蜂王浆蛋白的胰蛋白酶肽标记物作为潜在的内标。这12种麦卢卡蜂蜜特有的胰蛋白酶肽标记物在所有麦卢卡蜂蜜中均有存在，只是存在轻微的地区差异。相比之下，它们在非麦卢卡蜂蜜中的含量可以忽略不计。在所有蜂蜜中均检测到了源自蜜蜂的肽，其相对丰度相似，但差异足以排除它们作为内标的效用。麦卢卡蜂蜜的总蛋白含量与源自花蜜和蜜蜂的肽丰度之比呈反比关系。这一趋势揭示了蛋白质含量与蜜蜂对花蜜可能的加工时间之间的关联。总体而言，这些发现证明了肽谱分析作为一种替代方法，且可能是一种更可靠的麦卢卡蜂蜜鉴定方法的首次成功应用。
