Improving DNA isolation from honey for the botanical origin identification

Abstract

a b s t r a c tHoney is a natural product highly consumed due its known association with health benefits. Monofloral honeys are perceived as better quality products, being the most appreciated by consumers, thus attaining higher market values. Therefore efficient tools are needed as alternatives to the classical microscopic analysis presently used for the botanical origin identification of honey. In the present work, the use of DNA-based methods for the botanical species identification of honey is proposed. For this purpose, five DNA extraction methods (the kits NucleoSpin Plant (methods A and B) and DNeasy Plant Mini Kit, and the in-house CTAB-based and Wizard methods) combined with three different sample pre-treatments were applied to four honey samples (3 monofloral honeys of Calluna vulgaris, Lavandula spp. and Eucalyptus spp. and one multifloral honey). The 15 DNA extraction protocols were compared in terms of DNA integrity, yield and purity, as well as capacity of amplification targeting universal and adh1 specific genes of C. vulgaris. The results demonstrated the superior efficacy of the Wizard method in terms of DNA quality and amplification capacity, when combined with the sample preparation treatment with a mechanical disruption step of pollen to improve DNA yield. Although with considerable lower DNA yields, the CTAB and DNeasy methods were also successful because both were able to clearly amplify heather DNA from the monofloral heather honey.

Botanical authentication of lavender (Lavandula spp.) honey by a novel DNA-barcoding approach coupled to high resolution melting analysis

“…A description of each honey is presented in Table 2. Prior to DNA extraction, the honey samples were pre-treated to discard possible interferences for further analysis (Soares et al, 2015). Briefly, 50 g (4 tubes with 12.5 g each) of each honey sample were frozen (À80 C) overnight.…”

“…DNA from plant species and honey samples was extracted with the commercial kit NucleoSpin ® Plant II (Macherey-Nagel, Düren, Germany), according to the manufacture instructions with some minor modifications, as described by Soares et al (2015). All the DNA extracts were kept at À20 C until further analysis.…”

“…Species-specific real-time PCR assays with TaqMan™ probes were successfully developed to detect relevant species in Corsican honey (acacia, broom, citrus, clover, heather, eucalyptus, lavender, linden, oak, olive, rape, rockrose, rosemary, sunflower, and sweet chestnut) (Laube et al, 2010). However, previous sample pre-treatments and the selection/optimisation of DNA extraction from honey are crucial steps for further amplification by polymerase chain reaction (PCR) (Jain, Jesus, Marchioro, & Araújo, 2013;Lalhmangaihi, Ghatak, Laha, Gurusubramanian, & Kumar, 2014;Soares, Amaral, Oliveira, & Mafra, 2015).…”

A Critical Review of the Factors Available for the Identification and Determination of Mānuka Honey

“…Methods have been described to detect specific floral pollen DNA fragments in honey using PCR and metabarcoding (Jain et al 2013;Lalhmangaihi et al 2014;Guertler et al 2014;Bruni et al 2015;Soares et al 2015;Hawkins et al 2015;Torricelli et al 2016;Prosser and Hebert 2017) and recently advocated as a marker for mānuka honey (MPI 2017c). These markers indicate the presence but not the amount of mānuka honey in a sample.…”

DNA as a Biomaterial in Diagnosis of Food Adulteration and Food Safety Assurance

“…Finally, the in-house and interlaboratory validation evidenced the DNA extraction from five different samples (Honeydew Honey with multifloral honey, Wild flower honey "flowers of the mountain", Wild flower honey, Rape honey, Acacia-with multifloral honey) [38]. With the comparison of previous studies, an improved method for the efficient DNA extraction from honey samples were performed using commercial DNA isolation kits, finally stating that Wizard method with pretreatment has the maximum yield in the aspect of both purity and quantity [39].Baked products: Baked food stuffs consisting of biscuits, cake, waffle, etc., are mostly consumed by the school children. Soy based ingredients are the widely used for the production of these products.…”