Molecular Tracing of the Origin of Six Different Plant Species in Bee Honey Using Real-Time PCR

Abstract

The quality of honey is significantly influenced by floral origin. Mislabeling floral species occurs frequently in bee honey products. To protect consumers from economic fraud and maintain a fair market environment, methods to identify floral species in honey are necessary. In our study, real-time PCRs were established, targeting six honey types mainly produced in China (canola, Chinese milkvetch, Chinese chaste tree, locust tree, litchi, and longan). Sensitivity testing on DNA from plant tissues exhibited LODs of about 0.5-5 pg/μL. For DNA extracts of pollen sediments from different honey species, LODs ranged from 13.6 to 403.2 pg/μL. In an experiment to determine the practical LODs of honey in which adulterant honey was spiked in the genuine honey, adulterant honey as low as about 0.1-0.5% was detected in 90-100% in 10 parallel tests. Additionally, pollen was spiked in the honey and stored under various conditions to investigate the migration of pollen DNA into the honey supernatant. Finally, the efficiency of our method was investigated by testing honey samples of unknown compositions from different geographic regions. Of the 159 honey samples that were supposed to be monofloral that had been collected in five provinces, a small portion were found to be contaminated with foreign pollen (7%). The methods proved to be specific, sensitive, and reliable in identifying the six plant species in honey, which would be a useful tool during the market supervision and QC of honey products.

Optimización de extracción de ADN de polen apícola para caracterización molecular

“…Otros autores han reportado estudios metagenómicos donde la identificación a nivel especie es limitada o nula (Richardson et al 2015, Tanaka et al 2020. A la fecha diversos estudios con ADN genómico de polen demuestran que una herramienta eficiente para el monitoreo ambiental, ya que permite detectar no solo de la flora relevante en la alimentación de las abejas, sino también la identificación de plantas tóxicas (Bruni et al 2015), alergénicas (Kraaijeveld et al 2015), invasoras (Noël et al 2023) y transgénicas (Wu et al 2017, Bayram 2021.…”

Utilization of the Hollies (Ilex L. spp.): A Review

“…A comparison among nine Ilex species in Hong Kong found a large variation between species in nectar production, sugar concentration, and sugar composition, but the rate of Apis cerana Fabricius visits per flower was predicted only by the estimated total number of flowers per plant [42]. Ilex species are important sources for commercial honey production from honeybees in China [43], Nepal [44], Ethiopia [45], Kenya [46], Surinam [47], the USA [48,49], and no doubt other places. In the USA, specialty holly honeys derived from bees feeding on I. glabra, I. coriacea (Pursh) Chapm., or I. vomitoria are available on-line.…”

Honey authenticity: analytical techniques, state of the art and challenges

“…A PCR method accurately detected mono- and multifloral honey samples by targeting the cyt2b, matk, psbA, and ndhF genes of plant pollen. 83 After DNA extraction, real-time PCR was used for the amplification of the selected genes. The results showed that from the 159 samples (all characterized as monofloral), 11 samples (7%) were found to also contain pollen from other plants, and were thus mislabeled as monofloral.…”