ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of melatonin in bakery products using liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS)

Henryk Zieliński, Dorota Szawara-Nowak, and Wiesław Wiczkowski

Division of Food Science, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn 5, Poland

E-mail: h.zielinski@pan.olsztyn.pl

Abstract: Melatonin (N-acetyl-5-methoxytryptamine), the hormonal product of the pineal gland, has recently been reported as a multifaceted free radical scavenger and antioxidant. Melatonin production declines progressively with age. Therefore, supplemental administration or increased intake of melatonin from dietary sources may be beneficial in delaying age-related degenerative conditions. This study aimed to determine melatonin in commonly eaten bakery products based on wheat, rye or spelt flour formulations, which represented the most popular types of bread and roll in Europe. Melatonin was extracted from freeze-dried bread samples with methanol and its content was determined by micro-HPLC system coupled to triple quadrupole mass spectrometry (LC–MS/MS) of target analysis. Melatonin was identified in all types of bread and rolls, however, its content varied significantly, ranging from 0.26 ng/g to 3.21 ng/g of dry matter (DM). The best source of melatonin was mixed wheat-rye bread (average 3.02 ng/g DM) followed by rye bread (average 2.50 ng/g DM), whereas spelt bread, wheat and graham rolls were poor sources (below 0.54 ng/g DM). These findings may help consumers to select bread with high melatonin content. This study showed that micro-HPLC system coupled to triple quadrupole mass spectrometry can be successfully applied for the determination of melatonin in bakery products. Because of the relevance of melatonin as bioactive molecule with implications for food, nutritional sciences and human health, it was of interest to explore its levels in commonly daily taken bakery products.

Keywords: Melatonin; Bread; Roll; LC–MS/MS

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-016-0029-z

Chemical Papers 71 (6) 1083–1089 (2017)