Effect of Pollen Grains on the color of Honey from Melilotus officinalis (L.) Pall.

Abstract

Introduction. According to the Federal State Statistics Service, the Siberian Federal district produced 8,464.06 tons of natural polyand monofloral honey in 2019. The share of the Altai region was 45.37%, Krasnoyarsk region – 7.8%, regions, Omsk – 7.0%, and Novosibirsk – 6.3%. The color of honey is one of the main identifying characteristics of products. It largely depends on the chemical composition of pollen grains of honey plants. Therefore, it is relevant to study the color of honey from the nectar of Melilotus officinalis (L.) Pall.
 Study objects and methods. The research featured honey samples produced from the nectar of Melilotus officinalis (L.) flowers. The honey was centrifuged and pumped in 2018 on the territory of the Altai region. The research involved standard methods, as well as an authentic method for determining the dominant pollen grains. The method was based on preserving the morphological features of pollen grains and did not change their spatial location, thus making it possible to determine their real content in honey.
 Results and discussion. The honey color was affected by pollen grains of honey-bearing plants: 1) Melilotus officinalis (L.) Pall. (84.89%) > Fagopyrum tataricum (L.) Gaertn. (1.0%) > Convolvulus arvensis L. (0.97%) > Origanum vulgare (L.) (0.97%) > Brassicaceae Burnett, nom. cons. (11.20%); 2) Melilotus officinalis (L.) Pall. (49.24%) > Dracocephalum nutans L. (7.58%) > Trifolium pratense L. (9.09%) > Brassicaceae Burnett, nom. cons. (18.18%) > Sonchus arvensis L. (2.07%); 3) Melilotus officinalis (L.) Pall. (54.05%) > Helianthus annuus L. (14.87%) > Linaria vulgaris Mill. (2.70%) > Arctium tomentosum Mill. (4.05%) > Trifolium repens L. (8.47%) > Brassicaceae Burnett, nom. cons. (10.81%). Color and nutritional value depended mostly on two factors. The first factor was represented by flavonoid compounds (leucoanthocyanins, catechins, flavonols, etc.) of pollen grains of Melilotus officinalis (L.) Pall., Brassicaceae Burnett, nom. cons., and Helianthus annuus L. Their contents were 5.2, 3.1, and 2.8%, respectively. The other factor involved carotenoids – Trifolium pratense L., Trifolium repens L. and Origanum vulgare (L.). Their contents were 50.0, 37.3, and 28.7 mg/kg, respectively.
 Conclusion. The research featured honey from the flowers of Melilotus officinalis (L.) Pall. obtained from the South of the Siberian Federal District. Its color proved to be one of the main sensory properties necessary for establishing the botanical profile of the plants. The color depended on the secondary pollen grains of honey plants, containing flavonoid compounds and carotenoids.