The influence of different processing methods on the phytochemical composition of leaves and cones of common hop (Humulus lupulus L.)

Background. It has been established for a long time that medicinal plants contain a large number of active compounds that are used to treat many diseases. For the first time, a comparative study of the leaves and cones of common hops was conducted for the accumulation of phytochemical compositions. Commercial preparations of growth biostimulants (gibbersib, epin-extra) and bio-fertilizer (pudret) were selected. It was established that hops grown in the conditions of Tatarstan have a rich phytochemical composition and a high content of bioactive substances. can be recommended as a resource that will allow the pharmacological industry to use the highest quality raw materials.

Purpose. Conduct a comparative analysis of the phytochemical composition in the leaves and cones of common hop (Humulus lupulus L.) under different processing methods.

Materials and methods. Planting of rhizomatous hop cuttings was carried out at the beginning of May 2023 in protected soil under laboratory conditions. According to the experimental design, rhizome cuttings were planted in pots with soil to which pudret was added (bio-fertilizer from bird droppings dried in microwave rays, consisting of 88.4% organic matter, 4.59% nitrogen, 1.80% potassium, 3.70% phosphorus) at the rate of 10 g/kg of soil, in the second variant, rhizomatous hop cuttings were treated with gibbersib (666.6 μg/l) by spraying, and in the third variant they were treated with epin-extra (500 μl/l) also by spraying.

After 4 weeks, all variants and also the control were transplanted into open ground (soil acidity was 6.9, organic matter content (humus) 1.96%, nitrate nitrogen content 35.5 mg/kg, ammonia nitrogen 11.3 mg/kg, available phosphorus 584 mg/kg, the amount of exchangeable calcium was 13.25 mmol/100 g and exchangeable magnesium 1.5 mmol/100 g).

Samples for analysis (leaves and cones) were taken 12 weeks after planting in open ground (average night temperature was +140С).

The phytochemical composition in the leaves and buds was determined by spectrophotometric methods described in a study by Al Hussain et al (2023).

The experiments were carried out in six biological replicates. Statistical processing of the data was carried out using Excel 2016. The significance of the difference was determined using the Mann-Whitney test with р ≤ 0.05.

Results. Epin-extra increased the content of flavonoids, tannins and vitamin B2 to a greater extent, gibbersib increased the content of phenolic compounds, carotenoids, sugars and proteins, and powder increased the content of vitamin C, carotenoids, vitamin B2 and proteins.

Conclusion. Our research shows that hop extracts have a wider potential for use in medicine and food technology than just fermentation, and this is due to the possibility of improving the content of useful primary and secondary substances using synthetic growth regulators and bio-fertilizers. A large number of hop leaves remain an unused agricultural by-product, but our research has proven the possibility of using hop leaves as a source of primary and secondary metabolites in medicine (as a sedative, antimicrobial, diuretic, anti-inflammatory agent in the treatment of gastritis, cystitis, urethritis, kidney diseases, liver and gall bladder) and food industry (brewing industry, bakery production).