Hops Flavonoids' Continuous Extraction And Hops Essential Oil Microcapsules' Preparation

Hops are important raw material of beer brewing. They were rich with flavanoids, essential oil and have a broad spectrum of biological and pharmacological effects. With mechanized harvesting, the amount of defective hops increased. For full use of hops resources, study on the extraction of flavonoids and hops oil is essential.This paper used reflux extraction and sequential extraction with ultrasonic under negative pressure(SEUNP) to extract flavones, and extract essential oil with low pressure steam distillation or Simultaneous distillation and extraction(SDE) from hops. The resulting products were analyzed by fourier transform infrared(FT-IR) spectrum, gas chromatography-mass spectrometry(GC-MS) and so on.Results showed single factor test's better conditions of SEUNP were 55.0?, 70.0W, 65.0min, 75.0?, 1:20; orthogonal test's better Combination factor were 1:25, 90.0W, 78.0% ethanol, 50.0? and 50.0?, 66.0% ethanol, 1:15, 80.0W. The extraction rate and purityare were 85.60% and 23.24%. Contrasted the two extraction methods known that SEUNP has shorter time and lower temperature. It could effectively avoid active ingredients of hops invalid so provide conditions for essential oil's extraction.Studied on the purification of hops flavonoids by macroporous resin, FL-2 and FL-3 were screened out for their better comprehensive performance.Results showed essential oil extracted by low pressure steam distillation was easy separated, and the color was lighter. The extractive of SDE was light yellow with small amount of organic solvent. GC-MS results indicate that the characteristic materials were consistent with literature value. All those research certify the comprehensive utilization scheme of hops was feasible.At last, we prepared microcapsules by complex coacervation with ?-cyclodextrin and chitosan as composite wall material, twain 80 and glycerin as compound emulsifier. Microcapsules with good spherical degree and uniform particle size were made.The technique of this paper provides a good solution for hops application.