The Brewing Technology Of Kelp Beer And Its Functional Components Analysis

With the maturity of the beer industry,the development of the market and the demand of consumers for novelty,people's demand for beer began to tend to craft beer with more varieties and unique flavor.Functional beer is more and more favored by consumers because of its high nutrition and health care,multi taste and other advantages.In order to inherit and carry forward the idea of"medicine and food have the same origin"held by our country since ancient times,this research strives to combine traditional technology with modern science,integrate drinkability and functionality,endow craft beer with nutrition and health care function,and try to meet people's demand for taste and nutrition.Kelp beer is a combination of kelp and beer,giving beer unique taste of kelp,at the same time making beer with anticoagulant effect,in order to meet the needs of special people in cardiovascular sub-health.At present,there are few studies on the brewing technology and efficacy of kelp beer.The brewing technology of kelp beer was explored with kelp powder as raw material in this study:10 mg/m L,15 mg/m L and 20 mg/m L kelp powder were added to wort and fermentation broth,respectively,at 5 min before boiling and before cooling to brew finished kelp beer,the anticoagulant efficacy of the kelp beer was tested,and then the main physical and chemical indexes of the kelp beer were detected,such as color,foam,alcohol content,bitter unit,residual sugar and polysaccharide content.Finally,the flavor substances of kelp beer were analyzed by gas chromatography.Considering the anticoagulant effect,physical and chemical indexes,flavor components and industrial production cost,10 mg/m L kelp powder was added at 5 min before the end of boiling as a 100 L pilot-scale experiment.The APTT,TT and PT of kelp beer were 123.16±1.96 s,14.22±0.51 s and 32.80±0.26 s,respectively.All the indexes indicating that kelp beer has stable anticoagulant effect.The physical and chemical indexes of kelp beer were detected by BEERLab(color 17±0.02 EBC,bitterness 22.9±0.02 IBU,lactic acid 322±0.33 mg/L,alcohol 6.1±0.05%vol,residual sugar 2.1±0.21 g/L).The traditional method was used to determine the foam capacity,turbidity,total acid and p H value of the product,which were 801±0.31 s,122.0±0.13EBC,1.85±0.05 m L/100m L,and 4.5±0.01,respectively.All the indexes were in line with the Chinese national standard GB/T 4927-2008.Finally,the flavor components of kelp beer were detected by gas chromatography(the total content of main esters is 47.83mg/L,and the content of main higher alcohols is 194.69 mg/L).Kelp polysaccharide was extracted from kelp,and the kelp beer freeze-dried powder,control beer freeze-dried powder and kelp polysaccharide were determined by infrared spectroscopy.Compared with control beer,kelp beer has absorption peak in the infrared spectrum of 4000-500 cm^-1,which indicates that there are polysaccharides in kelp beer.The absorption peak at 2930 cm^-1 was one of the characteristic peaks of sugars.However,there was no absorption peak in control beer,and there were absorption peaks in kelp beer,kelp crude polysaccharide and fucoidan,which indicated that kelp beer added kelp polysaccharide.The absorption peak at 1257 cm^-1 was caused by the stretching vibration of S=O in-O-SO₃-,and there was no absorption peak in control beer.Kelp beer,kelp crude polysaccharide and fucoidan all showed absorption peaks,indicating the addition of sulfate group in kelp beer.The absorption peak at the 889 cm^-1 represents the characteristic absorption peak of pyran ring,which indicates that laminaria polysaccharide mainly passes through the sugar units?-glycosidic linkage;The characteristic peak of carboxyl group appeared at about 1607 cm^-1.Compared with the infrared spectra of control beer and kelp beer,the two absorption peaks of 889 cm^-1 and1607 cm^-1 did not appear in control beer,and obvious absorption peaks could be seen in kelp beer.It can be concluded that the anticoagulant effect of kelp beer is mainly due to the increase of kelp polysaccharide in kelp beer.For the kelp beer,color is amber,foam is rich,white and fine,and phenolic/ester aroma are obvious,but the phenolic aroma is stronger than that of ester.There are distinct kelp taste and flavor.