Brewing Technology Of Olive Wine And Effect Of Storage Time On Flavor Substances

At present,the olive resources are very rich in Guangdong.According to statistics,the planting area is more than 500,000 acre,with an annual output of 120,000 tons,and less than 60,000 tons of olives are processed every year.The rich output of olives provides sufficient raw materials for its deep processing.The main problems of the existing olive wine are:(1)The pectin content is high,and it is rich in a large amount of tannins and fibrous substances,and the juice yield rate is low,the yeast is difficult to ferment too;(2)The yeast variety is bad,the quality of the wine is poor,and the acetic acid bacteria are easily infected during the fermentation process;(3)Olive wine contains more viscous substances,macromolecular substances,salt substances and pectin,etc.,and the product is prone to a large amount of precipitation during shelf life;(4)Lack of the systematic which study on the flavor and aroma components of olive wine during storage cannot determine the effect of storage time on the quality of olive wine.In this paper,yellow olives were used as raw materials to study and optimize the technical parameters of pretreatment,fermentation process and clarification process of olive wine.The flavor substances were detected by liquid chromatography,and the aroma components were detected by GC-MS.According to the above method,the effect of storage time on the flavor and aroma components of olive fruit wine was studied..The results of the study are as follows:(1)Screening the enzymes for enzymatic hydrolysis of olive wine,and compounding the pectinase C-MAX with good enzymatic hydrolysis and cellulase CEL-01 to determine the optimal conditions for enzymatic hydrolysis of olive pulp:When the pectinase C-MAX was added at 25 mg/L and the cellulase CEL-01 was 1200 mg/L,the enzymatic hydrolysis was best at 16? for 17 h.Under this condition,enzymolysis effect is the best.Besides,the enzymatic hydrolysis rate was 59.30% and the juice extraction rate of pectinase was increased by 27.10%.(2)Fermented olive juice with Angel Yeast BV818,DV10 brewing active dry yeast and excellent STR yeast respectively.Through comprehensive comparison,the brewing strain of olive wine was determined to be STR yeast,and then the optimized fermentation experiment of olive wine was carried out by using STR yeast.The optimal conditions were obtained: STR yeast dosage 250 mg/L,fermentation initial sugar content 120 g/L,total acid 7 g/L,fermentation temperature 19?,fermentation time 32 days.Under this condition,the obtained olive wine had low volatile acid content and the quality is good.(3)The clarifying effect of the bentonite-chitosan composite clarifying agent on olive was the best.The clarification test of olive wine was carried out by using the bentonite-chitosan composite clarifying agent to obtain the optimal conditions: when the amount of scented bentonite was 0.5 g/L,the amount of chitosan added was 0.25g/L,and clarified at 17°C for 168 hours.Under this condition,the clarity of olive wine was 97.5%,which was 21.30% higher than that without clarifying agent,and the stability was good.(4)Organic acids,amino acids and volatile aroma components were tested for olive wines at different storage periods(0 months,4 months,8 months,24 months,36 months).With the increase of storage time,the ratio of total organic acid content in the wine was gradually decreased;the ratio of dextranic acid to total organic acid content gradually increased,while the content of acetic acid,malic acid and lactic acid were gradually decreasing;the content of pyruvic acid is maintained at a stable level.The maximum amino acid content per 100 grams of olive wine in 24 months is 0.2043 g.With the increase of storage time,the percentage of alcoholic substances in olive fruit wine increased;the types of other aroma components decreased;the main esters had the highest ethyl acetate content.