Study On The Preparation Of Monascus Pear Vinegar And Its Beverage Blending

Aiming at the problems of high yield of Anhui Dangshan pears and low utilization rate of deep processing of whole pears.In this paper,the pear residue,a by-product of pear juicing,was fermented by liquid fermentation of Monascus to extract the Monascus pear residue dietary fiber at first.The dynamic analysis of each index in the fermentation process was emphasized;Pear juice was used as raw material,the mixed fermentation of Monascus and yeast was used to produce pear wine and pear vinegar was fermented by acetic acid bacteria.The effect of Monascus fermentation on the quality of pear vinegar was studied;Finally,the Monascus pear residue soluble dietary fiber(MPSDF)was added to Monascus pear vinegar,and the blending process was optimized by single factor and orthogonal experiments to develop a Monascus pear vinegar beverage with high dietary fiber,which integrates the health function of Monascus,dietary fiber and fruit vinegar.The main research contents and results are as follows:(1)Dynamic analysis of components in liquid fermentation of pear residue by Monascus and research on the properties of dietary fiber(DF).The results showed that the logarithmic growth period of Monascus was 48-96 h.The color value of Monascus pigment increased gradually with the prolonging of fermentation time,and the highest color value was 87.67 U /m L.In the fermentation process,the contents of reducing sugar,Vc and flavonoids in pear residue showed different trends.In addition,the activity of amylase increased first and then decreased,and the maximum activity was 85.3 U/m L on the 4th day of fermentation.After fermentation,the activity of esterifying enzyme was significantly increased to 5.2 U/m L;The cellulase activity reached the maximum value of 0.23 U/m L on the 5th day of fermentation.Compared with enzymatic method,the fermentation with Monascus significantly increased the content of soluble dietary fiber,and decreased the ratio of insoluble dietary fiber(IDF)to soluble dietary fiber(SDF),with the ratio of IDF to SDF decreased from 6.49 to 3.92.The fermentation with Monascus significantly improved the physical and chemical properties,antioxidant activity and functional properties of dietary fiber.And the content of Monacolin K was1.42 mg/g,indicating that the Monascus pear residue dietary fiber is a functional product with health care effect.(2)Effect of Monascus fermentation on quality of pear vinegar.The quality changes of Monascus pear vinegar(YM-V)and control group pear vinegar(Y-V)were compared and analyzed.The results showed that the fermentation period of Monascus pear wine(YM-W)was shorter,which was 2 days,and the utilization rate of reducing sugar was higher;However,its alcohol content was slightly lower than that of the control group pear wine(Y-W),which was only 7.37%.The acidity of YM-V was 62.55 g/L,lower than that of Y-V.43,36,46 and 33 volatile flavor compounds were detected in YM-W,Y-W,YMV and Y-V,respectively.The mixed fermentation of Monascus and yeast significantly increased the types and contents of volatile flavor substances in pear wine and pear vinegar.The content of organic acids in pear vinegar increased from 34.94 mg/m L to36.53 mg/m L,and the content of amino acids increased from 2183.9 mg/L to 2374.28mg/L.Therefore,the fermentation of Monascus can effectively improve the flavor and quality of pear wine and pear vinegar.(3)The composition analysis of Monascus pear vinegar and the preparation of Monascus pear vinegar beverage with high dietary fiber.The results showed that the total phenol content increased and the flavonoid content increased to 9.81 mg/100 m L on the third day of fermentation,and then decreased slightly during the alcoholic fermentation stage.In the acetic acid fermentation stage,the total phenol content decreased at first,then increased and then decreased,and the flavonoid content gradually decreased.The trend of YM-V antioxidant activity was similar to that of total phenols and flavonoids.The blending process was optimized by single factor and orthogonal test.The optimal blending process of Monascus pear vinegar beverage with high dietary fiber was determined to be the supplemental level of YM-V was 28%,sucrose was 10%,and MPSDF was 1%.Under these conditions,the sensory score was 88.3.The research on the preparation of Monascus pear residue dietary fiber and the key technology of preparation of Monascus pear vinegar beverage provides reference for the deep processing and utilization of fruits and vegetables,and it is beneficial to improve the utilization rate of deep processing of fruits and vegetables and the economic added value of Dangshan pears.