Study On The Peeling Of Cyperus Esculentus And The Application Of Its Skin In Baked Food

Cyperue esculentus can be used as resource of oil and grain,and has high comprehensive utilization value.Cyperue esculentus is mainly planted on river beach and sandy land,not competing with grain for land.It is a key crop to improve the supply rate of edible oil in China.In the processing and comprehensive utilization of Cyperue esculentus,peeling difficulty is one of the technical bottlenecks perplexing the high-value utilization of Cyperue esculentus.At present,the reported peeling methods mainly include dry peeling with the help of mechanical shear and wet peeling with the help of strong alkali solution.The dry peeling by mechanical shearing has the disadvantages of low peeling rate and high loss rate of bean kernel.The wet peeling by alkali immersion has the problems of large alkali consumption and wastewater discharge,serious pollution and more loss of nutrients.In view of the above problems,based on the difference of toughness and brittleness between Cyperue esculentus skin and kernel,this study attempted to peel and separate the skin and kernel of Cyperue esculentus and its cold-pressed cake by appropriately crushing and screening Cyperue esculentus and its pressed cake,and achieved a more reasonable peeling effect.The peeling method had the advantages of simple process,economic operation,green and environmental protection.It could not only directly obtain the whole fat or defatted oil Cyperue esculentus powder with ideal peeling effect,but also would not affect the color and composition of Cyperue esculentus itself,creating favorable conditions for the high-value processing of Cyperue esculentus and the comprehensive utilization of kernel and skin.In addition,based on the preliminary discussion of the effective components contained in Cyperue esculentus skin,high fiber bread and biscuits rich in Cyperue esculentus skin were trial produced,which laid a foundation for the utilization of Cyperue esculentus skin in baked food.The main research contents and conclusions are as follows:(1)The effects of moisture content,temperature,crushing time and screening mesh on the peeling effect of Cyperue esculentus were investigated.On the basis of single factor test,taking the total color difference between Cyperue esculentus kernel powder and the color of standard sample as the response value,the conditions were optimized through response surface test design,and the best process conditions for Cyperue esculentus dry peeling were obtained: raw material moisture content of 6%,temperature of 46℃,crushing time of 14 s and screening mesh of 60.Under these conditions,the peeling index of Cyperue esculentus reached 87.3%,The mass loss rate after peeling was 31.3%.(2)The effects of moisture content,temperature,crushing time and mesh number on the peeling effect of cold-pressed cake made from Cyperue esculentus were studied.On the basis of single factor test,taking the total color difference between defatted Cyperue esculentus kernel powder and the color of standard sample as the response value,the conditions were optimized through response surface test design,and the best conditions for the peeling of Cyperue esculentus cold-pressed cake were obtained: raw material moisture content of 5%,temperature of 55℃,crushing time of 20 s and screening mesh of 60.Under these conditions,the peeling rate of Cyperue esculentus cold-pressed cake reached 92.2%,the mass loss rate after peeling was 22.5%.(3)Taking the by-product of Cyperue esculentus peeling as the research object,the main components of Cyperue esculentus peel were analyzed qualitatively and quantitatively by using identification methods such as color reaction and instrumental analysis,and the effective active components contained in Cyperue esculentus peel were preliminarily identified.The qualitative analysis of color reaction showed that the residue mainly contained amino acids,peptides,proteins,sugars,organic acids,steroids,triterpenoids,alkaloids,oils and volatile oils;Instrument analysis and quantitative detection found that the crude fiber,potassium and magnesium contents in Cyperue esculentus peel were high.From the results of component analysis,it coul be inferred that Cyperue esculentus skin has certain health care function and nutritional value.(4)The application of Cyperue esculentus skin in toast was studied.The effects of adding Cyperue esculentus skin to toast recipe on dough formation time,fermentation time,bread volume,specific volume,texture characteristics and sensory score were discussed.It was found that the appropriate amount of Cyperue esculentus skin in toast was 6%.Through the use of xylanase and fungi α-Amylase and lipase in bread formula could improve the quality of Cyperue esculentus skin toast,and the addition of Cyperue esculentus skin in the toast formula could be increased to 9%.(5)The application of Cyperue esculentus skin in crisp biscuits was studied.Through the establishment of fuzzy mathematics comprehensive evaluation model,the influence of different addition amount of Cyperue esculentus skin on the quality of crisp biscuits was analyzed.The results showed that the optimum addition amount of Cyperue esculentus skin in crisp biscuits was 6%.In order to further improve the addition amount of Cyperue esculentus skin in crisp biscuits,the optimum addition amount of auxiliary materials for making high Cyperue esculentus skin(12%)crisp biscuits was determined through single factor experiment and orthogonal experiment: water 14%,butter 25%,sugar 30%;The optimum ratio of sodium bicarbonate to ammonium bicarbonate in the bulking agent was 2:1.Compared with ordinary crisp biscuits,in addition to the slightly darker color and luster,Cyperue esculentus skin crisp biscuits had larger volume,smaller hardness,good bulk density and ductility,the content of crude fiber could reach 4.9%,the content of crude protein and ash was equivalent to that in ordinary crisp biscuits,and the content of crude fat and moisture met the requirements for crisp biscuits in GB / T 20980-2021.