Important progress has been made in the study of pectin extraction from passion fruit peel

 　Recently,the research team of the Chinese Academy of Thermal Sciences has made important progress in the deesterification of passion fruit peel pectin.Passion fruit peel pectin is a high methyl ester pectin.In the past,it was difficult to reduce the sugar content in gel foods.However,now this technology converts it into low methyl ester pectin(LMP)and replaces it by adding calcium ions.Sugar forms gel,and this deesterification process is of great significance in reducing the amount of added sugar in gel foods.

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 In this research,the team used four methods:low-temperature alkali method,normal temperature alkali method,enzymatic method and dielectric barrier discharge plasma-assisted enzymatic method(DBDE)to deesterify passion fruit peel pectin,and screened out the pectin with a similar degree of esterification.LMP analyzes its molecular weight,monosaccharide composition and gel properties.

 The results show that different deesterification methods have different effects on the structure and properties of LMP.Compared with untreated passion fruit peel pectin,the galacturonic acid content of LMP obtained by deesterification increased significantly,among which the LMP obtained by DBDE deesterification(LMP-DBDE)increased the most.The molecular weight of LMP decreased significantly after deesterification,among which the molecular weight of LMP-DBDE decreased the smallest.It is worth mentioning that LMP-DBDE exhibits higher apparent viscosity,thermal stability and gel properties,which is beneficial to gel formation.

 The study found that after 21 days of storage,whey separation did not occur in coagulated yogurt added with 0.40%LMP-DBDE,which significantly extended the shelf life of the coagulated yogurt.In summary,passionflower LMP treated with dielectric barrier discharge plasma-assisted enzymatic method has strong water-holding capacity and is a potential fat substitute with broad application prospects in low-fat dairy products.The resource reuse of custard fruit peel provides a new way.

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 The relevant research results were published in"Carbohydrate Polymers"under the title"Passion fruit peel-derived low-methoxyl pectin:De-esterification methods and application as a fat substitute in set yogurt".Assistant researcher Yang Yang from the Institute of Biology,Chinese Academy of Thermal Sciences,and Zhang Wenxing,a master's student from Hainan University,are the co-first authors.Researcher Sheng Zhanwu from the Institute of Processing is the corresponding author of this paper.This work was funded by the Hainan Provincial Science and Technology Talent Innovation Project and the basic scientific research business funds of central-level public welfare scientific research institutes.