Flavor Quality Was Evaluated And Research Of Malic-acid Metabolism-related Enzymes Of Functional Apple Excellent Strains

Malus sieversii f.neidzwetzkyana is the world’s cultivated apple ancestor species, genetic diversity is extremely rich, it have great potential for further use. But because of farmland reclamation and other reasons, Malus sieversii resources are severely damaged, on the verge of extinction. Therefore, individuals of F1segregated population were construct of Malus sieversii and Fuji apple initiatively from our research group in2006. In order to provide theory system of assessable standard and test material for breeding good flavor functional apple species, in this study, several functional apple excellent strains were selected for studying flavour quality and determinating malic acid and related enzyme activity in the process of fruit development.The main results are as follows:1) Altogether, eight kinds of volatile components including esters, alcohols and aldehydes were detected in4superior strains of Malus sieversii f. neidzwetzkyana F1while seven kinds of volatile components were detected in golden delicious; The aroma categories and their contents show tremendous variations. Red crisp acid5has the richest aroma components and their contents is the highest one among the investigated cultivars while red crisp1has the least aroma components and their contents is the lowest. The materials that were detected contains11or12kinds of characteristic aroma compounds except red crisp1which has only7kinds of characteristic aroma compounds. The contents of characteristic aroma compounds in4superior strains of M alus sieversii f. neidzwetzkyana F1were higher than that of golden delicious.2) Three sugars and organic acids were detected from5materials, fructose was the most dominant sugar, while the malic acid was the principle organic acid; sweetness value of sucrose is bigger than glucose in4superior strains, while in golden delicious sweetness value of glucose is bigger than sucrose.3) The fruits of tested were different in sugar/malic acid ratio and taste evaluation; Sugar/malic acid ratio was around20in red crisp4, red crisp3and golden delicious, and three materials were tastes sweet and sour moderate, while in red crisp acid5and red crisp1sugar/malic acid ratio was around14.59and11.59, and they tastes sour.4) The content of acid were falling in the process maturity in high-acid and low-acid strains, but in moderat-acid strain the content of acid were priority rised then ralled in the process maturity. When the apple matured the content of acid was higher than in moderat-acid and low acid strains.5) In the process of fruit development, the cytoplasm malic enzyme (cyME) which catalytic degradation of malic acid increased significantly, phosphoenolpyruate carboxylase (PEPC)and cytosolic malate dehydrogenase(cyMDH) which catalytic synthesis of malic acid increased unconspicuous or dropped, vacuolar H+-transporting adenosine triphosphatase(VHA) which provide power for malic acid transmembrane transport were dropped, this is relate with the malic acid were dropped in the process of fruit development.6) The malic acid cotent in H21-11is higher than other strains and’golden delicious’ isrelated to PEPC acticity which catalytic synthesis of malic acid and VHA acticity which provide power for malic acid transmembrane transport were higher than other strains, in most process of fruit development cyMDH acticity was higher in strain H21-11fruit than other strains.