The single-factor and orthogonal tests were conducted on temperature,concentration of citric acid,length of time and ratio of extraction to rose petal,for extracting red pigment in rose.The results showed that using citric acid was the key to extraction method;the pigment can be extracted thoroughly at 80 ℃ for 40min with 0.8% citric acid of 350 times capacity than petal;based on this test,the pigment was steady with the following treatments:adding Zn2+,Mg2+,Ca2+ below 0.4%,adding xylitol,oligoisomaltose be...
