Study On Betalains And Phenols Based On Pitaya Germplasm Resources

Pitaya is a typical tropical fruit with bright color,sweet taste and rich nutrition,which is very popular among consumers.Betalains and phenols in pitaya give the fruit excellent color or flavor and have antioxidant,anti-inflammatory,and cardiovascular disease prevention activities.Betalains and phenols are important components related wih pitaya quality.In order to clarify the characteristics of betalains and phenols in fruits of different pitaya varieties and their relationship with antioxidant activity and fruit color,as well as provide theoretical basis for the cultivation of excellent pitaya varieties,20 pitaya germplasms was used as materials.Betalains and phenols in the peel and pulp were screened with UPLC-Q-TOF-MS/MS.The types of betalains and phenols,the content of total betalains and total phenols,and the the correlation between oxidatant activity and fruit color were studied.The main results are as follows:1.Pitaya fruit is abundant in betalains and phenols.A total of 42 betalains and 53 phenols were found.Betalains components involve betanin,phyllocactin,decarboxylated phyllocactin,2-decarboxylated hylocerenin,indicaxanthin and et al.Phenolics components involve ellagic acid,caffeic acid,salicylic acid,catechin,rutin,quercetin,chlorogenic acid,catechol and et al.2.Discrepancies of betalains types and phenols types were found among different germplasms and the pulp and peel parts.On the whole,the red-peeled-red-fleshed varieties have more amounts of betalains and phenols than the red-peeled-white-fleshed varieties and the yellow-peeled-white-fleshed varieties.Betalains and phenols types in the peel are more abundant than the flesh part.More abundant levels of the types and the total contents of betalains and phenols,higher scavenging rates and deep colour(purple)was detected in the peels and fleshs of corresponding cultivars.On the opposite,weaker scavenging rates and low colour(white and yellow)was detected.(1)The peel of ‘Mihong’ contains the highest amounts of betalains(18),while the peel of ‘Wucihuanglong’ the lowest(3).The flesh of ‘Yuenanhongrou’ and‘Heyuan No.3’contain the highest amounts of betalains(17),while the flesh of‘Wucihuanglong’ the lowest(1).(2)The peel of ‘Jinghonglong’ contains the highest amounts of phenols(30),while the peel of ‘Hongrouyou 6’ the lowest(14).The flesh of ‘Wucihuanglong’contained the highest amounts of phenols(18),while the flesh of ‘Hongrouyou 6’ the lowest(6).3.The total betalains content,total phenols content,antioxidant activity and colour difference values of the peel and flesh varied greatly because of the diversity of20 pitaya germplasms.(1)Peel parts: The highest levels of the total betalains,total phenols were found in ‘Heyuan No.3’(16.90 mg/100g)and ‘Zilong’(27.50 mg GAE/100g),individually;The highest DPPH、ABTS scavenging rates of the total betalain extract were found in‘Zilong’(83.45%)and ‘Heyuan No.3’(96.31%%),individually;The highest scavenging rates of the total phenol extract were found in ‘Heyuan No.3’(58.86%)and ‘Yunlong No.2’(43.26%),individually.(2)Flesh parts: The highest levels of the total betalains,total phenols were found in ‘Yuenanhongrou’(36.60 mg/100g)and ‘Mihong’(38.52 mg GAE/100g),individually.The highest DPPH、ABTS scavenging rates of the total betalain extract were found in ‘Honglong No.2’(92.93%)and ‘Mihong’(98.10%),individually;The highest scavenging rates of the total phenol extract were found in ‘Mihong’(70.37%)and ‘N04-4’(41.12%),individually.4.Five cultivars with high antioxidant activity and having bright colour in peel and/or flesh were screened.(1)The peels of ‘Heyuan No.3’ and ‘Shihuoquan’,the flesh of ‘Mihong’ and‘Guihonglong’ and the peel and flesh of ‘N04-4’ were observed with strong antioxidant activity.Those germplasms are excellent materials for the cultivation of new functional varieties beneficial to human body health.(2)The fleshs of ‘Mihong’ and ‘Guihonglong’ were observed with strong antioxidant activity and bright colour,which is excellent cultivar suitable for consuming freshly.(3)The peel of ‘Heyuan No.3’ was observed with abundant betalains and bright colour,which is excellent cultivar suitable for processing,i.e.its peel can be used for producing of betalains extract and natural pigment food addictives.