Jianping Pan’s research while affiliated with Guangdong Academy of Agricultural Sciences and other places

As a local medicine and food, wampee fruit, with abundant bioactive compounds, is loved by local residents in Southern China. Titratable acid (TA), total sugar (TS), and total phenolic and flavonoid contents were detected, and phytochemical profiles and cellular antioxidant activities were analyzed by the HPLC and CAA (cellular antioxidant activity) assay in five sweet wampee varieties and five sour wampee varieties. Results showed that the average TS/TA ratio of sweet wampee varieties was 29 times higher than sour wampee varieties, while TA content was 19 times lower than sour wampee varieties. There were much lower levels of total phenolics, flavonoids, and antioxidant activities in sweet wampee varieties than those in sour wampee varieties. Eight phytochemicals were detected in sour wampee varieties, including syringin, rutin, benzoic acid, 2-methoxycinnamic acid, kaempferol, hesperetin, nobiletin, and tangeretin, while just four of them were detected in sweet wampee varieties. Syringin was the only one that was detected in all the sour wampee varieties and was not detected in all sweet wampee varieties. Correlation analysis showed significant positive correlations between TA with phenolics, flavonoids, and total and cellular (PBS wash) antioxidant activities, while there were significant negative correlations between TS/TA with phenolic and cellular (no PBS wash) antioxidant activities. This suggested that the content of titratable acid in wampee fruit might have some relationship with the contents of phenolics and flavonoids. Sour wampee varieties should be paid much attention by breeders for their high phytochemical contents and antioxidant activities for cultivating germplasms with high health care efficacy.

Wampee (Clausena lansium) fruit is a good resource for food ingredient because of abundant bioactive compounds. This study investigated phenolics, flavonoids, phytochemical composition and antioxidant activities of five different varieties of wampee fruit. Phytochemical composition was analysed by HPLC, and the antioxidant activities of wampee fruits were detected by ORAC, DPPH, FRAP and PSC assays. Results showed that the variety of ‘YangShanDuHe (YSDH)’ contained the highest contents of total phenolics and flavonoids, and the highest value of three phytochemical compounds: vanillic acid, ferulic acid and rutin. The sweet wampee variety ‘CongChengTianHuangPi (CCTHP)’ showed the lowest values of total phenolics, flavonoids and antioxidant activities. According to the rank of five different varieties by the values of total phenolic and flavonoid contents and antioxidant activities, YSDH was characterised having the highest antioxidant potential, while the least one was CCTHP. These results may provide health guidance for wampee processing and consuming.

Clausena lansium (Lour.) Skeels, commonly known as “wampee,” is an excellent food ingredient of medicinal value. Effects of leaf developmental stages on the composition of phenolics, flavonoids, and antioxidant activity were investigated. Phenolics composition was studied using HPLC-PAD, whereas antioxidant activity was estimated by oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) assays. Increase in bound flavonoids, quercetin, and cellular antioxidant activity was observed in bound and free fractions at different stages of leaf development. Predominantly, quercetin and ferulic acid contents were high in free and bound fractions of old leaves. In addition, phenolic components depicted highly significant positive association ( p < 0.05) with antioxidant activity. Overall, old leaves of wampee have utility value similar to leaf buds, so they could be a more sustainable and economical source of bioactive compounds for commercial application in nutraceutical and pharmaceutical industries.

"Yueyinzaocui" pear (Pyrus pyrifolia cv. "Yueyinzaocui") is a variety with good quality that is cultivated in the northeast area of Guangdong province in China and harvested from late June to early July, but it only has a 1-week shelf life. For the purpose of extending the shelf life of the "Yueyinzaocui" pear, 1μL/L of 1-MCP (methylcyclopropene) was used to treat postharvest fruit. The results showed that fruit firmness continuously decreased; however, the respiration rate, ethylene production, β-GAL (galactosidase) activity and β-GAL transcript level increased during storage at room temperature. Compared with untreated fruit, the decline of fruit firmness during storage was delayed in 1-MCP-treated fruit. Fruit respiration rate was decreased and the ethylene production peak was postponed by 1-MCP treatment. The activity of β-GAL and transcript level of β-GAL gene was reduced, and the shelf life of the "Yueyinzaocui" pear at room temperature was extended for 10 days by 1-MCP treatment. Practical Applications: The purpose of this research is to extend the shelf life of "Yueyinzaocui" pear, and the results of this study showed that 1-MCP (methylcyclopropene) treatment extended its shelf life by 10 days at room temperature. "Yueyinzaocui" pear will rot rapidly in 1 week because of β-galactosidase activity, which caused sale burden for farmers. So if the farmers use the method studied in this research, 1μL/L 1-MCP treatment, it would reduce their pressure and may increase their income.