Analysis of aroma compounds and nutrient contents of mabolo (Diospyros blancoi A. DC.), an ethnobotanical fruit of Austronesian Taiwan

AbstractDiospyros blancoi A. DC. is an evergreen tree species of high-quality wood. Mabolo, the fruit of this plant, is popular among the natives in Taiwan, but its potential in economic use has not been fully explored. Mabolo has a rich aroma. Of the 39 different volatile compounds isolated, its intact fruit and peel were found to both contain 24 compounds, whereas the pulp contained 28 compounds. The most important aroma compounds were esters and α-farnesene. Our data show that mabolo is rich in dietary fiber (3.2%), and the contents of other nutrients such as malic acid, vitamin B2, vitamin B3, folic acid, pantothenic acid, and choline chloride were 227.1 mg/100 g, 0.075 mg/100 g, 0.157 mg/100 g, 0.623 mg/100 g, 0.19 mg/100 g, and 62.52 mg/100 g, respectively. Moreover, it is rich in calcium and zinc; the contents of which were found to be 42.8 mg/100 g and 3.6 mg/100 g, respectively. Our results show that D. blancoi has the potential to be bred for a novel fruit

Establishment of the Optimal Conditions for Two–Dimensional Gel Electrophoresis of Papaya Seed Proteome

Papaya seeds are considered as a recalcitrant material for protein preparation in two-dimensional gel electrophoresis (2-DE) because of abundance of interfering compounds. We examined two protein extraction methods, the classical trichloroacetic acid (TCA)acetone precipitation (TCA-A) and phenol ammonium acetate-methanol precipitation (P-AA-M) methods, to evaluate their compatibility and efficiency of extracting papaya seed proteins in SDS-PAGE and two-dimensional (2D) gel electrophoresis analysis. Compared with TCA-A method, P-AA-M method showed better results, i.e., it increased at least five distinguished bands in SDS-PAGE, reduced problems of streaking and smearing in 2D gel, and enhanced resolution of detectable spots from 124±27 to 717±32. Comparison between traditional Coomassie Brilliant Blue R-250 staining and zinc-reverse staining was also conducted. The result showed that seven times more protein spots could be identified from 2D gel stained with zinc-reverse stain procedure. The resolution of 2D gel analysis for papaya seed proteome was further improved by utilizing pH 4-7 isoelectric focusing gel instead of pH 3-10 one. The protein spots picked from 2D gel through the protocol that we established were compatible with identification assessments of LC-MS/MS. Our data will serve as a platform and reference for future research in proteomics of papaya seeds or other recalcitrant plant materials

Effect of Harvest Maturity and Heat Pretreatment on the Quality of Low Temperature Storage Avocados in Taiwan

The present study aimed to find out the effects of different fruit maturities and heat pretreatments before storage on the quality of climacteric avocado fruit during low temperature storage. Two local cultivars, \u27Chanan\u27 and \u27Ching?Jin 2\u27, were chosen to analyze the relationship between the degree of fruit maturity at harvest and the quality of the fruits after low temperature (1℃) storage. Quality changes were observed in terms of color of skin, color of flesh, fruit hardiness, chilling injury and rottenness. Fruits of high maturity at harvest showed better storage quality in the two cultivars. Under the storage temperature of 1 ℃, fruit can be stored for 21 days for \u27Chanan\u27 and for 14 days for \u27Ching?Jin 2\u27 , and retained fully ripening quality after three days of ripening treatment at 21℃. Pretreatments of fruits were conducted by immersion of them in 38℃ water for 5, 15, 30 and 60 minutes to decrease the low temperature injury on avocado during 1℃ storage. The pretreatment for 30 minutes resulted in the optimum quality of \u27Ching?Jin 2\u27 fruit after four?week?storage at 1 ℃. Post?treatment of fruit for six hours under 38 ℃ air is recommended to reduce chilling injury in \u27Chin?Jin 2\u27 avocado before the 1℃ storage. Heat shock protein HSP 70 showed highly negative correlation with the chilling injury of fruit stored at 1 ℃