Study on Extraction and Stability of Proanthocyanidins in Plum (Prunus salicina Lindley)

• Main Authors: Lin, Chun-Jou, 林君柔
• Other Authors: Chang, Yung-Chung
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/k42j99

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 106 === Plum (Prunus salicina Lindley) are rich in nutrients, such as phenolic compounds, amino acids, minerals and vitamins. It’s an excellent source of bio-active ingredients. Proanthocyanidins is the composed of flavonoids, and it’s known as effective natural antioxidant and widely distributed in the plant, usually extract from grape seed. In this study, the aim is to extract total phenols and total proanthocyanidins from plums prepared by ethanol and then purification by HP-2MG resin for proanthocyanidin identification and the antioxidant activity determination, at the same time, the changes of total phenols, total proanthocyanidins, antioxidant capacity and pigment after storage were compared by mixing proteins. The results showed that 50% ethanol has the best extraction of total phenols and total proanthocyanidins from red plum peel (RPP), red plum flesh (RPF), yellow plum peel (YPP) and red plum flesh (YPF). Among, the contents of total phenols and total proanthocyanidins were the highest in the RPP and the lowest was the YPF, as well as, the two contents in the peel of both plums extracts are he noigher than the flesh. The HPLC analysis results showed that all plum extracts wert detected procyanidin B1, but grape seed was detected. In addition, gallic acid, (-)-catechin, (-)-epicatechin, procyanidin B2 and (-)-epicatechin-3-O-gallate were detected in both RPP and YPP, and gallic acid, (+)-catechin, (-)-epicatechin, procyanidin B2 were in YPF, but RPF was detected only gallic acid and procyanidin B2. In the antioxidant test, RPP has the highest of DPPH free radical scavenging capacity, 58.78 ± 0.4 μmole ascorbic acid equivalent (μmole/g DW). ORAC values of whole red plum and yellow plum were 3000.75 and 1705.11 μmole trolox/100g fresh weight respectively. The other hand, Fe3+ reduction capacity values was 11.008 and 1.839 mg ascorbic acid/100 g fresh weight respectively. Both ORAC and FRAP were peel of two plum extract higher than flesh extract. In storage test of RPP 50% ethanol extract (control) and its mixtures those mixes with soybean isolate protein, fish collagen hydrate and casein, at 37℃ for 28 days, results showed a significant decrease in the total phenols of the control, but the other samples keep at 84-81%. The control retained only 5.4% of the total proanthocyanidin content, while the other samples were 26-37% and soybean isolate protein was the best. The DPPH free radical scavenging capacity of control was better than other samples. About the stability of color, the absorbance of all the samples at 510 nm was increased, while the control was obviously greater than the other samples. In summary, RPP mix with protein can increase the total phenolic and total proanthocyanidins stability, and maintain the antioxidant capacity, as well as the color little change.