Biological activities and application of mucilage from Hylocereus costaricensis cladodes

• Main Authors: Chun-Fu Chuang, 莊淳富
• Other Authors: Chang, Yung-Chung
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/8hmc8m

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 107 === Hylocereus costaricensis belongs to the cactus family and is one of the important fruits in Taiwan. Cactaceae plants have thick cladodes (succulent cladodes) that contain mucilage is rich in bioactive substances and polysaccharides, the latter was used mainly for moisturizing and had many applications in the food, pharmaceutical and cosmetic industries. This study was to investigate the effect of pectinase pretreatment on the hot water extraction of bioactive substances and polysaccharides from old cladodes of Hylocereus costaricensis, and also to analyze the physiological activity of extracts and its related applications. After the cladodes was peeled and diced, added two volumes of water and homogenized, then extracted in a shaking water bath at 80 oC, 100 rpm for two hours. Finally, the mixture was filtrated through cotton cloth and centrifuged at 12,000 x g for 20 minutes. The residue of the filtration and centrifugation were repeated the extraction three times, then combined all the supernatant into the hot water extracts (HWE). On the other hand, the cladodes were homogenized and then treating with pectinase (0.5 g/L) for 16 hours before the hot water extraction. It would get the enzyme pretreatment hot water extracts (EPHWE). The results showed that the total sugar, total polyphenols, total protein, and antioxidant activities (DPPH, ABTS and ORAC) of EPHWE were significantly better than HWE, which were 15.30 and 14.20 mg/g F.W., total phenols 0.405 and 0.453 mg/g F.W., total protein 0.214 and 0.149 mg/g F.W., the IC50 values of DPPH free radical scavenging activity were 2.527 and 9.282 mg/ml, ABTS+ free radical scavenging activity were 1.262 and 4.518 mg/ml, ORAC value were 11.024 and 8.684 mM Trolox/g F.W. respectively. Furthermore, the HWE and EPHWE of extracting from cladodes cut in May, both with higher total sugar, total polyphenols and total protein than of prepared in September. The HWE and EPHWE were precipitated with 4 volumes of 95 % alcohol at 4°C for polysaccharide. Taking the supernatant of alcohol precipitation for antibacterial activity analysis and the alcohol precipitated polysaccharide for moisture adsorption and retention analysis. The results of antibacterial activity analysis showed that the supernatant of alcohol precipitation of EPHWE has good inhibitory activity against Staphylococcus aureus and Pseudomonus aeruginosa, which can maintain 90 % inhibition rate within 18 hours. In water adsorption and retention analysis, there is no significant difference in the moisture absorption rate between alcohol precipitated polysaccharide of EPHWE and HWE in the range of 41-96% RH. Under the relative humidity of 43 % at 25 °C, the water loss rate of alcohol precipitated polysaccharides of EPHW and HWE were 90.709 % and 93.829 %, respectively, but both were significantly higher than of glycerol 38.549 %. In summary, the pectinase pretreatment can effectively increase the total sugar, total phenolic content and antioxidant activity of the hot water extracts from cladodes of H. costaricensis. On the other hand, although the supernatant of alcohol precipitation of EPHWE has antibacterial activity, but the alcohol precipitate polysaccharides has no good moisture retention property. It need further experiments to confirm the potential of commercial application.