The Effects of High Pressure Processing (HPP) on Betanin and Antioxidant Capacities of Djulis (Chenopodium formosanum Koidz.)

• Main Authors: Sun, Li-Ching, 孫莉卿
• Other Authors: Tsai, Pi-Jen
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/35108559734546292130

碩士 === 國立屏東科技大學 === 食品科學系所 === 104 === The main functional components of djulis seeds are betanin and poly-phenol compounds. Study has been confirmed that the pigment from djulis seeds is a good source of natural pigment, is very unstable, especially under high water activity and high temperature. Therefore, betanin is submitted to color and antioxidant capacity losses during high temperature processing. High pressure processing (HPP) is a non-thermal processing technique could be used to prevent betanin degradation and maintain the natural flavor, color, and nutrient. In this study, there were four different types of processing (HPP 500 MPa/10℃/3 min; HPP 500 MPa/30℃/3 min; Pasteurized 65℃/30 min; cooked in boiling water for 20 min), and three different types of djulis (whole grain, hull, and dehulled seed). They were examined for their microbiological quality, color features, betanin, total free amino acids, SOD-like activity, antioxidant compositions (total phenols and total flavonoids) and antioxidant capacity (FRAP reducing power and DPPH scavenging activity). Correlation analysis and principal component analysis revealed the impact of high pressure processing (HPP) on the quality of djulis. The results indicated that the microbial concentration was reduced to 5 log units by HPP. The correlation among betanins, SOD-like activity, antioxidant capacity and compounds were highly positively related to whole grain and hull of djulis by HPP. From this study, it showed that betanin were highly positively correlated with SOD-like activity, total phenols, total flavonoids, FRAP and DPPH. Betanin content of djulis hull exhibited the highest (252.68 mg/100 g). After HPP, total phenols, total flavonoids, DPPH scavenging activity, SOD-like activity and betanin content could be retained more than 97, 97, 96, 94 and 86%, respectively. Compared to the control samples, HPP may increase the total free amino acid content and reducing power 15.20-24.84% (1479.43-1603.24 mg/100 g) and 9.88-19.12% (6896.00-7476.00 μmol/L), respectively. Therefore, HPP can maintain the antioxidant capacity and antioxidant compounds of djulis. In contrast, high-temperature processing (C) could seriously destroy the betanin with only 29.20-52.62% pigment remained. Therefore, thermal treatments temperature had the most important influence on betanin stability. The results of principal component analysis showed that the strongest correlation to the first principal component was the chroma value. The whole grain, hulled and hull of djulis can be distinguished into the two different surfaces. Whole grain and hull of djulis were allocated on the positive direction of first principal component. In summary, the high pressure treatment could retain more nutrients and pigments than the heat treatment. Consequently, HPP can be considered to replace thermal processing and to be applied in the maintenance of djulis pigment in the future.