제조 공정에 따른 커피 항산화능의 변화와 커피 박 추출물의 식품 소재화

Abstract

This study was carried out to measure the variation of coffee antioxidant ability according to extraction process. Total phenolic compounds content, DPPH radical scavenging effect, metal chelating effect, and reducing power of hot water extracts from green coffee bean, roasted coffee bean, mixtrue roasted coffee bean, and spent coffee ground was measured. As a result of total phenolic compound content, it was revealed that Vietnam coffee bean contained the largest amount of phenolic compound, showing the figures for three kinds of green coffee bean were 32.6(Brazil), 36.4(Colombia), 43.4(Vietnam) mg/g and roasted coffee bean were 7.5(Brazil), 29.5(Colombia) and 42.1(Vietnam) mg/g, respectively. On the other hand, there was a very small amount of phenolic compound (1.2 mg/mL) in spent coffee ground due to the decrease of total phenolic compound content during the extraction process. However, hot water extracts from green, roasted and mixture roasted coffee bean and spent coffee ground all showed 85% to 92% of the high DPPH radical scavenging activity in the concentration of 4 and 0.4 mg/mL. As a result of metal chelating effect, hot water extracts of green, roasted and mixure roasted coffee bean showed 78% to 84% of metal chelating effects in 4 mg/mL, and there were no significant difference. While hot water extract of spent coffee ground showed the lowest metal chelating ability. According to reducing power test, hot water extract of green coffee bean was calculated the highest reducing power and spent coffee ground showed higher recuding power than that of mixture roasted coffee bean. As the results of examining variation of coffee antioxidant ability according to extraction process, it is considered that spent coffee ground, a by-product of coffee, has antioxidant ability for food. Because it has not only high DPPH radical scavenging ability but metal chelating ability and reducing power, which are lower than those of coffee bean though. For development of spent ground's practical application, hot water extract of spent coffee ground was used in the process of manufacturing the salted mackerels, which has problems of quality deterioration and poor storing capability caused by rapid lipid oxidation. Consequently, the mackerels treated 15% of hot water extracts from spent coffee ground showed significantly low VBN and TBARS compared to untreated. Furthermore, for sensory test, the mackerels treated 10% and 15% of hot water extracts from spent coffee ground scored high. In conclusions, spent coffee ground inhibited oxidation of the mackerels resulting in increase of shelf-life and improved the sensual quality. It is considered that spent coffee ground could be applied to food materials.