KAJIAN BAHAN DAN RASIO JAHE MERAH (Zingiber officinale var.Rubrum) TERHADAP MUTU KIMIA, AKTIVITAS ANTIOKSIDAN DAN DAYA TERIMA PADA SIRUP KOPI ROBUSTA (Coffea canephora L.)

Coffee syrup is a processed coffee product that uses added sugar in a certain concentration, resulting in a thick solution with regular cooking. The type of coffee in the manufacture of coffee syrup is Robusta coffee because it has a stronger taste compared to other types of coffee such as Arabica and Liberica. Previous research conducted the manufacture of coffee syrup with the addition of spices. However, in terms of taste less favored by consumers. Therefore, an alternative to adding other types of spices is red ginger (Zingiber officinale var.Rubrum). The high content of oleoresin and essential oil compounds in red ginger compared to other types of ginger is believed to cause a stronger taste and aroma. In addition, red ginger has a high content of antioxidant activity. The addition of red ginger in the manufacture of coffee syrup can be done by making juice or by pressing. The experimental design in this study used a nested design. The parent factor is red ginger extract and red ginger by pressing, while the nested factor is the ratio of red ginger: steeping water added, namely 1:10, 1:15, 1:20. Parameters analyzed were antioxidant activity, viscosity, total sugar, and organoleptic (taste, preference, and aroma). Then caffeine analysis was carried out on coffee steeping water and coffee syrup without the addition of red ginger to determine the caffeine content of the heating effect. The results showed that the difference in red ginger treatment and the concentration given had an effect on antioxidant activity, viscosity, total sugar, organoleptic (taste, preference and flavor). The best treatment produced in J1[K3] was syrup with the addition of red ginger extract in a ratio of 1:20 with an average antioxidant activity of 62,5%, viscosity of 116,250 cPs, total sugar 76,836%, taste organoleptic 4,4, preference organoleptic 3,633, and aroma organoleptic 3,933. As for the addition treatment by pressing red ginger, the best results were obtained at a concentration of 20% J2[K3] with an average analysis of antioxidant activity 61,153%, viscosity 57,5 cPs, total sugar 71,417%, taste organoleptic 3,867, preferred organoleptic 3,6 and aroma organoleptic 3,900