Antioxidative and antimycotic effects of turmeric, lemon-grass, betel leaves, clove, black pepper leaves andGarcinia atriviridis on butter cakes

Abstract

Turmeric, lemon-grass, Garcinia atriviridis and clove were found to be effective in retarding mould growth in butter cakes. Betel leaves and black pepper leaves showed no antimycotic activity and may even promote mould growth in butter cakes. Turmeric, betel leaves and clove effectively retarded the rancidity of butter cakes and extended their storage life from 2 weeks (control) to more than 4 weeks. Lemon-grass, G atriviridis and butylated hydroxy toluene (BHT) extended the butter cake storage life to 4 weeks, while butylated hydroxy anisole (BHA) was only able to extend the storage life to 3 weeks. The thiobarbituric acid value (TBAV), peroxide value (PV) and anisidine value (AV) of cakes containing these extracts (0.1% w/w butter) and control cakes were significantly different (p < 0.05) during the 4 weeks of storage. Turmeric and betel leaves had the best antioxidative activities (TBAV = 0.62f, 0.64f; PV = 10.2cde, 15.29bc; AV = 3.05e, 3.63e; Totox V = 23.55b, 34.21b respectively), performing better than BHA or BHT (TBAV = 1.62c, 1.21cde; PV = 9.77de, 5.46ef; AV = 12.52c, 15.16b; Totox V = 32.06b, 26.08b respectively). Same letters superscripted on the mean values of samples indicate insignificant difference between them. The oxidative values of BHA and BHT in cakes were insignificantly different (p < 0.05) except in AV analysis, but significantly lower than control cakes (TBAV = 2.43b; PV = 23.09a; AV = 23.10a; Totox V = 69.27a). Clove and lemon-grass were also better than BHA/BHT and had the next strongest antioxidant activity (TBAV = 0.81ef, 0.98def; PV = 15.45b, 12.50bcd; AV = 3.11e, 7.20d; Totox V = 34.03b, 32.20b respectively). The AVs of cakes containing G atriviridis (25.03a) were similar to control cakes (23.10a) but the PVs were low (0.94f) throughout the storage period, indicating that G atriviridis increased the rate of conversion of hydroperoxides to aldehydes. Black pepper leaves appeared to be pro-oxidative (TBAV = 2.91a; PV = 10.45bcde; AV = 8.52d; Totox V = 29.40b). © 1999 Society of Chemical Industry