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Different maturity stages of Cosmos caudatus leaves have been used to prepare herbal tea were investigated for their effect on antioxidant activity and mutagenic activity. The analyses carried out were total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, β-carotene bleaching assay, oxygen radical absorbance capacity (ORAC) and Ames Salmonella mutagenicity. The results demonstrated that, C. caudatus herbal tea prepared from young leaves showed significantly highest antioxidant activity for all assays tested, followed by mixed leaves, mature leaves, old leaves and the lowest was in C. caudatus herbal tea from a commercial brand. Pearson's correlation coefficient also demonstrated that TPC and TFC displayed a strong correlation with all antioxidant activity assays, showing that these compounds were the major contributors to the antioxidant activity in C. caudatus herbal tea. However, all studied C. caudatus herbal tea showed no mutagenic effects against Salmonella typhimurium tester strain TA98 and TA100 with and without S9 metabolic activation. Hence, it can be concluded that, different maturity stages could affect the antioxidant activity in C. caudatus herbal tea as it reduced the antioxidant activity as maturity increased, but did not give any effect on the mutagenic activity.abstrak Kesan aktiviti antioksida dan mutagen ke atas teh herba yang dihasilkan daripada daun Cosmos caudatus pada tahap kematangan yang berbeza telah dikaji. Analisis yang dijalankan ialah jumlah kandungan fenolik (TPC), jumlah kandungan flavonoid (TFC), ujian penurunan ferik (FRAP), pemerangkapan radikal bebas 2-2-Difenil-1-pikrilhidrazil (DPPH), pelunturan β-karotena, kapasiti penyerapan radikal oksigen (ORAC) dan mutagenik Ames Salmonella. Keputusan menunjukkan bahawa, teh herba C. caudatus dihasilkan daripada daun muda mempunyai aktiviti antioksida yang tertinggi bagi kesemua asai yang diuji, diikuti oleh daun campuran, daun matang, daun tua dan nilai terendah diperoleh dari teh herba C. caudatus daripada jenama komersial. Pekali kolerasi Pearson juga memaparkan kolerasi yang kuat bagi TPC dan TFC dengan kesemua asai aktiviti antioksida yang dijalankan. Ini menunjukkan bahawa sebatian tersebut merupakan penyumbang utama kepada aktiviti antioksida di dalam teh herba C. caudatus. Walau bagaimanapun, kesemua teh herba C. caudatus yang dikaji tidak menunjukkan kesan mutagen terhadap strain penguji Salmonella typhimurium TA98 dan TA100 dengan dan tanpa pengaktifan metabolic S9. Sebagai kesimpulannya, peringkat kematangan daun yang berbeza boleh memberi kesan ke atas aktiviti antioksida di dalam teh herba C. caudatus, semakin meningkat kematangan daun yang digunakan, semakin rendah aktiviti antioksida, tetapi tiada kesan ke atas aktiviti mutagen.

In recent years, increasing consumption of herbal tea is a worldwide trend because of their refreshing taste, positive potential health effect, convenience, abundant resources and also cheaper in price. However, different maturity stages of plants being used as raw material could affect the antioxidant activity, colour and mineral content in herbal tea. Thus, this present study was aimed at determining antioxidant activity, colour and mineral content of herbal tea prepared from Cosmos caudatus (C. caudatus) leaves at three different maturity stages namely young, mature and old. All prepared herbal tea were analysed for total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, colour and mineral content. The results demonstrated that herbal tea prepared from young leaves had strong (p< 0.05) antioxidant activity compared to mature and old leaves for all assays tested. Pearson's correlation coefficient also revealed that TPC and TFC exhibited a strong positive correlation with reducing power but negatively correlated with DPPH scavenging activity indicating that these compounds are major contributors to the antioxidant activity. In fact, the darker (p< 0.05) colour of C. caudatus herbal tea prepared from young leaves relates to their higher antioxidant activity as compared to mature and old leaves. However, C. caudatus herbal tea prepared from old leaves showed significantly higher in mineral content compared to mature and young leaves. Hence, it can be concluded that, as maturity increased, antioxidant activity and colour in C. caudatus herbal tea decreased and vice-versa for mineral content.Keywords: herbal tea, Cosmos caudatus, maturity, antioxidant activity, colour, mineral content Abstrak Pada masa kini, peningkatan pengambilan teh herba menjadi ikutan terkini di seluruh dunia kerana rasa yang menyegarkan, mempunyai potensi yang positif terhadap kesihatan, sumber yang mudah didapati dan harga yang murah. Walaubagaimanapun, penggunaan sumber bahan mentah daripada tumbuh-tumbuhan pada peringkat kematangan yang berbeza mempengaruhi aktiviti antioksida, warna dan kandungan mineral di dalam teh herba. Oleh itu, kajian ini bertujuan untuk menentukan aktiviti antioksida, warna dan kandungan mineral di dalam teh herba yang dihasilkan daripada daun Cosmos caudatus (C. caudatus) pada tiga peringkat kematangan iaitu daun muda, matang dan tua. Semua sampel teh herba telah dianalisa untuk menentukan jumlah kandungan fenol (TPC), jumlah kandungan flavonoid (TFC), ujian penurunan ferik (FRAP), pemerangkapan radikal bebas 2-2-difenil-1-1pikrilhidrazil (DPPH), warna dan kandungan mineral. Keputusan menunjukkan bahawa, teh herba dihasilkan daripada daun muda mempunyai aktiviti antioksida yang tinggi (p< 0.05) berbanding dengan daun matang dan tua untuk semua asai diuji. ISSN -2506Dian Nashiela et al: ANTIOXIDANT ACTIVITY, COLOUR AND MINERAL CONTENT OF HERBAL TEA PREPARED FROM Cosmos caudatus LEAVES AT DIFFERENT M...