Indonesia merupakan produsen teh terbesar ke tujuh dunia dengan total produk mencapai 125 ribu ton pada 2016 yang berkontribusi sebesar 3% dari total produksi teh dunia. Kualitas produk teh merupakan faktor utama untuk meningkatkan daya saing produk teh Indonesia. Penelitian ini bertujuan untuk mengevaluasi kesesuaian mutu produk teh dengan persyaratan SNI. Parameter mutu yang dievaluasi meliputi kadar air, kadar abu total, kadar abu larut dalam air, kadar abu larut asam, dan kadar alkalinitas abu. Sebanyak 18 produk teh yang terdiri atas teh hitam, teh putih, teh hijau, teh hijau melati, dan bubuk teh hijau digunakan dalam penelitian. Hasil penelitian menunjukkan bahwa Kadar air dari 18 sampel produk teh berkisar antara 1,6% hingga 14%. Sebanyak 9 (sembilan) sampel produk teh memiliki kadar air yang melebihi standar yang disyaratkan oleh SNI. Produk teh hijau dan teh hijau melati memiliki kadar abu larut dalam air sebesar 33,25% dan 41,15% lebih rendah jika dibandingkan dengan persyaratan yang ditetapkan oleh SNI sebesar minimal 45%. Secara keseluruhan, produk teh telah memenuhi persyaratan SNI teh pada parameter kadar abu total, kadar abu tidak larut asam, dan alkalinitas abu. Beberapa parameter seperti kadar abu larut dalam air, abu tidak larut dalam asam, dan alkalinitas abu belum ditetapkan standarnya pada SNI 7707-2011 tentang teh instan dan SNI 01-1898-2002 tentang teh wangi. Penelitian lebih lanjut diperlukan untuk mengevaluasi mutu produk teh dari aspek kimia, cemaran logam mineral, dan mikrobiologi yang ditetapkan di SNI.

Tea is one of the most popular beverages in the world. Produced from Camellia sinensis leaves, tea has been studied to provide health benefits due to the content of important metabolites. This study aimed to investigate the catechin contents, antioxidant, and antibacterial activities of Indonesian tea varieties, namely green tea, black tea, and white tea. Tea infusion was prepared by extracting 1 g of each sample into 10 mL of distilled water and incubated at 80 °C for 60 min. The catechin and epigallocatechin gallate (EGCG) contents of tea extracts were determined using high-performance liquid chromatography (HPLC). Antioxidant activity was measured using the free radical method with 2,2-diphenyl-1-pycrylhidrazyl (DPPH), while antimicrobial activity was assesed using paper disc diffusion assay. The results indicated that green tea had the highest contents of catechin (646 ± 17.14 mg/L) and EGCG (997.8 ± 36.72 mg/L), and antioxidant activity with IC50 of 5.65 µg/mL. Furthermore, green tea and white tea extracts showed inhibitory activity against Gram-positive bacteria such as Micrococcus luteus, Bacillus subtilis, and Staphylococcus aureus whereas black tea had no activity against all bacterial strains tested. Generally, we concluded that white tea and green tea contributed to the higher content of catechins and exhibited strong antioxidant and antibacterial properties.

PENGARUH METODE FERMENTASI SUBSTRAT PADAT DAN SUBSTRAT TERENDAM PADA BIJI SORGUM TERHADAP KUALITAS TEPUNG

People’s interest in green tea powder is increasing currently. The addition of green tea powder to food products could increase antioxidant activity and other health benefits. GMB 7 and GMB 9 are local tea clones of the Assam variety widely planted in Indonesia’s tea plantation. This study aimed to determine green tea powder’s total polyphenols and antioxidant activity from local tea clones (GMB 7 and GMB 9). Total polyphenol and antioxidant activity were determined by Folin-Ciocalteau and free radical of DPPH methods, respectively. Our results showed that the total polyphenols of green tea powder were 27.61% and 27.31% for the GMB 7 and GMB 9 clones, respectively. Furthermore, the antioxidant activity of green tea powder with IC50 was 15.41 mg/L and 17.32 mg/L for clones GMB 7 and GMB 9, respectively. The results indicate the potential for the development and utilization of local clones to fulfill domestic green tea powder production. Further research is needed to determine the health benefits of green tea powder from clones of The Assam varieties.

Fixation is essential in green tea processing to inactivate the polyphenol oxidase enzyme. In Indonesia, green tea is made from the Assam variety and produced using the panning method. Few studies are reported on green tea made from Indonesian clones of the Sinensis variety. This study aims to identify chemical characteristics, antioxidant activity, and sensory evaluation of green tea from local clones of the Sinensis variety (GMBS 2, GMBS 4, and GMBS 5) with different fixation methods (panning and steaming). The results show that the caffeine content of green tea products ranged from 2.51-2.59% and 2.67-2.74% for panning and steaming methods. The panning method produced green tea with higher total polyphenol and flavonoid content than the steaming method. Green tea with the panning method has an IC50 value of 14.45; 14.41; and 17.41 mg/L for GMBS 2, GMBS 4, and GMBS 5, respectively. The panning method resulted in a smaller IC50 value than the steaming method for GMBS 2 and GMBS 4 clones. The steaming method produced green tea with a higher taste, aroma, and total score than those the panning method. However, different fixation methods did not significantly affect the appearance, liquor color, and leaf infusion. In conclusion, different fixation methods on GMBS 2, GMB 4, and GMB 5 produced green tea products that met the Indonesian National Standard 3945:2016. Further research is needed to determine the role of the plucking period/season and the characteristics of volatile compounds of green tea from GMBS clones with different fixation methods.