Utilising waste stem tea to produce instant tea
2010
Do Van Chuong
Stem tea (twig tea) makes up the highest proportion of 63% among kinds of refused teas. Although stem tea is waste one, the proportion of soluble substance in it is very high (28.8% compared to dried substance). Therefore, utilising this waste tea to produce instant tea, which is the ingredient for food or beverage, is very necessary. By organoleptic and chemical technique, the quality of stem tea collected at Hoai Trung Tea Ltd. Company (Phu Tho) is measured. The result shows that the quality of stem tea is not much worse than OP tea (a kind of best black tea for export in Viet Nam). The highest extraction efficiency can be reached up when the proportion of tea and water is 1/8, extract 2 times within 10 minutes at boil temperature. After that, extracted juice is steamed at 50-600C. Then the tea juice has the best quality in terms of colour and favour. To produce soluble tea powder, spray/freeze drying of the concentrated brew at 10-12 Bx, 1700C. The received instant tea has the humidity of about 1.5%. The instant tea which manufactured from waste stem tea has the same quality as the one which produced from processed tea. Extraction efficiency of stem tea compared to the initial one is 65.5%.
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