Conclusion
Ca2+ enhanced the astringent taste and weakened the bitter, umami and sweet tastes of the solutions of the main taste substances — EGCG, caffeine, theanine and sucrose solutions. Therefore, increasing the Ca2+ concentration influenced the appearance and the taste of the tea infusions prepared from instant green tea. The above results suggest that the preparation of green tea infusion frominstant green tea powder should use water with low Ca2+ concentration.