VARIATION OF SUGARS AND ACIDS DURING RIPENING OF PEARS AND IN THE PRODUCTION AND STORAGE OF PEAR CONCENTRATE

摘要

ABSTRACTMajor sugars (fructose, sorbitol, glucose, and sucrose) and acids (malic, citric, phosphoric, and quinic) of pears were isolated by ion exchange and quantitated by gas chromatography (Cc) of their trimethylsilyl derivatives (TMS) during ripening and in the production and storage of pear concentrate. Ripening pears attained maximum sugar content (13.5) and acidity (6 meq) at a flesh firmness of 6 lb. Apart from a small loss of sucrose at depectinization and concentration stages little change occurred during pear concentrate production. Accelerated storage (16 wk, 36°C) of the concentrate resulted in brown color development and 6 sugar loss. Sucrose hydrolysis and Maillard browning of reducing sugar account for this sugar loss