| 摘要 |
<p>PURPOSE:To elongate the browning time of the cut end of a lettuce by treating the cut end with a freshness-retaining agent containing protease as a main component. CONSTITUTION:The cut end of a lettuce is treated with an aqueous solution containing a protease as a main component. The addition of an antiopidant and/or cyclodextrin to the aqueous solution permits to further improve the activity thereof, and the simultaneous employment of both the components is preferable. The protease includes proteases originated from various sources such as papaia, fungi and borine pancreas. The antioxidant includes ascorbic acid, a salt thereof, catechol, a sorbic acid salt and vitamin E, and especially sodium ascorbate is preferable with respect to the pH of the aqueous solution. The concentrations of the protease, antioxidant and cyclodextrin in the aqueous solution of the freshness-retaining agent are preferably 0.01-0.1wt.%, respectively.</p> |
