真空浓缩对绿芦笋汁营养品质和风味的影响

Effect of Vacuum Concentration on Nutritive Quality and Flavor of Green Asparagus Juice

摘要:

为了探讨真空浓缩对绿芦笋汁营养品质和风味的影响，将新鲜绿芦笋汁于0.1 MPa、50 ℃条件下进行真空浓缩处理，分别得到固形物含量为10%、20%、30%和45%的四种浓缩汁，比较研究浓缩汁与新鲜汁的色泽、维生素C、总糖、总酚和总黄酮的含量，并运用顶空固相微萃取和气相色谱-质谱联用法对四种浓缩汁和新鲜汁的挥发性风味化合物进行对比分析。结果表明：真空浓缩对芦笋汁的营养品质和风味物质影响显著。随着浓缩汁固形物含量的增加，芦笋汁的绿色加深，色泽变暗，维生素C和总黄酮含量逐渐降低，而总糖和总酚含量增加。芦笋汁中的主要挥发性物质是醛类，其次是酮和醇；随着浓缩汁固形物含量的增加，风味化合物含量呈先增加后减少的趋势。固形物含量为30%的浓缩汁品质和风味保持较好。

Abstract:

To explore the effect of vacuum concentration on the nutritive quality and flavor of green asparagus juice, fresh juice was vacuum concentrated at 50 ℃ and 0.1 MPa. Four kinds of concentrated juice were obtained with soluble solid content of 10%, 20%, 30%, and 45%, respectively. The color, vitamin C content, total sugar content, total phenolic content, and flavonoid content were determined in the concentrated and fresh juice samples. Volatile flavoring compounds in the asparagus juice samples were comparatively analyzed by headspace solid-phase micro extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The results showed that vacuum concentration significantly affected the nutritive quality and flavoring compounds in green asparagus juice. As the soluble solid content increased, the color of the juice became dark-green, the vitamin C and total flavonoid contents decreased, and the total sugar and total phenolic contents increased. The main volatile compounds of green asparagus juice were found to be aldehydes, ketones, and alcohols. As the soluble solid content in the juice increased, the flavoring compound content first increased and then decreased. The quality and flavor were better preserved in the concentrated green as paragus juice with 30% soluble solid content.