野生蓝靛果发酵过程中品质变化及挥发性物质分析

Quality Changes and Analysis of Volatile Compounds of Lonicera caerulea L. during Fermentation

摘要:

本文研究了植物乳杆菌发酵蓝靛果浆及果汁的品质变化，分析了48 h发酵过程中pH、活菌数、总酚含量、花色苷含量、清除·OH能力、清除DPPH·能力、SOD酶活力和淀粉酶活力的变化，通过气相色谱-质谱联用法（GC-MS）分析了发酵48 h时蓝靛果浆及果汁的挥发性物质。研究发现，经过发酵，蓝靛果浆及果汁的品质变化如下：pH显著下降（p＜0.05），最终分别为3.71和3.51；植物乳杆菌数量在20 h和24 h达到最高，分别为7.42 Log CFU/mL和7.85 Log CFU/mL；总酚含量均在40 h时达到最大值，分别为0.89±0.06 mg/mL和0.70±0.02 mg/mL；花色苷含量显著降低（p＜0.05）；清除·OH能力在40 h时达到最高，分别为(83.12±3.59)%和(80.60±2.87)%；清除DPPH·能力变化不显著（p＞0.05）；SOD酶活力于36 h达到最大值，分别为(45.59±1.07) U/mL和(49.59±0.71) U/mL；淀粉酶活力于48 h达到最大值，分别为(8.77±0.37) U/mL和(11.93±0.57) U/mL。通过GC-MS分析，在发酵蓝靛果浆及果汁中分别检测出86种和70种挥发性物质。癸酸乙酯（34.42%）和辛酸乙酯（21.37%）是发酵蓝靛果浆中主要的挥发性物质；辛酸乙酯（20.67%）、乙基 9-癸烯酸酯（17.82%）和癸酸乙酯（15.51%）是发酵蓝靛果汁中主要的挥发性物质。癸酸乙酯是发酵蓝靛果中的特征性风味物质。

Abstract:

In this paper, the quality changes of Lactobacillus plantarum fermented honeysuckle (Lonicera caerulea L.) pulp and juice were studied. The changes of pH, viable cell counts, total phenolic content, anthocyanin content, hydroxyl radical scavenging ability, DPPH free radical scavenging ability, SOD activity and amylase activity were investigated during 48 h fermentation. The volatile compounds of honeysuckle pulp and juice at 48 h of fermentation were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that through fermentation, the quality changes of the honeysuckle pulp and juice were as follows: the pH decreased significantly (p＜0.05), and finally was 3.71 and 3.51, respectively. The number of Lactobacillus plantarum was 7.42 Log CFU/mL and 7.85 Log CFU/mL at 20 h and 24 h,respectively. The total phenolic content showed the highest value at 40 h, which was (0.89±0.06) mg/mL and (0.70±0.02) mg/mL, respectively.The anthocyanin content was significantly reduced (p＜0.05). The hydroxyl radical scavenging ability reached the highest point at 40 h, which was 83.12±3.59% and 80.60±2.87%, respectively. DPPH free radical scavenging ability did not change significantly (p＞0.05). The SOD activity reached a maximum at 36h, which was (45.59±1.07) U/mL and (49.59±0.71) U/mL, respectively. The amylase activity achieved the peak at 48 h,which was (8.77±0.37) U/mL and (11.93±0.57) U/mL, respectively. By GC-MS analysis, 86 and 70 volatile compounds were detected in the fermented honeysuckle pulp and juice, respectively. Ethyl decanoate (34.42%) and ethyl octanoate (21.37%) are the main volatile compounds in the fermented honeysuckle pulp; and ethyl octanoate (20.67%), ethyl 9-decenoate (17.82%) and ethyl decanoate (15.51%) are the main volatile compounds in fermented honeysuckle juice. Ethyl decanoate is a characteristic flavor compound in fermented honeysuckle.