乳酸菌发酵蜜桃果酱制作过程中理化性质和关键香气成分演化研究

目的 探究乳酸菌发酵蜜桃果酱制作过程中的品质特性及挥发性香气化合物变化情况，进一步筛选关键呈香物质。方法 采用顶空固相微萃取-气相色谱-质谱法测定乳酸菌发酵蜜桃果酱挥发性风味物质变化。同时, 测定样品的总多酚、总黄酮、有机酸、色泽等理化指标, 并进行感官方面的评定。结果 共检测到53种挥发性有机化合物, 其中醛类、酯类、醇类在蜜桃果酱中丰富。结合气味活度值(odor activity value, OAV>1), 初步筛选出芳樟醇、1-辛烯-3-醇、壬醛等10种关键呈香物质。在乳酸菌发酵过程中, 果酱样品的总多酚、总黄酮含量显著增加(P<0.05), DPPH自由基清除能力有所提高。但是, 浓缩(NS)和后杀菌(GZ)过程对热敏性物质破坏严重, 颜色接受度下降, 色泽参数(L*、a*、b*)出现明显变化。在发酵过程中, 乳酸-苹果酸含量变化具有相关性。对不同制作时期果酱的挥发性风味物质进行偏最小二乘回归分析, 各时期得以很好的区分, 且模型可靠。结论 乳酸菌发酵改善了蜜桃果酱的风味，明显提高活性物质的含量。

Study on evolution of physicochemical properties and key aroma components in honey peach jam with lactic acid bacteria fermentation

Objective To explore the quality characteristics and volatile aroma compounds of honey peach jam fermented by lactic acid bacteria, further screen the key aroma compounds. Methods Headspace solid phase microextraction-gas chromatography-mass spectrometry technology was used to determine the changes of volatile flavor compounds in honey peach jam fermented by lactic acid bacteria. At the same time, the total polyphenols, total flavonoids, organic acids, color properties of the samples were determined, and sensory evaluation was carried out. Results A total of 53 volatile organic compounds were detected, among which aldehydes, esters and alcohols were abundant in honey peach jam. Combined with the odor activity value (OAV>1), 10 key aroma compounds were preliminarily screened out, such as linalool, 1-octene-3-ol and nonaldehyde. During lactic acid bacteria fermentation, the contents of total polyphenols and total flavonoids in fruit jam samples increased significantly (P<0.05), and DPPH scavenging ability was improved. However, the process of concentration (NS) and post-sterilization (GZ) seriously damaged the heat-sensitive substances, the color acceptance decreased, and the color parameters (L*, a*, b*) changed obviously. During the fermentation process, the content of lactic acid-malic acid had a correlation. Partial least square regression analysis of volatile flavor compounds in honey peach jam during different production periods showed that different periods were well distinguished and the model was reliable. Conclusion Lactic acid bacteria fermentation improved the flavor of honey peach jam, and the content of active substances increased obviously.