Edmund Mach Foundation, San Michele all'Adige, Trento, Italy.
J Appl Microbiol. 2018 Aug;125(2):513-527. doi: 10.1111/jam.13774. Epub 2018 Jun 6.
Straw wine is a highly valuable oenological production, affected by relevant economical losses due to proliferation of spoilage micro-organisms during drying grapes, after being harvested. In this work, ozone was evaluated as a tool to preserve grapes during drying, in terms of both qualitative and quantitative changes induced in the epiphytic microflora. In addition, the alteration exerted by ozone on grapes' chemical composition was analysed.
Grapes from four vine varieties were treated with ozone produced by a cold plasma generator during the entire drying period (6 weeks). The microflora was quantified weekly by plate counts and characterized by 454-pyrosequencing, and was compared with identical, untreated grape samples. At the end of drying, an extensive chemical characterization of the whole mass of grapes by FT-IR and GC-MS was performed. Ozone counteracted the growth of microflora by reducing the microbial population up to 3 log units. From the qualitative point of view, ozone reduced the incidence of spoilage micro-organisms, such as Acetobacter and Botrytis cinerea, among the microbiota of grapes.
The statistical analysis discriminates grape samples based on the residual epiphytic microflora at the end of drying and not on their chemical composition. These evidences confirmed that ozone did control spoilage micro-organisms without altering the volatile profile of grapes. Chemical analysis revealed that untreated grapes are less suitable for winemaking owing to the deprivation of some valuable compounds during the microbial proliferation.
Ozone is an emerging tool in winemaking, recently applied for controlling spoilage micro-organisms in winery. The present study describes a new application of ozone as an effective and safe alternative to chemical preservatives which are actually involved in the control of microbial alterations of grapes.
稻草酒是一种极具价值的酿造品，但在葡萄收获后进行干燥时，由于腐败微生物的增殖，会导致相关的经济损失。本研究旨在评估臭氧作为一种工具，在葡萄干燥过程中，从定性和定量两个方面来保护葡萄，研究其对附生微生物区系的影响。此外，还分析了臭氧对葡萄化学成分的改变。
在整个干燥过程（6 周）中，使用冷等离子体发生器产生的臭氧处理来自四个葡萄品种的葡萄。每周通过平板计数定量微生物群，并通过 454 焦磷酸测序进行表征，并与相同的未经处理的葡萄样本进行比较。在干燥结束时，对整个葡萄质量进行了 FT-IR 和 GC-MS 的广泛化学特性分析。臭氧通过将微生物种群减少 3 个对数单位来抑制微生物的生长。从定性的角度来看，臭氧减少了葡萄微生物群中腐败微生物的发生，如醋杆菌和灰葡萄孢。
统计分析根据干燥结束时残留的附生微生物群来区分葡萄样本，而不是根据其化学成分。这些证据证实，臭氧可以控制腐败微生物，而不会改变葡萄的挥发性特征。化学分析表明，未经处理的葡萄由于在微生物增殖过程中失去了一些有价值的化合物，因此不太适合酿酒。
臭氧是一种新兴的酿酒工具，最近已应用于控制酿酒厂中的腐败微生物。本研究描述了臭氧作为一种有效且安全的替代化学防腐剂的新应用，这些防腐剂实际上参与了葡萄微生物变化的控制。
