Pontesegger Niklas, Rühmer Thomas, Siegmund Barbara
Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9/II, A-8010 Graz, Austria.
Research Centre for Fruit Growing & Viticulture Haidegg, Ragnitzstraße 193, A-8047 Graz, Austria.
Foods. 2023 Mar 27;12(7):1425. doi: 10.3390/foods12071425.
When new apple cultivars are planted, knowledge of their maturation and ripening behavior and, as a consequence, the best time for their harvest is of utmost importance for providing fruits of the highest quality to consumers. In this study, we followed the on-tree maturation and ripening behavior of organic Crimson Crisp apples over a period of almost 3 months. With the weekly analyses of basic fruit quality attributes (weight, fruit firmness, total soluble solids, titratable acids, starch degradation) in combination with the fruit volatilome (primary and secondary volatiles) and sensory analysis, we obtained a holistic picture of the maturation and ripening properties of this new variety. We could show that at the recommended harvest window, which is based on the degree of starch degradation alone, the fruit development is not finished. Synthesis of aroma volatiles-which is strongly related to the expression of pronounced fruity, apple-like flavor-requires two additional weeks of on-tree ripening. Results indicate an upregulation of 13-LOX at very early maturation stages, while upregulation of 9-LOX and enzyme systems involved in the β-oxidation pathway requires a prolonged on-tree maturation period. The results of this study demonstrate that the analysis of basic fruit quality attributes is not sufficient for understanding the properties of apples. However, we demonstrate that the analysis of the fruit volatilome is a valuable and necessary tool for optimizing the quality of new apple varieties.
当种植新的苹果品种时,了解它们的成熟和采后熟化行为,以及因此确定最佳采收时间,对于向消费者提供最高品质的水果至关重要。在本研究中,我们对有机绯红脆苹果在近3个月的时间里进行了树上成熟和采后熟化行为的跟踪。通过每周对基本果实品质属性(重量、果实硬度、总可溶性固形物、可滴定酸、淀粉降解)进行分析,并结合果实挥发物组(初级和次级挥发物)和感官分析,我们全面了解了这个新品种的成熟和采后熟化特性。我们发现,仅基于淀粉降解程度确定的推荐采收期内,果实发育尚未完成。香气挥发物的合成——这与浓郁的果香、苹果般的风味表达密切相关——还需要在树上再熟化两周。结果表明在非常早期的成熟阶段13-LOX上调,而9-LOX和参与β-氧化途径的酶系统上调则需要较长的树上成熟期。本研究结果表明,仅分析基本果实品质属性不足以了解苹果的特性。然而,我们证明果实挥发物组分析是优化新苹果品种品质的有价值且必要的工具。