Physicochemical Attributes, Volatile Profile and Sensory Quality of Organic Crimson Crisp Apples during On-Tree Maturation.

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 ß-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.

Prolonged on-tree maturation vs. cold storage of Hass avocado fruit: Changes in metabolites of bioactive interest at edible ripeness.

When the recipient of the product is relatively distant from the production area, it is necessary to use cold storage and controlled humidity to transport the avocado fruits. One of the main advantages of local avocado consumption lies on the possibility of prolonging on-tree maturation; this could foreseeably modify the metabolic profile of the fruit that reaches the consumer. In this work, the effect of prolonged on tree maturation (during different time intervals) on the final composition of avocado fruit (at edible ripeness) was evaluated and compared with the impact of the same periods after prolonged cold storage. The quantitative evolution of nine bioactive metabolites (7 phenolic compounds, pantothenic and abscisic acids) over 40 days (10-days intervals) was studied by using a solid-liquid extraction protocol and a LC-MS methodology. The results were discussed both considering the quantitative evolution of each individual compound and the sum of all of them.