Detached ripening of non-climacteric strawberry impairs aroma profile and fruit quality

Climacteric fruit show an autocatalytic burst in ethylene production during ripening and are therefore able to ripen detached from the plant. This detached ripening of climacteric fruit is a unique feature that is widely exploited by the postharvest industry. Non-climacteric strawberry on the other hand, ripens without the autocatalytic ethylene response. Surprisingly, we found that strawberry was capable of ripening after detachment at the green stage. This apparent ripening process was studied by comparing ethylene production and multiple fruit quality traits between strawberries that ripened on the vine versus detached. Our findings show that ethylene production is hardly influenced by the dissimilar ripening conditions, yet fruit quality is heavily affected. Importantly, detached strawberries did not reach the same fruit mass, lowering the market value of the detached ripened fruit. Furthermore, sugar and acid analysis showed that detached strawberries have a low malic acid, glucose, fructose and sucrose content compared to fruit ripened on the vine, indicating that a continuous supply of photosynthesis assimilates, water and nutrients by the plant is essential for normal fruit ripening. The unique aroma of strawberries was also heavily altered in detached ripened fruit. Detached strawberries had a lower abundance of most volatile compounds, except for alcohols, resulting in less intense aroma and unwanted off-flavors. It can be concluded that detached ripened strawberries are of inferior quality compared to normal vine-ripened strawberries and are unsuitable for marketing.