Effect of Vibration Stress on Selected Chemical Parameters of "Bluecrop" Highbush Blueberry (Vaccinium corymbosum L.) and Grape (Vitis vinifera L.)

Changes in the quality of fruits and vegetables are influenced by such factors as temperature, humidity and the composition of the atmosphere in which the fruits and vegetables are stored. During transport, an additional factor is vibration stress. This can lead to mechanical damage of the fruits and vegetables, which leads to deteriorated quality and, in extreme cases, spoiling. In order to preserve the best possible quality of fruits and vegetables despite their prolonged transport, they are maintained in an unripe condition and are later subject to forced ripening before selling. The aim of our investigations was to perform an analysis of the influence of vibration stress on the chemical parameters of fruits ("Bluecrop" highbush blueberry and grape) related to the process of their ripening. The identified parameters were the pH level, the content of total soluble solids, overall sugar, reducing sugars and ascorbic acid. The results of the performed investigations allowed for determining the levels of energy supplied in the form of vibration to the produce causing significant changes in its chemical parameters, indicating its accelerated ripening, as well as the levels of energy that result in changes leading to product spoilage.