Apple Firmness Prediction During Shelf Life Using the Finite Element Method and Acoustic Vibration Response

• Published in: Erwerbsobstbau 2023-12, Vol.65 (6), p.2197-2206
• Main Authors: Fathizadeh, Zahed, Aboonajmi, Mohammad, Hassan-Beygi, Seyed Reza
• Format: Article
• Language: English
• Subjects: Acoustic properties; Acoustics; Agriculture; Apples; Biomedical and Life Sciences; Correlation coefficient; Correlation coefficients; Finite element method; Firmness; Fruits; Humidity; Life Sciences; Modal analysis; Orchards; Original Article; Originalbeitrag; Plant Sciences; Relative humidity; Resonant frequencies; Shelf life; Storage conditions; Vibration; Vibration response
• ISSN: 0014-0309; 1439-0302
• DOI: 10.1007/s10341-023-00952-2

The geometric model of apple fruit was designed according to the properties and dimensions of ‘Gala’ apples that were harvested from apple orchards in the Damavand region of Iran. The designed models were assessed by modal analysis and their natural frequencies were obtained up to 50 modes. The results of modal analysis were compared with dominant frequencies, elasticity modulus and four firmness indices obtained from acoustic and vibration response methods. Results showed that there is a high correlation between the natural frequencies obtained from the modal method and the acoustic and vibrational properties of apples. Dominant frequencies in acoustic and vibration methods were used to calculate the firmness of two groups of apples during storage with two storage conditions (group 1: 0 ℃, 95% relative humidity, and group 2: 20 ℃, 40% relative humidity). In both storage conditions, among the indices of apple fruit, for the first group, vibrational firmness index with 96.5% and in the second group, vibrational frequency with 97.5% had the highest correlation coefficient with modal analysis frequencies. Indices including mass parameter had relatively less correlation with modal analysis frequencies.