Nondestructive detection of split pit in peaches using an acoustic vibration method

Ryohei Nakano, Hidemi Akimoto, Fumio Fukuda, Takashi Kawai, Koichiro Ushijima, Yosuke Fukamatsu, Yasutaka Kubo, Yuichiro Fujii, Ken Hirano, Kunihisa Morinaga, Naoki Sakurai

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


Split-pit in peach fruit is a problematic disorder. Split-pit fruit cannot be detected based on external appearance, and contamination of fruit by split-pit reduces its reliability in the marketplace. Here, we demonstrate that split-pit fruit can be identified by a nondestructive acoustic vibration method and a unique approach based on the ratio of the third (f3) to the second (f2) resonant frequency. The response-resonant frequency spectra showed that the peaks of f2 frequencies in split-pit fruit were shifted to much lower values than those in normal fruit, whereas those of f3 frequencies showed only small shifts. The calculated f3/f2 ratios in most normal fruit were in the range of 1.35–1.4, whereas those in split-pit fruit were 1.45–2.0. Analysis of more than 300 fruit samples revealed that by setting the f3/f2 cut-off value at >1.45, 95% of split-pit fruit in the fruit samples were detected, whereas only 1.5% of normal fruit were missorted as split-pit fruit. A model for simulating the vibration properties of peach fruit was developed by using the finite element method. The simulated vibration patterns showed that f3/f2 values were increased by the insertion of split pit, indicating that, at least partially, the observed high f3/f2 values in split-pit fruit directly reflected split-pit occurrence. These results clearly demonstrate that the use of f3/f2 ratios obtained using an acoustic vibration method can effectively detect fruit with split-pit. The possibility of installing acoustic vibration devices in peach sorting lines and the application of portable devices to unpicked fruit on the tree are discussed.

Original languageEnglish
Pages (from-to)281-287
Number of pages7
JournalHorticulture Journal
Issue number2
Publication statusPublished - 2018


  • Fruit disorder
  • Fruit quality
  • Peach stone
  • Resonant frequency
  • Sorting out

ASJC Scopus subject areas

  • Plant Science
  • Horticulture


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