Biological product testing using mechanical response

conference paper

English

Utility value of fruit can be judged by sensual perception or by standard mechanical–analytical scoring methods that are usually destructive and non-reproducible. Better objectivity may be reached by non-destructive methods, which are not familiarly known and used yet, mostly because of their sophistication and expensiveness. This topic is observed since 1968 in foreign literature. By our information, nobody was dealing with these problems in the Czech Republic. Thus, we decided to check these new trends and try to find our own optimal measuring method applicable in the area of investigation as well as processing of agricultural product. Typical example is impulse-response technique. This method uses determination of the resonance frequency of the fruit, which is obtained by excitation of the fruit (e.g. by stroke) and calculation of Fourier transformation of resulting signal. It is possible to determine the so-called stiffness factor S from the resonance frequency as follows, [1]: S= f2.m2/3 (1) where f is resonant frequency [Hz], m is mass of fruit [g]. The stiffness factor is in meaningful correlation with own stiffness of fruit and eventually another results of measuring. This paper explores the use of frequency response as a technique for non-destructive evaluation of the firmness of whole intact peach fruits.

Acoustic impulse-response technique, Non-destructive technique, Firmness

BEJČEK, L.; GRÄTZ, P.; KLUSÁČEK, S.

2003

13. 5. 2003

AMA Service GmbH

Wunstorf, SRN

203

208

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