Quantifying cucumber fruit crispness by mechanical measurement

Abstract

Fruit crispness is of great importance in cucumber as well as in other fruit vegetables, because it relates directly to the commercial value of the product. In breeding projects and pre-or postharvest studies of fruit texture, an effective quantification method has been desired to replace rough, qualitative evaluations of fruit texture based solely on human perceptions. We applied several analytical methods to the force-deformation curve to quantify cucumber fruit crispness and assessed the efficacy of these methods as candidate cucumber fruit crispness indicators for use in breeding or research. Texture parameters for the flesh and placenta of 12 cucumber cultivars, based on the crispness index, apparent fractal dimension, and power spectrum and peak analyses, were calculated from mechanical measurement results. There was a significant large genotypic (cultivar) effect on the texture parameter values and a lesser, but still significant, contribution from the environment. Furthermore, we found strong relationships between these texture parameters and sensory crispness. These results indicate that these methods for analyzing the force-deformation curve provide effective, quantitative indicators of fruit crispness, with considerable promise for application in scientific research and breeding programs.

Combining ability analysis of fruit texture traits in cucumber by mechanical measurement

“…Eight genotypes of cucumber representing differing levels of improvement status and a range of fruit textures (Yoshioka et al 2009), were crossed in a half-diallel mating system (excluding reciprocals) during winter (January to March) 2008 to produce 28 F 1 hybrids. Reciprocal cross was not examined because reciprocal differences were not significant for many agronomic traits, such as yield, plant morphological traits and fruit quality traits Kupper 1985, Navazio andSimon 2001).…”

“…The method for quantifying the texture of the sampled fruits has been described in detail by Yoshioka et al (2009). In summary, a transverse slice (15 mm thick) was obtained from the mid-region of each fruit and subjected to mechanical measurement.…”

“…The difficulty in evaluating texture traits other than firmness is one of the main barriers to substantial progress. Recently, improvements in computer and instrument performance have allowed researchers to develop new quantitative methods of evaluating fruit texture on the basis of mechanical (Horie et al 2004, Yoshioka et al 2009), acoustic (Sakurai et al 2005), and biorheological (Dan et al 2003(Dan et al , 2004) measurements instead of subjective sensory evaluation. Notably, Yoshioka et al (2009) applied several methods based on analyses of puncture test data (force-deformation curves), which are normally used for quantifying the texture of breakfast cereals, to cucumber fruit texture.…”

“…Next, the resulting hybrids were evaluated for 2 years. Fruit texture traits were quantified by the mechanical measurement method proposed by Yoshioka et al (2009). The quantitative scores of fruit texture were then subjected to Griffing's combining ability analysis (Griffing 1956), and the GCA and SCA of the parental genotypes were estimated.…”

Fruit Textures of Beit Alpha, Greenhouse, Japanese, Pickling, and Slicer-type Cucumbers

“…The crispness index (i.e., total of the absolute values of the secondary differentiation values of force), which is strongly correlated with sensory crispness (Yoshioka et al, 2009), was calculated from the force-distance curve data for the flesh (Horie et al, 2004). Since the crispness index has no unit, relative values of crispness indices were determined for comparison in each test.…”