• Food Science and Preservation
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• v.17 no.3
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• pp.370-375
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• 2010

Cherries (Prunus avium L) were selected at the light red (LR) and dark red (DR) stages of maturation. Soluble solid content and the physicochemical properties of fresh 'Bing' cherries were analyzed to identify an instrumental nondestructive attribute reflecting changes in sweetness. Soluble solid content was significantly correlated with various physicochemical properties (firmness, color, and acid level) in LR-stage cherries. In DR-stage cherries, only firmness was positively correlated with soluble solid content. A positive correlation was found between soluble solid content and firmness of 200 randomly selected cherries. Thus, flesh firmness may be a useful quality factor indicating potential consumer acceptance of 'Bing' cherries.

• Journal of Biosystems Engineering
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• v.37 no.4
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• pp.252-257
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• 2012

Purpose: The net rind pattern and color of melon surface are important for a high market value of melon fruits. The development of the net and color are closely related to the changes in shape, size, and maturing. Therefore, the net and color characteristics can be used indicators for assessment of melon quality. The goal of this study was to investigate the possibility of estimating melon soluble solids content (SSC) and firmness by analyzing the net and color characteristics of fruit surface. Methods: The true color images of melon surface obtained at fruit equator were analyzed with 18 color features and 9 texture features. The partial least squares (PLS) method was used to estimate SSC and firmness in melons using their color and texture features. Results: In sensing melon SSC, the coefficients of determination of validation (${R_v}^2$) of the prediction models using the color and texture features were 0.84 (root mean square error of validation, RMSEV: 1.92 $^{\circ}Brix$) and 0.96 (RMSEV: 0.60 $^{\circ}Brix$), respectively. The ${R_v}^2$ values of the models for predicting melon firmness using the color and texture features were 0.64 (RMSEV: 4.62 N) and 0.79 (RMSEV: 2.99 N), respectively. Conclusions: In general, the texture features were more useful for estimating melon internal quality than the color features. However, to strengthen the usefulness of the color and texture features of melon surface for estimation of melon quality, additional experiments with more fruit samples need to be conducted.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.166-176
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• 2012

Purpose: This study was conducted to investigate the potential of interactance mode of NIR spectroscopy technology for the estimation of soluble solids content (SSC) and firmness of muskmelons. Methods: Melon samples were taken from local greenhouses in three different harvesting seasons (experiments 1, 2, and 3). The fruit attributes were measured at the 6 points on an equator of each sample where the spectral data were collected. The prediction models were developed using the original spectral data and the spectral data sets preprocessed by 20 methods. The performance of the models was compared. Results: In the prediction of SSC, the highest coefficient of determination ($R_{cv}{^2}$) values of the cross-validation was 0.755 (standard error of prediction, SEP=$0.89^{\circ}Brix$) with the preprocessing of normalization with range in experiment 1. The highest coefficient of determination in the robustness tests, $R_{rt}{^2}$=0.650 (SEP=$1.03^{\circ}Brix$), was found when the best model of experiment 3 was evaluated with the data set of experiment 2. The best $R_{cv}{^2}$ for the prediction of firmness was 0.715 (SEP=3.63 N) when no preprocessing was applied in experiment 1. The highest $R_{rt}{^2}$ was 0.404 (SEP=5.30 N) when the best model of experiment 3 was applied to the data set of experiment 1. Conclusions: From the test results, it can be concluded that the interactance mode of VIS/NIR spectroscopy technology has a great potential to measure SSC and firmness of thick-skinned muskmelons.

• Journal of Biosystems Engineering
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• v.36 no.5
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• pp.369-376
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• 2011

The overall goal of this study was to examine the feasibility of predicting firmness of pear fruit by analyzing laser-induced light backscattering images. Thirty-five image analysis characteristics extracted from the laser-induced light backscattering images were used to build partial least squares regression (PLSR) models for predicting firmness of pear fruit. Experiments were conducted with three sets of pear samples which were in same "Shingo" cultivar, harvested in a same season, but produced in different counties. In every experiments with fruit samples produced in a same county, the correlation coefficients of prediction ($r_p$) and root mean square errors of prediction (RMSEP) of the models were 0.550~0.761 and 4.039~6.154 N, respectively. In an experiment with mixed fruit samples produced in different counties, the $r_p$ and RMSEP of the model were 0.669 and 5.02 N, respectively. The experiment results indicate that the analysis of laser-induced light backscattering images could be a useful tool for predicting firmness of pear fruit nondestructively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.878-885
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• 1997

Effect of various ingredients and cooling methods on the quality of modified Jeung-pyun(traditional Korean steamed rice cake) were studied. Three different kinds of wheat flours(strong, medium, and weak) were studied to evaluate the volume and firmness of Jeung-pyun. Weak flour showed the maximum volume and good sensory results. The optimum ratio of ingredients was flour : water ; sugar ; Tak-Ju=100 : 20 : 20 : 50 for steaned Jeung-pyun. When three different cooking methods were compared, the maximum volume showed from convection oven method, but the crust color of Jeung-pyun was like bread. Steaming method showed higher volume than that of product heated by microwave method. The optimum formula ratio for the microwave method was flour ; water ; sugar ; Tak-Ju = 100 : 30 : 20 : 50, which required 10% higher added water content than that of steaming. When wheat flour was used instead of rice flour, the addition of 5% normal corn starch increased volume of both steamed and microwave cooked products. In the case of added modified starches to Jeung-pyn, 5% $\alpha$-waxy corn starch showed the highest volume in steaming method. When rice flour was used, the addition of 5%$\alpha$-waxy corn starch also showed highest volume f both steamed and microwave cooked products. The firmness of steamed wheat flour Jeung-pyun, containing 5%$\alpha$-corn starch was higher firmness than that of control and other added samples. Microwave cooked products showed two or three times higher firmness of steaming products. The use of wrap(uni-wrap) and stabilizer(METHOCEL) decreased the firmness of microwave cooked wheat flour Jeung-pyun to 200~300g compared with that of untreated Jeung-pyun.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.2
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• pp.59-63
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• 2014

The quality changes of 'Fuyu' persimmon fruits chill-injured on tree with different time periods were evaluated during storage of 6 weeks at $0^{\circ}C$. There was no significant difference among treatments in the weight loss, which increased with storage time. Firmness was found to be very important factor determining the quality level of persimmon fruit during the storage. The increased chill-injured period decreased the firmness, indicating the rapid fruit softening. While the firmness of the persimmons not exposed to chill-injured condition was not changed significantly during the storage period, the firmness of persimmon fruits chill-injured for 1, 3, and 5 days decreased from 26.7, 16.1, 10.8 N to 18.2, 12.22, and 5.8 N for 6 weeks. The total solids content and total acidity did not significantly change during the storage period. The amount of ethylene production from the chill-injured fruits was almost 2 times higher than that without low temperature injury. The results indicated that persimmon fruit injured by low temperature exposure directly affected to the changes of its ethylene production and firmness during storage.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.45-50
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• 2001

Stem firmness and flowering response of cut lily as influenced by medium composition (Control: Upland soil, Pt: Peatmoss, Pe: Perlite, Ve: Vermiculite, Rrh: Rotted rice-hull, RPt: Russian Peatmoss) were studied. For 'Casa Blanca', plant height and length of flower stalk increased when bulbs were planted in Pt:Rrh:Ve(1:1:1, v/v), and dried leaves of lower part plants decreased by RPt:Pe:Rrh(1:1:1, v/v). In case of 'Marco Polo' plant height and length of flower stalk increased with Pt:Rrh(1:1, v/v) as compared to other treatment, number of leaves and dried leaves increased when bulbs were planted in RPt:Pe:Rrh(1:1:1, v/v) as compared to control. Flowering of 'Casa Blanca' was promoted in Pt:Pe:Ve(1:1:1, v/v) and 'Marco Polo' was accelerated in Pt:Rrh:Ve(1:1:1, v/v). Flower length of 'Casa Blanca' was increased by RPt:Pe:Rrh(1 :1 :1, v/v) as compared with control and 'Marco Polo' was increased when bulbs planted to Pt:Rrh(1 :1, v/v). Flower-bud blasting of two cultivars was increased with Pt as compared with other treatment. Stem firmness of 'Casa Blanca' was increased by Pt:Pe:Ve (1:1 :1, v/v), and especially, stem firmness of upper part plants was increased by Pt:Rrh(1 :1, v/v) in 'Marco Polo' as compared to control plants. but generally, stem firmness of 'Casa Blanca' was not influenced with all cultural media as compared to control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.911-916
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• 2004

Widely used vegetables such as onion, soybean sprout, and carrot in Korean dishes were studied to reduce losses in firmness during cook/chill storage for food service system. Blanching at 7$0^{\circ}C$ affect positively on textural properties of the three vegetables while reheating at the food service practice. Firmness of the vegetables was improved and stabilized with addition of calcium ion in blanching solution during storage at refrigeration temperature. Calcium was effective to improve or sustain firmness during blanching. The effect of calcium on firmness of blanched and cooked soybean sprout was less significant than that of carrot and onion, especially at short period of storage under refrigerated condition. In conclusion, low temperature blanching with calcium ion was effective to maintain firmness of the three vegetables before cooking while refrigerated storage of the cooked vegetables and subsequent reheating for food service system.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.700-708
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• 2012

In order to optimize a method to determine the firmness of Chinese cabbage, hardness of midrib tissues was examined based on their chronological order of emergence. Texture measurement using volodkevich bite jaws gave a consistent and highest regression ($r^2=0.85$) between firmness and the order of leaf emergence, while blade set, cylinder probe, and crisp fracture support rig showed a lower coefficient of determination. Thickness of midrib tissue within an individual head from 16 cultivars of Chinese cabbage was positively correlated with the order of emergence, becoming thinner toward inner leaves. Mean thickness of midrib tissue from the head ranged from 7.74 mm for 'CR-shingshing' and 9.28 mm for 'Norangyeorum'. The covariance of leaf thickness within a head was highly cultivar-dependent, ranging from 23.6% for 'Chihili' and 5.8% for 'Bulam'. Firmness of the midrib tissue, defined as maximum peak height per tissue thickness, became higher from outer to inner leaves, showing $2^{nd}$ order of regression. Mean firmness of the midrib tissue from individual head varied from 1.58 N for 'Rangno' to 3.46 N for 'CR-shingshing'. The $10^{th}$ or $11^{th}$ leaf brought the best correlation coefficient (r = 0.81) between firmness of an individual leaf and the mean firmness of the entire leaves in a head, suggesting a reliable and rapid method to estimate the firmness of a head in lieu of examining all leaves in the head. The relationship between firmness of midrib tissue and dry mass ($r=0.70^{**}$) as well as cell wall content ($r=0.58^*$) of the head were positively correlated. Results obtained from the present study suggested that a new method to determine midrib firmness would enable to clarify the relationship between textural quality of fresh Chinese cabbage and their processed product, 'Kimchi'. It will also be important to apply this method to screen textural quality of various genotypes under breeding programs.

• Near Infrared Analysis
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• v.1 no.1
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• pp.27-30
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• 2000

In this study, we investigated the feasibility of non-destructive determination of internal quality factors of Fuji apple fruit using near infrared(NIR) reflectance spectroscopy and developed the calibration models. As the reference methods, refractometer, titration and texture analyzer for sugar content, acidity and firmness were used, respectively. Samples were scanned from 1100∼2500nm with InfraAlyzer 500C spectrometer and SESAME software was used for data analysis. A multiple linear regression(MLR) analysis was performed to develop the calibrations. The correlation coefficient(R) and standard error of prediction(SEP) were as follows; 0.91, 0.41$^{\circ}$Brix for sugar content, 0.90, 0.04% for acidity and 0.84, 0.094 kg for firmness, respectively. This study shows that NIR spectroscopy can be used to evaluate the sugar content acidity and firmness of apple fruit with acceptable accuracy.