• Title, Summary, Keyword: firmness

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Firmness Measurement of Melon by Characteristics of Impact Signal (I) - Characteristics of Impact Signal of Melon - (충격신호 특성을 이용한 멜론의 경도측정(I) - 멜론의 충격신호특성 -)

  • Lee, Young-Hee;Choi, Dong-Soo;Choi, Seung-Ryul;Kim, Man-Soo;Kim, Ghi-Seok
    • Journal of Biosystems Engineering
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    • v.33 no.4
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    • pp.239-247
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    • 2008
  • Firmness is very important factor to evaluate the freshness and ripeness among the various factors, in concerning about the melon quality. This study was carried out to develop the technique using impact signal to measure the melon firmness nondestructively. Results of analyzing impulse signals of melons having different firmness levels showed that the firmness of melon affected various impulse responses including amplitude, transmitted time, maximum peak frequency, firmness index 1 ($f^2m$), and firmness index 2 ($f^2m^{2/3}$). Impulse signal amplitude was the best indicator to predict the firmness of melon because of a strong corelation ($R^2\;=\;0.9071$). Firmness index 1, firmness index 2, maximum peak frequency, and normalized transmitted time were also possible indicators with acceptable correlation values.

Prediction of Soluble Solid and Firmness in Apple by Visible/Near-Infrared Spectroscopy (가시광선/근적외선 분광분석법을 이용한 사과의 당도 및 경도 측정)

  • 최창현;이강진;박보순
    • Journal of Biosystems Engineering
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    • v.22 no.2
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    • pp.256-265
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    • 1997
  • The objectives of this study were to examine the ability to predict soluble solid and firmness in intact apples based on the visible/near-infrared spectroscopic technique. Two cultivars of apples, Delicious and Gala, were handled, tested and analyzed separately. Reflectance spectra, Magness-Tayor (MT) firmness, and soluble solids in apples were measured sequentially. Maximum and minimum diameters, height, and weight of apples were recorded before the MT firmness tests. A spectrophotometer was used to collect reflectance spectra of intact apples over a wavelength range of 400 to 2, 498 nm. The W firmness tests were conducted using a standard 11.1mm (7/16 in.) MT probe mounted in an Instron universal testing machine. A digital refractormeter was used to measure soluble solid contents in the apples. Apple samples were divided into a calibration set and a prediction set. The calibration set was used during model development, and the prediction set was used to predict soluble solids and firmness from unknown spectra. The method of partial least square (PLS) analysis was used. An unique set of PLS loading vectors (factors) was developed for soluble solid content and firmness. The PLS model showed good correlations between predicted and measured soluble solids of intact apples in 860~1078 nm of the wavelengths. However, the PLS analysis was not good enough to predict the apple firmness.

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Changes of Physicochemical Quality in Hardy Kiwifruit (Actinidia arguta) during Storage at Different Temperature

  • Park, Youngki;Kim, Chul-Woo
    • Korean Journal of Plant Resources
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    • v.28 no.3
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    • pp.329-332
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    • 2015
  • The effect of storage temperature and the storage period of hardy kiwifruits on the fruit firmness, soluble solids and fruit weight were studied in this work. The investigation was carried out on the Sae-Han cultivar of Actinidia arguta. It has an edible smooth skin and contains high amounts of sugar and vitamin C (ascorbic acid). In this research, the measurement of fruit firmness, soluble solids, and fruit weight were carried out at various temperatures (5, 10, 15, and 20℃) during 14 days. Fruit firmness rapidly decreased and soluble solids content increased at 15 and 20℃. We also investigated the correlation between fruit firmness and soluble solids content. There was a strong correlation between fruit firmness and soluble solids content. That means that fruit firmness affect the soluble solids content of hardy kiwifruit.

Development of Calibration Model for Firmness Evaluation of Apple Fruit using Near-infrared Reflectance Spectroscopy (사과 경도의 비파괴측정을 위한 검량식 개발 및 정확도 향상을 위한 연구)

  • 손미령;조래광
    • Korean Journal of Food Preservation
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    • v.6 no.1
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    • pp.29-36
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    • 1999
  • Using Fuji apple fruits cultivated in Kyungpook prefecture, the calibration model for firmness evaluation of fruits by near infrared(NIR) reflectance spectroscopy was developed, and the various influence factors such as instrument variety, measuring method, sample group, apple peel and selection of firmness point were investigated. Spectra of sample were recorded in wavelength range of 1100∼2500nm using NIR spectrometer (InfraAlyzer 500), and data were analyzed by stepwise multiple linear regression of IDAS program. The accuracy of calibration model was the highest when using sample group with wide range, and the firmness mean values obtained in graph by texture analyser(TA) were used as standard data. Chemometrics models were developed using a calibration set of 324 samples and an independent validation set of 216 samples to evaluate the predictive ability of the models. The correlation coefficients and standard error of prediction were 0.84 and 0.094kg, respectively. Using developed calibration model, it was possible to monitor the firmness change of fruits during storage frequently. Time, which was reached to firmness high value in graph by TA, is possible to use as new parameter for freshness of fruit surface during storage.

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Evaluation of Firmness and Sweetness Index of Tomatoes using Hyperspectral Imaging

  • Rahman, Anisur;Faqeerzada, Mohammad Akbar;Joshi, Rahul;Cho, Byoung-Kwan
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • pp.44-44
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    • 2017
  • The objective of this study was to evaluate firmness, and sweetness index (SI) of tomatoes (Lycopersicum esculentum) by using hyperspectral imaging (HSI) in the range of 1000-1400 nm. The mean spectra of the 95 matured tomato samples were extracted from the hyperspectral images, and the reference firmness and sweetness index of the same sample were measured and calibrated with their corresponding spectral data by partial least squares (PLS) regression with different preprocessing method. The results showed that the regression model developed by PLS regression based on Savitzky-Golay (S-G) second-derivative preprocessed spectra resulted in better performance for firmness, and SI of tomatoes compared to models developed by other preprocessing methods, with correlation coefficients (rpred) of 0.82, and 0.74 with standard error of prediction (SEP) of 0.86 N, and 0.63 respectively. Then, the feature wavelengths were identified using model-based variable selection method, i.e., variable important in projection (VIP), resulting from the PLS regression analyses and finally chemical images were derived by applying the respective regression coefficient on the spectral image in a pixel-wise manner. The resulting chemical images provided detailed information on firmness, and sweetness index (SI) of tomatoes. Therefore, these research demonstrated that HIS technique has a potential for rapid and non-destructive evaluation of the firmness and sweetness index of tomatoes.

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Effect of Ecklonia cava Powder on Color and Texture of Sugar-Snap Cookies

  • Park, Myeong Ju;Lee, Jun Ho
    • Food Engineering Progress
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    • v.15 no.1
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    • pp.85-89
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    • 2011
  • Freeze-dried Ecklonia cava powder was incorporated into cookie dough at 5 levels (0%, 1.5%, 3%, 4.5%, and 6%, w/w) by replacing equivalent amount of wheat flour of the cookie dough. After aging and sheeting, cookies were baked at $185^{\circ}C$ for 14 min in a convection oven. The baked cookies were cooled to room temperature for 30 min and packed in airtight bags prior to all measurements. Lightness $(L^*)$ decreased significantly as the E. cava powder content increased (p<0.05) and a decreasing trend in both redness ($a^*$-value) and yellowness ($b^*$-value) was observed. On the other hand, firmness increased significantly with an increase in E. cava powder content (p<0.05). Increases in E. cava powder concentration up to 6% in the cookie formulation significantly increased the intensities of all sensory attributes such as color, flavor, taste, and firmness (p<0.05). Correlation analysis indicated that the E. cava concentration correlated significantly with most of the properties except for $a^*$-value (p<0.01, 0.05, or 0.001). Properties such as firmness and sensory color and firmness correlated positively while $L^*$- and $b^*$-value correlated negatively with E. cava concentration. Sensory color correlated negatively with $L^*$- and $b^*$-value. Sensory firmness correlated positively with mechanically measured firmness.

Hyperspectral imaging technique to evaluate the firmness and the sweetness index of tomatoes

  • Rahman, Anisur;Park, Eunsoo;Bae, Hyungjin;Cho, Byoung-Kwan
    • Korean Journal of Agricultural Science
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    • v.45 no.4
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    • pp.823-837
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    • 2018
  • The objective of this study was to evaluate the firmness and the sweetness index (SI) of tomatoes with a hyperspectral imaging (HSI) technique within the wavelength range of 1000 - 1550 nm. The hyperspectral images of 95 tomatoes were acquired with a push-broom hyperspectral reflectance imaging system, from which the mean spectra of each tomato were extracted from the regions of interest. The reference firmness and sweetness index of the same sample was measured and calibrated with their corresponding spectral data by partial least squares (PLS) regression with different preprocessing methods. The calibration model developed by PLS regression based on the Savitzky-Golay second-derivative preprocessed spectra resulted in a better performance for both the firmness and the SI of the tomatoes compared to models developed by other preprocessing methods. The correlation coefficients ($R_{pred}$) were 0.82, and 0.74 with a standard error of prediction of 0.86 N, and 0.63, respectively. Then, the feature wavelengths were identified using a model-based variable selection method, i.e., variable importance in projection, from the PLS regression analyses. Finally, chemical images were derived by applying the respective regression coefficients on the spectral image in a pixel-wise manner. The resulting chemical images provided detailed information on the firmness and the SI of the tomatoes. The results show that the proposed HSI technique has potential for rapid and non-destructive evaluation of firmness and the sweetness index of tomatoes.

Stem Firmness and Flowering Response of Cut Lilies as Influenced by Medium Composition in Box Culture

  • Suh, Jeung-Keun
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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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.

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Effects of Preheating and Salt Concentration on Texture of Cucumber Kimchi during Fermentation (예열처리 및 염도가 오이김치의 숙성 중 질감에 미치는 영향)

  • Huh, Yoon-Jung;Rhee, Hei-Soo
    • Korean journal of food and cookery science
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    • v.6 no.2
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    • pp.1-6
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    • 1990
  • The purpose of this study was to investigate the effects of preheating and salt concentration on the fermentation rate and firmness of cucumber kimchi, and the relationship between firmness and the contents of pectin fractions, hemicellulose and cellulose during fermentation. For this purpose, pH, acidity, firmness and the contents of pectic fractions, hemicellulose and cellulose were studied. 1. The changes of pH and titratable acidity indicated that preheating and high salt concentration delayed the fermentation rate in cucumber kimchi. 2. After 9 days, preheated cucumber kimchi was firmer than nonpreheated cucumber kimchi. 3. During fermentation, the cucumber kimchi fermented at 5% NaCl was firmer than that femented at 2% NaCl. 4. After 9 days, preheated cucumber kimchi was higher in insoluble pectin (HCISP)content and lower in soluble pectin (HWSP & HXSP) content than nonpreheated cucumberkimchi and hese results in accord with those of firmness measurements. 5. During fermentation, the cucumber kimchi fermented at 5% NaCl was higher in insoluble pectin content and lower in soluble pectin content than nonpreheated cucumber kimchi, and these results were in accord with those of firmness measurement. 6. During fermentation, cellulose content decreased.

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Prediction of Pear Fruit Firmness by Analysis of Laser-induced Light Backscattering Images (레이저 역산란 광 영상분석에 의한 배 경도 예측)

  • Lee, Kyeong-Hwan;Suh, Sang-Ryong;Yu, Seung-Hwa;Yoo, Soo-Nan;Choi, Young-Soo
    • 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.