Judul: Deteksi Gejala Chilling Injury Buah Belimbing (Averrhoa carambola L.) Yang Disimpan Pada Suhu Rendah Dengan NIR Spectroscopy
Abstrak: Cold storage or low temperature storage is an effective method to extend the self life and assuring quality product of horticulture such as star fruit. However, stored in low temperature may cause chilling injury which decreases the quality of star fruit. Chilling injury of star fruit has correlation with the change of pH content during storage. The change of pH content during storage my be determined nondestructively using near infrared (NIR) Spectroscopy. The objectives of this study were to determine quality of star fruit during storage, to build calibration model of NIR reflectance spectra to predict the pH content during storage at 5 oC temperature, and to determine chilling injury symptoms based on change of ion leakage slope during storage using NIR reflectance. Calibration were built using partial least squares (PLS). Result of analysis showed that the change of pH content could be predicted well by NIR reflectance using the calibration model of PLS for star fruit stored at 5 oC. The change of ion leakage slope based on change of pH content also could be determined using NIR reflectance for star fruits stored at 5 oC.
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Judul: Determination of Chilling Injury Symptoms in Starfruit (Averrhoa carambola L.) Using Near Infrared Spectroscopy
Abstrak: Cold storage is an effective method to extend the self life and assuring quality product of horticulture such us starfruit. However, cold storage may cause chilling injury that will be lead to deterioration of product quality. Method for determination of chilling injury symptoms in starfruit has been developed using NIR absorbance spectra and two models of multivarians analysis i.e. Partial Least Squares (PLS) and Artificial Neural Network (ANN). PLS and ANN models were built from 63 pH values extracted from starfruit stored at 5oC (chilling temperature) for 30 days. PLS model resulted r, RMSEC, RMSEP and cv were 0.6115, 0.1456, 0.1632 and 4.43%, while ANN model were 0.5207, 0.1589, 0.1911, 5.24% respectively. PLS showed better results than that of ANN. PLS, then was used to predict the pH value from absorbance NIR spectra of 10 monitoring starfruit, which was stored at 5oC for 30 days. Results of pH prediction were used to determine the slope of ion leakage by equation Y = 0.0406x - 0.037 (where y is predictive of IL and x is pH value). The results showed that the highest of slope IL occured at days 6, the same result as obtained through destructive method at days 6, the result demonstrates that chilling injury may be determined using NIR absorbance spectra and PLS model.
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Judul: Urbanisasi dan Sektor Informal
Abstrak: Pertumbuhan penduduk yang tinggi yang terjadi di pedesaan mengakibatkan jumlah tenaga kerja setiap tahunnya meningkat dengan cepat. Keadaan ini mendorong penduduk desa untuk pindah ke kota, sehingga terjadilah apa yang dinamakan urbanisasi. Sementara sektor formal tidak mampu menyerap seluruh pertambahan angkatan kerja di kota, jasa sektor informal menjadi pilihan terbaik dewasa ini dan bahkan mungkin di masa mendatang.
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