Judul: Detection of Chilling Injury Symptoms of Salak Pondoh Fruit during Cold Storage with Near Infrared Spectroscopy (NIRS)
Abstrak: Salah satu penanganan yang tepat untuk mempertahankan mutu buah salak pondoh adalah dengan penyimpanan dingin. Namun penyimpanan dingin di bawah suhu penyimpanan optimum buah salak pondoh (15°C) dapat mengakibatkan chilling injury/CI. Penelitian ini bertujuan mengembangkan metode penentuan gejala CI buah salak pondoh selama penyimpanan suhu 5°C secara non-destruktif dengan NIRS. Pengukuran dilakukan selama 14 hari dengan mengukur parameter CI (pH dan IL) dan spektra reflektan NIR. Model kalibrasi NIR metode PLS terbaik untuk pendugaan pH dihasilkan dengan praperlakuan Savitzky-Golay Smoothing dengan rk = 0.81, rv = 0.76, SEC = 0.12%, SEP = 0.12%, CV = 2.97%, RPD = 1.66, serta konsistensi = 100.06%. Slope IL buah salak pondoh berkorelasi dengan pH berupa hubungan pola linier dengan persamaan y = 0.1735x – 0.4305. Nilai slope IL tertinggi diperoleh pada hari ke-4 penyimpanan yang artinya kebocoran ion telah mencapai puncaknya dan CI diprediksi telah terjadi pada hari ke-4 penyimpanan.
Keyword: chilling injury, ion leakage, NIR, pH, salak pondoh

Judul: Deteksi Chilling Injury pada Buah Mangga Gedong Gincu dengan Menggunakan Near Infrared Spectroscopy (NIRS)
Abstrak: Low temperature storage is a common method to extend postharvest life of fruits. However, for sensitive fruits such as mango low temperature storage may cause chilling injury. Chilling injury is one of serious problem for mango stored under low temperature. The symptoms of chilling injury during storage associated with the change in pH due to ion leakage. Chilling injury can be detected during storage destructively, but it will require time and a lot of samples. Alternatively, the detection can be performed non-destructively by using near infrared (NIRSpectroscopy). The purpose of this research is to build the NIR calibration models for predicting ion leakage relating to change in pH and the detection of chilling injury symptoms can be done through ion leakage existence. Reflectant NIR measurements conducted on mango fruit stored at a temperature of 8 °C and 13 °C. Determination of chilling injury symptoms was predicted based on change in pH and the rate of ion leakage forming. The analysis showed that NIR spectroscopy was able to predict the change in pH during storage of mango fruit at a temperature of 8 °C based on reflectance and PLS method. Moreover ion leakage could also be predicted properly through the pH of the NIR predictions. The developed method could detect the chilling injury on mangoes after three days storage at a temperature of 8 °C.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology