Judul: Pengaruh Proses Roasting terhadap Aktivitas Antioksidan Kopi Biji Carica Dieng (Carica pubescens)
Abstrak: Biji carica (Carica pubescens) sebagai diversifikasi minuman kopi bermanfaat sebagai antioksidan. Penyangraian menimbulkan degradasi metabolit sekunder, namun di sisi lain juga menghasilkan senyawa produk reaksi Maillard (MRPs). Penelitian ini bertujuan menentukan pengaruh penyangraian terhadap aktivitas antioksidan kopi biji carica dan korelasinya terhadap reaksi Maillard. Penyangraian dilakukan pada suhu 100–115℃, 150–165℃, dan 200–215℃, lalu dianalisis proksimat, total fenolik, antioksidan, dan FTIR. Kadar air dan abu biji kering memenuhi SNI 01-2907-2008. Kadar total fenolik 3,21–8,99 µg GAE/g dengan kadar tertinggi pada suhu 200–215℃. Aktivitas antioksidannya berkisar 83–459,67 ppm AEAC. Total fenolik dan antioksidan pada level sangrai 200–215℃ yang tinggi diduga berasal dari senyawa MRPs. Spektrum FTIR memperlihatkan vibrasi OH, C=C (aromatik), C=N, C=O, dan COH (fenol). Intensitas spektrum melemah pada suhu lebih tinggi, hanya gugus nCH pada level 200–215 ℃ yang semakin kuat. Analisis klaster Ward menunjukkan kemiripan spektrum pada ekstrak penyangraian suhu 100–115℃ dan 150–165℃., Carica seeds (Carica pubescens) as diversified coffee drinks serve as antioxidants. The roasting process generates degradation of a secondary metabolic compounds, but it produces a Maillard reactions product (MRPs). The study aims to determine the impact of the roasting process on the antioxidant activity of carica beans coffee and its correlation to Maillard's reaction. Samples roasting temperatures are 100–115℃, 150–165℃, and 200–215℃, then samples are analyzed for proximate, total phenolic, antioxidant, and FTIR. Moisture and ash content of dry seeds according to SNI 01-2907-2008. Total phenolic contents 3,21–8,99 µgGAE/g with the highest contents at temperature 200–215℃. The antioxidant activity 83–459,67 ppm AEAC. High phenolic contents and antioxidants at 200–215℃ levels are thought to be derived from MRPs compound. FTIR spectrum shows stretching of OH, C=C (aromatic), C=N, C=O, and COH (phenol). Spectrum intensity weakened at higher temperatures, only nCH stretching at 200–215℃ that’s getting stronger. Cluster Ward analysis shows a resemblance spectrum of 100–115℃ and 150–165℃ level’s roasting temperatures.
Keyword: antioxidant, carica dieng, cluster, phenolic content, roasting

Judul: Meta-analysis Effect of Types, Roasting Levels, and Origins of Coffee on Antioxidant Activity
Abstrak: Selama sepuluh tahun terakhir, kopi telah menjadi objek penelitian yang banyak diminati untuk diteliti. Sejumlah penelitian tentang pengaruh jenis, tingkat roasting, suhu dan waktu roasting, dan negara asal kopi terhadap aktivitas antioksidan menghasilkan kesimpulan yang bervariasi. Meta-analisis adalah sebuah metode untuk merangkum berbagai hasil penelitian dengan topik sejenis secara kuantitatif untuk mendapat suatu kesimpulan. Penelitian ini bertujuan mengidentifikasi jenis, tingkat roasting, suhu dan waktu roasting, serta negara asal kopi yang menghasilkan aktivitas antioksidan tertinggi melalui meta-analisis. Meta-analisis dilakukan melalui tahapan, pencarian literatur pada database ilmiah, seleksi literatur berdasarkan kriteria inklusi, pembuatan basis data, analisis data, dan interpretasi hasil. Meta-analisis dilakukan dengan melakukan analisis sub kelompok. Berdasarkan hasil meta-analisis, jenis kopi, tingkat roasting, suhu dan waktu roasting, serta negara asal biji kopi dapat berpengaruh terhadap aktivitas antioksidan kopi. Hasil meta-analisis menunjukkan bahwa kopi Arabika memiliki aktivitas antioksidan lebih tinggi dalum uji FRAP dan ABTS. Perbedaan hasil antar uji antioksidan disebabkan oleh perbedaan mekanisme setiap metode uji antioksidan atau kandungan senyawa kopi dalam menangkal radikal bebas. Tingkat roasting light menghasilkan antioksidan lebih tinggi dari dark dalam uji FRAP dan DPPH persen inhibisi. Parameter suhu roasting yang disarankan adalah 147–205oC dan pengaturan waktu roasting dengan tingkat light atau medium. Kopi yang berasal dari Brazil dan India menghasilkan biji kopi dengan aktivitas antioksidan lebih tinggi dibandingkan negara lain., Over the last ten years, coffee has become the object of research that is in great demand for research. Several studies on the effect of type, roasting level, roasting temperature and time, and country of origin of coffee on antioxidant activity yielded varying conclusions. Meta-analysis is a quantitative method for summarizing various research results on similar topics to get a conclusion. This study aims to identify the type, roasting level, roasting temperature and time, as well as the country of origin of coffee that produces the highest antioxidant activity through meta-analysis. Meta-analysis was carried out through stages, literature search in scientific databases, literature selection based on inclusion criteria, database creation, data analysis, and interpretation of results. Meta-analysis was carried out by conducting subgroup analysis. Based on the results of the meta-analysis, the type of coffee, roasting level, roasting temperature and time, and the coffee beans country of origin can affect the coffee's antioxidant activity. The meta-analysis results showed that Arabica coffee had higher antioxidant activity in the FRAP and ABTS assays. The difference in the results between antioxidant tests is caused by the different mechanisms of each antioxidant test method or the content of coffee compounds in counteracting free radicals. Light roasted coffee beans exhibited higher antioxidant activity than dark roasted beans in FRAP and DPPH assays. The recommended roasting temperature parameter is 147–205oC and the roasting time setting is light or medium. Coffee originating from Brazil and India produces coffee beans with higher antioxidant activity than in other countries.
Keyword: antioxidant activity, coffee types, country origin of coffee, meta-analysis, time and temperature roasting

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm