Judul: Pengaruh Kecepatan Agitasi dan Lama Reaksi terhadap Karakteristik Bahan Baku Spreads Hasil Interesterifikasi Enzimatik Minyak Sawit Merah
Abstrak: A blend of red palm olein (RPO)/red palm stearin (RPS) and coconut oil (CNO) (82.5:17.7, wt%) was modified by enzymatic interesterification using immobilized lipase from Candida antartica (Novozyme 435) to produce spreads base. Enzymatic interesterification was carried out at 60􀔨 and 10% enzyme of the total weight of substrates. The aim of this research was to study the effects of agitation speed and reaction time on characteristics of enzymatic interesterified products. The effects of agitation speed were studied in two different agitation speeds (100 and 200 rpm). The effects of the reaction time were studied in six different reaction times (1, 2, 4, 8, 16 and 24 hours). Comparison of characteristics were carried out between initial mixtures and enzymatic interesterified products by monitoring their carotene contents, slip melting points (SMP), solid fat contents (SFC), moisture contents and free fatty acids (FFA). Results of this study showed that agitation speed and reaction time had effects on characteristics of enzymatic interesterified products. The increasing of agitation speed decreased carotene content and increased SFC and FFA. The increasing of reaction time decreased carotene content and increased SMP, SFC, moisture content and FFA. The carotene contents of enzymatic interesterified products were 149.62-210.05 ppm and the carotene retentions were 70.51-97.79%. The SMP values of enzymatic interesterified products were 30.1‐35.9􀔨, the moisture contents were 0.104-0.143% and the FFA contents were 1.38-4.54%.
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Judul: Produksi Bahan Baku Spreads Kaya β-karoten Berbasis Minyak Sawit Merah Melalui Interesterifikasi Enzimatik Menggunakan Reaktor Batch
Abstrak: Interesterification of red palm oil (red palm olein/RPO and red palm stearin/RPS) and coconut oil (CNO) blends of varying proportions using a nonspecific immobilized Candida antartica lipase (Novozyme 435) was studied for the production of spread base. The interesterification reaction was held in a batch-type reactor. Two substrate blends were chosen for the production of spread base: 77,5:22,5 and 82,5:17,5 (RPO/RPS:CNO, by weight) through enzymatic interesterification in three different reaction times (2, 4, and 6 hours). RPO/RPS ratio was 1:1. Interesterification reactions were studied at 60oC at constant weight ratio (10%) of Novozyme 435. The reaction was carried out at steady agitation (200 rpm). The interesterified blends were evaluated for their physical characteristics (solid fat content/SFC and slip melting point/SMP) and chemical characteristics (moisture content, free fatty acid/FFA content and carotene retention). The results showed that all of the interesterified mixtures have a lower SFC and SMP values compared with the initial mixtures. SMP values and SFC increased in a longer reaction. SMP values were ranging from 30,8oC to 34,9oC. The moisture content and FFA content increased in a longer reaction. Carotene retentions were ranging from 74,80% to 81,08%. This study indicated that interesterified products have desirable physical properties for possible use as spread base rich in carotene.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf