Judul: Produksi bahan baku spreads kaya b-karoten berbasis minyak sawit merah hasil interesterifikasi enzimatik menggunakan reaktor packed-bed kontinyu
Abstrak: Minyak sawit merupakan bahan pangan nabati yang mengandung β-karoten tinggi. Salah satu produk minyak sawit yang tetap mempertahankan kandungan β-karoten di dalamnya adalah minyak sawit merah. Minyak sawit merah berpotensi dijadikan sebagai bahan baku spreads melalui proses intersesterifikasi enzimatik. Penelitian ini bertujuan untuk mempelajari pengaruh space time (residence time) terhadap karakteristik bahan baku spreads berbasis minyak sawit merah yang diproduksi secara interesterifikasi enzimatik menggunakan reaktor packed-bed kontinyu. Proses interesterifikasi enzimatik pada penelitian ini menggunakan reaktor packed-bed kontinyu yaitu merupakan reaktor dari bahan fiberglass, berbentuk kolom berjaket dengan diameter 21 mm dan panjang 62 mm. Proses interesterifikasi enzimatik secara kontinyu diharapkan dapat menjadi dasar proses produksi spreads kaya β-karoten skala industri. Enzim yang digunakan adalah lipase amobil dari Candida antartica (Novozyme 435). Salah satu variabel yang dapat diatur pada reaktor tersebut adalah laju aliran bahan baku menuju reaktor yang berhubungan dengan space time. Pada penelitian ini digunakan perlakuan space time (residence time) yaitu 10 menit, 15 menit, 30 menit, dan 60 menit. Analisis yang dilakukan adalah kadar asam lemak bebas, kadar air, slip melting point (SMP), solid fat content (SFC), dan total karoten.
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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: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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