Judul: Effect of Microwave Heating Power on Pectin Extraction of Sugar Palm Seed (Arenga westerhoutii Griff.)
Abstrak: Microwave-Assisted Extraction (MAE) has been employed as the new method to improve quality and yield of extracted pectin. Pectin is a polysaccharide, also known as a water-soluble fiber. The major use of pectin is as a gelling, stabilizing, and thickening agent in food systems. Each year, South East Asia countries have to import pectin because of the lack ability to produce pectin. Sugar palm seed is abundant in South East Asia and contain a large amount of dietary fiber, but the utilization of this commodity is still limited. The objective of this research is to determine the optimum extraction condition using microwave assisted extraction in relation to yield and quality of pectin. In this research, pectin extraction was performed using young sugar palm seed as raw materials. The effect of microwave power and extraction time on the yield of pectin was investigated. It was found that the yield of pectin ranged between 20.50- 39.31%. The highest yield of extraction obtained from pectin with microwave power 800 W for 7 minutes and the lowest yield obtained on extraction with microwave power 600 W for 3 minutes. Moreover, moisture content of pectin ranged between 9.58-11.83% and ash content ranged between 0.74-0.94% which is still meet the standard of pectin (less than 12% and 1%, respectively). The equivalent weight and methoxyl content of extracted pectin ranged between 847.95-1431.69 and 4.07-6.43%, respectively. The extracted pectin from sugar palm seed was categorized as Low Methoxyl Pectin (LMP) because its methoxyl content was below 7%. Other characteristics were galacturonic content and degree of esterification which is ranged between 34.64-57.11% and 63.93-72.97%, respectively. The comparison between extracted pectin and commercial pectin showed that characteristics of extracted pectin from sugar palm seed were better than commercial low methoxyl pectin. The methoxyl content of commercial low methoxyl pectin was 4.50%, so the extracted pectin was still better because it had methoxyl content below commercial pectin. It can be concluded that pectin from sugar palm seed had a good quality and had a potential to be developed become commercial pectin.
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Judul: Pemanfaatan Ekstrak Daun Parengpeng (Macaranga javanica Blume Mull. Arg) Sebagai Senyawa Antimikroba Pada Nira Aren dan Pengaruhnya Terhadap Mutu Gula Semut yang Dihasilkan
Abstrak: Aren plant is that produce sap as raw material for for palm sugar. The problems found in the use of palm juice is the time of process is very long and the distance between plantation and factory is too far. So that, new alternative is needed to overcome this problem. One of the solution is to add active ingredient from Macaranga javanica (Blume) Mull. Arg plant (parengpeng). The aim of this research is to investigate affectivity of parengpeng extract to preserve palm sap before actual produce palm sugar. The steps of this research is extraction of parengpeng, the determination of phytochemical content, the determination the determination of Minimum Inhibitory Concentrate (MIC) with the method of contact, and the manufacture of palm sugar with the addition of parengpeng extract at the concentration elected. The result showed that addition of 6% parengpeng will inhibits damage to palm sap. Total microbe count is significantly decrease compared to non-added palm sap. This also affecting the pH and acidity degree of palm sap mixture. The result showed more stable existence of acid material which also gives more stable fluctuation of mixture’s pH degree. The sensory properties however showed slightly undesired changes which are the color are less brown and have bitter taste. Organoleptic test showed slight decrease taste from the panelist compared to sugar available in the market produced by people in parigin village.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular