Acrylic acid is a hydrophilic monomer which becomes the most popular material used to synthesize superabsorbent polymer. In this recent study, acrylic acid was partially neutralized with KOH and mixed with chitosan to form a superabsorbent hydrogel poly (acrylic acid)-graft-chitosan by using of gamma ray irradiation technique. The aim of this study was to determine the optimum composition of KOH in acrylic acid partial neutralization process for enhancing the production of grafted polymer. The degree of neutralization was varied (0, 25, 50, 75, and 100)% and the effect on the superabsorbent characteristics were studied. Hydrogel products were characterized by Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). The gel content, swelling ratio, Equilibrium Degree of Swelling (EDS), and Thermal Analysis were also performed. The highest water swelling capacity was 715 (g water/g dry hydrogel), and the gel content was 91.23%, resulted from 75% of acrylic acid neutralization. The swelling capacity of the products was also tested in urea and NaCl solutions and reached 750 (g urea solution/g dry hydrogel) for urea and 378,33 (g NaCl solution/g dry hydrogel) for NaCl. The huge water absorption capacity indicated that the hydrogel from this research was a superabsorbent product which was suitable for hygiene products application. The degree of neutralization did not show a significant influence on the thermal resistance of the grafted hydrogel produced in this study.

The composition of mineral and vitamin from breadfruit is particularly known of having benefits compared to rice which is a main source of carbohydrate consumed by societies. The process of drying is one of the factors that affects foodstuffs quality. The aim of this research was to provide an understanding of drying phenomena from data experiment and discover the influence of drying air temperature to breadfruit drying time and rates. This research was conducted in several stages which are material preparation (breadfruit) by through downsizing process, then weigh the material (breadfruit) once every 5 minutes on each drying air temperature variations (50 ºC, 60 o C, 70 o C, and 80 o C). The research were conducted using breadfruit with the best drying time which is obtained at 60 0 C for 100 minutes. The lowest water content obtained was 0.4%, while the highest drying rate was 0.00144 Kg 2 /m 2 .s at 80 ºC of temperature.

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Indonesia sebagai salah satu penghasil rumput laut Eucheuma cottoni terbesar di Dunia maka di perlukan pengembanagn dalam penaganan hasil dari rumput laut yang dihasilkan salah satunya adalah tahap pengeringan rumput laut. Kandungan rumput laut merupakan salah satu bagian yang harus diperhatikan dalam pemrosesesan rumput laut. Mengingat manfaat rumput laut yang luas dalam industri kosmetik, pangan dan obat-obatan.Hasil penelitian ini bertujuan untuk menngetahui waktu dan suhu operasi dalam proses pengeringan serta memahami proses pengeringan. Berdasarkan hasil penelitian didapatkan massa kering rumput laut dalam 150 gram sebesar 12,75 gram serta kondisi optimum dalam proses pengeringan rumput laut, yaitu lama waktu pengeringan 4 jam dengan suhu 65 o C yang dinyatakan dengan nilai moisture content sebesar 0,16 kg H2O/kg RL dengan laju pengeringan sebesar 3,63 kg H2O/m 2 .jam dan sisa kadar air dalam rumput laut sebesar 1,36%

Sandy soil has a low ability to absorb and store low water, low nutrient content, and a high water evaporation rate, so it is not suitable to be used as agricultural land. Superabsorbents can be used to overcome these weaknesses. The purpose of this study was to measure the abilities of the superabsorbents, including water holding, swelling, and water retention of sandy soil enriched with superabsorbent, and to analyze the chitosan-graft-poly(acrylic acid) superabsorbent characteristics. The superabsorbent was prepared by mixing a chitosan solution with ammonium persulfate as an initiator and acrylic acid, which had been neutralized with KOH. Then, the mixture was cross-linked with N,N′-methylenebisacrylamide (MBA). The resulting superabsorbent gel was dried in an oven and then crushed for analysis. The results showed that an increase in chitosan concentration increased the gel fraction, swelling, reusability, and water holding. Meanwhile, an increase in chitosan concentration decreased water retention in sandy soils. The swelling kinetics can be predicted using the pseudo-second-order model with high accuracy (R2 value of 0.99).

ABSTRAKRumput laut adalah suatu komoditas utama perikanan budidaya di Indonesia yang menopang hampir 58% dari total produksi perikanan budidaya tahun 2016 yang mencapai 19,46 juta ton. Salah satu rumput laut yaitu rumput laut E. Cottoni diketahui memiliki kandungan senyawa fenolik yang merupakan salah satu kandungan rumput laut yang berperan sebagai antioksidan. Rumput laut Eucheuma Cottonii terdapat senyawa flavonoid seperti catechin (gallocathecin, epicathecin, catechin gallate), flavonols, flavonol glycosides, caffeic acid, hesperidin, myricetin yang berfungsi sebagai antioksidan. Tujuan mengetahui metode ekstraksi terbaik dalam uji kandungan fenolik dalam rumput laut (Euchema cotonii) dan menentukan konsentrasi optimal pada pelarut (metanol) dalam proses ekstraksi rumput laut (Euchema cotonii). Penelitin ini dilakuna dengan cara mengekstraksi kandungan rumput laut dengan berbagai metode ekstraksi yaitu maserasi, ultrasonic dan microwave dengan konsentrasi pelarut etanol (25% ;50% ;75%) lalu dilakukan pengukuran kadar total fenolik dengan metode folin ciocalteau dan dianalisa absorbansinya dengan spectrophotometer UV-Vis. Hasil Total Phenolic Compound (TPC) terbaik dalam penelitian ini yakni pada metode ekstraksi ultrasonik dan dengan pelarut etanol pada konsentrasi 50% yakni sebesar 961.081 mg GAE / g ekstrak Kata kunci : Eucuema Cottonii, ultrasonik,microwave, Kandungan senyawa fenolik. DENNI KARTIKA SARI, AHMAD DEZA, INA AMILATUL ILMA, RETNO SULISTYO DHAMAR LESTARI. ABSTRACTSeaweed is a major commodity of aquaculture in Indonesia which supports almost 58% of total cultivated fisheries production in 2016 which reaches 19.46 million tons. One of seaweed is seaweed E. Cottoni is known to contain phenolic compound which is one of the content of seaweed that acts as an antioxidant. Seaweed Eucheuma Cottonii contain flavonoid compounds such as catechin (gallocathecin, epicathecin, catechin gallate), flavonols, flavonol glycosides, caffeic acid, hesperidin, myricetin which acts as an antioxidant. The objective is to know the best extraction method in phenolic content test in seaweed (Euchema cotonii) and to determine optimal concentration on solvent (methanol) in seaweed extraction process (Euchema cotonii). The experiment was conducted by extracting seaweed content with various extraction methods of maceration, ultrasonic and microwave with ethanol solvent concentration (25%; 50%; 75%) and then measuring total phenolic content by folin ciocalteau method and analyzed its absorbance with UV-spectrophotometer Vis. The best result of Total Phenolic Compound (TPC) in this research is on ultrasonic extraction method and with ethanol solvent at 50% concentration is 961,081 mg GAE / g extract