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Dampak Oksidasi Protein oleh Sistim Oksidasi 2, 2’-azobis (2 amidipropane) dyhidrochloride (AAPH) dan Sistim Katalis Logam CuSO4 / H2O2 terhadap Komposisi Asam Amino Protein Daging Merah dan Putih Ikan Tongkol Putih Apituley, Daniel A.N.; Noor, Zuheid; Darmadji, Purnama; Suparmo, Suparmo
Agritech Vol 26, No 3 (2006)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9594

Abstract

Protein endured oxidative damage from oxygen radicals in 2,2’azobis (2 amidipropane) dyhidrochloride (AAPH) and catalysts CuSO4/H2O2 oxidation systems. Indications of oxidation could be seen in the development of carbonyl protein and other more reactive substances such as protein peroxide, denaturation of the protein, as well as damages on the amino acids constituents of the protein such as hystidine, arginine, tyrosine, metionine, cysteine and tryptophane. The research was aimed to study the effect of oxygen radicals exposure in AAPH and catalysts CuSO4/H2O2 oxidation systems on amino acid content of Thunus sp fish meat proteins. Result indicated that histamine, arginine, tyrosine, methionine, and phenylalanine amino acids in red meat undergone substantial reductions of 52.24%, 23.29%, 42.34%,22.22%, and 6.77% in AAPH system, and 12.34%, 27.59%,31.95%, 23.39%, and 13.02% in catalyst CuSO4/H2O2oxidation system, respectively. While milder reduction of those amino acids in white meat of 48.21%, 9.12%, 15.31%, 38.22%, and 22.44% in AAPH system, and 8.43%, 3.85%, 10.88%, 24.05%, and 57.25% in catalyst system, respectively.  It was obvious that red meat undergone more damages in both oxidation systems compared to the white meat counterpart.
Pertumbuhan Jamur, Sifat Organoleptik dan Aktivitas Antioksidan Tempe Kedelai Hitam yang Diproduksi dengan Berbagai Jenis Inokulum Nurrahman, Nurrahman; Astuti, Mary; Suparmo, Suparmo; Soesatyo, Marsetyawan HNE
Agritech Vol 32, No 1 (2012)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9657

Abstract

The quality of tempe is influenced by raw materials, processing and type of inoculum used. Black soybeans can beused as raw material for making tempe that has quality like tempe made from yellow soybeans. This study aims to determine the effect of  inoculum type and duration of incubation on the mold growth, organoleptic properties and antioxidant activity of black soybean tempe. This study uses mallika black soybean varieties as raw material for making tempe. Black soybeans that have been discarded skin, soaked and steamed,  then mixed with inoculum derived from pure cultures of Rhizopus stolonifer, R. oligosporus and R. oryzae. After it was incubated for 24, 30, 36 and 42 hours at a temperature 25-27 oC. The parameters were used mold growth, organoleptic properties and antioxidant activity of black soybean tempe. Results showed the treatment inoculum type and duration of incubation, effect on mold growth, organoleptic properties and antioxidant activity. Mold growth increased up to 36-hour long incubation, then decreased. Panelists gave the highest value in tempe that were incubated for 36 hours. There are a tendency long incubation tempe increased antioxidant activity.The conclusion of this research has the characteristics of Rhizopus stolonifer  relatively highest mold growth, organoleptic properties and antioxidant activity  that compared to other types of mold at the old30-hour incubation.ABSTRAKKualitas tempe dipengaruhi oleh bahan baku, proses pengolahan dan jenis inokulum yang digunakan. Kedelai hitamdapat digunakan sebagai bahan baku pembuatan tempe yang mempunyai kualitas seperti halnya tempe yang terbuat dari kedelai kuning. Penelitian ini bertujuan untuk mengetahui pengaruh jenis inokulum dan lama inkubasi terhadap pertumbuhan jamu, sifat organoleptik dan aktivitas antioksidan tempe kedelai hitam. Penelitian ini menggunakan kedelai hitam varietas mallika sebagai bahan baku pembuatan tempe. Kedelai hitam yang telah dibuang kulitnya, direndam dan dikukus kemudian dicampur dengan inokulum yang berasal dari biakan murni Rhizopus stolonifer, R. oligosporus dan R. oryzae. Setelah itu diinkubasi selama 24, 30, 36 dan 42 jam pada suhu 25-27 oC. Parameter yang diamati adalah pertumbuhan jamur, sifat organoleptik dan aktivitas antioksidan tempe kedelai hitam. Hasil penelitian menunjukkan perlakuan jenis inokulum dan lama inkubasi berpengaruh terhadap pertumbuhan jamur, sifat organoleptik dan aktivtas antioksidan. Pertumbuhan jamur meningkat sampai lama inkubasi 36 jam, kemudian turun. Panelis memberikan nilai tertinggi pada tempe yang diinkubasi selama 36 jam. Ada kecenderungan lama inkubasi tempe meningkat aktivitas antioksidannya. Kesimpulan dari penelitian ini Rhizopus stolonifer mempunyai karakteristik relatif lebih tinggi pertumbuhan jamur, sifat organoleptik dan aktivitas antioksidan dibandingkan jenis jamur yang lain pada lama inkubasi 30 jam.
Perubahan Aktivitas Antioksidan, Kadar Antosianin dan Polifenol pada Beberapa Tingkat Kemasakan Buah Duwet (syzygium Cumini) Lestario, Lydia Ninan; Suparmo, Suparmo; Raharjo, Sri; Tranggono, Tranggono
Agritech Vol 25, No 4 (2005)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9444

Abstract

Research on antioxidant activity, anthocyanin, and polyphenol contents of Java plum (Syzygium cumini) from several stages of maturity was carried out with three aims: to prove that the fruit contain anthocyanins; to compare antioxidant activity from three stages of fruit maturity; and to examine the possible correlation between maturation and antioxidant activity, anthocyanin and polyphenol contents. The fruit pulp was separated from the seed, frozen dried, and kept in freezer. The freezer dried fruit was extracted (macerated) with methanol-HCl 1% for overnight at 4ºC, and filtered with Whatman no 1 to obtain fruit extract. Anthocyanin-betacyanin testing was used to indicate that the fruit contain anthocyanin. Antioxidant activity test was conducted with ferri-thiocyanate method in linoleic acid emulsion system. Anthocyanin contents was determined with pH differential method, while its polyphenol with spectrophotometric method with Folin-CIocalteu reagent. The result showed that the fruit contained anthocyanin, ranging from 1,68 mg/g at young stage (green) to 29,39 mg/g at overripe stage (black), and showed that antioxidant activity was influenced by fruit maturity. With regard to fruit maturoty, the antioxidant activity of purple, red, adn green fruit were 64,75%, 62,42%, and 29,86% respectively; whereas that of BHT was 79,45%. It was noted that there were significant correlation between the level of anthocyanins, poluphenols, and the degrees of maturity. As the fruit maturity increased, the anthocyanin increased, but the polyphenol decreased. The fruit contained considerable amount of anthocyanins and had antioxidant activity that was influenced by stages of maturity. It was indicated that the more mature the fruit the higher anthocyanins and the lower polyphenols concentrations.
Hidrolisis Enzimatis Stearin Sawit Menjadi Monogliserida oleh Lipase dari Rhizomucor miehei dan Pankreas Karaouw, Steivie; Suparmo, Suparmo; Hastuti, Pudji; Utami, Tyas
Agritech Vol 33, No 1 (2013)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9567

Abstract

The objectives of the research were to evaluate the effect of the pH, ratio of substrate:phospate buffer, and reaction time on the enzymatic hydrolysis of palm stearin to obtain monoglyceride by R. miehei and pancreatic lipases. Hydrolysis was evaluated at various pH (6.0; 6.5; 7.0; 7.5 dan 8.0). Enzymatic hydrolysis reactions were held at various ratio of substrate:phospate buffer (10:1, 10:2, 10:3, 10:4, 10:5, 10:6) and duration time of 6, 12, 18, 24 hours by R. miehei lipase and 24, 30, 36, 42, 48 hours by pancreatic lipase. Enzymatic hydrolysis reaction was carried out in waterbath shaker 80 stroke/minute, at 40oC with R.miehei lipase and 37oC with pancreatic lipase. The hydrolysis products were monitored using TLC with petroleum ether:diethyl ether:acetic acid=60:40:1 as developing solvent on silica gel F254 20×20 cm plate. The results showed that optimum pH for both R. miehei and pancreatic lipases were 6.5 and their activities were 332.25 unit/g enzyme amobile and 228.04 unit/g enzyme, respectively. The highest monoglyceride fraction was obtained from ratio substrate:phospate buffer 10:1 at 18 hours of incubation by Rhizomucor miehei lipase (21,59%) and ratio substrate:phospate buffer 10:4 at 42 hours of incubation by pancreatic lipase (40,45%).ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh pH, rasio substrat:buffer fosfat dan waktu hidrolisis terhadap produksi monogliserida 2-monopalmitin secara enzimatis menggunakan lipase dari Rhizomucor miehei dan lipase pankreas. Hidrolisis dilakukan pada pH (6,0; 6,5; 7,0; 7,5 dan 8,0), dengan rasio substrat:buffer fosfat (10:1, 10:2, 10:3, 10:4, 10:5 dan 10:6) dan waktu hidrolisis (6, 12, 18 dan 24 jam) menggunakan lipase dari R. miehei dan (6, 12, 18, 24, 30, 36, 42 dan 48 jam) menggunakan lipase pankreas. Reaksi hidrolisis berlangsung dalam shaker waterbath 80 stroke/menit, pada suhu 40oC untuk lipase dari R. miehei dan 37oC untuk lipase pankreas. Hasil hidrolisis dianalisis dengan kromatografi lapis tipis (KLT) menggunakan larutan pengembang petroleum eter:dietil eter:asam asetat = 60:40:1 pada pelat silica gel F254 plat aluminiun 20×20 cm. Lipase R. miehei dan lipase pankreas memiliki pH optimum 6,5 dan aktivitasnya masing-masing 332,25 unit/g enzim amobil dan 228,04 unit/g bubuk enzim. Proporsi fraksi monogliserida tertinggi  diperoleh pada penggunaan lipase dari R. miehei dengan rasio substrat:buffer fosfat 10:1 dalam waktu 18 jam yakni sebesar 21,59 %, sedangkan penggunaan lipase pankreas menghasilkan fraksi monogliserida tertinggi dalam waktu inkubasi 42 jam pada rasio substrat buffer fosfat 10:4 menghasilkan 40,45%.
Efektivitas Poliamin terhadap Penghambatan Chilling Injury pada Beberapa Tingkat Kematangan dan Kemasakan Buah Pisang Mas (Musa paradisiaca, L.) Partha, Ida Bagus Banyuro; Suparmo, Suparmo; Gardjito, Murdijati; Wasono, Moh. Ali Joko
Agritech Vol 28, No 1 (2008)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9780

Abstract

A study on the effectiveness of polyamines on chilling injury inhibition of banana (Musa paradisiaca, L.) cv. Mas was conducted. It was aimed to identify the effectiveness of polyamines (putrescine, spermidine, spermine) on chilling injury at various levels of maturities and ripeness of banana cv. Mas. The present study exploited banana cv. Mas at 85 % of maturity, full ripe, over ripe, and soaking condition in polyamine solutions, i.e. putrescine (put), spermidine (spd), spermine (spm). The fruits were stored at 10 oC for 10 days and daily real time observations for emitted ethylene were conducted using photo-accoustic spectrometer, while espiration rate, reducing sugar content, textures, chilling injury index (necrosis and pitting) were observed every two days at room temperature after the fruits were keep out from cold storage. Result indicated that soaking in polyamines (putrescine, spermidine, spermine) was able to inhibit emitted ethylene, respiration rate, chilling injury index (necrosis and pitting) and textures softness of banana fruits. The most effective polyamines to inhibit chilling injury in banana cv. Mas fruits at any maturaties and ripeness level was putrescine compound. Putrescine was highly effective to inhibit the chilling injury of banana cv. Mas fruits at 85% maturity.ABSTRAKTelah dilakukan penelitian tentang efektivitas poliamin terhadap penghambatan kerusakan suhu dingin (chilling in- jury) pada buah pisang Mas (Musa paradisiaca, L.), dengan tujuan untuk mengetahui efektivitas poliamin (putresin, spermidin, spermin) terhadap penghambatan chilling injury pada beberapa tingkat kematangan dan kemasakan buah pisang Mas. Penelitian ini menggunakan buah pisang Mas tingkat kematangan 85 %, masak penuh, lewat masak dan perendaman dalam larutan poliamin yaitu putresin (put), spermidin (spd), spermin (spm) dengan konsentrasi 1,5 mM selama 8 menit Buah pisang disimpan selama 10 hari pada suhu 10 oC dan dilakukan pengamatan emisi etilen setiap hari secara real time menggunakan spektrometer fotoakustik, sedangkan laju respirasi, indeks chilling injury (nekrosis dan pitting) dan tekstur dilakukan setiap 2 hari pada suhu kamar setelah buah pisang dikeluarkan dari ruang pend- ingin. Hasil penelitian menunjukkan bahwa perendaman buah dalam larutan poliamin (putresin, spermidin, spermin) mampu menghambat laju respirasi, emisi etilen, indeks chilling injury (nekrosis dan pitting), dan pelunakan tekstur buah pisang Mas.  Jenis poliamin yang paling efektif untuk menghambat chilling injury pada buah pisang Mas untuk semua tingkat kematangan dan kemasakan buah adalah senyawa putresin (put), kemudian berikutnya spermidin (spd), spermin (spm). Senyawa putresin sangat efektif menghambat chilling injury buah pisang Mas pada tingkat kematangan85 %.
Potensi Senyawa Bioaktif Mesocarp Buah Lontar (Borassus fl abeliffer L.) sebagai Sumber Antioksidan Alami Idayati, Eny; Suparmo, Suparmo; Darmadji, Purnama
Agritech Vol 34, No 3 (2014)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9455

Abstract

This study was aimed to characterize the physical and chemical properties of borassus palm fruit mesocarp, to determine the best type of solvent to extract bioactive compounds by maceration method, and to evaluate the antioxidant properties of bioactive compounds using DPPH (1,1-difenil-2-pikrilhidrazil) method. Carotenoid was separated based on TLC (thin layer chromatography) method, which produced spots. To confi rm the results, the spots were scanned using UV-vis spectrofotometry. The results showed that the water content of borassus fruit mesocarp was 77.31%, while total fat, ash content, and tannin were 0.11%, 1.43%, 0.08%, respectively. Total Carotenoid was 8324.6 µg/100g with β carotene content was 6217.48 microgram/100g. The best solvent used in extracting the bioactive compounds was ethanol and acetone with (1:1) ratio. The highest yield was 4.3% and bioactive compounds in palm fruit mesocarp extracts as antioxidants was about 87% as carried out by DPPH method, so it could become a potential antioxidant. TLC Identifi cation produced two spots. One spot was identifi ed as carotenoids from xanthophyll group and the other one was β-carotene.ABSTRAKPenelitian ini bertujuan untuk karakterisasi senyawa bioaktif dalam mesocarp buah lontar berdasarkan sifat fisik dan kimia, mengetahui jenis pelarut terbaik untuk mengekstrak senyawa bioaktif dengan metode maserasi, serta mengevaluasi sifat antioksidan senyawa bioaktif mesocarp dengan metode DPPH (1,1-difenil-2-pikrilhidrazil). Dasar pemisahan karotenoid dengan metoda KLT (kromatografi  lapis tipis) pada ekstrak lalu dikuatkan dengan hasil scanning menggunakan spektrofotometer UV-Vis. Hasil penelitian menunjukkan bahwa mesocarp buah lontar mengandung kadar air 77,31%; total lemak 0,11%, kadar abu 1,43%; tanin 0,08%; total karotenoid 8324,6 µg/100g dengan kandungan senyawa  karoten 6217,48 µg/100g. Perlakuan pelarut terbaik untuk proses ekstraksi senyawa bioaktif adalah etanol dan aseton dengan rasio (1:1). Hasil rendemen tertinggi yaitu 4,3% dan potensi senyawa bioaktif dalam ekstrak mesocarp buah lontar sebagai antioksidan dengan metode DPPH yaitu sekitar 87%, sehingga berpotensi sebagai salah satu senyawa antioksidan. Identifi kasi dengan metode KLT yang menghasilkan 2 noda yaitu noda 1 diduga karotenoid dari golongan xantofi l dan noda 2 yatu  karoten.
Karakter Fisik dan Sensoris Produk Hasil Restrukturisasi Buah Nangka (Artocarpus heterophylla L.) dan Sawo (Manilkara achras (Mill.) Fosb) Selama Penyimpanan Beku Raharjo, Sri; Suparmo, Suparmo; Supartomo, Wahyu; Utama, Zaki
Agritech Vol 22, No 2 (2002)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.13569

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A model fruit product was prepared using fresh tropical fruits puree (jackfruit and sapodilla) and restructured using calcium-alginate gel forming methods (internal setting). Restructured fruit products were evaluated for texture (hardness), color, pH, and sensory properties after 0,1,2, and 3 months frozen storage at -15ºC. No significant change for pH was observed over the frozen storage period (3 months at -15ºC).
Potensi Bakteri Asam Laktat yang Diisolasi Dari Bekasam sebagai Penghasil Angiotensin Converting Enzyme Inhibitor pada Fermentasi “Bekasam-Like” Product Wikandari, Prima Retno; Suparmo, Suparmo; Marsono, Yustinus; Rahayu, Endang Sutriswati
Agritech Vol 32, No 3 (2012)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9616

Abstract

Bekasam, an traditional fermented fi sh is perceived to have antihypertensive activity, which was estimated to bethe activity of ACE inhibitory peptides, the product of proteolytic degradation of fi sh protein during the bekasamfermentation. Lactic acid bacteria was possibly to give a role on proteolytic degradation to produce ACE inhibitorpeptides in bekasam fermentation. Six strains of the selected strains of proteolytic lactid acid bacteria from bekasam,namely Lactobacillus plantarum B1765, L. plantarum T2565, L. plantarum N2352, L. plantarum B1465, Lactobacilluspentosus B2555, and Pediococcus pentosaseus B1661, were assessed for growth characteristics. The amount of peptidesas result of proteolitic degradation, and the inhibitory activities of ACE inhibitor which is released in fermentationof “bekasam-like” product. All selected strains grew well, exhibited proteolytic activity which was showed by theincreasing of peptides. The extent of proteolysis varied among strains and appeared to be time dependant. The highestpeptides (8.55 ± 0.05 mg/g sample) was found on L. plantarum B1765 and the smallest one (4.45±0.10 mg/g sample)on P. pentosaceus B1661. L. plantarum B1765 exhibited the highest ACE inhibitor activity (68.17±1.32%), followed by L. plantarum T2565 (62.54±2.11%), L. plantarum N2352 (61.56±1.32%), L. plantarum B1465 (59.85±1.58%), and L. pentosus B2555 (56.61±4.28%), whereas P. pentosaceus B1661 (18.66±3.91%) showed the smallest one.ABSTRAKBekasam adalah salah satu produk ikan fermentasi tradisional. Produk ini diduga mempunyai aktivitas antihipertensiyang disebabkan oleh aktivitas peptida Angiotensin Converting Enzyme (ACE) inhibitor yang dihasilkan dari degradasiproteolitik selama proses fermentasi bekasam. Bakteri asam laktat diduga berperan dalam degradasi proteolitikmenghasilkan peptida ACE inhibitor pada fermentasi bekasam. Sebanyak 6 strain bakteri asam laktat terpilih yangdiisolasi dari bekasam yaitu Lactobacillus plantarum B1765, L. plantarum T2565, L. plantarum N2352, L. plantarumB1465, Lactobacillus pentosus B2555, Pediococcus pentosaseus B1661 telah dikaji pertumbuhan, jumlah peptidayang terbentuk dari hasil degradasi proteolitik dan presentase penghambatannya terhadap aktivitas ACE selamafermentasi “bekasam-like” product. Semua strain dapat tumbuh dengan baik dan menunjukkan peningkatan jumlahpeptida dan peningkatan aktivitas penghambatan selama proses fermentasi yang bervariasi antar strain. Jumlah peptidatertinggi pada akhir proses fermentasi (8,55 ± 0,05 mg/g) dihasilkan L. plantarum B1765 dan terkecil (4,45±0,10mg/g) dihasilkan oleh P. pentosaceus B1661. L. plantarum B1765 juga menghasilkan aktivitas penghambatantertinggi (68,17±1,32%), diikuti oleh L. plantarum T2565 (62,54±2,11%), L. plantarum N2352 (61,56±1,32%), L.plantarum B1465 (59,85±1,58%), L. pentosus B2555 (56,61±4,28%), aktivitas penghambatan terkecil dihasilkan olehP. pentosaceus B1661 (18,66±3,91%).
Aktivitas Penangkapan Radikal DPPH Ekstrak Gambir (Uncaria gambir Roxb.) Rauf, Rusdin; Santoso, Umar; Suparmo, Suparmo
Agritech Vol 30, No 1 (2010)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9684

Abstract

Gambir contains high level of polyphenolic compounds known as catechins. The objectives of the research were to investigate the DPPH diphenyl picrylhydrayl radical scavenging activity of gambir extract and to identify the isolated phenolic compounds. Gambir was extracted with five types of solvents [aquadest, aquadest:ethanol (1:1), ethanol, ethanol:ethyle acetate, and ethyle acetate]. The DPPH radical scavenging activity of gambir extracts were higher than Rutin and BHT. The extractions with aquadest:ethanol, ethanol:ethyle acetate and ethyle acetate showed the highest scavenging activities of DPPH radicals 47.70 ± 0.60 %, 49.5 ± 0.68 % and 50.3 ± 0.74 %, respectively after incubation for 5 minutes. The rutin and BHT showed the lowest scavenging activities of DPPH radicals 3.07 ± 0.75 % and 4 ± 0.80 %, respectively. HPLC analysis showed that gambir extract contained simply catechin. ABSTRAKGambir mengandung komponen polifenol  yang cukup tinggi, yang dikenal sebagai katekin. Tujuan dari penelitian ini untuk mengetahui aktivitas penangkapan radikal DPPH diphenyl picryl hydraylekstrak gambir dan mengi dentifikasi komponen fenoliknya. Gambir diekstrak dengan lima macam sistem pelarut [aquades, aquades:etanol, etanol, etanol:etil asetat, and etil asetat]. Aktivitas penangkapan radikal DPPH ekstrak gambir lebih tinggi dari Rutin dan BHT Butylated hydroxytoluene. Ekstrak aquades:etanol, etanol:etil  asetat dan etil asetat menunjukkan aktivitas penangkapan radikal DPPH yang tertinggi masingmasing 47,70 ± 0,60 %, 49,5 ± 0,68 % and 50,3 ± 0,74 % setelah diinkubasi selama 5 menit. Rutin dan BHT menunjukkan aktivitas penangkapan radikal DPPH yang terendah masingmasing 3,07 ± 0,75 % and 4 ± 0,80 %. Hasil analisis HPLC menunjukkan bahwa ekstrak gambir mengandung katekin. 
Kinetika Oksidasi Minyak Ikan Tuna (Thunus sp) Selama Penyimpanan Husain, Rahim; Suparmo, Suparmo; Harmayani, Eni; Hidayat, Chusnul
Agritech Vol 36, No 2 (2016)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.12862

Abstract

Tuna fish oil (Thunnus sp) contains omega-3 fatty acids. It can be easily damaged by oxidation during storage. The rate of oxidation can be estimated by zero or first order of reaction. This research aimed to study the oxidation reaction during storage by determining the amount of activation energy (Ea) and constant change (k). The results showed that the value of k increases from 0.11 to 2.07 at a temperature 0 oC for the peroxide value while the numbers of TBA and acid number, respectively 0.041 increased 1.002, and k value of the acid number of 0.02 to 0.30 to 10, 20, 30 anda 40 oC. The activation energy (Ea) of oxidation reaction produced 50.07 Kj/mol.K peroxide value; 42.43 Kj/mol.K acid value and 57.69 Kj/mol.K. TBA value. The kinetic study showed an increasing oxidative deterioration of tuna fish (Thunnus sp) oil during storage by following the reactions of zero order or the reaction occurred slowly.ABSTRAKMinyak ikan tuna (Thunnus sp) mengandung asam lemak omega-3, sehingga mudah rusak akibat oksidasi selama penyimpanan. Kecepatan reaksi oksidasi dapat didekati melalui reaksi orde ke nol maupun orde pertama. Penelitian ini bertujuan untuk mempelajari reaksi oksidasi selama penyimpanan dengan menentukan besaran energi aktivasi (Ea) dan konstanta perubahan (k). Hasil menunjukkan bahwa nilai k meningkat dari 0,11 menjadi 2,07 pada suhu 0 oC untuk angka peroksida, angka TBA dan angka asam adalah 0,041 menjadi 1,002 dan 0,02 menjadi 0,30, yang terjadi pada suhu 10, 20, 30, dan 40 oC. Energi aktivasi (Ea) reaksi oksidasi yang menghasilkan angka peroksida 50,07 Kj/mol.K; angka asam 42,43 Kj/mol.K dan TBA 57,69 Kj/mol.K. Studi kinetika memperlihatkan bahwa terjadi peningkatan laju reaksi kerusakan oksidasi minyak ikan tuna (Thunus sp) selama penyimpanan dengan mengikuti reaksi orde ke nol atau reaksi berlangsung secara lambat.