Sri Raharjo
Jurusan Teknologi Hasil Pertanian, Fakultas Teknologi Pertanian, Universitas Gajah Mada, Yogyakarta

Published : 73 Documents
Articles

OXIDATIVE STABILITY OF CANARIUM NUT (CANARIUM INDICUM AND CANARIUM VULGARE) OIL DURING STORAGE AT 30 AND 40 0 C Djarkasi, Suhartati; Raharjo, Sri; Noor, Zuheid; Sudarmadji, Slamet
Jurnal Teknologi dan Industri Pangan Vol. 19 No. 2 (2008): Jurnal Teknologi dan Industri Pangan
Publisher : Departemen Ilmu dan Teknologi Pangan, IPB Indonesia bekerjasama dengan PATPI

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Abstract

The aims of this research were to study the effect of temperature and storage on the oxidative stability of crude and refined canarium nut oil extracted from the seeds of Canarium indicum and Canarium vulgare. The experiment was designed to include storage of two type of canarium nut oil at two different temperatures for up to 35 days. The oils (crude and refined) used had the similar condition. Parameter used for oxidative deterioration indicators were two peroxide value, TBARS (thiobarbituric acid reactive substances), and free fatty acid value. The result showed that refining oil can decrease component natural antioxidant of canarium oil cause more sensitive to the oxidation. Increased storage temperature can raise oxidation of crude and refined oils from both species Canarium. The peroxide values of crude and refined oils both Canarium indicum and Canarium vulgare stored at 30 °C were 2.17, 4.35, 3.36 and 3.77 meq O2/kg oil, respectively. When they were stored at 4?C the similar results were 6.21, 19.09, 8.12 and 17.23 meq O2/kg oil. Furthermore, TBARS value of crude and refined oils both for Canarium indicum and Canarium vulgare stored 30?C were 4.55, 7.78, 5.70 and 6.58 µmol MDA/kg oil. When they were stored at 40 °C the similar results were 9.99, 55.46, 12.46 and 43.62 µmol MDA/kg oil.Key words: Canarium nut oil, peroxide value, TBARS
THE ROLE OF SURFACTANT MICELLES ON THE PARTITIONING OF ANTIOXIDANT AND THE OXIDATIVE STABILITY OF OIL-IN-WATER EMULSION Sibuea, Posman; Raharjo, Sri; Santoso, Umar; Noor, Zuheid
Jurnal Teknologi dan Industri Pangan Vol. 19 No. 1 (2008): Jurnal Teknologi dan Industri Pangan
Publisher : Departemen Ilmu dan Teknologi Pangan, IPB Indonesia bekerjasama dengan PATPI

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Abstract

Lipid oxidation system in which the fat is dispersed as emulsion droplets is still not well understood, although a large number of food exist partially or entirely in the form of emulsions. Therefore, this study was intended to examine how surfactant micelles influence the partitioning of antioxidant and hydroperoxides and how it alter the oxidative stability of oil-in-water emulsion. To determine the ability of surfactant micelles upon the partitioning of antioxidant in oil-in-water emulsion, this type of emulsion, containing quercetin at 0, 25, 50, 75 and 100 ppm, were prepared with polyoxyethylene 100 stearyl ether (Brij 700) or polyoxyethylene sorbitan monolaurate (Tween 20) with acetate or phosphate buffer (pH 3.0 or 7.0). Structurally Birj 700 has 5 times longer polyoxyethylene groups than Tween 20. After preparation of the emulsion, surfactant micelles (0-2%) were incorporated into the continuous phase to give a final lipid concentration of 5%. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides, decreased with increasing quercetin concentrations. At pH 3, the peroxide value was higher than that at pH 7. Brij 70 decreased production of lipid hydroperoxides from palm oil-in-water-emulsions compared to the emulsions stabilized by Tween 20. the result showed that solubilization of quercetin into the aqueous into the aqueous phase by Brij or Tween micelles did not alter the oxidative stability of palm oil-in-water emulsion, suggesting that surfactant micelle influenced the oxidation rate by mechanism other than antioxidant solubilization. Key word : Quercetin, surfactant micelles, and oxidative stability
THE EFFECT OF SIZE REDUCTION AND PREPARATION DURATION ON THE ANTIOXIDANT ACTIVITY OF WHITE SAFFRON (CURCUMA MANGGA VAL.) Pujimulyani, Dwiyati; Raharjo, Sri; Marsono, Y; Santoso, Umar
Journal of Food and Pharmaceutical Sciences Vol 1, No 1 (2013): J.Food Pharm.Sci (January-April)
Publisher : Fakultas Farmasi, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (403.451 KB) | DOI: 10.14499/jfps

Abstract

Food processing is usually conducted through preparation stages such as peeling, slicing, or cutting. The purpose of this research was to determine the correlation between the antioxidant activity and the total phenolic compounds of white saffron as affected by different level of size reduction and the duration of rhizome preparation at room temperature. White saffron rhizomes were peeled, washed, and cut into 1x1x1 cm3. The whole white saffron was sliced diagonally at thickness of 4 x 2 mm, and grated. The antioxidant activity of the white saffron was determined by radical scavenging activity using 2-2-diphenyl-1-picrylhydrazyl (DPPH) radical and by ferric reducing antioxidant power FRAP) method. The total phenol and total flavonoid contents were also determined at 2, 4, and 6 hours, respectively. The result showed that the antioxidant activities, total phenolic and flavonoid contents due to the preparation of whole white saffron for 6 hour are not statistically different compared to those of fresh white saffron. The preparation of white saffron sliced at 2 mm and grated for 2 hour showed a significant decrease in the antioxidant activities, compared to those of fresh white saffron.Keywords: white saffron, preparation duration, antioxidant activity, total phenol
Degradasi Biksin Selama Pemanasan dan Pencahayaan Pranata, Ardiyanto; Raharjo, Sri; Santoso, Umar; Haryadi, Haryadi
Agritech Vol 26, No 4 (2006)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1272.612 KB) | DOI: 10.22146/agritech.9481

Abstract

The kinetics of thermal and light induced degradation of natural bixin in a mixture of ethanol and 2 % acetic acid (80 : 20) was studied as a function of temperatures 80, 98, and 125 OC for 120 minutes. Illumination was carried out either under fluorescent or incandescent lights, both at 4000 lux for 300 minutes. The bixin concentration during heating and illumination was analysed using HPLC. The method to determine the degradation rate constant for the decay of the products from bixin was obtained using a linear regression according to first order reaction.  The results indicated that the degradation rates of bixin at 125 OC were 5.5 and 3.8 times faster than that of 80 OC and 98 OC, respectively. The energy activation of bixin was 9.82 kcal/mol. The photodegradation rate constants of bixin under incandescent or fluorescent illumination was 2.8 x 10-3 and 3.3 x 10-3 minutes-l, respectively.
THE INFLUENCE OF PARTICLE SIZE AND GULURONIC/MANNURONIC PROPORTION OF ALGINATE ON PHYSICAL AND SENSORY CHARACTERISTICS OF RESTRUCTURED PRODUCTS FROM SOURSOP Raharjo, Sri; Utama, Zaki
Jurnal Teknologi dan Industri Pangan Vol. 14 No. 3 (2003): Jurnal Teknologi dan Industri Pangan
Publisher : Departemen Ilmu dan Teknologi Pangan, IPB Indonesia bekerjasama dengan PATPI

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Abstract

The application of restructuring technology is intended to add value for local fruits. Fresh and ripe sour sop fruits are frequently of having defective appearance, irregular shape and size, or showing signs of insect infestation which make the whole fruit is less acceptable by consumers. Previous study has indicated that sour sop fruit can be restructured into a fresh fruit product with acceptable sensory characteristics using calcium alginate gel system. This particular study was intended to determine the effect of alginate powder particles size and its guluronic/mannuronic proportion on the physical and sensorial properties of restructured sour sop. The restructured fruit product was evaluated based on its gel strength, pH colour, and sensory attributes which include taste, aroma, mouth feel, appearance, and hardness. Sour sop restructured by internal setting with coarse alginate powder (36 mesh) tend to have softer gel compared to the use of fine alginate powder (120 mesh). Different proportion of guluronic/mannuronic in the alginate used for the restructurization resulted in the same gel strength when calcium lactate powder was used. However, the use of encapsulated calcium lactate resulted in stronger gel with alginate containing higher proportion of mannuronic acid. The alginate particle size and proportion of guluronic/mannuronic content showed no significant difference in product colour and sensory attributes evaluated. Key words : Alginate, sour sop fruit, restructurization.
AKTIVITAS ANTIOKSIDAN ANTOSIANIN BERAS KETAN HITAM SELAMA FERMENTASI [ANTIOXIDANT ACTIVITY OF ANTHOCYANIN OF BLACK GLUTINOUS RICE DURING FERMENTATION] Suhartatik, Nanik; Cahyanto, Muhammad Nur; Raharjo, Sri; Rahayu, Endang S.
Jurnal Teknologi dan Industri Pangan Vol. 24 No. 1 (2013): Jurnal Teknologi dan Industri Pangan
Publisher : Departemen Ilmu dan Teknologi Pangan, IPB Indonesia bekerjasama dengan PATPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (365.215 KB) | DOI: 10.6066/jtip.2013.24.1.115

Abstract

Anthocyanin is a group of bioactive compound found to be abundant in black glutinous rice. It has been widely studied for their health beneficial effect. Hydrolysis of anthocyanin glycoside into anthocyanidin and sugar by ?,D-glucosidase is presumed to be the first step in anthocyanin metabolism. Enzymatic degradation of anthocyanin was reported to produce not only more stable compounds, but also healthier compounds with better bioavailability. Some species of Lactic Acid Bacteria showed ?,D-glucosidase activity. The research aims to study the functional property?s change?s of anthocyanin extracted from black glutinous rice as an antioxidant compound after being fermented using Lactobacillus plantarum Mut 7. The results showed that fermentation process did not give a significant effect to the antioxidant activity of black glutinous rice anthocyanin. The antioxidant activity as determined by Radical Scavenging Activity and Ferrous Reducing Activity Power value were 59.2% (6 hours of incubation, 30 mM anthocyanin) and 96.7% (5 hours of incubation, 10 mM anthocyanin). The lactic acid bacterial count increased up to 2 log cycle after being fermented for 5 hours.
Stabilitas Ekstrak Antosianin Beras Ketan (Oryza sativa var. glutinosa) Hitam selama Proses Pemanasan dan Penyimpanan Suhartatik, Nanik; Karyantina, Merkuria; Mustofa, Akhmad; Cahyanto, Muhammad Nur; Raharjo, Sri; Rahayu, Endang Sutriswati
Agritech Vol 33, No 4 (2013)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (490.062 KB) | DOI: 10.22146/agritech.9533

Abstract

anthocyanin pigments are responsible for the red, blue, and purple colour in crop produces such as fruits, vegetables, rice, and flowers. This bioactive compound has been developed for natural colorants in food products, especially functional foods. The aims of this research were to study the stability of anthocyanin and its colour during heating in various temperatures and during storage under different conditions. The results showed that the higher the heating temperature and the longer the heating time, the higher degradation of anthocyanin. Except for anthocyanin extract heated below 50 c for not more than 15 min, it has increased the anthocyanin stability. antioxidant activities (% RSa, radical scavenging activity and fRaP value, Ferrous Radical Activity Power) decreased after the extract were heated at 70c. Extracts stored at room temperature with neutral solution (pH 7.0) have decreased their level of anthocyanin from 25 to 1.87 mg/100 mL. Storage at low temperature had not reduced significantly their anthocyanin concentration. ABSTRAKAntosianin sebagai senyawa yang menyebabkan timbulnya warna merah, biru, dan ungu pada padi, buah, sayuran, dan produk hortikultura lainnya, sangat berpotensi untuk dikembangkan sebagai bahan pewarna alami pada produk pangan fungsional. Tujuan dari penelitian ini adalah untuk mempelajari stabilitas dan warna ekstrak antosianin dari beras ketan hitam selama proses pemanasan dan penyimpanan. Hasil menunjukkan bahwa semakin tinggi suhu pemanasan dan semakin lama waktu pemanasan, menyebabkan kerusakan antosianin semakin banyak. Kecuali pada pemanasan <50 c tidak lebih dari 15 menit yang dapat meningkatkan kestabilan antosianin. aktivitas antioksidan (% RSa, radical scavenging activity dan nilai fRaP, Ferrous radical Activity Power) mengalami penurunan setelah dipanaskan pada suhu 70 oc. Penyimpanan pada suhu kamar dan pH 7,0 dapat menurunkan kadar antosianin ekstrak dari 25 menjadi 1,87 mg/100 mL. Sedangkan penyimpanan pada suhu rendah tidak menyebabkan perubahan kadar antosianin yang berarti.
Karakteristik Fermentatif Medium deMann Rogosa Sharpe (MRS) Antosianin Beras Ketan Hitam (Oryza sativa var. glutinosa) Menggunakan Pediococcus pentosaceus N11.16 Suhartatik, Nanik; Karyantina, Merkuria; Cahyanto, Muhammad Nur; Raharjo, Sri; Rahayu, Endang Sutriswati
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 | Full PDF (243.746 KB) | DOI: 10.22146/agritech.9457

Abstract

Anthocyanin was a bioactive compound which has an anti-infl ammatory effect, anticancer, antimutagen, antioxidant, anticholesterol, and also acts as therapheutic agent for artherioschlerosis. Initial step for anthocyanin metabolism was hydrolyzed to anthocyanidin (aglikon) by β-D-glucosidase. Pediococcus pentosaceus N11.16 is known to be one of bacteria which has a capability to hydrolyze black glutinous rice anthocyanin extract. The aims of this research were to study the fermentative characteristics of MRS containing black glutinous rice anthocyanin medium (MRSm+Anthocyanin) using lactic acid bacteria P. pentosaceus N11.16. The results showed that P. pentosaceus N11.16 could grew well in this medium. Total acid producing bacteria increased untill 2 log cycle with antioxidant activity (%RSA) 75% and the Fe 3+ ion reducing capacity 36.75%. Phenolic compound in the MRSm+ anthocyanin was 584.05 mg asam galat/100 mL after being fermented for 16 hours. Phenolic compound in MRSm+anthocyanin medium were higher than MRSm or control medium (MRS). Beta glucosidase activities of the bacterial cell tend to be higher in the MRS anthocyanin medium than MRS without sugar and control medium.ABSTRAKLangkah awal dalam metabolisme antosianin, komponen bioaktif utama yang terdapat dalam beras ketan hitam, adalah hidrolisis menjadi antosianidin (aglikon) dengan memanfaatkan enzim β,D-glukosidase. Pediococcus pentosaceus N11.16 merupakan salah satu bakteri yang telah diisolasi dan teruji kemampuannya untuk menghidrolisis antosianin beras ketan hitam. Penelitian ini bertujuan untuk mempelajari karakteristik fermentatif medium fermentasi yang mengandung antosianin beras ketan hitam menggunakan bakteri asam laktat P. pentosaceus N11.16. Penelitian dilakukan dengan cara menguji kemampuan tumbuh isolat dalam medium MRS yang dimodifi kasi (MRSm) dengan penambahan antosianin beras ketan hitam. Hasil menunjukkan bahwa bakteri P. pentosaceus N11.16 mampu tumbuh dengan baik dalam medium MRS yang mengandung antosianin beras ketan hitam. Kenaikan mencapai 2 log cycle dengan aktivitas antioksidan (%RSA) mencapai 75% dan kemampuan menangkap logam mencapai 36,75%. Total fenol medium MRSm+antosianin mencapai 584,05 mg asam galat/100 mL medium setelah 16 jam fermentasi. Total fenol medium MRSm+antosianin cenderung lebih tinggi daripada MRSm atau kontrol (MRS). Aktivitas enzim β glukosidase sel bakteri cenderung lebih tinggi pada medium MRSm+antosianin daripada MRSm atau kontrol (MRS).
Formulasi dan Stabilitas Mikroemulsi O/W dengan Metode Emulsifikasi Spontan Menggunakan VCO dan Minyak Sawit Sebagai Fase Minyak: Pengaruh Rasio Surfaktan-Minyak Ariviani, Setyaningrum; Raharjo, Sri; Anggrahini, Sri; Naruki, Sri
Agritech Vol 35, No 1 (2015)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (135.676 KB) | DOI: 10.22146/agritech.9416

Abstract

This study was aimed to (1) formulate o/w microemulsion using different surfactant oil ratio, (2) determine the microemulsions stability toward centrifugation, heating and storage at room temperature, and (3) characterize microemulsions which were shown the best stability. Microemulsions were prepared using ternary food grade surfactant with low HLB (span 80), medium HLB (span 20 or span 40) and high HLB (tween 80), and surfactant oil ratio 2,3,4 and 5. VCO and palm oil were used as oil phase, whereas 10 μM phosphate buffer pH 7 was used as aqueous phase. O/W microemulsionwere formed at surfactant oil ratio 3 or more for VCO and at higher surfactant oil ratio (i.e 4 or 5) when palm oil was used as oil phase. Microemulsions with VCO as oil phase which were stable toward centrifugation, heating treatment and storage at room temperature i.e. microemulsions with surfactant oil ratio 4 or 5, while the use of palm oil as oil phase produce stable microemulsions at surfactant oil ratio 4. Microemulsions with surfactant oil ratio 4 showedthe best stability. This microemulsions have a monomodal particle size distribution, the mean particle diameter and viscosity reached 21.7 ± 0.02nm and 6.0 ± 0.10cp (VCO), 22.9 ± 0.15nm and 6.2 ± 0.05cp (palm oil).ABSTRAKPenelitian ini bertujuan untuk (1) formulasi mikroemulsi o/w dengan variasirasio surfaktan-minyak, (2) menentukan stabilitas mikroemulsiterhadap sentrifugasi, pemanasan dan penyimpanan suhu ruang, dan (3) karakterisasi mikroemulsi dengan stabilitas terbaik. Mikroemulsi dibuat menggunakan campuran tiga surfaktan food grade yaitu surfaktan HLB rendah (span 80), sedang (span 20 atau span 40), dan tinggi (tween 80), dengan rasio surfaktan minyak 2, 3, 4 dan 5. VCO dan minyak kelapa sawit digunakan sebagai fase minyak, 10 μM bufer fosfat pH 7 sebagai fase aqueous. Mikroemulsi o/w terbentuk pada rasio surfaktan minyak 3 atau lebih untuk penggunaan VCO dan pada rasio surfaktan minyak yang lebih tinggi (yaitu 4 atau 5) untuk penggunaan minyak sawit sebagai fase minyak. Mikroemulsi dengan fase minyak VCO yang stabil terhadap sentrifugasi, pemanasan maupun penyimpanan suhu ruang adalah mikroemulsi dengan rasio surfaktan-minyak 4 atau 5, sedangkan penggunaan minyak sawit sebagai fase minyak menghasilkan mikroemulsi yang stabil pada rasio surfaktan-minyak 4. Mikroemulsi dengan rasio surfaktan-minyak 4 memperlihatkan stabilitas terbaik. Mikroemulsi tersebut memiliki distribusi ukuran partikel monomodal, rerata diameter partikel dan viskositas mencapai 21,7 ± 0,02nm dan 6,0 ± 0,10cp (VCO), 22,9 ± 0,15nm dan 6,2 ± 0,05cp (minyak sawit).
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 | Full PDF (878.891 KB) | 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.