Saiful Rochdyanto, Saiful
Unknown Affiliation

Published : 9 Documents
Articles

Found 9 Documents
Search

Model Matematics Salinitas Air di Muara Sungai untuk Pengairan Tambak Udang Windu Sewoko, Andri; Rochdyanto, Saiful; Sudira, Putu
Agritech Vol 23, No 4 (2003)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.13505

Abstract

The salacca (Salacca zalacca cv. Pondoh) fruits were stored in various modified atmosphere conditions in the impermeable cuverles with the variation of oxygen concentration of 2, 4, 6 and 8%. carbon dioxide concentration of 1, 2. 3 and 4% and nitrogen concentration as the rest. The variation of temperature was 12, 20 and 24 C. Gases within each cuvette were replaced daily. The respiration rate of the fruit was mudded based on the enzyme kinetic theory. The result showed that the respiration model Mows the Michaelis-Menten enzyme kinetic, with CO2 as the uncompetitive inhibitor. The model was fit to predict the respiration rate of the fruit.
Analisis Komponen Pemanfaatan Air (Water Accounting) Sistem Irigasi Kalibawang, Kabupaten Kulon Progo E.K., Jonathan; Sudira, Putu; Rochdyanto, Saiful
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.13567

Abstract

Water accounting method can be used as a tool for analyzing and evaluating of water for different uses. The art of water accounting is so classify water balance components into water use categories that reflect the consequences of human intercentions in the hydrologic cycles. This study was conducted at Kalibawang Irrigation System which was located at Kulon Progo region. Result showed that gross inflow at Kalibawang Irrigation system during the growing poriod of 1999/2000 consisted of rainfall 17 % and irrigation water 83 %. The total use of water for any interest or total depletion (TD) is 53.22 %, water use to meet crop need or process depletion (PD) is 24.46 %, water outflow (O) of the system is 25.15% and the beneficial utilization or the irrigation system efficiency (BU) is 37.74 %. Water productivity per unit of gross inflow (PWGI) is Rp 63.74/m3, water productivity per unit of delivered water supply or irrigated water (PWWd) is RP 76.75/m3, water productivity per unit of available water (PWAW( is 89.41/m3.
Ketahanan Panas Cemaran Escherichia coli, Staphylococcus aureus, Bacillus cereus dan Bakteri Pembentuk Spora yang Diisolasi dari Proses Pembuatan Tahu di Sudagaran Yogyakarta Mailia, Reny; Yudhistira, Bara; Pranoto, Yudi; Rochdyanto, Saiful; Rahayu, Endang Sutriswati
Agritech Vol 35, No 3 (2015)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.9341

Abstract

Characteristics of tofu with higher a (0.89 to 0.90) and protein levels of 8% or more, made tofu to be a suitable medium for bacterial growth. This leads to out to be very easy to damage due to bacterial contamination. Contamination of bacteria is commonly found in the tofu because of contamination in the process making of tofu. Source of contamination can come out from the raw material, during the process of making tofu and hygienic sanitation level during processing. Generally, this study aimed to determine the level of contamination of Escherichia coli, Staphylococcus aureus, Bacillus cereus and spore-forming bacteria in the process of making tofu and study the properties of heat resistance of eachisolate. Phases of of the study started with the isolation and identification and then quantitative analysis of Escherichiawcoli, Staphylococcus aureus, Bacillus cereus and spore-forming bacteria in the tofu process from raw materials to end product, tofu, comprised from water and soybean, slurry, soymilk cooking, curd, whey and tofu. Isolates originating from the cooking process and the coagulation process was for testing the heat resistance (D value and Z value). D and Z values were calculated using linear regression. Escherichia coli found in the water, soybeans, soybean slurry, curd and tofu, the number 10 =4,83 min and the value of Z = 22.73°C. Staphylococcus aureus found in soybeans and curd, showed the number of 101-102 CFU/g. Escherichia coli GMP isolate had D60°C CFU/g. The Staphylococcus aureus GMP4 isolate, had D60°C 1=2.72 min and the value of Z = 18.87°C. The Staphylococcus aureus GMP 6 isolate, had D=2.54min and the value of Z = 18.18°C. Bacillus cereus found in the water, soybean, soybean slurry, soymilk cooking, curdand tofu, showed the number 102-103CFU/g. Bacillus cereus vegetative cells SK 2 had D=5.43 min and the value of Z = 22.72°C. Bacillus cereus vegetative cells SK 4 had D60°C 60°C =5.95 min and the value of Z = 22.22°C. Spore-forming bacteria found in water, soybean, soybean slurry from the grinding process, the process cooking of soymilk, the process of clotting, whey and tofu, showed the number of 102CFU/g.ABSTRAKKarakteristik tahu dengan a0,89-0,90 dan kadar protein 8% atau lebih, menjadikan tahu sebagai media yang cocok bagi pertumbuhan bakteri. Hal ini menyebabkan tahu menjadi sangat mudah rusak karena cemaran bakteri. Penelitian ini bertujuan untuk mengetahui tingkat cemaran Escherichia coli, Staphylococcus aureus, Bacillus cereus dan Bakteri pembentuk spora pada proses pembuatan tahu dan mempelajari sifat ketahanan panas dari masing-masing cemaran. Tahapan penelitian dimulai dari pengamatan proses pembuatan tahu, isolasi dan identifikasi dan analisa kuantitatif cemaran Escherichia coli, Staphylococcus aureus, Bacillus cereus dan bakteri pembentuk spora pada proses pembuatan tahu. Isolat yang berasal dari proses pemasakan dan proses penggumpalan digunakan untuk pengujian ketahanan panas dengan melihat nilai D dan Z menggunakan regresi linier. Escherichia coli ditemukan pada air, kedelai, bubur kedelai, gumpalan tahu dan tahu, dengan jumlah 10w1-10CFU/g. Isolat Escherichia coli dari proses penggumpalan (GMP), nilaiD60°C 2=4,83 menit dan nilai Z=22,73°C. Staphylococcus aureus ditemukan pada kedelai, gumpalan tahu dan tahu, dengan jumlah 10=2,72 menit dan nilai Z =18,87°C. Untuk isolat Staphylococcus aureus GMP 6, nilai D1CFU/g.  Isolat Staphylococcus aureus GMP 4, memiliki nilai D60°C60°C =2,54 menit dan nilai Z =18,18°C. Bacillus cereus ditemukan pada air,kedelai, bubur kedelai, sari kedelai masak, gumpalan tahu dan tahu, dengan jumlah 102-10CFU/g. Sel vegetatif Bacilluscereus yang berasal dari sari kedelai (SK) 2, memiliki nilai D60°C3=5,43 menit dan nilai Z =22,72°C. Untuk sel vegetatif  Bacillus cereus SK 4, memiliki nilai D60°C=5,95 menit dan nilai Z =22,22°C. Bakteri pembentuk spora ditemukan pada air, kedelai, bubur kedelai pada proses penggilingan, sari kedelai masak, gumpalan tahu, kecutan dan tahu, dengan jumlah 10CFU/g.
Pengembangan Model Operasi Pompa Berkelanjutan di Daerah Irigasi Sumur Pompa Dangkal Murtiningrum, Murtiningrum; Arif, Sigit Supadmo; Rochdyanto, Saiful
Agritech Vol 16, No 1 (1996)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.22510

Abstract

Model of sustainable pump operation in an unconfined groundwater irrigation system was developed to determine pump operation pattern which consist of the number of pumps, duration, and distance between pumps, so that crop water requirement is fulfilled and groundwater irrigation system is sustained. Total irrigation flow, EQpi, results in lowering water table which is called drawdown, sn. Drawdown sn should be less than di (sn< di) which (d1 is maximum drawdown which is affected by pump technology. Model outputs for the area of Sri Rahayu Farmer Group in Kedungtuban, Blora for existing cropping pattern show that average irrigation water requirement is 916.1mm/year and peak flow is 4.93 ips. It still can be fulfilled by 1, 2, 3, 4, or 9 pumps for 10 days operation continuously which is shown by the drawdowns which are less than maximum drawdown.
Pengukuran Kecepatan Aliran Bermuatan Sedimen di Saluran Irigasi Rochdyanto, Saiful
Agritech Vol 14, No 2 (1994)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.19280

Abstract

Study on the measurement of flow velocity in sediment-laden flow was carried out in Van Der Wig* irrigation Canal, Yogyakarta. Study was conducted in various of canal conditions and various of sediment concentration. Flow velocity was measured by using current meter and water sample was collected by using suspended sampler. Result of study shows that velocity distribution data can be suited by the power-law, although it does not seem to fit with equation that presented by Munson which is suitable with non-sediment laden flow in open channels. Due to the deviation on power-law graph, in order to find the average-measured-velocity which is match with the actual-velocity, the point of measurement should be 0,71 D (from the free water surface). The point of measurement at 0,6 J) such as already established by regulation will give an error about 14,35%.
Distribusi Kecepatan Aliran di Saluran Terbuka Pada Permukaan Saluran Bergelombang Rochdyanto, Saiful
Agritech Vol 12, No 3 (1992)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.19246

Abstract

Study on velocity distribution in wavy bed was conducted in a 10 m long, 0.5 m wide, 0.4 m depth glass-walled rectangular open channel. Flow characteristic was measured by hot wire anemometer and data was transferred to personal computer by digitizer. The Reynolds number which calculated from the maximum velocity are 3940,5630, 8190, and 12,930 respectively. Result of study shows that velocity data can not be approached by using the logarithmic law Mean while the power-law velocity distribution seems applicable in explaining the scanered velocity data. The velocity reduction about 0.21u/um in the area close to the bed and 0.05 u/um In the middle of turbulent boundary layer is disadvantage in the view point of hydraulic structure operation
Nilai Air dalam Hubungannya dengan Pendapatan Usaha Tani Rochdyanto, Saiful
Agritech Vol 7, No 1 (1987)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.18996

Abstract

.
Kinerja Alat Pencurah Sederhana Pada Sistem Irigasi Curah (Sprinkler Irrigation System) Rochdyanto, Saiful; Arif, Sigit Supadmo; Susilawati, Isti
Agritech Vol 17, No 2 (1997)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.19330

Abstract

The modification of fabricated sprinkler which is available in the market was done in order to solve several problems, such as : the performance is unsatisfied, the prize is relatively high, the construction is complicated, and the operation and maintenance is not too easy. The performance testing was carried out to six model of modification sprinklers, they were : Sl, S2, S3, S4, S5, and S6, and then compared with fabricated sprinkler (SP). Sprinklers were tested with several parameters, such as : water discharge, throw distance, water distribution pattern, water rate, and particle water diameter. Result of experiment showed that S5 gives the best performance. This model has upper arm length = 5.0 cm, lower arm length = 3.8 cm, nozzle angle in upper arm = 65°, nozzle angle in lower arm = 40°, the number of nozzle in each lower arm and top of arm is one. Comparing with fabricated sprinkler (SP), the prize of S5 model is relatively cheap. It is Rp. 5,575.00 for S5 and Rp. 17,500.00 for SP. Due to the construction is relatively simple and the product material is very easy to find in local market, so the model S5 can be introduced and developed to farmers in order to increase their agricultural production.
INAKTIVASI PANAS SPORA BACILLUS CEREUS PADA TAHU Yudhistira, Bara; Mailia, Reny; Rahayu, Endang S.; Pranoto, Yudi; Rochdyanto, Saiful
Jurnal Teknologi Hasil Pertanian Vol 10, No 1 (2017)
Publisher : Universitas Sebelas Maret (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (491.381 KB) | DOI: 10.20961/jthp.v10i1.17498

Abstract

As one of perishable food, tofu is susceptible for microorganisms contamination, an effort is needed to solve the problem. Heat treatment is one of the most common methods used to reduce microorganism population. This research aimed to analyze heat treatment effects of Bacillus cereus reduction in tofu. B. cereus isolate was obtained from soy milk cooking process during tofu production in Sudagaran Yogyakarta. D value measurement as parameter analysis was conducted at 80, 90, 100, 110, 120oC. The results showed that D90 value of B. cereus in tofu product was 29.41 minutes D120 value was 1.69 minute, while Z value was 33.33oC. D and Z value obtained was then used as pasteurization reference to extend shelf life of tofu. Pasteurization temperature of 95oC was based on household conventional boiling temperature, and the process time variations were 0, 10, 30 and 34 minutes. During tofu storage at 100C, analyses conducted were Total Plate Count, spore-forming bacteria, and B. cereus enumeration. Sensory parameter was also evaluated; including flavor, color, surface appearance, mucus presence, and texture. The longest shelf life 20 days was obtained by 34 minutes pasteurization and cool storage.