Judul: Upaya Pengurangan Pembentukan Senyawa Akrilamid  pada Pengolahan Keripik Pisang Ambon
Abstrak: Senyawa akrilamid terdapat dalam makanan yang diolah dengan proses pemanasan suhu tinggi. Pembentukan senyawa ini terjadi melalui reaksi Maillard yaitu reaksi antara asam amino dengan senyawa gula pereduksi seperti glukosa dan fruktosa. Asam amino yang diduga merupakan prekursor pembentuk akrilamid adalah asparagin. Penurunan pembentukan akrilamid dapat dilakukan dengan cara mengurangi prekursor pembentuknya dan optimasi proses pemanasan yang dilakukan. Reaksi pembentukan akrilamid diduga sejalan dengan reaksi pembentukan warna dan aroma dalam produk makanan.
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Judul: Perlakuan Blansir dan Edible Coating dari Pektin untuk Mereduksi Senyawa Akrilamida pada Proses Penggorengan Keripik Pisang Ambon
Abstrak: Acrylamide is a probable human carcinogen and is potentially formed in ambon banana chips due to its reducing sugar and asparagin content and the involvement of frying process. This research aims to reduce acrylamide formation in ambon banana chips by using blanching and pectin-based edible coating. Blanching treatment was conducted at 90 oC, and 100 oC for 1 minute while concentration of pectin-based edible coating was 0 and 2 % (w/v). Acrylamide level was analyzed by enzyme-linked immunosorbent assay (ELISA) method. Ambon banana chips prepared without blanching and edible coating contains 194.40 ppb of acrylamide. Edible coating reduced 33.02 % of acrylamide level whereas blanching at 90 oC and 100 oC reduced 20.06 % and 52.47% of acrylamide levels, respectively. Interestingly, combination of blanching and pectin-based edible coating could reduce intensively acrylamide level in banana chips until 90% of reduction. However, with only blanching pretreatment, it induced an important change in physical characteristics of products and reduced consumer preference which was indicated by lower hedonic scores compared to those of the control.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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