Judul: Aktivitas protease dan kandungan asam laktat pada yoghurt yang dimodifikasi Bifidobacterium bifidum
Abstrak: Yoghurt merupakan minuman hasil fermentasi dari susu murni. Yoghurt probiotik merupakan salah satu produk pangan fungsional melalui penambahan bakteri probiotik seperti B. bifidum. Penelitian ini bertujuan untuk mengukur aktivitas protease dan kandungan asam laktat pada yoghurt yang dibubuhi B. bifidum. Parameter yoghurt yang dimodifikasi dengan B. bifidum adalah kadar asam laktat dan aktivitas protease selama dua puluh lima hari penyimpanan. Kadar asam laktat diukur dengan metode titrasi asam basa, sedangkan aktivitas protease diukur dengan metode modifikasi Lowry. Yoghurt diuji tingkat penerimaannya oleh konsumen dengan uji organoleptik.
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Judul: Aktivitas protease dan kandungan asam laktat pada yoghurt yang dimodifikasi Bifidobacterium bifidum dan diinokulasi pseudomonas fluorescens
Abstrak: Main health benefical related to yoghurt is its ability to improve lactose digestion and to control the pathogenic bacteria in digestion tract. This benefical health is threatened by natural existence of contaminant in milk especially P. fluorescens, that reduces shelf life of milk. The aim of this research is to determine the antagonistic nature of B. bifidum in inhibiting growth P. fluorescens and the effect of B. bifidum on protease activity and lactic acid content of yoghurt inoculated by P. fluorescens. Antagonism test of B. bifidum to P. fluorescens is conducted using turbidimetric method. Total titratable acid was measured to determine the percentage of lactic acid content by using acid base titration principle. Protease activity was measured with modification of Lowry method. The result of antagonism test showed that B. bifidum can inhibit P. fluorescens with minimum inhibitory concentration (MIC) of 2%. Lactic acid content of yoghurt with formula 1:1:0, 1:1:0.5, 1:1:1, and 1:1:1.5 on 0 day was 0.3747%, 0.3654%, 0.3732%, and 0.347% respectively and then increased during 25 day storage to 0.5709%, 0.5202%, 0.6638%, and 0.5945% respectively. Addition of B. bifidum decreased protease activity indicated by less protease activity of yoghurt modified by B. bifidum till 15 day storage compared to yoghurt without B. bifidum.
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Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite