Judul: Efficacy of Ginger and Turmeric Rhizome Extracts As An Effort to Extend the Storage Period of Salak Pondoh Due to Fungal Infection. This research was conducted
Abstrak: Control of postharvest diseases of fruits using chemical fungicides so far are quite effective, but its side effect on human health is not recommended. Therefore, it is necessary to find another technique which is cheaper and safer using botanical fungicide. Red ginger and turmeric extracts have strong antifungal activities, consequently they were used in this study. This study aimed: 1) To determine the most often fungal species isolated and the most potential fungal isolate which cause postharvest disease of salak Pondoh; 2) To asses the effectiveness of red ginger and turmeric rhizome extracts in inhibiting the growth of the most potential fungal isolate; 3) To find the most effective coating formula i.e wax concentration in combination with extract concentration of botanical fungicide to maintain the quality of salak Pondoh during storage. Randomized block design was used to determine the efficacy of two factors, i.e botanical fungicides (red ginger and turmeric rhizome extracts) and three concentrations (20, 30 and 40 %) of each botanical fungicide extract. A complete randomized block design with three treatments was used to examine the effect of red ginger extract and wax on fungal infection of salak Pondoh during storage. The three treatments were 1) waxing 10%; 2) red ginger rhizome extract 30%; 3) the combination of ginger rhizome extract 30% and waxing 10%. Salak Pondoh not coated wax 10 % and red ginger extract 30 % was used as control. Three replicates were used either on treatment or control. Water content of salak Pondoh, fruit hardness, total dissolved solid, respiration rate, weight loss, organoleptic test were determine using oven method, reometer, refractometer, closed system, gravimetric, and panelist test, respectively. Twelve fungal isolats were found in salak Pondoh collected from seven traditional markets and supermarkets in Bogor. Nine isolates of them were Thielaviopsis paradoxa, three other isolates were Mucor sp. Geotricum sp. and Fusarium graminearum. Thielaviopsis. paradoxa was the most often isolated fungal species and it caused the disease on salak Pondoh. The most virulent isolate of T. paradoxa was PSYSI1 and its disease symptom was 2 010 mm2. The result indicated that red ginger and turmeric extracts inhibited the growth of the T. paradoxa PSYSI1 at the concentration of 30 % or more, but red ginger extract was more potential to inhibit the fungal isolate (100 %) compared to turmeric extract (34 %). The use of 30 % ginger extract in combination with 10% waxing could maintain the quality of salak Pondoh at room temperature (28-29oC) and 65-75 % RH until 12 days of storage, while the control only up to 9 days of storage.
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Judul: Pengaruh Ekstrak Lengkuas (Alpinia galanga L.Swartz) Terhadap Peningkatan Daya Simpan Buah Salak Pondoh (Sallacca edulis Reinw.)
Abstrak: Pondoh salacca fruit (Salacca edulis Reinw) is an Indonesia tropical seasonal fruit with non-climateric respiratory pattern and naturally perishable with 5 to 6 days of storage at the room temperature (Mahendra et al., 1993). Decrease the quality of fresh fruits generally occurs due to handling during harvest and post harvest inadequate, leading to various forms of mechanical damage, physiological, biological, and microbiological. The damage of salacca fruit especially caused by infection of yeast, the yeast grow in the skin of the fruit, the color of fruit flesh turn into brown, tender, wet, and even rotten, or, the skin of the fruit becomes very dry and hard, and this could caused problems when peeling it. Alpinia galangal (Alpinia galangal L. Swartz) is one of natural rhizome from Zingiberaceae Family that can be used as natural antimicrobes. In this study, to maintain the quality and to extend shelf life of Pondoh salacca fruit, immersion salacca fruit in Alpinia galangal extract, perforation packaging and low temperature storage were performed. The aim of this study is to determine the effect of Alpinia galangal extract to hamper the rotten of Pondoh salacca fruit, analyze physical and chemical conversion during storage and define the best temperature in effort to extend shelf life of Pondoh salacca fruit. This study applies MAP (Modified Atmosphere Packaging). The packages that were used in this study are holed polyethylene (PE) plastic bag sized 25 x 16 cm with 40 μm thickness. Design research that was used is completely randomized design in factorial pattern and four times repetition that were consist of Alpinia galangal concentration factor (consist of 3 levels that were A = 0% (v/v aquadest), B = 5% (v/v aquadest), and C = 10% (v/v aquadest). and storage temperature factor (consist of 3 levels that were T1 = 15oC (RH 85 – 90%), T2 = 22oC (RH 65 – 66%), and T3 = 31oC (RH 67-72%). The study result showed that the best treatment is salacca fruit immersion in 5% (v/v aquades) Alpinia galangal extract during 30 second and storage at temperature 15o C (RH 85-90%) could extend shelf life of Pondoh salacca fruit up to 21 days of storage with 8.33% damage percentage, 0.55% weight loss, 71.56% skin water rate percentage, 80.87% flesh water rate percentage, 17o brix total suspended solid, 0.18% total acid, and 25.83 mg vitamin /100 gram material. The result of organoleptic analysis showed that until the 30th day of storage, hardness, easiness-to-peel, color, flavor, and taste still generally could be accepted, while the black spot at fruit bottom and freshness parameter for salacca fruit that fruit immersion in 0% (v/v aquades) Alpinia galangal extract could not be accepted by panelist on 10 days of storage.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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