Judul: Development of Mangosteen Infusion Tea (Garcinia mangostana L.) Mixed with Blueberry.
Abstrak: Mangosteen infusion tea (MIT) is a tea product consisted of dried mangosteen pericarp (DMP). MIT has an unpleasant taste but has many benefits. An alternative to increase mangosteen pericarp (MP) consumption is using salt-bitter mixture interaction by soaking in 10% salt solution and taste masking using sweet-sour flavor from stevia and blueberry. This research aimed to develop MIT mixed with blueberry to meet optimal formula and determine its quality. MIT was mixed with blueberry and the formula optimized by Mixture Design D-optimal based on the value of non-sensory responses lightness (L) and oHue of MIT blueberry was measured by Hunter La*b*, Total Phenolic Content (TPC), and sensory responses including color, blueberry odor, sweet, grouping taste (bitter, astringent, aftertaste and sour) and overall liking. Three components were constrained as DMP (60-70%), blueberry powder (20-30%), and stevia (5-10%). The result of optimal formula consisted of 64.20% DMP, 26.59% blueberry powder, 9.21% stevia with desirability value 0.858. The lightness value of optimum formula was 23.80, oHue was 261, TPC value was 3.07 g GAE/100 g. Sensory evaluation score results for color, blueberry odor, sweet, grouping taste, and overall liking were 7.62, 5.50, 6.22, 6.41, and 6.77 respectively. Total viable count and yeast & mold of the optimal formula was 6.1x101 CFU/g, and 3.2x101 CFU/g has complied with Indonesian Regular Standard for black tea in tea bag packaging. The result of sensory and consumer acceptance test showed that MIT mixed with blueberry have potential market proven by 88% of consumer accepted MIT mixed with blueberry and 77% willing to buy if it sold on the market.
Keyword: Consumer acceptance, mangosteen infusion tea, product development, D-optimal, taste masking

Judul: Polyphenol Extraction from Mangosteen Pericarp (Garcinia mangostana L.) and Its Application in Tea Product
Abstrak: Mangosteen pericarp has high polyphenol content that have disease preventive properties. The objective of this research was to utilize mangosteen pericarp from waste into added value and to evaluate stability on polyphenol content of green tea drink with mangosteen pericarp extract. Mangosteen pericarp was dried at 50ºC using tray dryer and the moisture content reached 7.43±0.10%. Dried pericarp was extracted with distilled water at 1:5 ratio (w/v). Green tea drink was added by mangosteen pericarp extract with seven different concentrations (0.1-0.7%). The extract then was infused into green tea drink which was mixed with three different concentrations of citric acid (0.06, 0.1, and 0.2%). The result showed that mangosteen pericarp extract had total phenolic compound (127.39±1.19 mg GAE/ml sample), DPPH (4491.63±67.52 μmol Trolox/ml sample), and FRAP (21,492±134.50 mM asorbic acid/ml sample). The maximum concentration of mangosteen pericarp extract in the tea drink that can be accepted by panelist was 0.4%. Tea with the highest concentration of citric acid (0.2%) had the lowest pH (2.79), the highest total phenolic compound (25.48±0.38 mg GAE/ml sample), DPPH (57862.08±1248.85 μmol Trolox/100 ml sample), and FRAP (5,681.11±33.39 mM asorbic acid/ml sample) compared with other treatments (p<0.05). Therefore, the study concluded that mangosteen pericarp extract can be applied in tea drink and provided more polyphenol content for the product. In addition, polyphenol was more stable in acid condition.
Keyword: Polyphenol, Antioxidant capacity, Mangosteen pericarp, Tea, Citric acid.

Judul: Kerusakan bantalan rel kereta api di wilaya inspeksi 2 jalan dan bangunan perusahaan jawatan kereta api (pjka),cirebon
Abstrak: Kereta api merupakan salah satu sarana angkutan yang murah, cepat dan aman serta dapat mengangkut barang dalam jumlah besar. Kelancaran operasi sarana angkutan tersebut banyak ditentukan oleh kondisi jalan rel, termasuk kondisi bantalannya. Dalam hal ini bantalan rel kereta api dapat dibuat dari kayu, logam, atau beton. Namun demikian kayu merupakan bahan yang paling banyak digunakan sebagai pembuat bantalan rel kereta api di berbagai negara. Kenyataan menunjukkan bahwa kayu yang digunakan sebagai bantalan rel kereta api sering mengalami berbagai macam kerusakan yang menyebabkan bantalan tidak berfungsi lagi atau menurun fungsinya. Di Indonesia, informasi mengenai jenis dan tingkat kerusakan bantalan kayu masih sangat kurang, pada- hal informasi tersebut sangat penting sebagai dasar pertimbangan dalam rangka pemeliharaan jalan kereta api, agar umur pakainya (service life) lebih lama.
Keyword: bantalan rel