The objective of this research was to determine the effect of Uncaria gambir Roxb filtrate addition on functional edible films based on corn starch. This study used a Factorial Randomized Completely Design with two treatments and three replication for each treatment. The first factor was the concentration of Uncaria gambir Roxb filtrate (20%, 30%, 40%) and the second factor was the mixing separation method (filtering, centrifuge 1000 rpm, centrifuge 2000 rpm). The results showed that treatment of Uncaria gambir Roxb filtrate and the mixing separation method had significant effect on thickness, elongation percentage, water vapour transmission rate, antioxidant and antibacterial activities of edible film. The interaction of Uncaria gambir Roxb filtrate and the mixing separation method had significant effect on water vapour transmission rate. The best treatment based on edible film characteristics was 40% concentration of Uncaria gambir Roxb filtrate and the mixed separation method of 1000 rpm centrifugation.

The objectives of this research were to study the effect of fish and flour formulation as well as centre point temperature on the thermal diffusivity and shelf life of pempek lenjer. The parameters observed were the temperature of pempek at several position: i.e. (r 0 ) = 0 cm, r 1 = 1 cm, r 2 = 2 cm, cooking time, change of textural value, total volatile nitrogen and total microbes of pempek during storage. Data temperature distribution was analyzed by using diffusivity at center point model, and random diffusivity models through computer program of Engineering Equation Solver (EES) Ver 8.91. The shelf life data was analyzed by using linear regression to determine the relationship between storage time and the measured variables which was followed by calculating using Arrhenius method to compare the decrease of pempek lenjer quality. The results showed that thermal diffusivity coefficient of pempek lenjer for formula 1 was in the range of 0.321 to 1.515 .10 -7 m 2 /s, for formula 2 was in the range of 0.297 to 1.389.10 -7 m 2 /s, for formula 3 was in the range of 0.378 to 1.471 . 10 -7 m 2 /s and for formula 4 was in the range of 0.2778 to 1.620.10 -7 m 2 /s.The research results showedthat longerstorage time results in lower values of texture, but produced higher value of total volatile nitrogen and total microbes. The lowest Eavaluefrom the measured variablewas totalmicrobes which can be used as the main parameter of deterioration for pempek lenjer during storage. The shelf life of pempek lenjer based on total microbes value was in the range of 27 to 33 hours Abstrak Tujuan penelitian inimempelajari pengaruh formula ikan dan tepung, serta suhu terhadap difusivitas panas dan umur simpan pempek lenjer. Variabel yang diukur adalah suhu sampel pempek pada titik pusat (r 0 ) = 0 cm, r 1 = 1 cm, r 2 = 2 cm,lama pemasakan pempek, perubahan nilai tekstur, total volatil nitrogen dan total mikroba selama penyimpanan. Data distribusi suhudianalisis menggunakan model difusivitas panas pada titik sebarang, dan model difusivitas panas pada titik pusat dengan program computer Engineering Equation Solver (EES) Ver 8.91. Data umur simpan dianalisismenggunakan regresi linier untuk melihat hubungan antara lama penyimpanan dengan tekstur, total volatil nitrogen, dan total mikroba yang diukur, dan dilanjutkan dengan perhitungan cara Arrhenius untuk membandingkan penurunan mutu pempek lenjer. Hasil penelitian menunjukkan bahwa koefisien difusivitas panas pempek lenjer pada formula 1 adalah interval 0,321 -1,515. 10 -7 m 2 /s, pada formula 2 adalah 0,297 -1,389.10 -7 m 2 /s, pada formula 3 adalah 0,378 -1,471. 10 -7 m 2 /s, dan formula 4 adalah 0,2778 -1,620.10 -7 m 2 /s.Semakin lama penyimpanan, tekstur semakin menurun, tetapi total volatil nitrogen dan total mikroba semakin meningkat. Nilai Ea terendah pada total mikroba, sehingga dapat dijadikan parameter kunci kerusakan pempek lenjer selama penyimpanan. Umur simpan pempek "lenjer" berdasarkan total mikroba selama 27 -33 jam.Kata kunci : difusivitas panas, umur simpan, pempek

ABSTRAKPenelitian ini bertujuan untuk mengetahui karakteristik edible film komposit berbasis pati jagung yang dinkorporasikan dengan minyak sawit dan Tween 20. Rancangan penelitian yang digunakan adalah rancangan acak lengkap faktorial (RALF) dengan dua faktor perlakuan yang setiap perlakuannya diulang sebanyak tiga kali. Faktor pertama adalah konsentrasi minyak sawit (1%; 2%; 3%) v/v dan faktor kedua adalah konsentrasi Tween 20 (0,5%; 1,0%; 1,5%) v/v. ABSTRACTThe aim of this research was to determine the characteristics of composite edible film based on corn starch with the addition of palm oil and Tween 20. This study used a Factorial Randomized Completely Design with two treatments and three replications for each treatment. The first factor was the concentration of palm oil (1%; 2%; 3%) v/v (1; 2: and 3 %v/v), the second factor was the concentration of Tween 20 (0.5%; 1.0%; 1.5%)v/v. The observed parameters includes water vapour transmission rate, water content, thickness, compressive strength, elongation percentage, dan solubility. The results showed that palm oil addition had significant effect on thickness, elongation percentage, water vapour transmission rate, water content, the addition of Tween 20 had significant effect on the elongation percentage and compressive strength. The interaction between palm oil and the Tween 20 addition had significant effect on thickness, elongation percentage, and solubility. The optimum treatment based on physical and chemical charateristics of composite edible film was palm oil concentration of 1% and Tween 20 of 1% with thickness 0.23mm, elongation percentage 21.67%, solubility 89.9%, water vapour transmission rate 16.80%, water content 19.28%, and compressive strength 5.53gf.

Duku (Lansium domesticum), tropical exotic fruit, was successfully preserved by drying using exposure to infrared radiation emitters. Response surface methodology (RSM) is used to optimize independent variables (IRE distance of 6 cm and 10 cm, IRE temperature of 200 °C, 300 °C, 400 °C, and IRE exposure time of 50 s, 60 s, 70 s, and to produce response variables (weight loss, fruit firmness, titratable acidity, total soluble solid, and browning index).  It could be concluded from the optimization performed that drying duku skin in a whole fruit by exposing the fruit to the infrared emitter resulted in a duku fruit with a relatively good physical and chemical conditions and still be consumable. The IRE distance of 6 cm gave a desirability value of 0.80 while the IRE distance of 10 cm gave a desirability value of 0.92 however the IRE distance of 6 cm gave a better storage time.  The IRE distance of 6 cm has an optimum value of weight loss 2.2%; optimum value of fruit firmness of 40.92 N; optimum value of total soluble solid of 17.48 brix; optimum value of titratable acidity of 0.33%; and optimum value of browning index of 0.9. The fitting model base on RSM resulted from this research indicated that this study could be used as the basis for alternative process in food processing of duku but still need further research to increase the shelf life and a better result in the chemical and physical characteristics of duku.

Infrared radiation has a potential for drying agricultural commodities such as the peel of duku. Drying of duku's peel in a whole duku using infrared radiation could become an effective method to eliminate the water on the peel but not in the flesh and could increase the shelf life of duku. The objective of this study was to investigate the potential of using infrared radiation for drying the peel of duku which would increase the shelf life of duku during storage. Duku's peel drying process was achieved by means of heating duku using a pairs of electric infrared emitters (IRE) facing each other with the emitter distance of 6 cm and 10 cm for a relatively short heating time of 50, 60, 70 and 80 seconds and after that stored at a cool room at the temperature of 15 °C for the length of one month. During storage, the physical and chemical changes of duku were then evaluated. It was found that the weight loss, fruit firmness, and total soluble solid of duku dried by means of exposing to Infra Red Emitter (IRE) were significantly affected by the distance of IRE, the temperature of IRE and the time exposed to IRE. However the titratable acidity only affected significantly by the distance of IRE. There were no significantly changes of browning index on duku during drying by exposing to IRE and while stored up to 25 th day of storage. Drying duku by exposing it to IRE show a slightly better shelf life than the previous work.