UJI KINERJA MESIN PENGUKUS KERUPUK DAN ANALISIS PERUBAHAN SIFAT FISIK ADONAN KERUPUK SELAMA PROSES PENGUKUSAN

Steaming process is an important step in crackers manufacturing. This process is generally performed with less hygienic in small industries of crackers, because the equipment used do not meet the standards of food processing. The objective of this research is to design the hygienic dough crackers steamer with proper capacities as needed. Performance of equipment was evaluated by testing the uniformity of room and dough temperature during steaming and calculates the efficiency of energy use. Changes in the physical properties of dough such as the viscosity, density, and water content are evaluated to determine the success of steaming proccess. This research has been carried out by using 3 variations of capacity, i.e 20 kg, 40 kg, and 80 kg, and it was repeated 3 times for each capacity. During the steaming proccess, changes of room and dough temperature, density, and the water content of dough were observed with 10-minute time interval measurement. The changes viscosity of dough was observed by using Brookfield viscometer at 4 variation temperatures, i.e 29oC, 30oC, 35oC, and 40oC. The efficiency was calculated based on the amount of energy use for water heating to produce steams, the evaporation energy, the product heating energy and heat production from the fuel. Based on technical analysis, the distribution of room and dough temperatures on steaming machine were less homogeneous. It because of the distribution of vapor on steaming machine room was unhomogeneous. The result of efficiency analysis shows that value of ias was on a range between 45,96 � 53,46 %. Increased capacity up to 80 kg was improved the efficiency of energy use during steaming proccess. Characterization of crackers dough that performed based on viscosity suggest that it was an pseudoplastic fluid type, with n amount 0.3079 � 0.6651 and k 0.35 � 0.67 in average. Density of the crackers mixture is 1.1286 � 1.2095 gr/cm3 and water content is in a range of 39.158 � 42.5316 %