Teaching the Effect of Liming Concentration on Mechanical Characteristics of Cowhide Crackers for Senior High School Students.

The purpose of this study is to analyze the effect of liming concentration on the mechanical characteristics of cowhide crackers and to analyze the results of learning science about food mechanical characteristics related to the food chemical composition in high school students. The cowhide crackers production is carried out through the process of washing, liming, deliming, cutting, seasoning, drying, and frying the cowhide. The mechanical characteristics of the cowhide crackers were tested through the hardness and puncture strength test. Also, teaching and learning are conducted using experimental demonstration methods to 18 students through three stages, namely given a pretest; given an instructional video, and given posttest. The results of the research from cowhide crackers production with various concentrations show that the best cowhide crackers are obtained at a liming concentration of 93 grams because of the better level of crispiness than others. The mechanical properties change due to lime reduce the water and protein content in cowhide. The learning result about effect of food chemical composition on mechanical composition on cowhide crackers showed that experimental demonstration is effective in improving student learning outcomes because the average posttest score after video presentation is higher than pretest score. Furthermore, this research is important to analyze and inform the effectiveness of the use of instructional media in the science teaching and learning process. [ABSTRACT FROM AUTHOR]