Abstract Bose is a traditional Indonesian food made from a mixture of corn grits and beans that are cooked for a long time. Bose has the potential to be processed into instant food. This study aims to examine the effect of adding several types of beans (soybeans, mungbeans, and peanuts) and the length of soaking time (2, 9, and 16 hours) on the physicochemical and sensory properties of instant Bose. A completely randomized design was used in this study. Instant Bose with the addition of soybeans had the highest protein and iron content, while instant Bose with the mungbeans addition had the highest carbohydrate content. The addition of peanuts in instant Bose resulted the highest fat content, the longest rehydration time and the highest hardness compared to the other treatments. The longer soaking time decreased the nutritional value of instant Bose, speeded up rehydration time, increased swelling volume, and decreased hardness. Based on the sensory analysis, instant Bose made from a mixture of soybeans with the soaking time of 16 hours showed the highest preference. This kind of Bose contained 15.32% protein, 4.85% fat, and 1.85% iron with a rehydration time of 8.38 minutes and a hardness of 664.24 N.

Abstract The presence of calcium oxalate is the major obstacle in flour processing of Amorphophallus muelleri tuber since the calcium oxalate can induce skin irritation and is harmful to kidneys. The development of a rapid analytical method to detect calcium oxalate in Amorphophallus flour is required. This research was intended to evaluate the use of some analytical methods (FTIR, SEM-EDS, XRD, XRF, and titration methods) in calcium oxalate detection in Amorphophallus muelleri flour prepared from different treatments (soaking in water (W), solution of sodium bisulfite 1000 ppm (B), solution of sodium chloride salt 3% (S), solution of sodium bisulfite 1000 ppm and sodium chloride salt 3% (BS)). Results showed that the presence of oxalate in Amorphophallus flour can be detected in the FTIR spectra from the C=O group at a wavenumber of 1610 cm-1. SEM images confirmed that calcium oxalate in Amorphophallus flour existed as raphide crystals in which their quantity can be estimated by the EDS feature of SEM. The presence of calcium oxalate crystals in Amorphophallus flour can be differentiated from other salts present in the flour by XRD. XRF can be used as a rapid analytical tool to detect the presence of calcium oxalate in Amorphophallus flour. The potassium permanganate titration technique can be used as a reference method for other rapid analytical methods in detecting calcium oxalate in Amorphophallus flour.

Abstract The development of banana-based snack bars that fulfill the nutritional requirement for toddlers is required. In this study, we analyzed the effects of different concentrations of banana puree, banana flour and potato starch on the characteristics of inulin, dietary fiber, protein, and potassium as well as the hardness of banana bars using response surface methodology. In total, 14 experimental models were generated using a simplex lattice design. Results demonstrated that the quadratic model appeared to be the best fitting model for assessing dietary fiber and hardness response of banana bars; meanwhile, the linear model was found to be the best fitting model for assessing protein and potassium response, and the special cubic model was best fitted for assessing inulin response. Results of the optimization process suggested that banana bars prepared using 20% banana puree, 20.50% banana flour and 9.50% potato starch was the best solution for this combination of variables, with a desirability value of 0.923.

Abstract Extraction and coagulation techniques are essential stages in tofu production. This research studies the effect of extraction and coagulation techniques on physicochemical properties of soybean extract, soy pulp, and tofu. This study applies three extraction techniques, namely manual heat extraction, manual cold extraction, and cold extraction using mechanical devices. They used nigari coagulant. As a control, the process of making tofu follows the procedure process as in the small industry of tofu with whey coagulant. The measurement of material mass balance is done at each stage of the process, while the evaluation of the product includes water content, ash, protein, fat, magnesium, and texture. The experimental results show that an increase in the ratio of water to soybeans and the increase of extraction temperature can increase the amount of extracted protein. The coagulation using nigari produced 22.18 kg tofu in hot extraction treatment, 19.61 kg in cold extraction and 17.60 kg in machine extraction. The control treatment produced 36.8 kg of tofu. The water content in the control treatment was higher than the other three treatments. Protein levels, magnesium levels, hardness and chewing power for treatment with nigari coagulant were significantly higher than those with whey.