17G-25 |
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A. Valdez-Fragoso, J. R. Pérez-Carrillo, M. Y. Leal-Ramos, L. D. ARGÜELLES PIÑA, M. L. Ballinas-Casarrubias, and H. Mújica-Paz. Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua, Av. Universidad S/N, Chihuahua, 31170, Mexico Thermal and physical properties of fresh jalapeño pepper are of practical utility in commercial transactions, in the design of cleaning, grading and processing equipment, and in optimization of thermal processing. This study was conducted to determine geometric dimensions, bulk density, apparent density, thermal conductivity, thermal diffusivity, and heat capacity of fresh jalapeño pepper (Capsicum annuum L., var. Tula). The geometric dimensions were determined by measuring length, major, intermediate and minor diameter with a vernier caliper. Surface area of pepper was calculated by Baugerod’s method. Bulk density, apparent density, and inter-particle porosity were determined by standard methods. Thermal conductivity and thermal diffusivity were measured with a single needle probe (KD2, Decagon) and heat capacity with a differential scanning calorimeter (Netzscht-200PC). Pepper samples were also tested for firmness by puncture test (TA-XT2) and color (Miniscan, Hunter Lab). The mean values of length, major, intermediate and minor diameter were 6.3 ± 0.6, 2.5± 0.23, 2.6 ± 0.2, 1.9 ± 0.2, respectively. Surface area of jalapeño pepper was 17.2 cm2, in average. Bulk density varied between 295 and 350 kg/m3 and apparent density between 959 and 967 kg/m3. Inter-particle porosity ranged between 0.61 to 0.63. Thermal conductivity and thermal diffusivity were found to be 0.494 ± 0.043 W/m ºC and 0.118 ± 0.011 mm2/s, respectively. Heat capacity varied from 4.24 to 4.48 J/kg ºC in the range of 26-54 ºC. The mean values of L*(19.5 ± 2.6), a* (-7.85 ± 1.4), and b* (9.9 ± 3.7) were determined. The maximum force to penetrate fresh pepper tissue was 1432 ± 241 grams. Objective properties and quality characteristics of jalapeño pepper were obtained for quality control and processing applications.
Session 17G, Food Engineering: Physical, chemical and electrical properties
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