TY - JOUR
T1 - Effects of drying air temperature on the structural properties of garlic evaluated during drying
AU - López-Ortiz, A.
AU - Rodríguez-Ramírez, J.
AU - Méndez-Lagunas, L. L.
N1 - Funding Information:
The authors would like to thank the SIP and the COFAA of the Instituto Politécnico Nacional for the facilities provided to carry out this investigation, and their generous financial support of the project SIP-20110358 and scholarship from CONACyT.
PY - 2013/10/3
Y1 - 2013/10/3
N2 - Second order phase transitions may occur in foodstuffs during the convective drying process. These transitions involve physicochemical changes, which influence both structural properties and drying behavior. The aim of this study was to examine the effects of drying air temperature and the second order phase transition of garlic on the changes in particle density, apparent density, apparent porosity, effective diffusivity, and cracking produced during drying. Garlic slices were dehydrated at three air temperatures (40, 50, and 60°C). The moisture content (X), inside temperature (Ti), surface temperature (Ts), apparent (ρb) and particle (ρp) densities of garlic slices were measured during drying. Porosity (ε) was calculated based on the data collected for ρp and ρb. Glass transition temperatures (Tg) and micrographs were obtained for both raw and dehydrated garlic. A critical point in the intersection of Ti, Ts, and Tg was found; this point was identified as a second order phase transition. Diffusivity and slope changes in ρb, ρp, and ε with respect to moisture content were found to be related to this critical point. Experimental data for ρb, ρp, and ε was fitted to a nonlinear equation with three exponential terms with respect to moisture content, with an R2 > 0.85. Less dense products were found to be more porous, with more cracking, higher moisture diffusivity, and lower Tg at the end of the drying process.
AB - Second order phase transitions may occur in foodstuffs during the convective drying process. These transitions involve physicochemical changes, which influence both structural properties and drying behavior. The aim of this study was to examine the effects of drying air temperature and the second order phase transition of garlic on the changes in particle density, apparent density, apparent porosity, effective diffusivity, and cracking produced during drying. Garlic slices were dehydrated at three air temperatures (40, 50, and 60°C). The moisture content (X), inside temperature (Ti), surface temperature (Ts), apparent (ρb) and particle (ρp) densities of garlic slices were measured during drying. Porosity (ε) was calculated based on the data collected for ρp and ρb. Glass transition temperatures (Tg) and micrographs were obtained for both raw and dehydrated garlic. A critical point in the intersection of Ti, Ts, and Tg was found; this point was identified as a second order phase transition. Diffusivity and slope changes in ρb, ρp, and ε with respect to moisture content were found to be related to this critical point. Experimental data for ρb, ρp, and ε was fitted to a nonlinear equation with three exponential terms with respect to moisture content, with an R2 > 0.85. Less dense products were found to be more porous, with more cracking, higher moisture diffusivity, and lower Tg at the end of the drying process.
KW - Apparent density
KW - Apparent porosity
KW - Glass transition temperature
KW - Microstructure
KW - Particle density
UR - http://www.scopus.com/inward/record.url?scp=84871256887&partnerID=8YFLogxK
U2 - 10.1080/10942912.2011.599090
DO - 10.1080/10942912.2011.599090
M3 - Artículo
SN - 1094-2912
VL - 16
SP - 1516
EP - 1529
JO - International Journal of Food Properties
JF - International Journal of Food Properties
IS - 7
ER -