Modeling the Drying Behavior of Unsalted and Salted Catfish (A rius sp.) Slabs

Abstract

The effect of air temperature on the drying behavior of unsalted and salted catfish (Arius sp.) slabs (10 × 5 × 1 cm) was investigated. Drying at 30 and 40C occurred in both the constant rate and falling rate periods, while drying at 50 and 60C occurred in the falling rate period only. Drying rate constants increased from 0.0474 to 0.2352 1/h for unsalted slabs and from 0.0819 to 0.3038 1/h for salted slabs as drying temperature increased from 30 to 60C. Diffusion coefficients increased from 1.61 to 5.79 × 10 -10 m 2 /s in unsalted slabs and from 2.31 to 8.55 × 10 -10 m 2 /s in salted slabs. Six mathematical thin layer drying models were applied to the moisture ratio data and the two-term model gave the best prediction. The rehydration ratio averaged 1.20 and 1.22 for unsalted and salted slabs, respectively. A drying temperature of 50C for 8 h is recommended. PRACTICAL APPLICATIONSDrying of both fresh and salted fish continues to be of importance in many developing countries as a preservation method. In the Caribbean region, dried, salted fish remains a very popular part of the cuisine due to the flavor, and many imported brands dominate the supermarket shelves due to the poor inferior sensory characteristics and keeping quality of locally produced salted fish. Improvement in the drying methods for local and regional fish types requires a better understanding of the drying mechanisms and how drying is affected by various controllable factors. The present work seeks to investigate the drying of locally available catfish (Arius sp.). It focuses on the interaction between process conditions, drying kinetics and product quality to arrive at clear conclusions which can facilitate the improved production of dried, salted catfish fillets and which can be beneficial to the industry.for animal feeding (Waterman 1976;Fellows and Hampton 1992). In order to prevent spoilage, the moisture content of fish needs to be reduced to 25% or lower depending upon the oiliness of the fish (Fellows and Hampton 1992). Salting of fish before drying has been traditionally used to improve the shelf life and impart flavor. Salted dried fish having moisture contents in the range of 35-40% (wb) and salt contents in the range of 15-20% (wb) will have a minimum good quality storage life of 3 weeks to 2 months (FAO 1981).The main considerations in any drying process are to produce a dried product in the shortest possible time, with the lowest negative impact on product quality, using the

Effects of Different Drying Methods on Drying Kinetics, Microstructure, Color, and the Rehydration Ratio of Minced Meat

“…Equation (3) uses an analytical solution and neglecting shrinkage, constant temperature, and diffusion contribution, as well as uniform starting moisture distribution. Equation (4) [21]:MR=8π2true∑n=0∞1(2n+1)2exp(−(2n+1)2π2Defft4L2),where, MR is the moisture ratio, t drying time, D eff effective diffusivity (m 2 /s), n is the number of terms of the Fourier series, and L slices are half slab thickness (m). For long drying times Equation (4) can be further simplified in Equation (5) [22]:MR=8π2exp[−π2Defft4L2],…”

Fluidized Bed Drying of Pumpkin (Cucurbita sp.) Seeds

“…The analysis of the drying data was done as previously described [25,26]. Drying curves (moisture content g H 2 O/g DM versus time t) and drying rate curves (rate g H 2 O/g DM.min versus average moisture content g H 2 O/g DM) were constructed.…”

Thin‐layer drying behavior of West Indian lemongrass (Cymbopogan citratus) leaves

“…The sample weight data (g) at the end of the drying process and the moisture content of the final dried sample were used to back‐calculate the moisture content of the respective samples at each point during the drying process (Mujaffar & Sankat, , ). The drying rate constant ( k ) was determined from a plot of ln MR versus time ( t ) based on Equation and the effective moisture diffusivity ( D eff ) values calculated using Equation with the thickness of the leaves (2 L ) being 0.5 cm.…”

“…The sample weight data (g) at the end of the drying process and the moisture content of the final dried sample were used to backcalculate the moisture content of the respective samples at each point during the drying process (Mujaffar & Sankat, 2005, 2015.…”