Effect of Pre-Frying Treatments on Moisture Content, Effective Moisture Diffusivity and Oil Uptake Content of Deep-Fat Fried Shitake Mushrooms (Lentinus edodes)

Abstract

Oil absorption of foods is a significant problem found in deep-fat frying products. Fried products affect commonly health status such as obesity, cardiovascular disease, etc. Therefore, pre-frying treatment is often used to decrease partial moisture content in foods prior to frying in order to reduce oil absorption of products during frying. In the present study, pre-frying processes consisted of 3 methods: (i) drying for 30 min with a hot air oven at 130 °C, (ii) freezing for 24 h with a freezer at -18 °C, and (iii) drying for 30 min at 130 °C then freezing for 24 h at -18 °C. The results indicated that water removal with a combination of drying at 130 °C for 30 min and freezing at -18 °C for 24 h prior to deep-fat frying provided a decrease in moisture ratio causing low moisture content and oil uptake content in deep-fat frying mushroom products. The products had high scores of overall acceptability (7.07±1.53). The result indicated that oil uptake content of mushrooms using incorporated methods as mentioned above decreased with increasing temperature. The effective moisture diffusivity (D_eff) was also higher than that of mushrooms using the other methods at all frying temperatures.