Avaliação das propriedades físico-químicas do pulmão suíno desidratado em air-fryer:: potencial uso como ingrediente em alimentos para animais de estimação (pet foods)

Abstract

The present study evaluated the feasibility of the air-frying technique in dehydrating pork lungs, aiming to utilize this raw material, which has high nutritional value and is currently underutilized, as an ingredient in pet food. To achieve this, the influence of two convective drying temperatures in the air-fryer (90 and 150°C) on the characteristics of dried pork lungs was investigated. To reach a 70% humidity level (on a wet basis) at 90°C, a drying time of 60 minutes was required, while at 150°C, the time to reach the same humidity was 15 minutes. In the kinetics at 90°C, it started with 5.75 g of water/g of dry solids and ended with 0.10 g of water/g of dry solids. In the kinetics at 150°C, it started with 5.31 g of water/g of dry solids and ended with 0.40 g of water/g of dry solids. After drying, the determined humidity was 1.89% (90°C) and 0.9% (150°C) on a wet basis, hygroscopicity of 12.96% and 12.37% (90 and 150°C, respectively), water activity of 0.302 (90°C) and 0.323 (150°C), bulk density of 475.32 Kg/m³ and 580.24 Kg/m³ (90 and 150°C, respectively). A change in color was also noted, where the dried sample deviated in color from the fresh lung with an overall color difference of 30 on the CieLab scale. The values of the colorimetric parameters found for drying at both temperatures were close: L*90°C = 14.96; a*90°C = 3.76; b*90°C = 7.28 and L*150°C = 14.11; a*150°C = 3.65; b*150°C = 7.28. With the granulometric analysis, a Sauter diameter of approximately 0.17 mm was obtained. These results showed that the air-frying method proved to be effective for drying pork lungs, achieving high temperatures and reducing the operation time from 150 minutes (90°C) to 35 minutes (150°C). Thus, the powder obtained by this method has potential application in the food and pet food industries.