Impingement drying for preparing dried apple pomace flour and its fortification in bakery and meat products

This study aimed to evaluate impingement drying (ID) as a rapid drying method to dry wet apple pomace (WAP) and to investigate the fortification of dried apple pomace flour (APF) or WAP in bakery and meat products. ID at similar to 110 A degrees C reduced the moisture content of apple pomace from 80 % (wet basis) to 4.5 % within 3 h, compared with 24 h to 2.2 % using 40 A degrees C forced-air drying and similar to 60 h to 2.3 % using freeze drying. Furthermore, ID enhanced the extractable phenolic compounds, allowing for a 58 % increase in total phenolic content (TPC) compared with wet pomace, a 110 % and 83 % higher than TPC in forced-air dried and freeze dried samples, respectively. The 15-20 % APF-fortified cookies were found to be similar to 44-59 % softer, similar to 30 % more chewy, and similar to 14 % moister than those of the control. WAP-fortified meat products had significantly higher dietary fiber content (0.7-1.8 % vs. 0.1-0.2 % in control) and radical scavenging activity than that of the control. These results suggest that impingement drying is a fast and effective method for preparing dried APF with highly retained bioactive compounds, and apple pomace fortified products maintained or even had improved quality.