Air impingement to reduce thawing time of chicken fingers for food service

Air impingement (AI) thawing was studied as alternative to time-consuming thawing, conventionally performed in refrigerators for food service. Chicken fingers’ bags (200 g), surrounded by Tylose to simulate a food service grid load, were thawed in an AI prototype. Nine combinations of process parameters (distance food to nozzles, air speed, air temperature, number of stages, and stage durations) identified by genetic algorithm optimization were applied. The optimization aimed at minimizing thawing time, food overheating (above 0℃), and food temperature unevenness. Samples were assessed for thawing time (to 0℃), thawing loss, water-holding capacity, firmness, microstructure, and FTIR spectra. AI allowed up to 85% thawing time reduction compared to refrigerator (4 ± 1℃), while thawing loss, water-holding capacity, and firmness were not significantly different (p >.05). Histological analysis and FTIR spectra indicated AI as an interesting technology to preserve tissue structure. Novelty impact statement: In this paper, air impingement (AI) is applied for the first time to quickly thaw chicken fingers while avoiding overheating (above 0℃) and structural modification of meat. These results support air impingement as a valid alternative to refrigeration thawing, commonly applied for food preparation in food service.