Physico-chemical and sensory characteristics of freeze-dried and air-dehydrated yogurt foam

TY - JOUR

T1 - Physico-chemical and sensory characteristics of freeze-dried and air-dehydrated yogurt foam

AU - Carvalho, Maria Joao

AU - Pérez-Palacios, Trinidad

AU - Ruiz Carrascal, Jorge

PY - 2017/7/1

Y1 - 2017/7/1

N2 - Foaming followed by drying is a potential methodology for production of crispy snacks, especially at a restaurant or catering level. The influence of either freeze-drying or air-drying on the physicochemical (weight loss, moisture content, water activity, instrumental colour, instrumental texture), structural (Scanning Electron Microscopy –SEM-) and sensory features of whipped yogurt foam was studied. Air-dried (AD) yogurt foams showed significantly higher water activity values than freeze-dried (FD) ones. In the instrumental texture analysis, FD foams had a significant lower maximum force (hardness) and total number of fracture events than AD ones. For instrumental colour, FD foams showed higher values for lightness and lower for yellowness and browning index. SEM images evidenced that FD foams kept the foamed structure, while the structure of AD ones was totally collapsed. Sensory results indicated a higher degree of hardness and crispness in AD foams than in FD ones. Using different drying technologies, dried foams can be tuned to show completely different features.

AB - Foaming followed by drying is a potential methodology for production of crispy snacks, especially at a restaurant or catering level. The influence of either freeze-drying or air-drying on the physicochemical (weight loss, moisture content, water activity, instrumental colour, instrumental texture), structural (Scanning Electron Microscopy –SEM-) and sensory features of whipped yogurt foam was studied. Air-dried (AD) yogurt foams showed significantly higher water activity values than freeze-dried (FD) ones. In the instrumental texture analysis, FD foams had a significant lower maximum force (hardness) and total number of fracture events than AD ones. For instrumental colour, FD foams showed higher values for lightness and lower for yellowness and browning index. SEM images evidenced that FD foams kept the foamed structure, while the structure of AD ones was totally collapsed. Sensory results indicated a higher degree of hardness and crispness in AD foams than in FD ones. Using different drying technologies, dried foams can be tuned to show completely different features.

U2 - 10.1016/j.lwt.2017.02.039

DO - 10.1016/j.lwt.2017.02.039

M3 - Journal article

SN - 0023-6438

VL - 80

SP - 328

EP - 334

JO - LWT -Food Science and Technology

JF - LWT -Food Science and Technology

ER -