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Effect of Freezing Rate and Microwave Thawing on Texture and Microstructural Properties of Potato ( Solanum tuberosum )
Author(s) -
Phinney David M.,
Frelka John C.,
Wickramasinghe Anita,
Heldman Dennis R.
Publication year - 2017
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/1750-3841.13690
Subject(s) - texture (cosmology) , solanum tuberosum , microwave , air temperature , materials science , chemistry , carbon dioxide , food science , botany , meteorology , biology , physics , organic chemistry , quantum mechanics , artificial intelligence , computer science , image (mathematics)
Food freezing is a preservation process that works by lowering temperature while simultaneously decreasing water activity. It is accepted that although freezing preserves foods, it generally has a negative effect on textural quality. This research investigated the texture response of potatoes ( Solanum tuberosum ) as a function of time to freeze (defined as the time for the center temperature to reach −20 °C) and thawing process. Potatoes slices (6 mm) were blanched then frozen in an ethanol/carbon dioxide bath, a pilot scale high velocity air freezer (HVAF) and a still air freezer to achieve various times to freeze. Slices were stabilized at –20 °C and thawed by 2 methods; room temperature air and microwave. Afterwards, samples were allowed to come to room temperature prior to texture profile analysis (TPA). Results indicate a maximum texture loss of the potato was reached at a time to freeze of approximately 8 min (corresponding to the HVAF). The texture difference between room temperature and microwave thawing methods was not shown to be significant ( P = 0.05). SEM images showed the cellular structure of the potato in a HVAF to be similar to that of the still air freezer, validating that the matrix was maximally damaged in both conditions. This work created a continuous quality loss model for the potato as a function of time to freeze and showed no textural benefit to high velocity over still air freezing.