Maintaining the structural integrity of cell walls
largely determines the texture of fruit products during
freezing processes. Strawberries undergo major textural
changes when frozen, and varietal differences in quality
after thawing are not readily predicted from mechanical
and sensory testing of the fresh fruit. The objectives of
this study were to develop a quantitative sensory texture
profile of three strawberry varieties, individually quick
frozen (IQF), to determine differences in cell wall
composition and structure, and to relate the sensory and
compositional profiles to differences in instrumental
values of firmness.
Intervarietal differences in IQF strawberries of
Benton, Totem, and Selva varieties were examined and a
summary of major findings follows.
Drip-loss measurements, and work-of-compression on
thawed berries were correlated to sensory ratings. Puree
viscosity was highest in Selva samples, lowest in Bentons and shows potential as a screening test for strawberry
cultivars. Firmness of thawed, whole Selva berries was
rated 4x and 2x as compared to Bentons and Totems,
respectively, via sensory profile evaluation with magnitude
estimation scaling. Fractionation of fruit cell walls
showed Selva had the highest percentages of
acetone-insoluble solids. Total pectin content and
absolute weight percentages of uronic acids and neutral
sugars did not show major differences. Ratios of: 1)
uronic acids to neutral sugars, 2) uronic acids to
rhamnose, and 3) neutral sugars to rhamnose followed trends
of increasing with varietal firmness in water-soluble
polysaccharides (WSP) and decreasing in chelator-soluble
polysaccharides (CSP). Ratios of galactose to arabinose
decreased with increasing firmness scores in WSP and
increased in CSP. Selva had the highest amount of high
molecular-weight polymers in water-soluble and
chelator-soluble polysaccharides. / Graduation date: 1986
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27536 |
| Date | 11 March 1986 |
| Creators | Buerger, Michelle Carlene |
| Contributors | Wrolstad, Ronald E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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