Different concentrations of various browning inhibitors and a firming agent were
evaluated to prevent browning and softening of Bartlett, Bosc and Anjou pear slices
during cold storage at 2-4°C. Browning inhibition effect of Semperfresh, Snow Fresh
and cysteine were compared with that of 4-hexylresorcinol (4-HR). The effect of
ripeness on color and texture changes as well as the influence of storage temperature on
texture and color retention was investigated. 4-HR residual content under different
treatment conditions and its sensory properties were analyzed. 4-HR was an effective
browning inhibitor at concentration as low as 0.005% when combined with 0.5% ascorbic
acid (AA). Cysteine (0.5%) with 0.5% ascorbic acid (AA) effectively inhibited Anjou
and Bosc pear slice browning for 25 days and its sensory properties merit further study.
A combination of 1.0% AA and 1.0% calcium lactate prevented Anjou pear slices from
discoloration, but also caused tissue leaking and softening. Semperfresh and Snow Fresh
did not maintain flesh color effectively. 1.0% calcium lactate maintained slice firmness
at an acceptable level for 30 days when the average firmness of whole pears at slicing
was 49, 38 and 43 Newton (N) for Bartlett, Bosc and Anjou respectively. A storage
temperature of 0°C significantly retained better texture than the control of 2-4°C. Slices with acceptable texture and color were achieved by treatment with a solution of 0.01% 4-HR, 0.5% AA, and 1.0% calcium lactate for 2 min, vacuum packaging, and storage at 2-4°C for 30 days for Bartlett and Bosc, and 15 days for Anjou.
4-HR residual content increased with increasing dipping times and concentrations,
with the latter being the major factor. The 4-HR residual decreased with storage time for
all the treatments. Sensory tests indicated that panelists detected the overall differences
between 0.01% 4-HR treated samples and the controls for both Bartlett and Anjou pears
(P<0.01). There were no significant differences in preference between treated sample
and control for Anjou pears. / Graduation date: 1999
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26139 |
| Date | 25 September 1998 |
| Creators | Dong, Xiaoling |
| Contributors | Wrolstad, Ronald E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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