S294 - Participant Bio

Jeff Brecht

Title: Professor

Institution : Univ. of Florida, Gainesville, FL, Horticultural Sciences Dept.

Research Topics: Hot water pretreatments of whole fruit to reduce fresh-cut processing-related stress reactions; edible film coating on fruit to reduce surface drying and create MA in slices; effect of coatings on flavor volatile maintenance (with Baldwin); Processing and storage temperature effects on respiratory RQ changes and re-equilibration in vegetables following cutting.; using MCP to investigate role of wound ethylene in behavior of fresh-cut vegetables; investigating wound severity and temperature effects on putative Maillard reaction upon cooking in fresh-cut sweetcorn kernels.

Commodities : Mango, melting vs. nonmelting flesh peaches, sweetcorn, and romaine lettuce.

Instrumentation : Automatic titrimeter, Hunter Colorquest (tristimulus and scanning), Minolta Chromameter, Drill press-mounted effe-gi and Instron (for texture), GC’s for CO 2/O 2/ethylene/ethanol/acetaldehyde/ and sugars, spectrophotometer.

Suggestions for standardization of procedures:

• Sensory evaluation when you don’t have the facilities or time to use a trained panel (maybe better addressed by the Quality Subcommittee).
• Color and pigment measurements and analysis. I’m skeptical of a lot of the tristimulus data I see reported because my experience is that it is almost meaningless if more than one pigment is changing/involved (eg., if carotenoids are changing and browning is also occurring in some treatments, the hue and chroma values are not comparable). I also wonder if it’s possible to get usable data on individual pigments by scanning extracts containing a mixture of pigments. I’d like to avoid separation by chromatography, especially HPLC, which in my experience involves more time repairing than measuring.
• Who has method/instruments for CO 2/O 2 measurement that they are really happy with? Is there an easier, more repeatable method than GC for accurately measuring levels of a few tenths of a percent?

Phone: 352-392-1928, x213

e-mail: jkbrecht@ufl.edu

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