30B-3 |
Objective quality assessment of CA stored sliced zucchini (Cucurbita pepo L. cv. Elite) using electronic nose, machine vision and instron. |
N. DEMIR1, M. O. Balaban1, and G. S. Riad2. (1) Food Science and Human Nutrition Department, University of Florida, P.O. Box 110370, Gainesville, FL 32611, (2) Horticultural Sciences Department, University of Florida, P.O. Box 110690, Gainesville, FL 32611-0690 Biochemical changes and microbial spoilage in fresh-cut products result in color, texture and flavor changes. Controlled atmosphere (CA) packaging is a method to extend the product's shelf life. Electronic nose, machine vision and Instron provide objective quality evaluation. The objective was to measure quality changes in CA stored sliced zucchini using e-nose, machine vision and Instron, and to correlate e-nose, color, and texture data with sensory and microbial results. Sliced zucchini were put into plastic containers (~200g/container), and flushed with 2 different CA compositions (2%O2+7%CO2 and 2%O2+15%CO2, balance being N2) and air as control. Samples were stored up to12 days (10°C, RH=95%) and evaluated every other day using e-nose, machine vision and Instron. Sensory parameters were evaluated by panelists. Aerobic microbial counts were performed. Color and e-nose data were evaluated by Discriminant Function Analysis (DFA). Treatments and storage times were used as grouping variables. Correct classification rates (CCR) were calculated. Cross validation was performed. Average L a b values and % color changes showed that the best color preservation was with15%CO2treatment. CCR for color data were 100%,100%,96% for air,7%CO2 and15%CO2 treatments, respectively. DFA of e-nose data for storage time gave CCR of 100%,100%,100% for gas concentrations. DFA analysis of storage time by combined treatments gave CCR of 91%.Cross-validation for different treatments and storage times were calculated. Results showed that CA was significant in suppressing microbial growth and had significant affect on browning, discoloration, hardness, crispness, off-odor and zucchini aroma (p>0.0001). Correlations between shear, hardness (R2=0.85) and crispness (R2=0.83) were analyzed. E-nose, color machine vision and Instron systems can rapidly and quantatively determine quality of CA stored sliced zucchini. This is a step towards objective determination of overall quality of foods.
Session 30B, Fruit & Vegetable Products: Sensory, Product Development, Fresh-Cut, and Storage
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