39B-15

N. DEMIR, M. O. Balaban, and F. Erdogdu. Food Science and Human Nutrition Department, University of Florida, Gainesville, FL 32611

Enzymatic browning in processed fruits and vegetables has been controlled by sulfites, ascorbic acid, 4-Hexyl resorcinol, honey, and their combinations. Determination of color changes by conventional methods requires extensive sample preparation, use of chemicals and instruments, and long experimental times. Color analysis using machine vision can reduce experimental time and sample preparation, requires no chemicals and can also give information when color and surface is not uniform.

The objective of this study was to measure, with a computer vision system, the color changes of banana slices dipped in different solutions and air dried.

Bananas (Musa acuminata) were sliced (0.5 cm in thickness) and immediately dipped in the following solutions for 1.5 hrs: 30, 60 and 200ppm Sodium Meta Bisulfate (SMB); 0.5 and 1% Ascorbic acid (AA); 50 and 100 ppm 4-Hexyl resorcinol (4HR); 0.5% citric acid, and combinations of water-honey (1:1); water-sugar (1:1); 200ppm SMB+0.01% 4HR+0.75%CA; 0.1%CA+ 50ppm 4HR; 200ppm SMB + %0.3CA; 0.1% CA+50ppm 4HR; 200ppm SMB+water-honey (1:1). Dipping in pure water was used as control. Video images were captured before and after dipping, and analyzed using the software. The changes in the 512 segment RGB color information over time were measured.

Average L a b values showed that the best color preservation was with water+honey (1:1). Sulfites bleached the surface, resulting in unattractive colors, alone or in combination with other chemicals. 4HR resulted in colors close to the control. Ascorbic acid formed pinkish colors (Strecker degradation). Rates of reduction in lighter colors as well as increases in darker colors will be presented.

This method can rapidly and quantatively determine browning rates, and determine most effective anti-browning solutions. The disappearance of lighter colors as well as the formation of darker colors can be analyzed in non-uniform colors and surfaces.