EFFICIENCY ABOUT THE MAINTENANCE OF COLORING MINIMALLY PROCESSED POTATOES WITH ACTIVE COATING USING SURFACE AND RESPONSE METHODOLOGY

Nowadays, there is an increasing demand for practical foods that require less preparation time or are ready for consumption. Following this trend, minimally processed potatoes (MPP) may be convenient due to its preparation time, shipping losses and storage space. However, this product is susceptible to enzymatic browning. Since food is typically felt by visual perception, this study aimed to evaluate the maintenance of vegetable coloration with an active coating. The potatoes were purchased from Volta Redonda (RJ), sanitized, cut into a stick shape, wrapped in active whey protein-based coating (WPC) incorporated with antioxidants (ascorbic acid (AA) / citric acid (CA)), being stored in polypropylene pots covered with PVC film, at 10 ° C. Surface and Response Methodology (SRM) was used, with Central Composite: Orthogonal as the model for experimental design, where the factors Time (days), AC concentration (% m / m) and AA concentration (% m / m) ) were evaluated. The response variables evaluated were the staining parameters: L*a*b*, Chroma, Browning Index (BI), Color Index (CI), Hue-Angle and Total Color Difference (ΔE). The staining parameters were analyzed by colorimeter (Minolta CM-5-ID). Altogether, 23 experimental trials were performed using 0%, 1% and 2% for AA; 0%, 1.5% and 3% for AC and 0, 5 and 10 days of storage. By the SRM, equations were adjusted according to the influence of each factor. For L *, b *, Chroma and BI, only time influenced potato color, while IC, ΔE, and Hue-Angle showed influence of Time, AA and AC. While a* proved to be influenced by time and CA, where the variation up to 1.5% was optimal up to 5 days of storage. Therefore, MPP with active coating (1.5% AC and 0% AA) demonstrated acceptable visual perception for up to 5 days of storage through SRM.