91C-34 |
Effect of air humidity on the quality of product during baking |
M. R. ZAREIFARD and M. Marcotte. Food Research and Development Center, Agriculture Canada, 3600 Casavant O., Ste. Hyacinthe, QC J2S 8E3, Canada Aside from oven temperature profile in baking, air characteristic including temperature, velocity and humidity are also influencing factors in industrial oven. Less work has been carried out with respect to the air humidity compared with the temperature and velocity of air. The objective of this study was to investigate the effect of air humidity on the quality of a cake. A typical vanilla cake was baked with a typical humidity profile ranging from 33 to 38 °C. Four other constant dew points were selected as 0, 25, 35 and 45 °C. Other characteristics of the profile such as oven, air temperature and air velocity were kept the same. A tray of 32 cakes was baked three times for each condition. The moisture content (MC) of the cake was evaluated using freshly baked samples. Other samples were randomly packed after cooling and stored for measurement of color, texture, and pH. It was observed that the most significant effect of the air humidity was on the overall appearance of the cake. Less humidity of the air was associated with darker cakes. The surface of the cake was more shiny and fragile with higher air humidity. There was not a significant effect on the texture and pH of the cake neither on the overall moisture content. By increasing the overall heat flux the final moisture content can be decreased for a given time to the desired point. However, the color of the product may not be acceptable. Since the consumer tolerance of MC and color of this specific product is very narrow from the quality control point of view, it is important to know that by adjusting the humidity of the air and the oven temperature simultaneously, both quality parameters of color and MC can be achieved.
Session 91C, Food Engineering: Food process engineering
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