Evaluation And Design Of A Steam Cooking Process For Gakenkey Production

ABSTRACT 

Kenkey is a traditional fermented cornmeal product that is native to the coastal regions of Ghana. The traditional method of cooking Ga-kenkey takes a lot of time and features a high degree of variability in the sensory attributes of the kenkey balls. A major source of variability is due to the way the Ga-kenkey balls are arranged in the cooking pot in relation to the amount of water used in cooking. The objective of this study was to develop a cooking process that would reduce the cooking time for Ga-kenkey, as well as assure consistent product quality irrespective of location in the cooking pot. The study was in three parts: (a) a survey of Ga-kenkey processors to get insights on their processing techniques, challenges as well as best practices (b) The second part of the study involved the determination of cooking times, heat transfer profiles in the three layers of Ga-kenkey in the cooking pot, determination of quality attributes of Ga-kenkey that consumers rate, optimization of steaming process for Ga-kenkey production. (c) The third part of the study involved the design of a steam cooker for Ga-kenkey to assure uniform product quality irrespective of location in the cooking pot. The results showed that 98% of the respondents were females with a majority of them aged between 31-40 years. Most of the kenkey processors (66%) indicated that kenkey requires about 3 hours to cook. The most used technique by the kenkey processors (62%) was touching the kenkey ball to determine the degree of cook whiles increasing the intensity of the fire was the technique most used by processors (80%) in ensuring that the Ga-kenkey cooks fast. Difference in variability among the kenkey layers were observed for moisture, colour, texture, firmness and heat penetration. The bottom layers of kenkey had the highest values for moisture (66.4+0.7), lightness (58.37+0.10), degree of gelatinization (50.4+0.1) and rate of heat penetration but the least values for hardness (3.066+0.515) as well as the other texture parameters. Gakenkey from the bottom had the most acceptable preference score (1.73). Steam cooking of iii Ga-kenkey was affected by the steam cooking time and the presence or absence of corn husk in the steaming cage. The steam cooked Ga-kenkey reached its highest values for moisture (65.4+0.2) and degree of gelatinization (85.9+0.4) after 15 minutes of steam cooking. Ga-kenkey with corn husk in the steaming cage showed a lower rate of heat penetration compared to Ga-kenkeys without corn husk in the steaming cage. Ga-kenkey steam cooked for 5 minutes with husk had the most preferred sensory score (3.20). It is concluded that variability exists at the different layers of Ga-kenkey within the same cooking. Ga-kenkey from the bottom layer of the cooking pot is most preferred by consumers. Steam cooking with husk gives a better steam cooked Ga-kenkey. A stainless steel with thickness of 0.055 cm is required for designing a pressure cooker of volume 437,000cm3 for cooking 200 balls of kenkey at a pressure of 40 Kpa.