Evaluation of Quality Characteristics and Intake of Acrylamide by Consumers of Roasted Coffee in Kenya

Abstract

Coffee farming is a vital sector in Kenya, supporting over 250,000 farmers. The study aimed to comprehensively assess both the quality characteristics and acrylamide intake of commonly consumed roasted coffee in Nairobi and Kiambu Counties. Therefore, there was need for exploration of roasting conditions for the coffee industry to optimize processes for an enhanced coffee experience. The study conducted a physicochemical characterization of coffee samples including among others, the concentrations ofacrylamide, iron, Zinc, Phosphorus, Calcium, Magnesium, potassium, sodium, and caffeine,survey on consumers' awareness of acrylamides, influence of temperature-time combinations on acrylamide concentration and Sensory analysis to evaluate overall acceptability and shelf life stability. The data was analysed using the statistical software R. The Analysis of Variance (ANOVA) revealed statistically significant differences (p<0.05) in acrylamide concentration, calcium content, magnesium content, and caffeine concentration among the selected coffee brands. However, no significant differences (p > 0.05) were observed for the other characteristics, In assessment consumers' awareness of acrylamides, the results showthat 12.8% respondents were aware of the link between acrylamides and foodborne illnesses, while 87.2%were not aware. On the influence of temperature-time combinations, three roasting temperatures (180, 200 and 220°C), each having three-time combinations (5, 10 and 15 minutes) were used. There were significant (p<0.05) changes in acrylamide levels across the temperature time combinations, with the mean acrylamide concentrations (μg/kgvarying in Arabica coffee, ranging from 5.7 at 220oC/15min to 49.7 at 180°C.5mins (49.68 ± 2.07) The linear model indicated a high significant (p<0.05) relationship between roasting conditions and acrylamide concentration. In Robusta variety, mean acrylamide concentrations ranged ranging from 7.03 ± 2.44 at 220oC/10min to 51.59 at 180°C.5mins The results revealed a significant effect (p<0.05) of temperature-time combinations on acrylamide concentration. Sensory analysis was conducted to evaluate parameters including overall acceptability using independent panelists. Higher roasting temperatures led to superior sensory scores and acceptability, with the lowest at 180°C.5mins (3.46 ± 1.55). to highest at 220°C.15mins (4.56 ± 1.57).Shelf-life analysis of the coffee emphasized the crucial role of proper storage conditions in maintaining the freshness and sensory quality of coffee throughout its shelf xvi life. In conclusion, this study revealed significance both quality characteristics and acrylamide intake and there is need for quality control measures in the coffee industry to ensure consistent quality and safety. The significant impact of roasting conditions on acrylamide concentration and the potential benefits of higher temperatures is evident. The implementation of robust quality control measures is recommended, alongside further exploration of the health impact of acrylamides, consumer awareness and development of effective monitoring methods. Keywords: Coffee, Consumption, Acrylamide, Roasting, Monitoring