Impact of konjac glucomannan on ice cream-like properties

Abstract

Objective: This study was carried out to investigate the effect of using konjac fiber as alternative to fat and stabilizers replacer during making of free fat ice cream-like on its properties and its production cost. Methodology: Four concentrations (0.1, 0.3, 0.5 and 0.7%) of konjac glucomannan as fat and stabilizer replacer dietary fiber were used for making free fat ice cream-like compared with full fat ice cream (6% fat) as control. Control ice cream consists of 6% fat (derived from fresh cream 60% fat), 11% milk solids-not-fat (derived from cream, fluid skim milk and skim milk powder), 16% sucrose and 0.5% commercial stabilizer and emulsifying plus grade. Other free fat treatments made by the same method, which consists of other constituent’s ratios. All ice cream treatments were made and stored at -25°C. Results: The obtained results revealed that there were highly significant differences in the overrun and the product volume per 1 L mix among all konjac treatments and control, except T1 and T4 (0.1 and 0.7% konjac), it were insignificant. According to melting properties significant differences among all konjac treatments and control were found, except T2 and control (0.5% konjac), it was insignificant. Economically, T1 (0.1% konjac) and T2 (0.3% konjac) were much lower cost and more highly profitability (3.26 and 3.23%) than the control (1.28). Moreover, T1 (0.1% konjac) and T2 (0.3% konjac) were characterized with the highest sensory evaluation, compared with control, while T3 and T4 achieved less scores. Conclusion: Free fat, emulsifying and stabilizers ice cream-like as a functional dairy product, can be made by adding 0.3% konjac dietary fiber (T2) as the optimal concentration instead of full fat and commercial emulsifying and stabilizers with a decrease in the economic cost up to 41%.