DESIGN, PRODUCTION AND CHARACTERIZATION OF NEW PROTEIN SWEETENERS

14th workshop on bioactive peptides, 12-14 giugno 2014

Ecotoxicological survey of MNEI and Y65R-MNEI proteins as new potential high-intensity sweeteners

Low-calorie sweeteners are widespread. They are routinely introduced into commonly consumed food such as diet sodas, cereals, and sugar-free desserts. Recent data revealed the presence in considerable quantities of some of these artificial sweeteners in water samples qualifying them as a class of potential new emerging contaminants. This study aimed at evaluating the ecotoxicity profile of MNEI and Y65R-MNEI, two engineered products derived from the natural protein monellin, employing representative test organism such as Daphnia magna, Ceriodaphnia dubia, and Raphidocelis subcapitata. Potential genotoxicity and mutagenicity effects on Salmonella typhimurium (strain TA97a, TA98, TA100, and TA1535) and Escherichia coli (strain WP2 pkM101) were evaluated. No genotoxicity effects were detected, whereas slight mutagenicity was highlighted by TA98 S. typhimurium. Ecotoxicity results evidenced effects approximately up to 14 and 20% with microalgae at 500 mg/L of MNEI and Y65R-MNEI, in that order. Macrophytes and crustaceans showed no significant effects. No median effective concentrations were determined. Overall, MNEI and Y65R-MNEI can be classified as not acutely toxic for the environment

A preliminary study on the application of natural sweet proteins in agar-based gels

Natural sweet proteins may be used as sugar replacer in simple liquid food systems but their applicability in more complex matrices has not been investigated yet. Gelling agent nature and texture characteristics as well as type and distribution of a stimulus in a gel could affect taste perception through inhibition or enhancement of tastants migration to the receptors. The mechanical, nonoral texture and time-intensity sweetness characteristics of sweet proteins MNEI and super sweet Y65R mutant, aspartame and saccharin added at a concentration iso-sweet to 40 g/L of sucrose in three agar gel concentrations (1%, 1.5%, and 2%) were evaluated. The results have shown that agar concentration and agar sweetener interaction particularly affect mechanical fracture stress and non oral hardness of the sweetened gels. Time intensity results illustrated that unlike in solution, the intensity of sweet taste in a gelled system over time decreases. Indeed, the behavior of the sweet proteins differed greatly in the gelled system compared to when they are in solutio