Dados do Trabalho

Título

SORVETE PREBIÓTICO SEM ADITIVOS: Efeito da substituição do emulsificante por inulina

Introdução

The use of additives in Ice cream produces desirable characteristics, but they have been associated with health problems, increasing the search for clean-label products. Inulin, in addition to its prebiotics effects, has been used for emulsion stabilization, but little is known about its effects on clean-label ice creams.

Material e Métodos

This study aimed to study the effect of replacing the emulsifier by inulin. 2 ice creams were made (CONV-0.5% of Emustab® and GR-4.2% of GR Orafiti® inulin). The difference (3.7%) was completed with non-fat dry milk (Molico®). The mix was evaluated for viscosity and the ice cream for overrun, melting, rheology, optical microscopy, cryo-microscopy and hardness. Analyzes were carried out in triplicate and tested statistically by Student’s t test at significance level of 5%.

Resultados e Discussão

The emulsifier substitution by inulin significantly decreased the mix viscosity in both pasteurized (50.7 vs 46.5mPa.s) and matured mix (59 vs 52mPa.s), but did not influenced the soluble and total solids, nor moisture. However, the prebiotic ice cream showed significantly lower overrun (25 vs 48%) and start melting time (11 vs 20 min), but higher hardness (120 vs 70 N). The prebiotic melted ice cream showed significantly different rheological behavior, such as increased viscosity (45 vs 20mPa.s), consistency factor (0.3 vs 0.07mPa.s) and a more pseudoplastic characteristic. It could be observed in optical microscopy the presence of smaller fat droplets (400x) and clusters of air bubbles (40x) in prebiotic ice cream, as well as smaller ice crystals (6±3 vs 12±6µm) in cryo-microscopy.

Conclusão

Inulin stabilizes the emulsion by continuous phase thickening [1], different than glycerol or sorbitan esters emulsifiers that provide surface-active properties at the fat–water interface controlling the coalescence of the fat during ice cream dynamic freezing [2]. Therefore, the use of only inulin, may have increased the fat destabilization (coalescence) during dynamic freezing, producing a harder ice cream that takes longer to melt. The studied inulin wasn’t enough to replace the commercial emulsifier. Therefore, to manufacture a prebiotic “clean label” ice cream, may be necessary to adjust the product formulation in order to control the fat destabilization and produce a softer and creamier ice cream.