Integrating bacterial cellulose in artisanal ice cream: a farm-to-fork sustainable approach

Abstract

This study explored the use of bacterial cellulose (BC) in milk-based cocoa ice cream as possible dietary fibers. BC fibers were added in 1%, 3%, and 5% wt. amounts, resulting in notable changes in texture, density, melting behavior. The ice cream transitioned from a Bingham to a Herschel-Bulkley fluid, while density rose with higher fiber content. Although hardness and gumminess slightly increased, the 5% wt. BC sample formed a more cohesive network structure when melted. Ice nucleation was delayed, with the first melt drop appearing later as BC content rose up to 22 minutes for the 5% wt. sample. Caloric content dropped by up to 21% corresponding to the highest amount of BC, making it a healthier dessert option. However, sensory testing showed that 1% and 3% wt. BC formulations were the most appealing to consumers.

Fig. 1. The morphology of BC fiber before purification.

a and after purification and grinding (b) determined by SEM analysis.

Fig. 2. XRD pattern of the investigated samples.

The blue lines indicate the theoretical position of I_β cellulose (ICDD card no. 03-0289).

Fig. 3. Rheology of the non-frozen BC-based ice cream formulations.

Shear stress (Pa) as a function of shear rate (1/s) for classical ice cream IC (a), and the modified formulations (ICBC1) (b), (ICBC3) (c), (ICBC5) (d); shear rate up and down curves are presented as black/square marker (a) and red/dot marker (b) with both fitting curves (purple line - a, and green line -b).

Fig. 4

DSC analysis of BC pristine sample.

Fig. 5. Optical microscopy of BC-based samples at different temperatures.

Optical microscopy images acquired on the BC sample at 60, 220, and 240 °C.

Fig. 6. DSC analysis of the BC-based ice cream samples.

DSC analyses of the BC-based ice cream samples between −60 °C and +60 °C.

Fig. 7. Optical microscopy of the BC-based ice cream samples.

Optical microscopy images of the BC-based ice creams samples upon heating at different temperatures (−40, 0, and 50 °C).

Fig. 8. Melting rate of the BC-based ice-cream samples.

Graph representing the meting percentage in time for the BC-based formulations (blue line/dot marker – ICBC1; red line/square marker– ICBC 3; black line/triangle marker ICBC5).

Fig. 9. Color analysis of BC-based ice-cream samples.

Color analysis of ice cream samples and registration of brightness (“L*” parameter), reddish color (“a*” parameter), and yellowish color (“b*” parameter) for all BC-based ice creams; the image was extracted from Color Data Software CM-S100w, SpectraMagicTM NX.

Fig. 10. Color attribution for brightness, reddish and yellowish color parameters.

Color attribution for L*, a*, and b* parameters (A), and overall color determination (B) extracted from Color Data Software CM-S100w, SpectraMagicTM NX.

Fig. 11. Spider diagram describing sensorial characteristics of the BC-based ice cream samples.

Spider diagram regarding the descriptive test of the ice cream samples based on sensorial characteristics: (1) external appearance – color; (2) external appearance – homogeneity; (3) taste – sweet; (4) taste – sour; (5) taste – bitter; (6) Taste – of cocoa; (7) Taste – chemical; (8) flavor – pleasant cocoa; (9) consistency – creamy; (10) consistency – unctuous; (11) consistency – white ice crystals; (12) texture – firm; (13) aftertaste – pleasant; (14) aftertaste – unpleasant.