Dados do Trabalho

Título

STUDY OF MECHANICAL, PHYSICOCHEMICAL, AND THERMAL TRANSFORMATIONS DURING RIPENING OF ARTISANAL COLONIAL CHEESE

Introdução

Artisanal colonial cheese (ACC) is known for its texture and color formed during ripening, which is influenced by the composition of nutrients present. This research aimed to evaluate mechanical, physicochemical, and thermal changes occurred in the ACC during ripening.

Material e Métodos

Eight ACC were made from two producers (CF, RG), with raw milk, and ripened for 1, 7, 14, and 21 days (CFd1, CFd7, CFd14, CFd21, RGd1, RGd7, RGd14, RGd21). The analyses performed were texture profile analysis (TPA), colorimetry (L, a*, b*), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC).

Resultados e Discussão

TPA revealed higher values (p<0.05) of hardness, and chewiness in the final period of ripening (CFd21, RGd21) and higher springiness, cohesiveness, gumminess, and resilience values (p<0.05) at the beginning (CFd1, RGd1), being the results related to water content. Colorimetry presented higher luminosity in the ACC crumb (p<0.05) (79.25±3.30–88.14±1.17). Rind demonstrated a greenish tendency in a* in the initial period (p<0.05) (-3.08±0.13 – -0.58±0.42), changing to reddish in the final period (0.53±0.12–2.08±0.39). In the cheese crumb, all samples revealed a greenish tendency (-3.30±0.17 – -2.44±0.14). Cheese rinds presented higher b* values after 21 days (p<0.05) (CFd21–37.39±4.63; RGd21–40.72±1.13). FTIR main data are related to the intensity of regions associated with moisture content, with higher percentages of transmittance in the region 3700–3100 cm-1 (CFd7, CFd14, RGd7), and related to the secondary structure of the protein peaks associated with amide I, presenting three different structural variations during ripening (β-turn–1668.10-1660.39 cm-1; α-helix–1656.53-1650.75 cm-1; random coil–1646.89-1641.11 cm-1). DSC showed endothermic transitions characteristic of milk fat melting. The first peak (15.50–20.50°C) was attributed to the melting of shorter chain fatty acids, and the second peak (35.83–36.85°C) was attributed to the melting peaks of longer chain fatty acids, mainly polyunsaturated. When observing the enthalpy values (peak 1–15.21-19.31 J/g; peak 2–2.67-5.73 J/g), a greater energy requirement for the fusion of short-chain fatty acids was required.

Conclusão

The biochemical transformations during ripening mainly promoted changes in texture, yellowing of the rind, and changes in spectroscopy, with variations in the intensity of the peaks of molecular bonds and the secondary structure of the proteins.