In contact with water, chia seeds release mucilage (MC), which is a source of various health-promoting compounds including dietary fibres. MC has been previously used as a thickening agent in cow milk yoghurt, but there are no available data on its application in goat milk. In this study, three goat milk yoghurts (without—MC0, with 1.5%—MC15 and with 3% mucilage—MC30) were produced. The rheology, texture, microbial counts, syneresis, microstructure and sensory acceptance of the yoghurts were investigated. The MC addition resulted in a reduced hysteresis area, but increased yoghurt viscosity at lower shear rates. It also improved all texture parameters at both concentration levels, while syneresis values were reduced only in sample MC30. The MC addition promoted lactobacilli viability in both supplemented yoghurts. The texture perceived by sensory evaluation was rated the highest for the sample MC30, which was also the most accepted by consumers overall. Critical attributes that reduced the acceptability of all yoghurts were flavour and acidity. In conclusion, chia seed mucilage can be used as a functional ingredient in goat milk yoghurt to produce an innovative dairy product and meet consumer expectations.
Various factors affect rennet coagulation and consequently cheese yield, but the subject of research has been mainly the cow milk. For the purpose of goat cheese production optimization, this paper investigated the influence of enzyme concentration (0.01–0.054 g/L), pH (6.5–6.1) and temperature (27–35 °C) on rennet coagulation of goat milk. Coagulation time (RCT), aggregation rate (AR), and gel firmness (G’60 and GF), were measured by oscillatory rheometry. The decrease in rennet concentration extended RCT. At lower rennet concentrations, a lower AR was recorded, which ranged from 0.02 Pa/s to 0.05 Pa/s. The decrease in pH from 6.5 to 6.1 caused a two times shorter RCT, and a two times faster AR. There was no effect of pH on the firmness of the rennet gel. The increase in coagulation temperature from 27 °C to 35 °C reduced the RCT of pasteurized milk from 12.6 min to 8.6 min, and caused a linear increase in the AR, but did not significantly affect the firmness of the gel. The present study revealed that the optimization of the rennet coagulation process could be directed towards pH lowering, or temperature increase, since they accelerate the process, but do not alter the examined gel firmness parameters.