Table 2. Mathematical model equations to present the impacts of extraction temperature and time on extraction yield and gel strength of the gelatin extracted from Korean native black goat skin

Independent variable Model equation Lack of fit r2 p-value
Extraction yield –22.89+0.990X1+0.99X2–0.00697X12+0.036X22–0.0116X1X2 0.629 0.95 <0.001
Gel strength 256.0–0.79X1+35.1X2+0.0055X12–4.65X22–0.159X1X2 0.139 0.83 0.013
X1, extraction temperature (°C); X2, extraction time (h).