Colloquium Biometricum

Tom: 46 Strona: 15

Autorzy:

Tytuł:
Comparison of Parmesan cheese drying course by means of regression methods

Język: Angielski

Słowa kluczowe:

linear regression

hypothesis testing

Streszczenie:
The aim of the article is to compare regression lines which describe relations between the inverse of water content in cheese and time of drying. Each line involves one of the combinations of Parmesan’s type cheese piece sizes (4 mm, 6 mm) and drying temperatures (30°C and 50°C) and piece size of 8 mm dried in 50°C. Regression lines were compared for five combinations of piece sizes and drying temperatures. The duration of the drying process was ten hours. Regression coefficients in the equations were compared using partial F-test. Multiple pair comparisons were examined by means of SimReg procedure. The latter method allowed to identify pairs of significantly different regression equations as well as pairs of equations that do not differ significantly. A similar analysis was performed for the observations regarding the second drying period (from 5th to 10th hour of drying). In addition to the aforementioned methods also the procedure of determining groups of mutually parallel straight lines was used. The application of that method enabled the division of five equations into two groups.