In dan2cil/tecTools: A collection of small function for Food Technologists

The ctest() function is used to calculate the melting point of chocolate using the collapse test method

Function

Below the sintax of the function ctest():

ctest(analisi, xlim, ylim, main='Collapse test', point=F, values=T, dt=F, mm=1)

where:

analisi :   analysis data frame (see below)
xlim    :   x axix limits                                                             c(26, 35)
ylim    :   y axis limits                                                               c(0, 5)
main    :   graph title                                                         'Collapse test'
point   :   boolean, T=print points on graph, F=print only line                               F
values  :   boolean, T=print derivative values on graph, F=don't print values                 T
dt      :   boolean, T=plot derivatives on graph                                              F
mm      :   integer, moving average step (1=no moving average)                                1

Analysis data frame

The analysis data file, must contain the following field:

Test        :   test label (used in the legend)
Temperature :   temperature values in °C
Gap         :   thickness of the chocolate sample

as the following example:

library(tecTools)
data('choc_ctest')
knitr::kable(head(choc_ctest))

Softening point calculation

The onset softenening point is calcolated as as the intersection of:

• the tangent to the curve at the starting point displayed
• The tangent to the curve point of the curve displayed

knitr::include_graphics("Calcolo_onset.png")

Examples

In the following graph we could compare the melting point of three differnt chocolate:

library(tecTools)
data('choc_ctest')
ctest(choc_ctest)

...the same graph with plotted the point of minimum and maximum of the derivative:

library(tecTools)
data('choc_ctest')
ctest(choc_ctest, value=T)

...the same with first and second derivative plotted:

library(tecTools)
data('choc_ctest')
ctest(choc_ctest, dt=T)

The ctest() function return a list with all the results:

library(tecTools)
data('choc_ctest')
a <- ctest(choc_ctest, dt=T)
str(a)

Reference

The function ctest() is based on the following article ^[available to the library author]:

"Metodo collapse test" Soremartec DTS Analiysis Method

"Characterization of Heat Resistant Milk Chocolate" - Master Michele Ferrero 2010
Carolina Dicolla, Swamy Anantheswaran, Doug Broun

dan2cil/tecTools documentation built on Dec. 19, 2021, 8:04 p.m.