Calculator for Safe Storage time and Integration of Germination over Storage time model

 HGCA, Home Grown Cereals Authority (UK), subsidary of United Kingdom Agriculture and Horticulture Development Board (AHDB)
HGCA Quality Calculator for Safe Storage time
http://data.hgca.com/calculator/

Sadly, I cannot find the reference to calculation steps they use to calculate the safe storage time. I could  use that piece of information to explain my integration of calorific value over storage period.

YEAH, I found a paper that uses the same concept my supervisor, Dr. S suggested me to use to integrate the calorific value over storage period. Dr. S mentioned that he got the idea from a method that is used in estimating the germination percentage of grain over storage. I'm so thrilled!
http://www.plosone.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0062868&representation=PDF

A number of symbols and their definitions

1. Thermal time (TT) model: Predict the effect of temperature on seed germination by assuming a range of temperatures, the base temperature for germination (T_b) is constant and the thermal time required for germination of a given fraction of seeds is a normal or log normal distribution among seeds in a population.
2. Maximum Lifetime Threshold (MLT): assume that there is a maximum potential lifetime for each seed, which distributes normally among individual seed in a population, and that the time to germination of a given seed is inversely proportional to the difference between the aging time and the maximum potential lifetime of that seed.

TT model
1/t_g     = germination rate
g           = germination percentile
T          = linear function of temperature at a suboptimal range
Θ_T(g) = thermal time to germination of a given percentage g and T. It is found that assumption of a log normal distribution of Θ_T(g) is applicable for germination prediction of aspen seeds, i.e.
probit(g) = (ln((T - T_b) x t_g ) - ln(Θ_T(50)))/σ_p,max
T_b       = the base temperature

MLT model
p         = aging time
p_max(g) = the maximum potential lifetime above which seed germination cannot occur for a given percentage g and is assumed to be normally distributed among seeds in a population
Θa       = an "aging time constant"

Aging thermal time model
ΘAT     = aging thermal time
ΘNT     = normalized aging thermal time