[Study on NIR Model Transfer between Similar Kinds of Fruits Based on Slope/Bias Algorithm].

In order to expand the application range of the model for a single kind of fruits in the portable near infrared instrument, this paper comes up with a new method for the soluble solid content (SSC) model transfer between different kinds of fruits. This method is focusing on the idea of model transfer between different instruments. Based on the similar physical and chemical properties of apples, peaches and pears, such as the range of SSC content, fruit size and the thickness of peel, a simple Slope/Bias algorithm is applied to the transfer of apple SSC partial least square (PLS) model. After that, it can be used to predict pear & peach SSC value with very little extra samples. It’s more convenient and costs less by using this method. For pear samples, by using extra 35 standard samples to transfer apple SSC model, RMSEP reduced from 1.009 °Brix to 0.565 °Brix. For peaches, extra 40 standard samples led to a significant reduce of RMSEP from 1.726 °Brix to 0.677 °Brix after model transfer. To validate the feasibility of this model transfer method, both pear and peach SSC models were tested using the same Slope/Bias algorithm model transfer respectively. A pear SSC model was firstly set up and then transferred with Slope/Bias method. Taking 30 standard apples as samples, RMSEP value reached 0.597°Brix, while taking 40 standard peaches as samples, RMSEP value reached 0.689°Brix. The peach SSC model was transferred in the same way. For apples, using 35 standard samples, RMSEP value reached 0.654°Brix, and for pears, using 30 standard samples, RMSEP value reached 0.439°Brix. These results show that slope/bias algorithm can be used to transfer model between similar kinds of fruits such as apples, pears and peaches. The paper provides innovative ideas for the model transfer among similar kinds of materials, so that the portable near infrared instruments can be used more conveniently and widely.