Principal component analysis (PCA) and multiple linear regression (MLR) statistical tools to evaluate the effect of E-beam irradiation on ready-to-eat food

The effect of E-beam irradiation on cooked and dry cured Iberian ham, minced meat, smoked salmon and soft cheese, which have different chemical compositions with respect to protein, fat, moisture, free amino acids, amino acid decomposition products and preservatives intentionally added (nitrate and nitrite), was evaluated. A decrease up to 50% in fat content was observed with the irradiation increase for cooked ham and smoked salmon. Protein was modified only in cooked ham samples, while free amino acid amounts were significantly affected in all cases. Nitrate and nitrite content were affected in cooked and Iberian ham, with losses up to 100%, and in smoked salmon. Principal component analysis (PCA) was used to model the data. The results obtained made it possible to establish that radiation doses of 6 and 8 kGy produce chemical composition changes in practically every foodstuff. At the radiation of 2 kGy, which is the dose required to reach the food safety objective (FSO), dry cured Iberian ham was the least affected food, whereas minced meat and cooked ham were the most affected. Stepwise multiple-linear regression (MLR) explained changes in nitrate and nitrite content with the radiation dose applied and the food chemical composition (especially with moisture, fat and protein).