In this study, the usefulness of different mathematical models to predict the retention of ascorbic acid (AA), total phenols (TP) and DPPH radical scavenging activity (SA) of pasteurized pineapple juices during storage has been evaluated. The results indicate that first-order kinetic model provided the best prediction of the degradation of AA (MAE = 0.0059; MRE = 0.0117; MSE = 0.0001; R 2 = 0.9995) whereas Weibull model provided the less satisfactory prediction (MAE = 0.2387; MRE = 0.2911; MSE = 0.0769; R 2 = 0.9993). In addition, zero-order (MAE = 0.0016; MRE = 0.0017; MSE = 0.0000; R 2 = 0.9992) and first-order (MAE = 0.0027; MRE = 0.0029; MSE = 0.0000; R 2 = 0.9989) kinetic models are adequate models for application in the prediction of TP loss, and first-order kinetic (MAE = 0.0294; MRE = 0.0549; MSE = 0.0015; R 2 = 0.9845) and Weibull (MAE = 0.0533; MRE = 0.0881; MSE = 0.0044; R 2 = 0.9823) models are recommended to predict the change of SA. These results show that the behaviors of AA, TP and SA during storage of juices can be accurately described by different prediction models. Therefore, the selection of the most adequate model is of great importance to predict nutritional deterioration in food products during storage.

We investigated if elevated CO₂ could alleviate the negative effect of high temperature on fruit yield of strawberry (Fragaria × ananassa Duch. cv. Toyonoka) at different levels of nitrogen and also tested the combined effects of CO₂, temperature and nitrogen on fruit quality of plants cultivated in controlled growth chambers. Results show that elevated CO₂ and high temperature caused a further 12% and 35% decrease in fruit yield at low and high nitrogen, respectively. The fewer inflorescences and smaller umbel size during flower induction caused the reduction of fruit yield at elevated CO₂ and high temperature. Interestingly, nitrogen application has no beneficial effect on fruit yield, and this may be because of decreased sucrose export to the shoot apical meristem at floral transition. Moreover, elevated CO₂ increased the levels of dry matter-content, fructose, glucose, total sugar and sweetness index per dry matter, but decreased fruit nitrogen content, total antioxidant capacity and all antioxidant compounds per dry matter in strawberry fruit. The reduction of fruit nitrogen content and antioxidant activity was mainly caused by the dilution effect of accumulated non-structural carbohydrates sourced from the increased net photosynthetic rate at elevated CO₂. Thus, the quality of strawberry fruit would increase because of the increased sweetness and the similar amount of fruit nitrogen content, antioxidant activity per fresh matter at elevated CO₂. Overall, we found that elevated CO₂ improved the production of strawberry (including yield and quality) at low temperature, but decreased it at high temperature. The dramatic fluctuation in strawberry yield between low and high temperature at elevated CO₂ implies that more attention should be paid to the process of flower induction under climate change, especially in fruits that require winter chilling for reproductive growth.