Metabolism of bioactive compounds and antioxidant activity in bananas during ripening

Prediction of Bioactive Compounds and Antioxidant Activity in Bananas during Ripening Using Non-Destructive Parameters as Input Data

Vegetable quality parameters are established according to standards primarily based on visual characteristics. Although knowledge of biochemical changes in the secondary metabolism of plants throughout development is essential to guide decision-making about consumption, harvesting and processing, these determinations involve the use of reagents, specific equipment and sophisticated techniques, making them slow and costly. However, when non-destructive methods are employed to predict such determinations, a greater number of samples can be tested with adequate precision. Therefore, the aim of this work was to establish an association capable of modeling between non-destructive-physical and colorimetric aspects (predictive variables)-and destructive determinations-bioactive compounds and antioxidant activity (variables to be predicted), quantified spectrophotometrically and by HPLC in 'Nanicão' bananas during ripening. It was verified that to predict some parameters such as flavonoids, a regression equation using predictive parameters indicated the importance of R2, which varied from 83.43 to 98.25%, showing that some non-destructive parameters can be highly efficient as predictors.

Quantification of flavonoids, minerals, and pigments present in "Nanicão" bananas during the ripening process

Banana is one of the most consumed and popular fruits in all regions of the world, being cultivated mainly in tropical countries. It is not only a rich source of vitamins A, C, and B, calcium, iron, potassium, phosphorus, and other vitamins and nutrients, but it also contains several types of antioxidants with high nutritional value. In this context, the current study aimed to quantify the content of ascorbic acid, flavonoids, pigments, and minerals present in "Nanicão" bananas during the ripening process. As demonstrated, the level of flavonoids was higher in ripe and overripe fruits, whereas the mineral composition was high only at ripening stage 4 (more yellow than green) a stage that should be prioritized when recommending fruit consumption to the population deficient in these minerals. Regarding pigments, there was a reduction in chlorophylls a and b and an increase in carotenoids and anthocyanins in peels and pulps. PRACTICAL APPLICATION: Flavonoids are phenolic, bioactive compounds with proven antioxidant and anti-inflammatory activity and products of the plant's secondary metabolism. The degradation of chlorophylls and synthesis of carotenoids and anthocyanins, and as a consequence of the latter pigment, the increase in flavonoids in the pulp was evident during the monitoring of ripening, mainly in the fruit peels in relation to pigments. Minerals are essential elements, the main ones provided in balanced diets and important for dietary and nutritional health.

Productive and Physico-Chemical Parameters of Tomato Fruits Submitted to Fertigation Doses with Water Treated with Very Low-Frequency Electromagnetic Resonance Fields

It is known that poorly performed fertigation directly impacts on tomato production and biometric components. In addition, consumers are also affected by interrelated characteristics that interfere with the acceptability of the fruit, such as the physicochemical parameters and nutrients in the fruit. Thus, eco-friendly technologies, such as irrigation with ultra-low frequency electromagnetic treated-water, which attenuates the inadequate management of fertigation, are essential to improve marketable fruit yields. Thus, the objective of the present work was to investigate the impact of treated water with very low-frequency electromagnetic resonance fields in physical, chemical and nutritional parameters at different nutrient solution strengths in tomato fruits. In this study, experiments were carried out in randomized blocks and five doses of fertigation were used (1.5; 2.5; 4.0; 5.5; and 7.0 dS m−1), employing two types of water: electromagnetically treated and untreated. It can be seen that the fertigation affected some parameters, mainly the number of fruits with blossom-end rot, fruit size, and weight. Variance analysis (ANOVA) was performed with the subsequent use of the Tukey test. In all statistical tests, a confidence level of 95% was considered. The soluble solids content increased by 28% as a function of the fertigation doses. The electromagnetically treated water reduced the number of fruits with blossom-end rot by 35% (p < 0.05). Overall, electromagnetic water improved the physicochemical quality parameters and the nutritional status of tomato fruits. Thus, this study demonstrated that green technology could leverage tomato fruit production and quality.