Temperature and storage time increase provitamin A carotenoid concentrations and bioaccessibility in post-harvest carrots

Correlation of skin color and plasma carotenoid-related metabolites of ornamental koi carp under temperature fluctuations

The skin color of koi carp (Cyprinus carpio L.) is one of the traits that most influence their ornamental and economic values. The present study suggested the effects of temperature fluctuation on koi carp in terms of skin color and plasma carotenoids and related-metabolites. The main results were as follows. (1) The vulnerability of koi skin color to acute temperature stress was in the order of white koi> black koi> yellow koi. Both high- (25°C-30°C-25°C) and low-temperature (25°C-20°C-25°C) fluctuations tended to decrease the saturation of white koi. The temperature fluctuation had little effects on the skin color of black and yellow koi. (2) Targeted metabolomics analysis indicated that the effects of cooling stress on oxycarotenoids of all five koi varieties were reversible. The plasma oxycarotenoids in mirror koi with all colors were insensitive to acute heat stress. However, the cooling process from a high temperature (30°C-25°C) still made contributions to the increase of oxycarotenoids. (3) The principal component analysis confirmed the deviation of carotenoid-related metabolites after high temperature fluctuation and the reversibility after low temperature fluctuation. Finally, the correlation analysis revealed that koi skin brightness was negatively correlated with the plasma guanine content and that temperature fluctuations might change koi skin brightness via the L(-)-epinephrine-guanine pathway. The red hue and yellow hue were negatively correlated with the oxycarotenoids in plasma, suggesting that oxycarotenoids were favorable for enhancing koi skin color saturation. Overall, this study revealed the direct action of temperature fluctuations on the skin color and carotenoid-related metabolites of koi.

Post-Harvest Atmospheric Pressure and Composition Modify the Concentration and Bioaccessibility of α- and β-Carotene in Carrots and Sweet Potatoes

Provitamin A (proVA) carotenoid synthesis and degradation are strongly influenced by environmental factors, including during post-harvest storage. Hypobaric and hyperbaric storages increase the shelf-life of many crops, but their effects on proVA carotenoids are not known. Our aim was to investigate the effects of modifications of atmospheric pressure and composition on α- and β-carotene concentration and bioaccessibility during the post-harvest storage of carrots and sweet potatoes. Vegetables were stored for 11-14 days at 20 °C in the dark in chambers with modified pressure and O2 concentrations. In carrots, α- and β-carotene concentrations increased significantly during storage, but compared to the control, they were significantly lower in hyperbaria (-23 and -26%, respectively), whereas they did not differ significantly in hypoxia and hypobaria. In sweet potatoes, α- and β-carotene concentrations decreased significantly during storage, but neither hypoxia, hypobaria nor hyperbaria led to any significant change compared to the control. There was a significant increase for carrot α- and β-carotene bioaccessibility in hypobaria and hyperbaria, while there was a significant decrease for sweet potato β-carotene bioaccessibility in hypobaria/hypoxia and normobaria/hypoxia (-45% and -65% vs. control, respectively). Atmospheric pressure and composition during the post-harvest storage of carrots and sweet potatoes modified the concentration and bioaccessibility of proVA carotenoids.

Use of Inverse Method to Determine Thermophysical Properties of Minimally Processed Carrots during Chilling under Natural Convection

The aim of this study was to determine the thermophysical properties and process parameters of cylindrical carrot pieces during their chilling. For this, the temperature of the central point of the product, initially at 19.9 °C, was recorded during chilling under natural convection, with the refrigerator air temperature maintained at 3.5 °C. A solver was created for the two-dimensional analytical solution of the heat conduction equation in cylindrical coordinates. This solver and the experimental data set were coupled to the LS Optimizer (V. 7.2) optimization software to simultaneously determine not only the values of thermal diffusivity (α) and heat transfer coefficient (hH), but also the uncertainties of these values. These values were consistent with those reported in the literature for carrots; in this study, the precision of these values and the confidence level of the results (95.4%) were also presented. Furthermore, the Biot numbers were greater than 0.1 and less than 40, indicating that the mathematical model presented in this study can be used to simultaneously estimate α and hH. A simulation of the chilling kinetics using the values obtained for α and hH showed good agreement with the experimental results, with a root mean square error RMSE = 9.651 × 10^-3 and a chi-square χ² = 4.378 × 10^-3.

Root Vegetables-Composition, Health Effects, and Contaminants

Root vegetables are known all over the world, but they are being less and less consumed by individuals. The main purpose of this article was to summarize the benefits, health effects, and threats associated with the consumption of carrot, celery, parsley, beetroot, radish, turnip, and horseradish. They are characterized by high nutritional value due to their richness in dietary fiber, vitamins, and minerals. One of their most important features is their high content of bioactive compounds, such as polyphenols, phenols, flavonoids, and vitamin C. These compounds are responsible for antioxidant potential. Comparison of their antioxidant effects is difficult due to the lack of standardization among methods used for their assessment. Therefore, there is a need for a reference method that would allow for correct interpretation. Moreover, root vegetables are characterized by several health-promoting effects, including the regulation of metabolic parameters (glucose level, lipid profile, and blood pressure), antioxidant potential, prebiotic function, and anti-cancer properties. However, due to the type of cultivation, root vegetables are vulnerable to contaminants from the soil, such as toxic metals (lead and cadmium), pesticides, pharmaceutical residues, microplastics, and nitrates. Regardless, the low levels of toxic substances present in root vegetables do not pose health risks to the average consumer.

Using black soldier fly larvae reared on fruits and vegetables waste as a sustainable dietary source of provitamin a carotenoids

We showed that black soldier fly larvae reared on fruits and vegetables rich in provitamin A carotenoids can accumulate significant amounts of these vitamin A precursors. Using a simulated gastro-intestinal digestion model, we demonstrated that α- and β-carotene from the larvae are as bioaccessible as from the fruits and vegetables they were reared on. We calculated that provitamin A carotenoid-rich larvae have the capacity to provide more vitamin A than fruits and vegetables rich in these molecules. Remarkably, the incorporation of usual quantities of these larvae in feed could cover the needs of several production animals for this vitamin. Thus, our findings suggest that rearing black soldier fly larvae on by-products or waste rich in provitamin A carotenoids could be a sustainable strategy to recycle a fraction of vitamin A back into the food chain and could represent a new approach to fight against vitamin A deficiency.