Domestic cooking practices influence the carotenoid and tocopherol content in colored cauliflower.

Cauliflowers are generally associated with healthy diets due to their positive impact on health. This research aims to evaluate the effects of cooking processes (boiling, steaming and microwaving) and different preparation times, on the content of carotenoids and provitamin A and tocopherols, in cauliflowers and to verify the effect of the cooking process on maintaining the coloring. The results revealed that the thermal processinfluencedthe antioxidant compounds releaseindependent of genotype. The highest content of zeaxanthin and lutein was found in 'Verde di Macerata' after boiling for 20 min. 'Cheddar' presented the highest content of all carotenoids and when steamed for 20 min, the highest levels ofprovitamin Awere observed.Microwaved and bolied 'Grafitti' for longer times showed the highest retention of tocopherol. The cooking did not negatively affect the visual aspect. 'Verde di Macerata' and 'Cheddar' may be good sources of carotenoids and tocopherols.

Delaying the harvest induces bioactive compounds and maintains the quality of sweet potatoes.

We have identified the best harvesting periods, related to higher bioactive compound content and post-harvest quality, for minimally processed sweet potatoes with orange pulp and cream pulp. Quality loss in minimally processed sweet potatoes occurred due to browning in cv. Mãe de Familia and ESAM1 and to whitening in cv. Paraná. Both Mãe de Família and ESAM1 presented higher peroxidase and polyphenol oxidase activities at 120 days, and cv. Paraná contained high levels of provitamin A. ß-carotene was the major carotenoid (up to 99%) in orange pulp. All cultivars harvested at 150 and 180 days and minimally processed showed the best visual quality, the highest bioactive compound content, and no microbial infection. Delaying the harvest also increase the antioxidant activity in orange roots, which was associated with a high content of carotenoids and phenolic compounds, resulting in an increase in the nutritional quality of the product. PRACTICAL APPLICATIONS: Postharvest techniques can improve the visual and phytochemical quality of vegetables and extend their shelf life. The present research provides the best harvesting periods for minimally processed cream and orange sweet potato roots with higher postharvest qualities. Delaying the harvest resulted in a product with better visual quality, higher levels of bioactive compounds, which are highly beneficial to health, for example, ß-carotene, and no microbiological contamination. Our results may contribute to improvements in the current knowledge about harvesting times for sweet potato growers who aim to produce high quality, minimally processed products with a longer shelf life.

Biogenic Amines and the Antioxidant Capacity of Juice and Wine from Brazilian Hybrid Grapevines.

Some biogenic amines (BAs) are used as quality markers in grape-derived products. The prolife of 9 BAs was determined in juices and wines elaborated from hybrid grapes. Low levels of histamine, tyramine and cadaverine were found. Juices elaborated from 'BRS Rúbea' showed the highest tyramine levels (1.56 mg/L), while no histamine was found in wines elaborated from 'Seleção 34' and its higher content was detected in 'BRS Carmem' (3.55 mg/L). Juices elaborated from 'BRS Violeta' showed elevated content (472.88 mg/L) of total phenolic compounds (TPC) and mono-hydrated serotonin (6.20 mg/L), and wines elaborated from 'Violeta' presented a high serotonin mono-hydrate content (23.63 mg/L) and high antioxidant activity with FRAP test (77.24 mmol FeSO4/L). Juices elaborated from hybrid grapes 'BRS Violeta' and wines from 'BRS Violeta', 'Seleção 34' and 'Seleção 13' had high levels of bioactive compounds, emphasizing the great potential of these cultivars for winemaking.

Bioactive Amines Screening in Four Genotypes of Thermally Processed Cauliflower.

Biogenic amines are important indicators of food quality with recognized antioxidant capacity. Diets that are rich in these compounds promote several benefits for human health, although the consumption in excess may result in food poisoning. This study aims to screen the levels of biogenic amines in four colored cauliflowers, before and after cooking (boiling, steaming, and microwaving). In addition, the levels of tryptophan and 5-hydroxytryptophan, two serotonin precursors, were analyzed. Our results reveal that thermal processing shows a tendency to increase tryptophan levels and reduce 5-hydroxytryptophan in colored cauliflowers. A reduction of the tryptophan and increase in serotonin contents in 'Cheddar', steamed or microwaved, was observed. A higher level of histamine was observed in the genotype 'Forata' after cooking, whereas melatonin levels were higher after steaming and microwaving. The lowest levels of biogenic amines and amino acids were observed in 'Graffiti'. All the colored cauliflowers that were analyzed presented a chemical quality index (CQI) below the pre-established limits, indicating that are safe for consumption, even after cooking. We conclude that the levels of biogenic amines and amino acids in colored cauliflower are safe for human consumption and do not present health risks. Therefore, the consumption of these genotypes, raw or cooked, is a good source of bioactive compounds.