Effects of Traditional and Novel Cooking Processes on the Nutritional and Bioactive Profile of Brassica oleracea (Kale)

Table 2

Different cooking methods and their impact on nutritional status and changes in the bioactive compounds.

Kale type	Major findings				Reference
	Processing methods	Nutritional status	Types of bioactive compounds (BCs)	Major finding
Brassica oleracea var. acephala cv. Galega	Boiling and vacuum cooking	Vitamin and minerals	Phenolic compounds, ascorbic acid, total chlorophyll, and antioxidants	The outcome suggested that the vacuum cooking method can be used as an alternative to traditional cooking methods.	[3]
Brassica alboglabra	Microwave cooking, boiling, and steaming	Fiber and ash	Total phenolic content and antioxidants	Microwave steaming can be recommended for cooking greenish vegetables due to the health benefit (increased antioxidant activity) convenience and similar cooked food properties (color and texture).	[37]
Brassica spp.	Cooking, blanching, freezing, and canning	Fiber	Ascorbic acid, β-carotene, and phenolic compounds	Results showed that some bioactive compounds (ascorbic acid) are lost due to these treatments whereas other compounds are less affected or may even increase in concentration.	[44]
Brassica oleracea var. acephala cv. Galega	Boiling, steaming, microwaving, pressure cooking, and vacuum cooking	Minerals (potassium and calcium)	Antioxidants, total flavonoids and organic acids	The current outcomes showed that the different cooking methods have different effects on the bioactive compounds in kale. However, it can be important the optimization of such methods in order to minimize losses of the nutritional properties.	[61]
Kale	Boiling, microwaving, pressure cooking, and steaming	—	Antioxidants and soluble and hydrolysable polyphenolic content	The finding investigated that steaming is the best cooking method for increasing the concentration of polyphenols and antioxidants whereas microwaving is the least recommended method.	[35]
Kale (fresh and frozen)	Boiling, microwaving, and steaming	—	Total phenolic content and antioxidants	Outcomes showed that frozen uncooked samples contained a higher antioxidant capacity than the fresh. However, the freezing process may be enhanced the antioxidant capacity of the kale.	[34]
Kale	Boiling, stir-frying, microwaving, and steaming	Vitamin C	Total carotenoids, total chlorophylls, total flavonoids, and total phenolic contents	The finding verified that water-soluble phytochemicals are significantly decreased by boiling. However, stir-frying gave the highest degradation ratio for all phytochemicals, and steaming gave the lowest degradation ratio.	[4]
Brassica oleracea var. acephala	Electric stove top	Vitamin C	β-Carotene, total polyphenols, antioxidant, indole-3-carbinol, indole-3-acetonitrile, total indoles, and total isothiocyanate	The results noted that fresh and cooked kale had similar antioxidative potential.	[2]