Effect of different atmospheric and subatmospheric cooking techniques on qualitative properties and microstructure of artichoke heads

Modern and traditional cooking methods affect the antioxidant activity and phenolic compounds content of Trachystemon Orientalis (L.) G. Don

Trachystemon orientalis (L.) G. Don is a medicinal plant with beneficial effects on human health. Its antioxidant and phenolic compound content is higher than most natural plants. This is the first study on the cooking of this consumed plant. This study investigated how different cooking methods and times affect the antioxidant activity and phenolic compound content of Trachystemon orientalis (L.) G. Don. The Folin-Ciocalteu method (FCR), ferric-reducing antioxidant power (FRAP), copper-reducing antioxidant capacity (CUPRAC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were used to evaluate the antioxidant activity and total phenolic content (TPC). Phenolic compounds were also determined by high-performance liquid chromatography (HPLC). Microwave cooking, stir-frying and sous vide increased TPC and antioxidant activity (p<0.05). Steaming decreased TPC and antioxidant activity (p<0.05). It was determined that the best cooking method and time was stir-frying for 15 minutes (TPC, CUPRAC and FRAP values 45.18±3.91 mg GAE/g DW, 15559.39±106.90 mmol Troloks/g DW and 555.10±24.05 μmol Fe (II)/g DW, respectively). Raw Trachystemon orientalis (L.) G. Don was detected with caffeic acid (31.53±0.25 mg/100 g DW). New phenolic compounds (protocatechuic acid and p-coumaric acid) were formed by boiling, stir-frying, microwaving, and sous vide methods. In conclusion, regarding antioxidant activity and phenolic compounds of Trachystemon orientalis (L.) G. Don; the best cooking methods are microwave, stir-frying, and sous vide (p<0.05). The most wrong cooking method is steaming (p<0.05).

Effect of different atmospheric and subatmospheric cooking techniques on physical and chemical qualitative properties of pork loin

In this paper, the effects of four cooking procedures were evaluated, two occurring in atmospheric (in ventilated and steam oven) and two in subatmospheric (vacuum and sous vide cooking) conditions on pork Longissimus lumborum. The main objective of the study was to compare and evaluate the physical and chemical characteristics. Samples were cooked in four independent trials namely Oven (O), Steaming (ST), Vacuum Cooking (VC) and Sous Vide (SV). The analyses included temperature, cooking effect, percentage weight loss, texture (cutting and double compression tests), colour (superficially and inside the sample), microstructure (optical microscopy) and fibres shortening analysis. To assess cooking effects on significant nutritional constituents, the fatty acid composition and the content of B vitamins were analysed. Volatile profiles of samples were also compared using solid-phase microextraction. SV cooking resulted in the less favourable meat texture, presenting the highest hardness and chewiness. Moreover, high hardness values measured on SV samples is also related to the high weight loss. The technique of oven cooking (O) demonstrated superior results in terms of mechanical properties, which are closely associated with the cooking values. Specifically, the cook value C0 was significantly higher in the case of oven cooking compared to SV, VC, and ST. Mild temperature conditions and cooking times of the four considered cooking techniques did not induce significant variations in the fatty acid composition and volatile profile. Conversely, SV and VC allowed the highest amount of vitamin B retention in cooked meat. This work suggests that some differences emerged on the effects due to sub-atmospheric and atmospheric cooking compared to traditional ones.

Comparison of Phenolic Compounds and Antioxidant Activities of Raw and Cooked Turkish Artichoke Cultivars

The objective of this work was to determine the total phenolic compounds and antioxidants in raw and cooked Sakiz and Bayrampasa variety artichokes in parts such as inner bracts, stems, receptacles, and outer bracts. The artichokes were cooked by boiling, microwaving, and baking methods, and total phenolic compounds and antioxidants of cooked artichokes were evaluated. While TPC (total phenolic content), DPPH (2,2-diphenyl-1-picryl-hydrazine), and CUPRAC values for the leaves of raw Bayrampasa artichoke were found to be 686 mg gallic acid equivalent (GAE)/100 g, 478 mg TE/100 g, and 4,875 mg TE/100 g, respectively, TPC, DPPH, and CUPRAC values for stems of Sakiz artichoke were determined to be 1,579 mg GAE/100 g, 1,259 mg TE/100 g, and 3,575 mg TE/100 g. A significant increase in the content of TPC, DPPH, and CUPRAC values was observed for all cooking applications of both artichokes. DPPH and CUPRAC values increased by 11 and 43 times and 17 and 6.7 times after baking of Sakiz and microwave cooking of Bayrampasa, respectively. Chlorogenic acid, cynarine, and cynaroside content of both artichokes had an increment after all cooking applications. Chlorogenic acid content was improved 29 and 58 times after baking of Sakiz and microwave cooking of Bayrampasa, respectively.