Thermal inactivation of peroxidase and polyphenoloxidase enzymes in mate leaves (Ilex paraguariensis) in a conveyor belt oven

Abstract

2014) Thermal inactivation of peroxidase and polyphenoloxidase enzymes in mate leaves (Ilex paraguariensis) in a conveyor belt oven,

Effect of Cooking Method on Vitamin C Loses and Antioxidant Activity of Indigenous Green Leafy Vegetables Consumed in Western Uganda

“…Though hydrogen peroxide can be reduced to water via catalase activity, excessive production could be harmful and therefore the need for other scavengers. The decrease in hydrogen peroxide scavenging activity of cooked Amaranths and Solanum extracts coupled with the fact that steaming did not cause significant variation in their hydrogen peroxide scavenging activity compared to the raw implies that the prooxidant activity may be due to peroxidase enzymes, which are inactivated by high temperatures such as boiling [ 33 – 35 ]. The increase in hydrogen peroxide scavenging activity exhibited by cooked Curcubita extracts could be explained by the fact that the leaves are harder compared to Amaranth and Solanum , and heating coupled with homogenization caused a more efficient release of antioxidants enzymes [ 32 ].…”

Evaluation of blanching technology in green color preservation in yerba-mate as a substitute for conventional process

“…The enzymatic crude extract was obtained according to procedures previously described, [28][29][30] with adaptations. A sample composed of 20 g of in natura yerba-mate leaves, subjected to heat treatments dened by factorial design was homogenized in 0.05 mol L −1 phosphate buffer (pH 7.5) and 3.0% (p/p) polyvinylpyrrolidone.…”

“…The PFO and POD activities were measured at 420 nm and 470 nm, respectively, according to the methodology dened in previous studies. [28][29][30] For quantication of PFO activity, to a glass tube containing 2.8 mL of 0.05 M phosphate buffer (pH 8.5) and 100 mL of 0.1 M pyrocatechol in 0.1% polysorbate (Tween 80), was added 100 mL of crude extract. In relation to the POD activity measurement, to a glass tube containing 2.725 mL of 0.05 M phosphate buffer (pH 4.7), 100 mL of 0.2 M hydrogen peroxide solution, and 100 mL of guaiacol in 0.1% polysorbate (Tween 80), was added 100 mL of crude extract.…”

Microwave drying of yerba mate leaves: kinetics modeling and techno-economic analysis

“…Its leaves are rich in bioactive compounds (e.g., chlorogenic and caffeic acids, caffeine, theobromine) (GERKE et al, 2018;RODRIGUEZ et al, 2023), resulting in a crescent interest in developing new products from this matrix. Industrial processing of yerba mate leaves (YML) is essential on the inactivating of its oxidase enzymes (NABECHIMA et al, 2014), its procedure is dated from the 19 th century and consists in a two-step mechanism (TOMASI et al, 2021), summarized in the block diagram (Figure 1).…”

“…Although it is widely used in the mate industry, the sapeco-step may be harmful to the final product due to the direct contact of the smoke and the leaves, which results in the contamination of the dried yerba mate with carcinogenic compounds such as polyciclic aromatic hydrocarbons (PAHs) and anthraquinones (ATQ) (GARCÍA LONDOÑO; POK; RESNIK, 2020;NABECHIMA et al, 2014;TOMASI et al, 2021). Alternative drying techniques for YML have been exploited, but according to (TOMASI et al, 2021), the microwave assisted drying (MWD) is the most promising method, for it preserves the most the green color on the leaves and is efficient on the maintenance of the bioactive compounds.…”