A study on degradation kinetics of ascorbic acid in drumstick (Moringa olifera) leaves during cooking

Abstract

The kinetics of ascorbic acid degradation in drumstick (Moringa olifera) leaves as well as in pure ascorbic acid solutions at the initial concentrations present in drumstick leaves over a temperature range of 50-120 • C (isothermal temperature process) has been studied. The degradation kinetics of ascorbic acid was also evaluated in normal open-pan cooking, pressure-cooking and a newly developed and patented fuelefficient eco cooker (non-isothermal heating process). The ascorbic acid degradation followed first-order reaction kinetics where the rate constant increased with an increase in the temperature. The temperature dependence of degradation was adequately modelled by the Arrhenius equation. A mathematical model was developed using the isothermal kinetic parameters obtained to predict the losses of ascorbic acid from the time-temperature data of the non-isothermal heating/processing method. The results obtained indicate the ascorbic acid degradation is of similar order of magnitude in all the methods of cooking.

CHANGES IN APPARENT VISCOSITY AND VITAMIN C RETENTION DURING THERMAL TREATMENT OF BUTTERNUT SQUASH (CUCURBITA MOSCHATA DUCH) PULP: EFFECT OF RIPENING STAGE

“…Cooking is often responsible for the greatest losses of ascorbic acid, and the extent of the loss depends upon variations in the cooking methods and periods (Lee and Kader 2000; Nisha et al. 2004; Bineesh et al. 2005).…”

Dynamics of Selected Bioactive Substances Changes in Cucurbita Moschata Duch. Ex Poir. After Storage and Different Methods of Technological Processing

“…Cooking is o en responsible for the greatest losses of ascorbic acid, and the extent of the loss depends upon variations in the cooking methods and periods (Bineesh et al, 2005). Because the preparation and stabilization of home-cooked products, such as soups and sauces from squash pulp, would involve thermal treatments, the ascorbic acid retention in squash pulp held for 30 min at 95 o C was investigated.…”

Effect of heat and thermosonication treatments on watercress (Nasturtium officinale) vitamin C degradation kinetics

“…Some studies have been reported on the degradation of vitamin C in thermally processed fruits and vegetables like grapefruit juice (Saguy, Kopelman, & Mizrahi, 1978), orange juice (Johnson, Braddock, & Chen, 1995), lime, lemon, grapefruit and tangerine (Alvarado & Viteri, 1989), cupuaçu nectar (Vieira et al, 2000), tomatoes (Dewanto, Wu, Adom, & Liu, 2002), green asparagus (Esteve, Frígola, Martorell, & Rodrigo, 1999), amla (Nisha, Singhal, & Pandit, 2004), drumstick (Bineesh, Singhal, & Pandit, 2005) and strawberry products (Castro, Teixeira, Salengke, Sastry, & Vicente, 2004). However, few works have been reported on kinetic data for vitamin C degradation in leafy vegetables during thermal processing.…”

“…Since there are few research studies on the thermal degradation of vitamin C in leafy vegetables (Bineesh et al, 2005;Negi & Roy, 2000), and none at all for watercress thermosonication blanching, the objective of this work was to determine the degradation kinetics of vitamin C in watercress with a combined method of heat and ultrasound. Thus, the findings will help to optimise the design of watercress blanching conditions.…”