Antioxidative Activities of Selected Malaysian Herb Extracts during Accelerated Oxidation Test and Deep- Fat Frying

The potential use of selected Malaysian herb (Murraya koenigii, Curcuma longa, Citrus hystrix and Pandanus amaryllifolius) leaf extracts as natural antioxidant were evaluated in antioxidant assay, accelerated oxidation test and deep fat frying. They were analyzed for antioxidant activity using 1-1-diphenyl-2-hydrazyl (DPPH) radical- scavenging activity assay and linoleic acid model system. The extracts at different concentrations were added to refined, bleached and deodorized (RBD) palm olein and heated to frying temperature, analyzed for peroxide value, anisidine value, free fatty acid and oxidative stability index (OSI). From there, optimum concentration was chosen and 40 hr frying experiment was being carried out. The polyphenol content ranged from 101.4 mg in P. amaryllifolius to 116.3 mg C. longa. The antioxidative activity of the extracts in both assays followed the decreasing order of: C. longa> M. koenigii> C. hystrix> P. amaryllifolius. 2000 ppm was chosen as the optimum concentration to be used in deep frying experiment. Extracts of Pandanus amaryllifolius and Citrus hystrix exhibited protective activity towards RBD palm olein that was comparable to BHT (p>0.05) during frying. The extracts were useful in improving and also maintaining the sensory characteristics of French fries. The French fries treated with herb extracts were acceptable by panelists until day 5 of frying. The natural antioxidants significantly (p<0.05) lowered the rate of oil oxidation during deep- fat frying and maintaining the quality of French fries. They exhibited excellent heat- stable antioxidant properties are good natural alternative to existing synthetic antioxidants for the food industry

Antioxidative properties of Pandanus amaryllifolius leaf extracts in accelerated oxidation and deep frying studies

The potential uses of Pandanus amaryllifolius leaf extract as a natural antioxidant were evaluated in refined, bleached and deodorized (RBD) palm olein, using accelerated oxidation and deep frying studies at 180 °C from 0 to 40 h. The extracts (optimum concentration 0.2%) significantly retarded oil oxidation and deterioration (P < 0.05), comparably to 0.02% BHT in tests such as peroxide value, anisidine value, iodine value, free fatty acid, oxidative stability index (OSI), polar and polymer compound contents. In sensory evaluation studies, different batches of French fries were not significantly different (P < 0.05) from one another for oiliness, crispiness, taste and overall acceptability when the same oil was used for up to the 40th hour of frying. P. amaryllifolius leaf extract, which had a polyphenol content of 102 mg/g, exhibited an excellent heat-stable antioxidant property and may be a good natural alternative to existing synthetic antioxidants in the food industry

Antioxidative properties of curcuma longa leaf extract in accelerated oxidation and deep frying studies.

The antioxidative properties of Curcuma longa (turmeric) leaf extract were evaluated in refined, bleached and deodorized (RBD) palm olein using accelerated oxidation and deep frying studies at 180 °C for up to 40 h. The extract was capable of retarding oil oxidation and deterioration significantly (P < 0.05) at 0.2% concentration, better than 0.02% BHT for the Oxidative Stability Index (OSI) in an accelerated oxidation study and also the peroxide value in deep frying studies. In sensory evaluation, the French fries were acceptable and were not significantly different (P < 0.05) from one another for color, oiliness and crispiness throughout the 40-h frying study. Curcuma longa leaf extract, which had a polyphenol content of 116.3 ± 0.2 mg/g, possessed heat-stable antioxidant properties and may be a good natural alternative to existing synthetic antioxidants in the food industry

Commercialized innovative herbal products from UPM

The product invention is an additive which can be incorporated into edible oil composition especially cooking oil to provide therein antioxidant effect and reduce oil adsorption into the food prepared. The additive is composed of biophenolics formulated from plant extracts of the Rutaceae family. The antioxidant characteristics of Rutaceae leaf alcohol extract were evaluated in refined, bleached and deodorized (RBD) palm olein at 180oC using an accelerated oxidation and deep frying studies for up to 40 hours. The extract, at the optimum concentration 0.1%, retarded oil deterioration significantly (P<0.05) in deep frying studies, comparable to 0.02% BHT (Butylated Hydroxy Toluene) in tests such as peroxide value, anisidine value, free fatty acid, Oxidative Stability Index (OSI), polar and polymer compounds content. The sensory evaluation of french fries fried in oil containing the extract showed significant (P<0.05) improvement in crispiness, taste and overall quality, especially after the 40th hour of frying compared to those similarly fried in the control oils and the oils containing BHT. The polyphenols content of the extract were 103.2 mg/g gallic acid equivalent. Rutaceae leaf extract exhibited excellent heat stable natural antioxidant properties that retarded oil degradation and improved the quality of the fried product

An additive for edible oil composition.

An extract derives from plant parts of Rutaceae plant family to be incorporated into a cooking oil composition for reducing oil absorption into food fried in the cooking oil composition thereof