Reduction of Roasted Peanut Lipid Oxidative Rancidity by Power Ultrasound and Edible Coatings Containing Natural Extracts

Abstract

The antioxidative potential of jujube extract, pomegranate extract and tocopherol mixed into carboxymethyl cellulose (CMC) solution then coated on roasted and roasted–sonicated peanuts was investigated. The concentration of jujube and pomegranate extracts added into the CMC solution was 1,000 ppm, while synthetic tocopherol was 250 ppm. Antioxidant effect was determined by the measurement of oxidative stability index. After 12 weeks of storage at 35C, the reduction in oxidation was 14.5 and 19.7% for samples roasted–coated with CMC added with extracts of jujube and pomegranate extract, respectively, as compared to uncoated sample (R as a control). Meanwhile, the oxidative stability of samples roasted–sonicated coated with CMC added with extracts of jujube and pomegranate was significantly (P < 0.05) improved by 24.8 and 31.8%, respectively, in relation to the control. However, it was observed that samples with tocopherol did not have any improvement in oxidative stability of the roasted peanuts. Sonication treatment beyond coating improved the storage stability of the samples mixed with jujube extract, pomegranate extract and tocopherol by 10.3, 12.1 and 3.2%, respectively. It is concluded that jujube and pomegranate extracts can control roasted peanut lipid oxidation during storage. PRACTICAL APPLICATIONS This study showed that a combination of power ultrasound treatment and an edible coating of carboxymethyl cellulose mixed with natural plant extracts can be used for delaying the oxidation of roasted peanuts. The delaying development of oxidation compounds in roasted peanuts is very useful to the peanut industry. This process can be used for the preparation of shelf‐stable peanut products for the purpose of reaching distant markets, to be used during extended storage period. Likewise, the peanuts can be packed without the need to modify the packaging atmosphere or use of expensive packages.

Antioxidant Containing Gum Cordia Coatings for Control of Peanut Oxidation

“…Adhesion is an important property of polymer and is defined as tendency of surface mol-ecules of different substances to cling one another, such as clinging of coating material to food surfaces. Similar, prooxidant effect of alpha tocopherol has been reported in previous studies (Wambura et al 2010(Wambura et al , 2011. Better deposition of gum cordia ultimately resulted in better performance throughout the storage.…”

“…Edible coatings prevent moisture loss and reduce oxygen diffusion in nuts (Quezada-Gallo 2009). Carboxymethyl cellulose (CMC; Wambura et al 2008Wambura et al , 2010Wambura et al , 2011, whey protein isolate (WPI; Mate et al 1996;Min and Krochta 2007;Han et al 2008) and corn zein (Wambura et al 2008) have been reported as coatings to retard the oxidative rancidity in peanuts. Carboxymethyl cellulose (CMC; Wambura et al 2008Wambura et al , 2010Wambura et al , 2011, whey protein isolate (WPI; Mate et al 1996;Min and Krochta 2007;Han et al 2008) and corn zein (Wambura et al 2008) have been reported as coatings to retard the oxidative rancidity in peanuts.…”

Gum Cordia: A novel edible coating to increase the shelf life of Chilgoza (Pinus gerardiana)

“…The effectiveness of coating with tocopherol is highly dependent on the concentration and temperature (Tasan & Demirci, 2005). Similar, pro-oxidant effect of alpha tocopherol has been reported in peanut as well (Wambura et al, 2010;Wambura, Yang, & Mwakatage, 2011).…”

“…The role of phenolic compounds has been reported to improve the oxidation retardation capabilities of edible coatings (Mestrallet, Nepote, Quiroga, & Grosso, 2009;Wambura et al, 2010Wambura et al, , 2011. It is therefore, most likely that the effectiveness of methanolic extract of Cordia is due to these compounds.…”

“…Edible coatings in nuts may prevent moisture loss and oxygen diffusion, and could be used as a vehicle for additives such as antioxidants (Quezada-Gallo, 2009). Carboxymethyl cellulose (CMC), whey protein isolate (WPI) and corn zein have been reported as coating materials to retard the oxidative rancidity in nuts (Wambura, Yang, & Mwakatage, 2010).…”