Antioxidant Properties of Selected Plant Extracts and Application in Packaging as Antioxidant Cellulose‐Based Films for Vegetable Oil

Abstract

Selected plant extracts including cinnamon, clove, ginger, green tea and thyme were investigated for their antioxidant activity by using both -carotene-linoleate bleaching agar well diffusion and -carotene-linoleate bleaching broth assays, and for radical scavenging activity against free radicals using a 2,2-diphenyl-1picrylhydrazyl assay. Undiluted plant extracts (except ginger oil) showed a yellow zone of -carotene ranging from 15.3 to 38.2mm in diameter. At a concentration of 50LmL -1 , thyme yielded the highest antioxidant activity (260%), followed by ginger (254%), cinnamon (108%), clove (106%) and green tea (101%), respectively. Conversely, at a plant extract concentration of 0.39mL mL -1 solution in ethanol, green tea yielded the highest radical scavenging activity (94.3%), followed by clove (93.4%), cinnamon (91.1%), thyme (30.4%) and ginger (8.29%), respectively. The minimum oxidative bleaching inhibitory concentrations (MOBICs) of these plant extracts were determined using a b-carotene-linoleate bleaching broth dilution assay ranging from 0.195 to 50mLmL -1 . The MOBICs of plant extracts in a range of 0.195-1.56mLmL -1 could reveal an ability to inhibit the oxidation of b-carotene-linoleate broth. Cellulose-based film containing cinnamon, clove or green tea showed positive activity against b-carotene-linoleate oxidation and 2,2-diphenyl-1-picrylhydrazyl radicals. Protective effects of plant extracts incorporated in cellulose-based pouches in stabilizing soybean oil were tested by measuring their peroxide values and free fatty acid contents during accelerated storage. Green tea-incorporated cellulose-based pouches exhibited stronger antioxidant properties in soybean oil than do butylated hydroxyanisole-incorporated cellulose-based pouches. This study showed the potential use of plant extracts as antioxidants for food packaging application.Free radical scavenging activity using DPPH scavenging method. Cellulose-based films containing cinnamon oil, clove oil or green tea extract also showed positive radical scavenging activity against DPPH radicals (Table 3). Their relative activity was cloveÀ>cinnamonÀ>green teaÀcellulosebased film. It is interesting to note that all plant extract cellulose-based films were more effective against DPPH radicals in comparison with the b-carotene-linoleate bleaching assay. 132P. PHOOPURITHAM ET AL.

Spices and Herbs as a Source of Natural Antioxidants for Food

“…After 8 weeks under accelerated storage conditions, the antioxidant effects of clove oil yielded inhibition rate of 10.6%. This study showed the potential use of plant extracts (cinnamon and clove oil) as antioxidants for food packaging application (Phoopuritham et al, 2012).…”

Biopolymers of WPI/CNF/TEO in preventing oxidation of ground meat

“…For nanobiopolymers films, emulsion A (4 ml) was added to test tubes containing nanobiopolymers, cut into 2 × 2 cm pieces (Phoopuritham, Thongngam, Yoksan, & Suppakul, ). Two solutions, one with no antioxidant (control) and the other without β‐carotene (emulsion B — white), were prepared.…”

Antioxidative Packaging System

“…Structures such as porous solid food can be protected by the migration of volatile active agents in antioxidant packaging systems (Figure 6.2B). Antioxidants of natural origin that have been studied in the development of antioxidant packaging include tocopherol, ascorbic acid, curcumin, tyrosine, essential oils and plant extracts of barley husks, borage, cinnamon, citronella, clove, ginger, green tea, marigold, murta leaves, rosemary, oregano, and thyme (Camo et al, 2008;Colín-Chávez et al, 2012;Gemili et al, 2010;Gimenez et al, 2011;Gutiérrez et al, 2012;Nerin et al, 2008;Phoopuritham et al, 2012;Sonkaew et al, 2012;Wessling et al, 1999). Scavenging of vapor-phase radicals has been suggested as a possible mechanism.…”

“…Synthetic antioxidants of BHA and BHT, which have been used to protect polymers during film manufacture, have some degree of volatility and could migrate to the contained solid food through the gas phase (Miltz et al, 1988;Wessling et al, 2001). Antioxidant films from rosemary, oregano, clove, and cinnamon could play a role in inhibiting oxidative quality deterioration for systems with both indirect and direct contact between the packaged food and the film (Camo et al, 2008;Nerin et al, 2008;Phoopuritham et al, 2012). Antioxidant films from rosemary, oregano, clove, and cinnamon could play a role in inhibiting oxidative quality deterioration for systems with both indirect and direct contact between the packaged food and the film (Camo et al, 2008;Nerin et al, 2008;Phoopuritham et al, 2012).…”