Retard Oil Oxidation Research Articles

Carboxymethyl cellulose based films enriched with polysaccharides from mulberry leaves (Morus alba L.) as new biodegradable packaging material

The objective of this study was to determine the properties of a new active packaging film developed by the addition of mulberry leaves polysaccharides (MLP) into carboxymethyl cellulose (CMC). Biodegradable CMC-MLP films were fabricated by casting method with various concentrations of MLP (1, 5 and 10 % w/w). The addition of MLP into the CMC matrix resulted increased thickness (0.126 to 0.163 mm) and roughness of the films. Also, the decline in moisture content from 27.91 to 14.12 %, water vapor permeability from 8.95 to 5.21 × 10−10 g−1 s−1 Pa−1, and a swelling degree from 59.11 to 37.45 % were observed. With the increasing concentration of MLP, the mechanical properties of the films were improved and higher dispersion of UV light were noted. Fourier transform - infrared spectroscopy (FT-IR) and X-ray diffraction revealed good inter-molecular interaction between CMC matrix and MLP. The prepared films showed excellent thermal stability, antioxidant and antibacterial properties as well as susceptibility to biodegradation in the soil environment. Moreover, it was proved that the films have ability to retard oil oxidation. Overall, it was concluded that CMC-MLP films constitute a promising biomaterial that may be applied as active food packaging.

Antioxidant and antimicrobial packaging films developed based on the peel powder of different citrus fruits: A comparative study

Citrus is the largest fruit crop planted worldwide. However, the global citrus fruit processing byproducts have not been fully utilized up to now. Citrus peels contain valuable biopolymers and bioactive substances, which are suitable to develop food packaging films. In this study, active packaging films were prepared by directly utilizing citrus peels in their powder form. The films produced from the peel powder of four different citrus fruits (orange, lemon, pomelo and mandarin) were compared for their structural and functional properties. Results showed the four kinds of citrus peel powder contained 16.36%–23.80% pectin, 5.68%–8.23% protein, 3.17%–7.65% lipid, 2.88%–6.27% crude fiber and 11.45–15.47 mg GAE/g polyphenols. Four kinds of citrus peel powder based films exhibited rough surface and transverse with yellow or flesh color. These films had 0.124–0.157 mm of thickness, 18.16%–25.25% of moisture content, 51.98–121.64°of water contact angel, 1.34–1.92 × 10−10 g m−1 s−1 Pa−1 of water vapor permeability, 0.36–0.69 cm3 mm m−2 day−1 atm−1 of oxygen permeability, 8.26–9.14 MPa of tensile strength and 8.05%–17.18% of elongation at break. These films also showed strong antioxidant and antimicrobial activity, which retarded corn oil oxidation. Among the films, mandarin peel powder based film was most effective in retarding oil oxidation due to the excellent light and oxygen barrier capacity and antioxidant activity of the film. Results suggested mandarin peel powder based film was suitable for the active packaging of corn oil.

Xanthan gum-assisted fabrication of stable emulsion-based oleogel structured with gelatin and proanthocyanidins

Oleogelation based on emulsion using food-approved biopolymers is a feasible strategy to substitute solid fat with harmful trans and saturated fatty acids, providing food products with a better nutritional profile. However, oil with high content of unsaturated fatty acids is prone to oxidation, resulting in quality loss of food products. In the present study, proanthocyanidins from Chinese bayberry leaves (BLPs) were incorporated into emulsion-based oleogel to remedy the defect through the formation of colloidal complexes with gelatin. Oleogel stabilized with the colloidal complexes showed higher stability with lower oil loss and higher gel strength, compared to that with gelatin only. Then different polysaccharides were applied to further promote oleogel stability. However, polysaccharides abrogated the promotive effect of BLPs and resulted in comparable stability of oleogels with BLPs or not, which was confirmed with cryo-SEM observation. Then the application of oleogel with BLPs as margarine alternative was verified with batter properties, quality loss of cakes and oil stability in cakes. Batter properties of oleogel with BLPs were comparable to that without BLPs, and more close to margarine than oil. For quality loss, textural properties of oleogel cakes with BLPs or not resembled each other and were significantly better than oil cakes in hardness and chewiness and margarine cakes in cohesiveness. Particularly, BLPs were verified to retard oil oxidation in both oleogel and cakes prepared with oleogel. Overall, incorporation of BLPs into oleogel was feasible to improve its oil stability and keep its application in cake products.

Characterization and antioxidant activity of trilayer gelatin/dextran-propyl gallate/gelatin films: Electrospinning versus solvent casting

In this study, trilayer films were prepared with an electrospun dextran interlayer, and gelatin outlayers fabricated by solvent casting and electrospinning, respectively. The trilayer film either with casted or electrospun outlayers showed an enhanced thermal stability, and acceptable color and opacity properties. Compared to the electrospun outlayers, the casted outlayers endowed the trilayer film with improved oxygen and water vapor barrier properties, and significantly enhanced the elastic modulus and tensile strength, indicating a greater resistance to deformation. The DPPH radical-scavenging activity assay indicated that the applied electrospun or casted outlayers effectively prolonged the release time of propyl gallate from the interlayer by 2-fold or more, with a sustained antioxidant activity. These results suggest the promising applications of multilayer films as active packaging materials with prolonged release of antioxidants to retard oil oxidation in the food industry.

Frying stability of canola oil supplemented with ultrasound-assisted extraction of Teucrium polium.

In this study, antioxidant activity and protective effects of Teucrium polium extract in stabilizing of canola oil during frying were tested and compared to synthetic antioxidant, BHA. Total phenolic, α‐tocopherol, flavonoid, and condensed tannin content of Teucrium polium extracted by ethanol ultrasound‐assisted were 60.90 mg/g, 103.66 μg/ml, 4.36 mg/g, and 3.77 mg/g, respectively. Moreover, IC50 of the extract was 924.21 ppm. Canola oil samples containing 200, 600, and 1,000 ppm of the extract were heated at 180˚C for 30 hr and compared with BHA. Progress of oil oxidation was determined by measuring their peroxide value (PV), acid value (AV), iodine value (IV), carbonyl value (CV), color index (CI), conjugated diene value, and total polar compounds (TPC). The results showed that the extract was capable of retarding oil oxidation and deterioration significantly (p < .05) at all concentrations during frying. So, Teucrium polium extract can be used as natural antioxidant to retard oil oxidation.

Characterization of fish sausage manufactured with combination of sunflower oil and fish oil stabilized with fish roe protein hydrolysates.

The present study aimed to determine the effect of adding protein hydrolysates obtained after 30, 60, and 90min enzymatic hydrolysis of fish roe on properties of silver carp sausages enriched with fish oil during storage at 4°C for 30days. Properties of the fortified sausages were determined by assessment of primary and secondary oxidation, fatty acid composition, microbial spoilage, texture, and organoleptic properties. The results indicated that the hydrolysates could retard oil oxidation and microbial spoilage and preserve n - 3 fatty acids in fish sausages during the refrigerated storage. Also, they rendered firmer microstructure with smaller oil droplets to the sausages. Fish sausages fortified with the hydrolysates were lighter and exhibited better textural and sensory properties. It can be concluded that enzymatic hydrolysates from discarded fish roe can be added to fish sausages containing fish oil to retard oil oxidation and microbial spoilage and improve sausage properties.

The effect of high-density polyethylene active packages containing rosemary extract powder on oxidative stability of sunflower oil

The effect of high-density polyethylene (HDPE) active packages containing rosemary extract powder (REP) on the oxidative stability of sunflower oil was studied in the present investigation. The antioxidant free sunflower oil was packed in HDPE bottles containing 3% of REP and 3% of butylated hydroxytoluene (BHT). The treatments were stored at 25 °C and 40 °C for 120 days. The migration of BHT and carnosic acid as the main antioxidant agent of REP was determined using high performance liquid chromatography (HPLC). Measuring the peroxide, p-anisidine, thiobarbituric acid (TBA) values and induction period, both treatments showed a significant (p < 0.05) higher oxidative stability compared to control samples but no considerable (p < 0.05) difference was seen between two treatments despite lower migration of carnosic acid than BHT. Results indicate that use of antioxidant active packages can be an effective method for retarding oil oxidation and rosemary can be as strong as synthetic antioxidants in increasing the oxidative stability of the oil.

Effect of Cross-Linking of Interfacial Sodium Caseinate by Natural Processing on the Oxidative Stability of Oil-in-Water (O/W) Emulsions

This study investigated how enzymatic cross-linking of interfacial sodium caseinate and emulsification, via high-pressure homogenization, influenced the intrinsic oxidative stability of 4% (w/v) menhaden oil-in-water emulsions stabilized by 1% (w/v) caseinate at pH 7. Oil oxidation was monitored by the ferric thiocyanate perioxide value assay. Higher homogenization pressure resulted in improved intrinsic emulsion oxidative stability, which is attributed to increased interfacial cross-linking as indicated by higher weighted average sedimentation coefficients of interfacial protein species (from 11.2 S for 0 kpsi/0.1 MPa to 18 S for 20 kpsi/137.9 MPa). Moderate dosage of transglutaminase at 0.5-1.0 U/mL emulsion enhanced intrinsic emulsion oxidative stability further, despite a contradictory reduction in the antioxidant property of cross-linked caseinate as tested by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. This implied the prominent role of cross-linked interfacial caseinate as a physical barrier for oxygen transfer, hence its efficacy in retarding oil oxidation.

Comparison Antioxidant Properties Extract of Touyserkani Variety of Walnut Leave with two Extraction Methods (Traditional Method and Microwave Assisted Extraction)

The aim of this study is extraction of phenolic compounds from walnut leaves of touyserkani variety with two extraction methods (traditional method and with microwave assisted extraction (MAE)) and evaluation of their antioxidant activity. Total Phenolic contents and antioxidant properties of aqueous, methanol (80%) and ethanol (50%) extracts in different times was determined. At the next stage, effect of methanol extract on retarding of oxidation of soy oil was assessed. All of extracts showed antioxidant activity in a concentration-dependent way. In MAE, methanol extract had highest total phenol whose content is 89.15 ± 0.25 mg/g. the ethanol extract presented highest activity in radical-scavenging activity (EC50 = 27.90 µg/ml), reducing power assay (EC50 = 93.26 µg/ml) and antioxidant activity assay (EC50=68.23 µg/ml). Also extract at 1000 ppm could control oxidation of soy oil and this extract was effective than all of synthesis antioxidant in retarding oil oxidation Hence we can present walnut leaves as a potential source of phenolic compounds and natural antioxidant.

Antioxidative Properties of Curcuma longa Leaf Extract in Accelerated Oxidation and Deep Frying Studies

AbstractThe 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 &lt; 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 &lt; 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.

Evaluation of Capsicum as a Source of Natural Antioxidant in Preventing Rancidity in sunflower Oil

Solvent extraction to obtain oleoresins of flavonoid and carotenoid extracts was done from 200 grams of commercial paprika powder. Petroleum ether was used to defat the sample. Methanol and n-butanol were used in turn to extract the polar flavonoids, while chilled acetone and petroleum ether were used in turn for the extraction of nonpolar carotenoids. The flavonoid yield was 5.92grams while that for the carotenoids was 39.15 grams per 100g of the powder. These residues were tested on sunflower oil to evaluate their antioxidant effects. The accelerated methods used for oxidation were the Automated Rancimat, Oven heating and UV light at 254 nm. The oxidation of sunflower oil was measured using changes in peroxide values and the UV absorbances (Conjugated diene) at 232 nm, E1% 1cm. The extracts tested possess antioxidant effect and this phenomenon was enhanced by increasing their concentration, since they were impure. The major components of paprika (b-carotene and capsanthin) were also tested on the oil as pure standards while Butylenehydroxytoluene (BHT) was used as a standard antioxidant. Results showed that carotenoids seemed to be effective in retarding oil peroxidation under photoxidation, while showing pro-oxidant activity under oven heating autoxidation, and showing slight antioxidant activity under Rancimat autoxidotion tests. The flavonoids were effective in retarding oil oxidation under both photoxidation and thermal autoxidation tests, with the column separated fractions 3 and 4 conferring better antioxidant activity under the Rancimat test. These column separated fractions, were identified by the UV Spectra as 3-hydroxyflavanones or dihydroflavonols. Key words: Paprika, Carotenoids, Flavonoids, natural antioxidants. J Food Tech in Africa (2002) 7, 68-72