• Title/Summary/Keyword: Oxidative Stability

Search Result 420, Processing Time 0.023 seconds

Thermal and Electrochemical Properties of Polymannuronate-polyaniline Nanocomposites

  • Basavaraja, C.;Veeranagouda, Y.;Kim, Na-Ri;Jo, Eun-Ae;Lee, Kyoung;Huh, Do-Sung
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.5
    • /
    • pp.1097-1100
    • /
    • 2009
  • New types of conducting polyaniline-polymannuronate (PANI-PM) composites were synthesized by in situ deposition techniques in an aqueous media. By dissolving different weight percentage of polymannuronate (PM) (5, 10, 15, and 25%), the oxidative polymerization of aniline was carried out using ammonium per sulfate as an oxidant. The obtained composites were studied for their thermal stability and electrochemical behavior. The thermal stability of PANI-PM composites is lower than PANI, which supports a strong interaction between PANI and PM. However, the composites show an appreciable electrochemical behavior. Based on these observation the PANI-PM composites can be explored in different fields such as electric devices, sensors, functional coatings, etc.

Effects of Seed Germination on Oil Oxidation and Tocopherol Stability of Perilla Oil (들깨의 발아가 들깨유의 산화 및 토코페롤 안정성에 미치는 영향)

  • Hwang, Hyun-Suk;Choe, Eun-Ok
    • Korean Journal of Food Science and Technology
    • /
    • v.43 no.3
    • /
    • pp.255-262
    • /
    • 2011
  • Auto- and photo-oxidative stability of oil extracted from germinated perilla seeds during storage at $60^{\circ}C$ for 4 days was studied by determining peroxide and conjugated dienoic acid values. Tocopherol contents during oil oxidation were also monitored by high performance liquid chromatography. Perilla oil was oxidized and tocopherols were degraded during storage at $60^{\circ}C$ regardless of the presence of light. Light increased oil oxidation and tocopherol degradation. Seeds germinated for 12 h had increased tocopherol contents in the oil and improved the auto- and photo-oxidative stability of the perilla oil. Tocopherol played a more important role as an antioxidant in the presence of light than in the absence of light.

The Effect of Low Erucic Acid Rapeseed Oil for the Preparation of Mayonnaise on Quality Characteristics (마요네즈 제조시 품질특성에 미치는 저에루신산 유채유 혼합의 영향)

  • Kim, Jae-Wook;Son, Yang-Do;Hong, Ki-Ju;Yoo, Moo-Yeong;Jeong, Gae-Whan;Hur, Jong-Wha
    • Korean Journal of Food Science and Technology
    • /
    • v.27 no.3
    • /
    • pp.298-302
    • /
    • 1995
  • This study was performed to know the availability of low erucic acid rapeseed oil (LEAR oil) for vegetable oil in commercial mayonnaise preparation. Mixed oils (blended soybean oil with LEAR oil) were prepared and mayonnaises were prepared with these oils and then compared the quality characteristics of these samples. The oxidative stability of vegetable oil with Rancimat test showed that LEAR oil was higher stability than soybean oil, and became higher with increase of LEAR oil ratio. Quality characteristics of mayonnaises with these oils showed that mayonnaise with mixed oils was preferred to that with LEAR oil itself. Furthermore, the quality characteristics of mayonnaises with mixed oils of soybean oil $(20{\sim}60%)$ plus LEAR oil $(80{\sim}40%)$ were better than those of mayonnaise with soybean oil solely.

  • PDF

Comparison of Butylated Hydroxytoluene, Ascorbic Acid, and Clove Extract as Antioxidants in Fresh Beef Patties at Refrigerated Storage

  • Zahid, Md. Ashrafuzzaman;Seo, Jin-Kyu;Parvin, Rashida;Ko, Jonghyun;Yang, Han-Sul
    • Food Science of Animal Resources
    • /
    • v.39 no.5
    • /
    • pp.768-779
    • /
    • 2019
  • This study was performed to assess the comparison of the effects amongst butylated hydroxytoluene (BHT), clove extract (CE), and ascorbic acid (AA) as antioxidants on the oxidative stability and color values in fresh beef patties. The adding of BHT, AA, and CE to patties significantly restrained lipid oxidation, lowered hue angle as color value, and expanded redness and chroma values of fresh beef patties in comparison to the control (p<0.05). BHT and AA significantly led to impede the protein oxidation of patties by lowering carbonyl content (p<0.05). CE had no negative effect on protein oxidation. The antioxidant effects of BHT, AA, and CE were obviously manifested. Nonetheless, BHT, AA, and CE appeared to have insignificant difference of each other for lowering the protein oxidation at the end of storage. BHT and CE represented lowered lipid oxidation in comparison to AA. The antioxidant effects of BHT, AA, and CE on lipid oxidation were more marked than the effects on protein oxidation. Furthermore, CE as a natural antioxidant evinced the efficiency in oxidative stability and color stability in fresh beef patties. The study implied that CE could substitute the use of BHT and AA when making beef patties during storage.

Muscle-specific color stability in fresh beef from grain-finished Bos indicus cattle

  • Salim, Ana Paula A.A.;Suman, Surendranath P.;Canto, Anna C.V.C.S.;Costa-Lima, Bruno R.C.;Viana, Fernanda M.;Monteiro, Maria Lucia G.;Silva, Teofilo J.P.;Conte-Junior, Carlos A.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.7
    • /
    • pp.1036-1043
    • /
    • 2019
  • Objective: To investigate the color and oxidative stabilities of longissimus lumborum (LL) and psoas major (PM) muscles from grain-finished Bos indicus cattle in Brazil. Methods: The LL and PM muscles were obtained 24 h post-mortem from eight (n = 8) Nellore bull carcasses, fabricated into 1.5-cm steaks, aerobically packaged, and stored at $4^{\circ}C$ for nine days. Steaks were analyzed for myoglobin concentration, pH, instrumental color, metmyoglobin reducing activity (MRA) and lipid oxidation. Results: The LL steaks exhibited greater (p<0.05) redness, color stability, and MRA than their PM counterparts on days 5 and 9. The LL and PM steaks demonstrated similar (p>0.05) lightness and yellowness on days 0, 5, and 9. On the other hand, PM steaks exhibited greater (p<0.05) myoglobin concentration, pH, and lipid oxidation than their LL counterparts. Conclusion: These results indicated that muscle source influenced the color and oxidative stabilities of beef from grain-finished Bos indicus animals. These results highlighted the necessity of muscle-specific strategies to improve the color stability of beef from grain-fed Bos indicus cattle.

Feeding influences the oxidative stability of poultry meat treated with ozone

  • Ianni, Andrea;Grotta, Lisa;Martino, Giuseppe
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.6
    • /
    • pp.874-880
    • /
    • 2019
  • Objective: Ozone is considered a strong antimicrobial agent with numerous potential applications in the food industry. However, its high oxidizing potential can induce alterations in foods by acting on the unsaturated fatty acids. The aim of this study was to investigate the effect of ozonation on the oxidative stability of chicken breast meat obtained from animals subjected to different feeding strategies. Methods: Samples were obtained from commercial hybrid chickens (ROSS 508), some of which were nourished with a feed enriched with fats of animal origin, while the lipid source was vegetal for the remaining birds. Samples of meat belonging to both groups were treated with ozone and then analysis was performed to evaluate alterations in physical properties, lipid content, fatty acid profile, and oxidation stability. Results: Ozone induced a significant reduction in drip loss in meat samples obtained from animals nourished with vegetable fats; this nutritional strategy also produced meats leaner and richer in polyunsaturated fatty acids. Thiobarbituric acid reactive substances, useful for the assessment of lipid oxidation, were higher in samples obtained from animals fed with vegetable fats with respect to diet based on the addition of animal fats. Conclusion: The ozone treatment improved the physical parameters of meat samples obtained from animals fed with vegetable fats, however the same samples showed a higher lipid oxidation compared to what observed in the case of the dietary intake of animal fats, probably as a consequence of the marked increase in polyunsaturated fatty acids which are more susceptible to peroxidation.

The protective effects of trace elements against side effects induced by ionizing radiation

  • Hosseinimehr, Seyed Jalal
    • Radiation Oncology Journal
    • /
    • v.33 no.2
    • /
    • pp.66-74
    • /
    • 2015
  • Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) induced by ionizing radiation in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against radiation-induced DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity induced by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against radiation without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects induced by ionizing radiation.

Physicochemical Characteristics and Oxidative Stabilities of Defatted Mealworm Powders under Different Manufacturing Conditions (제조 방법을 달리한 갈색거저리 유충 탈지 분말의 물리화학적 특성 및 저장 안정성)

  • Son, Yang-Ju;Hwang, Ja-Young
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.27 no.2
    • /
    • pp.194-203
    • /
    • 2017
  • Mealworm, a type of edible insect, is a superior food material suitable for industrial products. In this study, four different defatted mealworm powders were prepared to determine proper manufacturing conditions. Solvent extraction method reduced lipid contents of mealworms more than pressed mealworms, and lowered lipid contents caused bright colors and good physicochemical properties for powders. In comparison, differences among milling machines used for making powders were strongly related with average size of particles. Meanwhile, the predicted shelf-life of defatted mealworm powders judged by accelerated experiments was 1 year or longer. To enhance shelf-life of mealworm powders, addition of tocopherol to mealworm powders at a concentration of 0.2% could intensify oxidative stability and microbial inhibition.

Extended H$\ddot{u}$ckel Calculations on the Oxidative Addition Reaction of $(TBA)_2Pt(CN)_4$ with Halogen

  • Ko, Jae-Jung;Park, Kuk-Tae;Lee, Ik-Choon;Lee, Bon-Su
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.5
    • /
    • pp.443-447
    • /
    • 1989
  • The mechanism on the oxidative addition reaction of $(TBA)_2\;Pt(CN)_4$ with $Cl_2$ has been studied by means of extended Huckel calculations. Among two possible mechanisms, computational calculations demonstrated that the linear approach of $Cl_2$ to a $Pt(CN)_4$ moiety is more favourable than three-centered transition state. From our calculations, the most stable process is that a $Pt(CN)_4$ moiety interacts with $Cl_2$ in the linear transition state and the cleavage of Cl-Cl bond in a coordinated halogen occurred spontaneously, giving rise to a trans product by back-attacking a $Pt(CN)_4Cl$ moiety by Cl. The process consists of the comparison in the stability of each intermediate with use of bonding and potential energy.

Studies on the Variation of Physico-Chemical Characteristics During Storage and Frying (고추씨 기름의 저장 및 가열에 따른 이화학적 변화에 관한 연구)

  • Choi, Young-Jin;Ko, Young-Su
    • Korean journal of food and cookery science
    • /
    • v.6 no.2
    • /
    • pp.67-76
    • /
    • 1990
  • To observe the propability as the frying oil and oxidative stability of red pepper seed oil, some physico-chemical tests of the oil were examined during 21 days storage period at 5$^{\circ}C$, 15$^{\circ}C$ and 30$^{\circ}C$, and AOM value determined and after heating the oil at 180${\pm}$5$^{\circ}C$ for 40 hours with or without antioxidants. The analysis storage stability of red pepper seed oil showed that the quality of storage group at 5$^{\circ}C$ was almost as good as fresh oil, and the storage group at 30$^{\circ}C$ showed certain degree of rancidity. Change of physico-chemical characteristic during storage were so small so that storage stability of red pepper seed oil was found to be good. AOM stability of red pepper seed oil was 7 hours which is lower than other vegetable oil, but the degree of stability grew greatly after adding phenolic antioxidants, such on TBHQ or PG. As for the chemical change after heating continuously for 40 hours, acid value, peroxide value and refractive index increased, but iodine value decreased as the heating processed. The fatty acid composition also showed the remarkable reduction of linoleic acid. The addition of antioxidants resulted in the delay of oxidation, the degree of which was greater in TBHQ than in PG.

  • PDF