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The objective of the study was to assess consumer exposure to warmed-over flavour, their eating habits with respect to pre-cooked stored meats, awareness of antioxidants and attitudes towards the use of natural antioxidants as preservatives in meat and meat products.

A total of 238 Check-All-That-Apply (CATA) design questionnaires were used to gather information from the University of Fort Hare community in the Eastern Cape province of South Africa.

The majority of the respondents had been exposed to warmed-over flavour before. More than half of the respondents did not know about antioxidants. Respondents were in support of the use of natural antioxidants in meat and meat products.

The study mainly captured consumer habits based on living arrangements. Age influence could not be extrapolated due to the nature of the population, which was being studied. The population was limited to the University community, which is mainly made up of not so widely spread age groups and more or less similar levels of education. As a result, the findings and conclusions may not be a true reflection of the general public consumers in terms of age, level of education and employment status.

This research presents an original insight into consumer habits concerning the purchasing and storage of pre-cooked meat and meat products. The study revealed that most consumers nowadays prefer ready-to-eat or pre-cooked meat and meat products due to convenience. The warmed-over flavour is common in pre-cooked meats. The findings suggests that the meat industry has to improve the shelf-life of pre-cooked foods such that warmed-over flavour development is delayed to fit into the current consumer habits. In recent years there has been a growing interest in the use of natural antioxidants to improve shelf-life of muscle foods. However, there is a dearth of information on consumer attitudes towards the use of natural antioxidants as preservatives. This study reveals that consumers are willing to try products formulated using natural antioxidants.

The purpose of this paper is to investigate the potential of fruit waste materials from fruit industry as sources of powerful natural antioxidants.

The peels of mango, rambutan, and santol were extracted and analyzed for their antioxidant activity. Pork ball samples were prepared and treated with different natural extracts at various concentrations, namely 0.05, 0.10, 0.15, and 0.20% (v/w), compared with the control (no natural extract), and then stored at 4°C. The samples were investigated at the zeroth, third, fifth, eighth and tenth day to find out the antioxidant activity of the total phenolic content and lipid oxidation including the evaluation of the change of rancid flavor and color during storage. All statistical results were analyzed by RCBD using SPSS at p⩽0.05.

During storage, the amount of phenolic compound in a pork ball by adding fruit extracts at various concentrations slightly decreased, while the lipid oxidation slightly increased. Mango extract showed the best efficiency to delay lipid oxidation in the pork ball for ten days followed by santol extract and rambutan extract. For sensory evaluation, the pork ball with fruit extract at various concentrations showed the lower rancidity development than control, and mango extract at 0.20% (v/w) showed the best delaying rancidity during ten-day storage. Thus, mango peel extract at 0.20% (v/w) showed the highest effectiveness of antioxidant activity against lipid oxidation in pork ball.

This study was continued from the previous research which investigated the best extraction condition for by-products of mango, rambutan, and santol. From that study, the authors found that the crude extracts need further research on their antioxidant property in foods. The research findings have provided information regarding the interesting new natural antioxidant that can be applied into lipid-containing foods to delay the rancidity and extend the shelf life.

The objective of this study was to evaluate the antioxidant effect of oregano and thyme extracts isolatedly and combinedly applied in soybean oil.

Soybean oil containing 3,000 mg/kg of oregano and thyme oleoresins and the mixture of both, as well as soybean oil containing TBHQ (50 mg/kg) and soybean oil free of antioxidants, were subjected to accelerated oven test (60°C/10 days). Samples were collected every two days and analyzed as to their peroxide and conjugated diene values.

The mixture of oleoresins and consequent increase of concentration were as effective as the antioxidant TBHQ.

These studies may prove to be beneficial to the exploitation of natural antioxidant sources for the preservation and/or extension of raw and processed food shelf life. Therefore, they could also be applied in the area of pharmaceuticals for the protection of human life.

This study offers information on the use of natural antioxidants as an alternative to the use of synthetic antioxidants, which might be considered toxic.

This research aims to evaluate the antioxidant potential of oregano extract (OE), as well as its isolated and synergistic effect when applied to soybean oil (SO) under thermal oxidation.

In order to determine the antioxidant activity of oregano extract and its synergistic effect with tert‐butylhydroquinone (TBHQ), thermal oxidation was performed using the following treatments: SO, SO with 50 mg/kg of TBHQ, SO with 3,000 mg/kg of OE, and SO with 3,000 mg/kg of oregano extract and 50 mg/kg of TBHQ (mixture). The treatments underwent heating at 180°C for 20 hours, and analyses of oxidative stability, total polar compounds, tocopherols and fatty acids composition were performed. The results obtained were subjected to analysis of variance and Tukey test for averages at 5 percent, using the program ESTAT version 2.0.

Considering the results of antioxidant activity and total phenolic compounds, it was possible to verify that the ethanolic extract of oregano has presented antioxidant potential. Furthermore, considering the results obtained in the analyses of oxidative stability, polar compounds, tocopherols and fatty acids profile, it was possible to observe that the extract has prevented lipid oxidation when added to SO.

The study offers information on the use of natural antioxidants as an alternative to the use of synthetic antioxidants, which can be considered toxic.

Equisetum arvense L. (Equisetum) is a weed that is very difficult to remove because of its deep roots. The purpose of this paper is to examine the dyeability and antioxidant activity of Equisetum extracted from hot water.

Dry Equisetum was extracted at 100°C for 2 h, and its dyeability according to time, temperature and repetition cycle, and the mordant effect by skim milk powder were confirmed. The color change according to the K/S, fastness to rubbing, light, sweat and washing, UV protection rate and antioxidant activity were evaluated.

UV‒Vis spectroscopy showed that the Equisetum extract contained a flavonoid compound. The addition of Equisetum to artificial silk produced the greatest color difference when dyed at 60°C for 1 h, and the K/S value increased slightly after the pre-mordant treatment. In the fastness test, light and washing had no significant effect, but the fastness to rubbing was very good at Grades 4 and 5, and there was also a considerable improvement in the UV protection rate. The antioxidant activity of the extract was confirmed by an analysis of the radical scavenging ability through the DPPH (1,1-diphenyl 2-picryl-hydrazyl) and ABTS ([2,2’- azino-bis (3-ethylbenzothialzoline-6-sulfonic acid) diammonium salt]) tests.

These results revealed a new natural antioxidant-containing dyestuff, weed grass, which is easy to obtain, easy to use as a dyeing material and has excellent antioxidant activity in an extracted dye solution and dyeing fabric.

The purpose of this paper is to study the efficiency of lignin/silica and calcium lignate/calcium silicate as natural antioxidants in styrene-butadiene rubber (SBR) vulcanizates.

It has been found that thermal aging data of the aged sample revealed that SBR vulcanizate undergoes crosslink reactions that lead to embrittlement and ultimately failure. Incorporation of lignin/silica or calcium lignate/calcium silicate, however, resulted in significant improvement of the degradation profile of the vulcanizates at 90±1°C. Loss of tensile strength and flexibility during aging of the SBR compounds with 8 phr lignin/silica or calcium lignate/calcium silicate was mild relative to unfilled polymer, indicating a restricted degradation due to the presence of the investigated compounds. The results obtained revealed that the investigated compounds are good antioxidant, and the evaluation was confirmed by physico-mechanical properties of the vulcanizates, FT-IR spectroscopy, transmission (TEM) and scanning (SEM) electron microscope.

It was noticed that SBR vulcanizates having 8 phr of lignin/silica or calcium lignate/calcium silicate exhibited the best mechanical properties in comparison with other concentrations (1, 2, 4, 6 and 10 phr). Also, results revealed that the lignin/silica derivatives are efficient antioxidants in SBR vulcanizates compared to vulcanizates containing conventional antioxidants used in rubber industry, namely polymerized 2,2,4-trimethyl-1, 2-dihydroquinoline (TMQ), and N-isopropyl-N'-phenyl-P-phenylenediamine (IPPD).

All these results indicated that lignin/silica and calcium lignate/calcium silicate in SBR had good heat resistance and aging resistance, calcium lignate/calcium silicate has an application limitation as not all vulcanizates need to use CaCO₃/calcium salts.

Lignin is usually seen as a waste product of pulp and paper industry and is often used as fuel for the energy balance of the pulping process. It is simple isolation along with silica from rice straw and using it as an antioxidant added further practical utility for this waste.

The importance of lignin/silica derivatives is arisen from their biodegradability and their ease availability from rice straw black liquor.

The cowpea plant, being affordable and protein‐rich, is considered poor man's meat. The aim of this paper is to undertake a detailed investigation regarding in vitro total antioxidant capacity (TAC) and chemical constituents of the vegetable oils from seeds of this plant, taking its nutritional value into consideration.

Vegetable oils of different indigenous cowpea varieties were obtained using soxhelt extraction assembly and subjected to GC‐MS analyses and various antioxidant assays including 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulpohonic acid) (ABTS) radical cation scavenging, ferr, 2.2′‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging, total phenolic contents (TPC), lipid peroxidation inhibition, and iron chelation activity.

Various chemical constituents including different hydrocarbons, tocopherols, ketones, fatty esters, estragole and cedrene were identified. TPCs were found to be 5.439, 5.7279, 7.6126, 6.7573 and 10.0591 mg/L gallic acid equivalent for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively. Employing ABTS radical decoloration assay a significant linear correlation (R²=0.997, 0.996, 0.997, 0.996 and 0.997 for S.A. Dandy, Elite, White Star, CP‐386 and FBD Rawan varieties, respectively) was found between the percent inhibition of ABTS radical cation and the amount of vegetable oils. The percent inhibition of the Fe(II)‐Ferrozine complex formation was found to be 29.45, 53.76, 82.91, 86.59 and 57.87 for the same varieties, respectively.

GC‐MS and standard in vitro antioxidative capacity analyses data clearly demonstrated the potency of the cowpea as antioxidant and radical scavenger plant which may be used as a good source of natural antioxidants. The plant seeds may prove a better and cost‐effective substitute of expensive food items.

This study aims to compare the antioxidant and antimicrobial activity of different parts (tip, mid and base portion) of lemongrass leaves for application as a natural ingredient in the functional drink.

Lemongrass leaf powder was prepared from different parts of leaves and evaluated for nutritional composition. Additionally, the extracts of different portions of lemongrass leaves were analyzed for total phenolics, free radical scavenging activities, ferric reducing antioxidant potential (FRAP) and antimicrobial activities for their application in food products.

Tip portion of lemongrass leaf anticipated significantly (p < 0.05) higher contents of ash, protein, calcium, potassium and iron i.e. 6.2 mg/100 g, 18 mg/100 g, 340 ppm, 819 ppm and 32 ppm, respectively. Maximum (p < 0.05) phenolics (14.7 mg GAE/100 g), 2,2-diphenyl-1-picryl-hydroxyl (86.3%) and FRAP (200 mmol/100 g) were observed in lemongrass leaf tip methanolic extracts. Moreover, lemongrass leaf tip hydro-methanolic extracts portrayed maximum zone of inhibition against E. coli and Staphylococcus aureus i.e. 16.7 and 18.2 mm, respectively.

This study demonstrated higher antimicrobial and antioxidant activities of the tip of lemongrass leaves as compared with mid and base portions, hence suggesting its role in the improvement of physicochemical, antimicrobial and antioxidant properties of food products. Consequently, the application of lemongrass methanolic extract up to 10% remarkably enhanced the nutritional value and sensorial acceptance of the beverages.

The present research draws evidence from laboratory analysis of fresh lemongrass grown in Pakistan. The findings suggest that lemongrass methanolic extracts could be used as a nutritionally rich source of antioxidant activity in functional drinks.

The purpose of this paper is to evaluate the oxidative stability of soybean oil added by Lentinus edodes and Agaricus blezei extracts in accelerated storage test.

The following treatments were subjected to accelerated storage test in an oven at 60°C for 15 days: Control (soybean oil without antioxidants), TBHQ (soybean oil+100 mg/kg of TBHQ), BHT (soybean oil+100 mg/kg of BHT), L. edodes (soybean oil+3,500 mg/kg of L. edodes extract) and A. blazei (soybean oil+3,500 mg/kg of A. blazei extract). The samples were taken every three days and analyzed for peroxide values and conjugated dienes.

At the end of 15 days, the treatments TBHQ, A. blazei, L. edodes, Control and BHT showed 6.47, 8.81, 41.53, 71.28 and 78.40 meq/kg, respectively, for peroxide values and 0.37, 0.40, 0.67, 1.07 and 1.00 per cent, respectively, for conjugated dienes.

The research indicates that mushrooms may be a promising source of natural antioxidants. Therefore, natural extracts of mushrooms can be applied to vegetable oils as a way to reduce the degradation caused by lipid oxidation.

The purpose of the study was to explore the possibility of utilization of epigallocatechin-3-gallate (EGCG) as a novel preservative in cheese. EGCG has strong antioxidant and antimicrobial properties and may be commercially exploited as a natural antioxidant and preservative in cheese like products which are highly susceptible to lipid oxidation.

The study was conducted to evaluate the possibility of using EGCG as a natural antioxidant and preservative in cheese. Kalari, a hard and dry cheese, was used as a model and treated with different concentrations of EGCG (0, 0.05 and 0.10 per cent) and aerobically packaged within low-density polyethylene pouches and assessed for oxidative stability and storage quality under refrigerated (4 ± 1°C) conditions.

EGCG showed a significant (p < 0.05) effect on the lipid oxidative stability as the treated products exhibited significantly (p < 0.05) lower thiobarbituric acid reactive substances (milligram malonaldehyde/kg) values. A significant (p < 0.05) effect was also observed on the microbiological characteristics of the products, as treated products showed significantly (p < 0.05) lower values for total plate count (log cfu/g), psychrophilic count (log cfu/g), yeast and mould count (log cfu/g) and free fatty acid (% oleic acid) values. Coliforms (log cfu/g) were not detected throughout the storage period. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the treated products. EGCG successfully improved the oxidative stability and storage quality of Kalari.

The results suggest that EGCG might be useful to the dairy industry as an efficient alternative to synthetic antioxidants and preservatives.