Improving water quality and mitigating CH4 and N2O production in urban landscape water simultaneously by optimizing calcium peroxide dosage.

Recent studies show that greenhouse gas (GHG) emissions from urban landscape water are significant and cannot be overlooked, underscoring the need to develop effective strategies for mitigating GHG production from global freshwater systems. Calcium peroxide (CaO2) is commonly used as an eco-friendly reagent for controlling eutrophication in water bodies, but whether CaO2 can reduce GHG emissions remains unclear. This study investigated the effects of CaO2 dosage on the production of methane (CH4) and nitrous oxide (N2O) in urban landscape water under anoxic conditions during summer. The findings reveal that CaO2 addition not only improved the physicochemical and organoleptic properties of simulated urban landscape water but also reduced N2O production by inhibiting the activity of denitrifying bacteria across various dosages. Moreover, CaO2 exhibited selective effects on methanogens. Specifically, the abundance of acetoclastic methanogen Methanosaeta and methylotrophic methanogen Candidatus_Methanofastidiosum increased whereas the abundance of the hydrogenotrophic methanogen Methanoregula decreased at low, medium, and high dosages, leading to higher CH4 production at increased CaO2 dosage. A comprehensive multi-objective evaluation indicated that an optimal dosage of 60 g CaO2/m2 achieved 41.21 % and 84.40 % reductions in CH4 and N2O production, respectively, over a 50-day period compared to the control. This paper not only introduces a novel approach for controlling the production of GHGs, such as CH4 and N2O, from urban landscape water but also suggests a methodology for optimizing CaO2 dosage, providing valuable insights for its practical application.

Hydrogen peroxide oxidation modifies the structural properties and allergenicity of the bee pollen allergen profilin.

Bee pollen is a byproduct of pollination, which is a necessary process to produce foods. However, bee pollen can induce significant food-borne allergies. We previously identified a bee pollen-derived pan-allergen in the profilin family, Bra c p. Herein, we aimed to reduce Bra c p allergenicity via protein oxidation with hydrogen peroxide and explore the changes induced. Ion-mobility mass spectrometry revealed aggregation of the oxidized product; we also found irreversible sulfonation of the free sulfhydryl group of the Bra c p Cys98 residue to a more stable cysteine derivative. A significant proportion of the α-helices in Bra c p were transformed into ß-sheets after oxidation, masking the antigenic epitopes. An immunoassay demonstrated that the IgE-binding affinity of Bra c p was decreased in vitro after oxidation. To our knowledge, this is the first report describing the application of protein oxidation to reduce the allergenicity of profilin family member in foods.

Potential of indigenous plants seed extracts of Anisophyllea boehmii and Aframomum sanguineum from Burundi to protect against oil oxidation.

The objective of seed extracts from Anisophyllea boehmii and Aframomum sanguineum were to evaluate their ability to stabilize against oxidation of oils exposed to sunlight on one hand and subjected to high temperatures on the other hand. Determination of the peroxide value (PV) showed that the extracts had reduced the oxidation of sunflower oils. After 8 weeks of sunlight exposure, the concentration of 265.45 mg/l of A. boehmii extract showed a PV of 30.78 meq O2/kg, 67.4 mg/l extract of A. sanguineum had a PV of 42.75 meq O2/kg while the oils without extracts had a very high PV (125.06 meq O2/kg). Heating of the oils to 180°C for 8 hours was found, with A. boehmii extract (265.45 mg/l), to have a PV of 29.66 meq O2/kg, with that of A. sanguineum, while the PV of the oils without extract reached 50.66 meq O2/kg. In the light of these results, the seeds of A. boehmii and A. sanguineum contain antioxydant compounds, which, once extracted, can be used for many purposes in the food processing, pharmaceutical and cosmetic industries.

Colorimetric determination of peroxide value in vegetable oils using a paper based analytical device.

Peroxide value (PV) is one of the most typically used quality parameters to monitor lipid oxidation. Here, a simple paper-based analytical device (PAD) has been developed to determine PV in vegetable oils. The analysis is based on setting up the iodometric titration, where hydroperoxides in the oil are reacted with excess iodide ions to generate iodine molecules, on the paper substrate. The device is composed of two paper layers acting as reaction and detection zones, aligned in a metallic mold. A well-defined inverse logarithmic calibration curve was established between the measured PV by the official iodometric method (ISO;3960, 2017) and the color intensity of PAD. It offered a working range of 0.01-30.0 meq/Kg. The limit of detection of 0.015 meq/Kg demonstrated enough sensitivity of the method to estimate peroxide value in edible oils. On-site and visual detection, low cost, simplicity, and less solvent consumption are advantages of the proposed device.

1H LF-NMR Self-Diffusion Measurements for Rapid Monitoring of an Edible Oil's Food Quality with Respect to Its Oxidation Status.

The food quality of edible oils is dependent on basic chemical and structural changes that can occur by oxidation during preparation and storage. A rapid and efficient analytical method of the different steps of oil oxidation is described using a time-domain nuclear magnetic resonance (TD-NMR) sensor for measuring signals related to the chemical and physical properties of the oil. The degree of thermal oxidation of edible oils at 80 °C was measured by the conventional methodologies of peroxide and aldehyde analysis. Intact non-modified samples of the same oils were more rapidly analyzed for oxidation using a TD-NMR sensor for 2D T1-T2 and self-diffusion (D) measurements. A good linear correlation between the D values and the conventional chemical analysis was achieved, with the highest correlation of R2 = 0.8536 for the D vs. the aldehyde concentrations during the thermal oxidation of poly-unsaturated linseed oils, the oil most susceptible to oxidation. A good correlation between the D and aldehyde levels was also achieved for all the other oils. The possibility to simplify and minimize the time of oxidative analysis using the TD NMR sensors D values is discussed as an indicator of the oil's oxidation quality, as a rapid and accurate methodology for the oil industry.

Effects of Ligustrum robustum (Rxob.) Blume extract on the quality of peanut and palm oils during storage and frying process.

The potential uses of Ligustrum robustum (Rxob.) Blume extract as a natural antioxidant to protect the quality of different oils during storage and frying process were studied. The results showed that L. robustum extract has been shown to retard the decline in the quality of both oils based on the tests of acid value, peroxide value, p-anisidine value, color, volatile flavor, and fatty acid compositions, and the protective effect of L. robustum extract on the quality of peanut oil was better than that of palm oil. By the component analysis, L. robustum extract was found to have a total phenols content of 140.75 ± 1.52 mg/g, and ligurobustoside C was identified as the main phenolic compound. The thermogravimetric and differential scanning calorimetry results showed that L. robustum extract enhanced the oxidative stability of peanut and palm oils. In addition, Fourier transform infrared results indicated that L. robustum extract had protective effects on the C=C bond and ester bond of oil molecule. Moreover, by using electron spin resonance technique, L. robustum extract showed the ability to inhibit and scavenge alkyl-free radicals in both oils. The present results suggested that L. robustum extract may protect the quality of oils during the storage and frying process by inhibiting the oxidation of unsaturated fatty acids and might be a potential natural antioxidant in the food industry. PRACTICAL APPLICATIONS: The excellent antioxidant ability of Ligustrum robustum (Rxob.) Blume extract on the oxidation of different oils and its low price indicated that it could be used as a new low-cost natural antioxidant in oil processing.

Evaluation of the Effect of Elite Jojoba Lines on the Chemical Properties of their Seed Oil.

Jojoba oil (JO) extracted from seeds has outstanding properties, including anti-inflammatory, antioxidant, and antibacterial activities, and can be stored forlong periodsof time. The unique properties of jojoba oil depend on its chemical composition; therefore, the effect of the jojoba genotype on the chemical properties and active components of the seed oil was evaluated in this study. Oil samples were collected from 15 elite Egyptian jojoba lines. The chemical composition, such as moisture, crude fiber, crude oil, ash, and crude protein of elite lines' seeds was determined to investigate the variation among them based on the jojoba genotype. In addition, the iodine value was obtained to measure the degree of jojoba oil unsaturation, whereas the peroxide number was determined as an indicator of the damage level in jojoba oil. Fatty acid composition was studied to compare elite jojoba lines. Fatty acid profiles varied significantly depending on the jojoba genotype. Gadoleic acid exhibited the highest percentage value (67.85-75.50%) in the extracted jojoba oil, followed by erucic acid (12.60-14.81%) and oleic acid (7.86-10.99%). The iodine value, peroxide number, and fatty acid composition of the tested elite jojoba lines were compared withthose reported by the International Jojoba Export Council (IJEC). The results showed that the chemical properties of jojoba oils varied significantly, depending on the jojoba genotype.

Comparison of the Oil Quality of Light and Dark Walnuts under Different Storage Conditions.

The skin of the walnut kernels can get dark during the pre- and post-harvest stages of the production. Dark kernels are less palatable for most consumers but are still edible and maybe preferable, especially in the ground form, for industrial use. In this study, we investigated the differences between oil oxidation indexes, fatty acid and tocopherol compositions of the oils, total polyphenol contents and antioxidant capacities of the extracts of light and dark walnuts. In addition, we evaluated the effects of packaging under nitrogen and vacuum-packaging techniques and storage temperature on these characteristics of both light and dark walnuts during storage for 6 months. Peroxide values and free fatty acid contents of all samples were higher at the end of storage compared to initial values, being more noticeable at 20°C than at 4°C. Increases in the free fatty acid contents were quite higher in dark walnuts than the light ones (6.1 and 3.1 fold, respectively) and the highest values of conjugated diene and peroxide were determined in the samples packaged under air and stored at 20℃. Dark walnuts had lower total phenolic, α- and γ-tocopherol contents and antioxidant activities compared to the light ones. Total phenolic and tocopherol contents decreased over time. We conclude that due to the antioxidant compounds in the fruit, oxidation parameters of dark walnuts are still acceptable at the end of 6-month storage even in the packages with air and at non-refrigerated conditions.

Analytical methods for determining the peroxide value of edible oils: A mini-review.

Edible oils are prone to oxidation during processing and storage that may negatively affect the oil quality and human health. Determining the peroxide value (PV) of edible oils is essential because PV is one of the most typically used quality parameters to monitor lipid oxidation and control oil quality. Many approaches have been developed to determine the PV of oils. Among them, iodometric titration is the commonly used method for PV determination. Considering the limitations related to titrimetric methods, such as time and environmental concerns, several instrumental techniques have been considered as reliable alternatives. The advantages and limitations of classical titration and instrumental methods are summarized in this review. The prospects and reformative aspects for the future applications of these approaches in PV determination are also discussed.

Quality assessment of cold-pressed strawberry, raspberry and blackberry seed oils intended for cosmetic purposes.

BACKGROUND: Cold-pressed berry seed oils are used for consumption and other applications including skin and hair care. They are natural products which gain the attention of customers. In this study, strawberry, raspberry and blackberry seed oils used for cosmetic purposes, purchased from three different European producers, were analyzed. The aim of the study was to assess the quality and oxidative stability of the berry fruit oils, thus they were analyzed after purchase and after 4 and 8 weeks of storage at room temperature. METHODS: Acid and peroxide values were determined in the tested oils, as was oxidative stability, which was measured using pressure differential scanning calorimetry (PDSC). Additionally, fatty acid profiles and thei. RESULTS: nd. Cold-pressed berry seed oils are used for consumption and other applications including skin and hair care. They are natural products which gain the attention of customers. In this study, strawberry, raspberry and blackberry seed oils used for cosmetic purposes, purchased from three different European producers, were analyzed. The aim of the study was to assess the quality and oxidative stability of the berry fruit oils, thus they were analyzed after purchase and after 4 and 8 weeks of storage at room temperature. Materials and methods. Acid and peroxide values were determined in the tested oils, as was oxidative stability, which was measured using pressure differential scanning calorimetry (PDSC). Additionally, fatty acid profiles and their distribution at sn-1,3 and sn-2 positions of triacylglycerols were characterized. Results, principal. Most of the fatty acids of the tested berry seed oils are polyunsaturated fatty acids (67.04-74.95%). The results show the low quality of the tested oils in terms of oxidative stability (high peroxide values: 21.9-249.6 mEq O2/kg oil). CONCLUSIONS: Based on this study, it is necessary to evaluate the effects of these products on the body. Moreover, standards clarifying the oxidation of cosmetic oils should be set internationally.

The effects of microwave application on the physicochemical properties of bacaba (Oenocarpus bacaba Mart.) oil.

BACKGROUND: Bacaba (Oenocarpus bacaba Mart.) has a high yield of oil, with the potential to produce biologically active natural products and can be considered a new "superfruit" with high value added. METHODS: Acid value, peroxide value, refractive index, saponification value, p-anisidine value, relative density, iodine value, total oxidation value, specific extinction coefficients at 232 and 270 nm (K232 and K270), ΔK, and color were determined. RESULTS: The most significant changes in the quality values, such as peroxide (26.25 mEq·kg-1), p-anisidine (11.41), acidity (14.66 mg KOH·g-1 oil), and total oxidation (63.92) were determined for 15 min of microwave heating. CONCLUSIONS: The microwave heating promoted the acceleration of oxidative processes showing that, overall, much care should be taken when heating the bacaba oil by microwave to avoid oil degradation.

Effects of Harvest Time on the Yield, Quality and Active Substance of Torreya grandis Nut and Its Oil.

Torreya grandis is an important economic tree species in China. It provides nutritional value and is important to the health care industry. There are ongoing issues with product quality which are primarily related to improper management and early harvest. This study was carried out during the fruit ripening processes to evaluate the influence of harvesting date on T. grandis quality, and to determine the optimal harvest period. The effects of harvest time on the variation of quality and nutritional parameters of T. grandis nuts and its oil were evaluated, and the optimal harvest period was determined. The results showed that harvest timing had a strong effect on both oil yield and quality. Prolonged ripening could induce higher levels of kernel rate, fruit inclusions, oil and nutritional quality. When the sample harvested in the mid-September, the kernel rate and oil content were increased by 1.88±0.31% and 6.65±0.47%, respectively, compared to samples harvested in the beginning of late-August. Similarly, the mid-September harvest resulted in total unsaturated fatty acids content of the oil being increased by 5.3±0.34%, the FFA and peroxide value being decreased by 40.7±0.15% and 76±0.08%, respectively, and total tocopherols and free amino acids were increased 7.5±0.24% and 47.3±0.15%, respectively, compared to the samples harvested on Aug. 25. The results indicated that the optimal harvest time of T. grandis fruits was mid-September as it was beneficial for improving the quality of T. grandis nut and its oil. It was suggested that T. grandis fruit should be harvested later.

Chemical and Physical Characterization of the Hackberry (Celtis australis) Seed Oil: Analysis of Tocopherols, Sterols, ECN and Fatty Acid Methyl Esters.

For the very first time, the nutritional and physicochemical properties of the oil extracted from hackberry Celtis australis fruit were investigated with the aim of possible applications of such wild fruit oil. The physicochemical properties such as peroxide value, acidity, saponification, iodine value and total fat content of the extracted oil were examined extensively. The obtained results showed that peroxide value, acidity, saponification, iodine value and total fat content of the extracted oil were found to be 4.9 meq O2/kg fat, 0.9 mg KOH/g fat, 193.6 mg KOH/g fat, 141.52 mg I2/g fat and ~5%, respectively. The predominant fatty acid found in this wild fruit is linoleic acid which was calculated to be 73.38%±1.24. In addition, gamma-tocopherol (87%) and ß-sitosterol (81.2%±1.08) were the major tocopherol and sterol compositions found in Celtis australis seed oil. Moreover, equivalent carbon number (ECN) analysis has indicated that the three linoleic acids are the main composition of the triacylglycerols extracted from Celtis australis. Also, the high value of omega 6 and ß-sitosterol make this oil applicable in cosmetics and pharmaceutical applications.

Physico-Chemical Analysis and Fatty Acid Profiling of Fenugreek (Trigonella foenum-graecum) Seed Oil Using Different Solvents.

Fenugreek (Trigonella foenum-graecum) a native to Southern Europe, Mediterranean region and Western Asia has been used as a spice all over the world to increase the sensory quality to the food. It is also known for its medicinal properties such as anti-diabetic, anti-carcinogenic, hypocholesterolemic and immunological activities and can also be used as a food stabilizer and emulsifying agent. The ash, protein, moisture and fiber content of defatted fenugreek seed powder obtained were 9%, 23.04%, 3.8%, 25.47% respectively. So, this study is systematically intended to determine the fatty acid composition, to be best among the different solvents used are the ethanol, petroleum ether, acetone and hexane for the extraction of the fenugreek seed oil and to analyze its susceptibility to oxidation. This study was carried out to investigate and examine the results such as acid value, peroxide value, saponification value, iodine value and the physical properties such as the color value and the refractive index of the seed oil. The results stipulate that the oil extracted using the solvent hexane had better quality and yield. Linoleic acid (41.97%) followed by alpha-linolenic acid (29.33%) and cis-9 oleic acid (12.95%) was found as the primary fatty acids present in the oil extracted using hexane. Along with these fatty acids, the PUFA content of hexane oil (71.30%) was also observed to be in a good range. So, on comparing these results with codex standards, it revealed that it can be considered as edible oil with further purifications.

Effect of Frying on Physicochemical and Sensory Properties of Potato Chips Fried in Palm Oil Supplemented with Thyme and Rosemary Extracts.

Quality parameters of potato chips (flat and serrated) fried either in palm oil (PO) alone or containing natural (thyme (TPO) and rosemary (RPO) extracts) and synthetic BHT (BPO) antioxidants were evaluated during storage period. The free fatty acid and peroxide values of chips fried in PO (control) were found between 0.18 and 0.21% to 1.00 and 1.04 meqO2/kg during the first storage month, respectively. However, these values were 0.07-0.10% and 0.55-0.90 meqO2/kg for chips fried in TPO, respectively. The water contents increased when storage time increased from 1 to 7 month and their values changed between 0.49 and 1.95% (flat potato chips in BPO) and between 0.88 and 1.24% (serrated potato chips in TPO). The total trans-fat contents were 0.13% (serrated potato chips in BPO) and 0.35% (both flat and serrated potato chips in PO) at the start of storage. The total trans-fat content after 7 months were 0.13% (PO fried flat and serrated potato chips) and 0.17% (serrated potato chips fried in BPO, TPO and RPO). The acrylamide contents varied between 152 (serrated potato chips in PO) and 540 µg/kg (flat potato chips fried in RPO) at the beginning of storage. However, the acrylamide contents changed during 7th storage month and ranged from 182 (serrated potato chips in PO) to 518 µg/kg (flat potato chips in RPO). Among fatty acids, while palmitic acid are determined between 37.14 (flat chips in PO) and 41.60% (serrated chips in TPO), oleic acid varied between 30.0 (flat chips in RPO) and 33.00% (serrated chips in PO). Sensory evaluation showed that PO containing antioxidants showed better consumer preference for potato chips until the end of storage.

Effect of Star Fruit (Averrhoa carambola L.)By-product on Oxidative Stability of Sesame (Sesamum indicum) Oil under Accelerated Oven Storage and during Frying.

Aim of this study was to evaluate the effect of star fruit (Averrhoa carambola L.) by-products (peel and residue) on stability of sesame (Sesamum indicum) oil against oxidation. Antioxidant properties of extract of peel and residue at different time durations of extraction were determined and found that peel contains higher antioxidant potential than residue. Thus, extract of peel obtained after 24 h extraction was used to study its effectiveness on oxidative stability of sesame oil during accelerated oven storage and frying using the butylated hydroxytoluene (BHT) (200 ppm) as the reference antioxidant (positive control) and oil without added antioxidant as the negative control. The oxidative stability of the oil was determined by evaluating peroxide value, p-anisidine value, thiobarbituric acid reactive substances (TBARS) value, total oxidation (TOTOX) value, conjugated diene (CD) and conjugated triene (CT) values, and iodine value. Peel extract at different concentrations (200-1000 ppm) was tested. The oil added with peel extract exhibited higher stability against oxidation than the controls during oven storage test. Extract at 1000 ppm significantly increased the stability of sesame oil during frying as compared with controls. Thus, star fruit peel extract could be an alternative to synthetic antioxidants to suppress oxidation of edible oils.

Effect of Rosemary Extracts on Stabilitiy of Sunflower Oil Used in Frying.

The oxidative stability of sunflower oil containing rosemary essential oil and extracts in the oil during frying were followed by measuring peroxide value. Variation in the values of L* of the frying oil containing extract was less than that of frying oil containing essential oil. a*-Value of the fried oil containing extract highly significant decreased. Increase in the value of b* of 1. and 2. frying oil with 0.5 % rosemary essential oil was less. b* Value of the frying oils containing rosemary extract increased compared to b* values of frying oils containing essential oil. b* Value of the frying oil that the essential oil of rosemary added showed less increase than b* value of the frying oil that extract of rosemary. The viscosity values of frying oils containing rosemary extract changed between 30.3 mPas (1. frying oil containing 0.5% extract) and 35.5 mPas (2. frying oil containing 0.5% extract). In addition, free fatty acidity values of frying oils containing essential oil at 0.1, 0.3 and 0.5% levels ranged from 0.160% (1. frying oil containing 0.5% essential oil) to 0.320% (1. frying oil containing 0.3% essential oil). Peroxide values of frying oils containing rosemary extracts were determined between 12.84 meq O2/kg (1. frying oil containing 0.1% extract) and 28.98 meq O2/kg (2. frying oil containing 0.1% extract). Peroxide value of frying made with 0.3 % the rosemary essential oil increased less than that of made with the raw sunflower oil (control) (p < 0.05). Whenever rosemary essential oil and rosemary extract compare, the essential oil seems to be more effective on the peroxide value of the frying oil. The essential oil of rosemary have been effected more from the extracts of rosemary on the oxidative stability of sunflower oil.

Thermal Stability and Sensory Acceptance of Cupcakes Containing Red Palm Olein.

The study was designed to evaluate the nutritive value, thermal stability and consumer acceptance of cupcakes baked with red palm olein compared to palm olein. Thermal stability was evaluated for acidity, peroxide, p-anisidine and total oxidation value (cumulative between peroxide and p-anisidine values), as well as fatty acid composition. The concentrations of phytonutrients including tocopherols and tocotrienols, alpha- and beta-carotene after baking were also determined. Acceptance of the cupcakes was assessed using a structured hedonic scale of five points by 29 panelists. As compared to initial test oil (red palm olein), acidity (red palm olein, 0.07±0.01% vs cupcakes containing red palm olein, 0.09±0.01%; P=0.0232), peroxide value (red palm olein, 0.33±0.05 meq O2 kg-1 vs cupcakes containing red palm olein 0.73±0.06 meq O2 kg-1; P=0.0011) and total oxidation value (red palm olein, 2.24±0.13 unit vs cupcakes containing red palm olein, 3.09±0.17 unit; P=0.0012) were found to be higher in cupcakes containing red palm olein, which is within the acceptable rancidity range (peroxide value < 7.5 meq O2 kg-1) for snack food category. No changes were found on oxidative parameters (acidity, peroxide, p-anisidine values and total oxidation value) in cupcakes containing palm olein. Cupcakes made with red palm olein retained nearly 100% of alpha- and beta-carotenes upon baking. Tocopherol homologues were stable in both comparisons, with 95% retention as compared to tocotrienol homologues (~85%). Cupcakes made from red palm olein received higher score (mean=3.29) in sensory evaluation as compared to cupcakes containing palm olein (mean=3.07). The study, therefore, encourages the inclusion of red palm olein in the formulation of bakery products.

New Rare Ent-Clerodane Diterpene Peroxides from Egyptian Mountain Tea (Qourtom) and Its Chemosystem as Herbal Remedies and Phytonutrients Agents.

Genus Stachys, the largest genera of the family Lamiaceae, and its species are frequently used as herbal teas due to their essential oils. Tubers of some Stachys species are also consumed as important nutrients for humans and animals due to their carbohydrate contents. Three new neo-clerodane diterpene peroxides, named stachaegyptin F-H (1, 2, and 4), together with two known compounds, stachysperoxide (3) and stachaegyptin A (5), were isolated from Stachys aegyptiaca aerial parts. Their structures were determined using a combination of spectroscopic techniques, including HR-FAB-MS and extensive 1D and 2D NMR (1H, 13C NMR, DEPT, 1H-1H COSY, HMQC, HMBC and NOESY) analyses. Additionally, a biosynthetic pathway for the isolated compounds (1-5) was discussed. The chemotaxonomic significance of the isolated diterpenoids of S. aegyptiaca in comparison to the previous reported ones from other Stachys species was also studied.

Influence of Sumac Extract on the Physico-chemical Properties and Oxidative Stability of Some Cold Pressed Citrus Seed Oils.

The acidity values changed between 1.03 mgKOH/100g (control) and 1.11 mgKOH/100g (0.1% extract) for orange oil, 1.06 mgKOH/100g (0.5% extract) and 1.13 mgKOH/100g (0.1% extract) and 1.25 mgKOH/100g (0.5% extract) and 1.31 mgKOH/100g (control) for mandarin oil. The peroxide values were determined between1.37 meqO2/kg (0.5% extract) and 1.43 meqO2/kg (0.1% extract) for orange oil, between 1.24 meqO2/kg (control) and 1.27 meqO2/kg (0.1% extract) for lemon and 1.60 meqO2/kg (0.5% extract) and 1.71 meqO2/kg (control) in mandarin oil samples. The viscosity values of samples changed between 0.051 Pa.S (control) and 0.065 Pa.S (0.5% extract) for orange, 0.051 Pa.S (control) and 0.067 Pa.S (0.5% extract) lemon and 0.044 Pa.S (control) and 0.057 Pa.S (0.5% extract) in mandarin oil samples. At the end of storage study (28th day), the acidity values significantly changed, and their values ranged between 2.28 mgKOH/100g (0.5% extract) and 3.64 mgKOH/100g (control) in orange, 1.67 mgKOH/100g (0.5% extract) and 2.28 mgKOH/100g (control) in lemon and 1.74 mgKOH/100g (0.5% extract) and 2.36 mgKOH/100g (control) in mandarin oil samples. While peroxide values vary between 11.68 meqO2/kg (0.5% extract) and 32.57 meqO2/kg (control) for orange, 12.55 meqO2/kg (0.5% extract) and 34.63 meqO2/kg (control) for lemon and between 17.56 meqO2/kg (0.5% extract) and 37.81 meqO2/kg (control) for mandarin oils, viscosity values after 28 day storage changed between 0.123 Pa.S (0.5% extract) and 0.675 Pa.S (control) in orange, 0.257 Pa.S (0.5% extract) and 0.697 Pa.S (control) in lemon and 0.215 Pa.S (0.5% extract) and 0.728 Pa.S (control) in mandarin oil samples.