Fresh Orange Peel Research Articles

Construction of Riboswitches for Screening Antibacterial Agents from Forest Plants

Forest plants contain abundant natural products, providing a valuable resource for obtaining compounds with various functional activities, such as antimicrobial, lipid-lowering, and immunoregulatory activities. The development of efficient tools for rapidly screening functional natural products from forest plants is essential for human health. In this study, we constructed some transgenic strains (Escherichia coli) containing Ahy1-1 riboswitches that respond to cyclic di-guanylate (c-di-GMP), serving as a novel bacteriostatic target. The Ahy1-1 riboswitches contained the LacZ gene (encoding β-galactosidase) and c-di-GMP aptamer in order to monitor β-galactosidase activity due to changes in c-di-GMP. After co-incubating with extracts from fresh orange peel, fresh tea leaves, and Fuzhuan brick tea, the orange peel exhibited a significant inhibition of c-di-GMP generation. The extract of tea leaves had a minor influence on the synthesis of c-di-GMP, whereas Fuzhuan brick tea, which is fermented by various microorganisms, inhibited the production of c-di-GMP. Our constructed transgenic strains could be used to screen for antibacterial agents from forest plants. Beyond antibacterial agents, other functional compounds from forest plants could be selected by designing diverse riboswitches.

Equilibrium Kinetic and Thermodynamic Adsorption of Ni and Cd Ions from Waste Water Using Orange Peel

The aim of this study is to evaluate fresh orange peels as low cost available adsorbent for removing nickel and cadmium ions from laboratory solutions and record the adsorption capacity, which represents the amount of up take per amount of fresh orange peels (FOP). Fourier-Transform Infrared Spectroscopy (FTIR) analyses of FOP was carried out and comparing with the peaks of standard FTIR of cellulose matter to show functional groups and finger print that found in FOP formula. Batch experiments were carried out at different conditions: Ni and Cd ions initial concentration are (10, 20, 30, 40, and 50) ppm, FOP dosage (0.5, 0.75, 1, and 1.5) g, pH (3.5, 5, and 6), contact time (30 to 240) min and temperature (28, 35, and 45) oC where recorded. The results showed that the removal percentage of Ni and Cd increased with increasing FOP dosage. Initial Ni and Cd concentration, pH, and contact time. The best Ni and Cd Removal% where 64% and 80%, respectively at optimum conditions with FOP dosage of 1 g, pH of 6, initial concentration of 50 ppm and contact time of 120 min, where the calculated adsorption capacity was 2.9 mg/g for Ni and 4 mg/g for Cd. In case of the thermal study, best result was obtained at 45 oC with removal% of 65% for Ni and 78% for Cd and adsorption capacity of 2.8 mg/g and 3.7 mg/g for Ni and Cd, respectively.

Modification of pectin with high-pressure processing treatment of fresh orange peel before pectin extraction: Part I. The effects on pectin extraction and structural properties

The possibility of utilizing endogenous plant pectin methyl-esterase (PME) to modify pectin in source material prior to pectin extraction is proposed and explored in this study. This is based on the reports about activation of endogenous PME in plant-based foods by high-pressure processing (HPP) treatment. Fresh orange (Hamlin) peel from a local commercial juice plant was pretreated with HPP at different combinations of pressures and durations, followed by pectin extraction with a commercial method. The effects of HPP pretreatments on pectin yield and structural properties of the extracted pectins were determined. HPP pretreatment increased the yield of subsequent pectin extraction by 41.10 %. Crude extracts from HPP-treated peels showed higher PME activities than the untreated peel. Pectins extracted from HPP pretreated peel (Hp) had a lower degree of methyl-esterification (DM), accompanied by an increase in degree of blockiness (DB) of non-esterified galacturonic acid (GalA) than the control (pectin extracted from un-treated peel). GalA content and linearity of pectin (LP) were higher, while neutral sugar content and degree of branching (DBr) were lower in Hp. The reduction in weight average molecular weight of Hp was minor, and it was positively correlated with a reduction in neutral sugars, indicating an effect of pectin debranching without degradation of the pectin main chain. The effects of HPP on the pectin main chain, degree, and distribution of methyl-esterification in this study were similar to the reported effects of orange PME on extracted pectin. The identified pectin structural features were validated by Fourier Transform Infrared Spectroscopy analysis and a newly developed lateral flow assay. The study indicates that HPP modification of pectin structure in fresh orange peel before pectin extraction may be an efficient and economical way to generate pectin with desirable structural features and to increase pectin yield.

Modification of pectin with high-pressure processing treatment of fresh orange peel before pectin extraction: Part II. The effects on gelling capacity and emulsifying properties of pectin

The most important functionalities of pectin are gelling and emulsifying properties, which can be tailored by modifying pectin structure through chemical/enzymatic treatments or physical processes. In a companion article (Zhao et al., 2023), the modification of pectin structure with high-pressure processing (HPP) was reported. In this study, the functionalities of the HPP-modified pectins (Hp) were evaluated and compared with commercial low methoxy (LM) and high methoxy (HM) pectins. The calcium sensitivity of Hp was comparable to that of commercial LM pectin, which was remarkably higher than the control pectin extracted from untreated peel and commercial HM pectin. Hp had a dramatically higher gelling capacity for calcium-mediated gelation than the control and commercial HM pectin. The strength and viscoelastic properties of Hp-calcium gels were comparable to that of commercial LM pectin. Meanwhile, most of the Hp also showed a comparable gelling capacity for sugar-acid-mediated gelation to that of the control and commercial HM pectin. Hp also had higher emulsifying stability than the control and commercial pectins. The increased capacity of Hp for calcium-mediated gelation was attributed to the block-wise distribution of non-esterified galacturonic acid (GalA) introduced by the HPP treatment, and the higher emulsifying stability was mainly attributed to the debranching of pectin. The study further confirmed that pectin functionalities were highly correlated with its structural properties. The data reveal the great potential of producing low-cost, high-quality pectins with increased gelling capacity and a broadened scope of applications, by adding a simple HPP pretreatment of fresh source material for pectin extraction.

Atsiri Oil Potential of Peel of Kaffir Lime, Lime, and Calamansi Orange as Antioxidant and Antibacteria

Orange is a member of the Rutaceae family which is known as one of the horticultural crops that is widely cultivated in the tropical and subtropical regions of southern Asia. Citrus plants such as fruit peels are used as a source of essential oil-producing ingredients that have antioxidant and antimicrobial activity. This study aims to determine the potential of kaffir lime, lime, and calamansi orange peel essential oils as antioxidants and antibacterials. Scoping review uses the PEOS framework and several databases such as the electronic database Atlantis Press, PubMed, ScienceDirect, and the Google Scholar search engine. Search results that meet the criteria are then analyzed using PRISMA Flowchart, Data Extraction, and Theme Mapping. The results of the scoping review study of 74 articles related to titles and abstracts, 8 articles met the inclusion and exclusion criteria. Essential oils from kaffir lime peel (Citrus hystrix), lime (Citrus aurantifolia), and calamansi orange (Citrus microcarpa Bunge.) have antioxidant and antibacterial activities. The higher the concentration of essential oils from the peel of the fruit, the greater the antioxidant and antibacterial activity produced. Fresh orange peel essential oil has the strongest antioxidant and antibacterial activity compared to orange twig and leaf oil.

Nutritional Analysis of Sweet Orange Peel Extract for Development of Obesity Treatment

Obesity is a complex chronic disease that becomes the main factor of cardiometabolic diseases such as heart diseases, stroke and diabetes mellitus. Oxidative stress is involved in the obesity pathogenesis. Diet and physical exercise are recommended for obesity treatment but many obese people have low compliance to these treatments. Sweet orange (Citrus sinensis L.) is an Indonesian fruit with high production per year. This fruit pulp contains high vitamin C level, which is widely used as a strong anti oxidant to inhibit oxidative stress. However, sweet orange peel is just thrown in the soil and becomes rubbish. Therefore, the aim of this study was to analyze nutritional contents of sweet orange peel extract (OPE). Fresh orange peels were obtained from a local market at the Surakarta city and the dried orange peels were extracted using ethanol solvent. Carbohydrate, protein, and fat levels were determined using the existing method at the Food Technology Laboratory while vitamin C and Magnesium (Mg) levels were determined using the spectrophotometric and SSA-flame methods respectively. 100g OPE contained 68.88% carbohydrate, 3.23% protein, 3.41% fat, 1556.6 mg vitamin C and 239.74 mg Mg. In conclusion, the OPE is a good source of vitamin C and Mg, which can be developed as a nutraceutical for obesity treatment. Further investigation is required to determine active compounds in the OPE, which enhances the beneficial effects of vitamin C and Mg.

Comparative GC Analysis of Valencia orange Ripe and Unripe Peel Essential Oils, Nano-formulation, Anti-Helicobacter Pylori and Anti-inflammatoryEvaluation: in vitro and in silico

Peptic ulcer associated with H. pylori infection and antibiotics resistance warranted the execution of the foregoing study to produce natural and safe alternatives. GC-MS analysis of the essential oil derived from the ripe and unripe peel of Citrus sinensis var. Valencia grown in Egypt was investigated besides its anti-Helicobacter pylori and COX-2 inhibition actions. Ripe mature peels displayed a higher oil yield than unripe ones (0.8 and 0.6%, respectively). Twenty-nine compounds were identified in all samples with volatile monoterpenes as the predominant class, (88.90% and 90.62% in fresh ripe peel (P1) and dried ripe peel (P2), respectively, however unripe fresh orange peel (P3) showed a lower quantity (83.95%). D-Limonene was the major compound in P1 and P2 (85% and 88 %, respectively), while 73% were found in P3. In comparison to standard Clarithromycin (MIC90 = 1.95 ± 0.002 μg/ml), the nano-hexosomal formula of P1 reduced H. pylori action more than P1 alone with MIC90= 1.95 ± 0.0029 μg/ml and MIC90= 3.90 ± 0.006 μg/ml for formulated and unformulated P1, respectively. An anti-inflammatory assay via COX-2 inhibition revealed that the formulated P1 is more potent (IC50= 0.85 μg/ml) than P1 alone (IC50= 2.04 μg/ml) in comparison with Celecoxib® (IC50= 0.28 μg/ml). To unravel the mechanism of the anti-Helicobacter pylori activity, an in silico study on D-Limonene has been performed, using H. pylori urease enzyme, which revealed that D-Limonene showed promising binding scores. Thus, Valencia orange peel essential oil offers a natural, cheap, and relatively safe candidate to combat Helicobacter pylori infection.

Essential Oil Extraction from Orange and Lemon Peel

The one-third of all food produced for human use is wasted each year which has made food waste a serious problem all around the world. Citrus juice manufacturing factories generate peel leftovers that can account for 50-60% of the weight of the fruit, contributing significantly to food waste. This study investigates the extraction of orange and lemon peel oils using the Soxhlet process and their analysis via gas chromatography. The aim is to identify and quantify key volatile compounds present in these oils, thereby putting the leftover peels to use. Fresh orange and lemon peels were transformed into zest and extracted using Hexane and Ethanol as solvent in a Soxhlet apparatus. Gas chromatography with a specialized column and detector unveiled major volatile compounds, including limonene, linalool, citral. These compounds contribute to the characteristic aroma and potential bioactivity of the oils. Orange peels displayed notably higher limonene content compared to lemon peels. This approach illuminated the chemical composition of the oils, offering opportunities in food, cosmetics, and fragrance industries. Orange peels contained 70-90% limonene, significantly more than lemon peels. The study concluded that peels harbor 28 volatile substances, with limonene responsible for their distinctive citrus scent. In sum, this research underscores the effectiveness of Soxhlet extraction, providing insights into orange and lemon peel oils’ composition using Gas chromatography and applications.

Antimicrobial & Free Radical Scavenging Activities of Green Synthesised Copper Nanoparticles from <i>Musa acuminata</i> and <i>Citrus sinensis</i> Peel Extracts

The biosynthesis of nanoparticles is a kind of bottom-up approach where the main reaction occurring is reduction/oxidation. Re-cently, green synthesis of nanoparticles using plant extracts has gained more attention, since they are simple, cost-effective, non-toxic, environment friendly and easily scaled up for large-scale synthesis. There is a great demand for synthesizing Copper nano-particles (CuNPs) by simple and less expensive methods. The peels of a variety of fruits have gained attention as a natural source of antioxidants. Green synthesis of CuNPs was successfully obtained from bio-reduction of copper sulfate pentahydrate solutions using <i>Musa acuminata</i> and <i>Citrus sinensis</i>. CuNPs have been appropriately characterized using UV-vis spectroscopy and SEM analysis. It was observed that CuNPs synthesized from dried orange peel extract had better anti-microbial and antioxidant activi-ty than the fresh orange peel and showed great activity than all the other three samples. Since copper is well-known for its anti-microbial properties, we assumed that fabricating CuNP from banana and orange peel extract can increase its efficiency. The antimicrobial activity of the nanoparticles was analyzed using gram-positive (<i>Staphylococcus aureus</i>), gram-negative (<i>Escherichia coli</i>), and fungal (<i>Aspergillus niger</i>) species. Due to their benign and stable nature and antimicrobial property, these CuNPs may be well utilized for industrial and medicinal purposes.

Facile, One Pot Synthesis of Indoloquinoxaline and its Derivatives Using Aqueous Orange Peel Extract at Room Temperature

A current report expresses that Orange Peel Extract use as catalyticmedium for the synthesis of Indoloquinoxaline derivatives from commercially available starting materials. Isatin and O-phenylenediamine in presence of fresh orange peel extractresulted into desired product at room temperature in a given reaction condition. Advantages of this method include greener and cleaner conditions, shorter reaction time, and good to moderate yield of products. A simple one-pot procedure has been developed for the synthesis of Indoloquinoxaline derivatives from readily available starting materials.

Effect of high pressure carbon dioxide on the browning inhibition of sugar-preserved orange peel

In the present study, the effect of high pressure CO2 (HPCD) pretreatment on the browning of reducing sugar-preserved orange peel was evaluated. Fresh orange peel cubes were subjected to different pressures (4, 7.4 and 9 MPa; 31 °C; 20 min). The changes in the browning-related components during the processing (pretreatment, sugar curing, and thermal drying) of preserved orange peel were studied. The results shown HPCD treatment could slow down the enzymatic browning and Maillard reaction in orange peel. Specifically, A significant decrease in PAL activity (p < 0.05) was found in all HPCD-treated samples. The total phenolic compound, free amino acid, and reducing sugar content in the HPCD-treated samples were higher than in the untreated ones. HPCD treatment inhibits the activity of PAL due to the acidic effect of CO2, and reduces the dissolved oxygen inside the tissue during the decompression process, thereby slowing down the enzymatic browning in orange peel; while the interaction of CO2 and basic amino acids protects the alkali amino acids, thereby slowing Maillard reaction during orange peel sugar curing stage. HPCD pretreatment at 9 MPa could effectively inhibit the browning of processed orange peel (p < 0.05). HPCD application under appropriate treatment conditions has practical implications for the inhibition of browning and provides theoretical support for other preserved fruits.

Chemical composition, antimicrobial and antioxidant activities of Algerian Citrus sinensis essential oil extracted by hydrodistillation assisted by electromagnetic induction heating.

Hydro-distillation assisted by electromagnetic induction heating (H-EMIH) was employed to extract essential oil (EO) from Algerian fresh orange peels (Citrus sinensis). H-EMIH was compared with conventional hydro-distillation (C-H) in terms of hydro-distillation time, yield, chemical composition and, antibacterial and antioxidant activities. It was found that extraction of EO with H-EMIH gave a maximal yield of 3.77% in 35min whereas C-H gave 2.72% in 41min. The extracts obtained by both techniques were analyzed by Gas Chromatography-Mass Spectrometry. Their chemical compositions are relatively similar; limonene and β-myrcene were found as the principal compounds. The antioxidant activity results demonstrated that EO extracted by H-EMIH showed the highest capacity of radical scavenging than EO isolated by C-H process. Otherwise, it was found that EO extracted by H-EMIH exhibited an antimicrobial potentialslightly higher than that extracted by C-H.

Perbandingan Metode Microwave Hydrodiffusion and Gravity (MHG) dan Microwave Steam Diffusion (MSDf) untuk Mengekstrak Minyak Atsiri dari Kulit Jeruk (Citrus Aurantium L.)

Orange production in 2020 projected to reach more than 3.2 million tons, with an estimated growth of 4.93% per year. As a result, large amounts of orange peel are available as a by-product and are treated as waste, creating environmental problems. This problem can be turned into potential if essential oils can be extracted from orange peels. The purpose of this study is to compare the methods of Microwave Hydrodiffusion and Gravity (MHG) and Microwave Steam Diffusion (MSDf) in terms of extraction time velocity, yield, electricity consumption, environmental impact (CO2 gas emissions) and their chemical composition. In this study, 300 grams of fresh orange peel (Citrus aurantium L) used with three microwave power variations: 136 watt, 264 watt, and 440 watt and extraction time of 15 minutes, 30 minutes, 45 minutes, and 60 minutes. The MSDf method produces yields faster than the MHG method at an optimal power of 264 W. In the 20th minute, the MSDf method produces an essential oil yield of 1.95%, while the MHG method produces 1.93% yield at the 40th minute. The MSDf method provides the number of oxygenated compounds (1.4%) is higher than the MHG method (1.12%). This study shows that the MSDf method can produce better quality oils as like as the MHG method. Based on the electricity consumed ratio, the MSDf method is 50% more energy-efficient than the MHG method. Emissions of CO2 gas released into the air in the MSDf method (0.07 kg) are also less than MHG (0.14 kg), so the impact on the environment is not too significant.

Influence of drying techniques on bioactive properties, phenolic compounds and fatty acid compositions of dried lemon and orange peel powders.

Lemon peel powder (LPP) obtained after drying (microwave, infrared, and oven) showed the lowest (58.72%) DPPH-radical scavenging activity in oven-dried and the highest (67.84%) in infrared-dried LPP while that of fresh lemon peel remained 63.22%. Orange peel powder (OPP) showed the lowest DSA (61.65) after microwave and the lowest (63.54%) after infrared-drying while that of fresh orange peel was 63.48%. Total phenolics were between 114.58 (fresh) and 179.69 mgGAE/100g (oven) in LPP and between 158.54 (fresh) and 177.92 mgGAE/100g (infrared) in OPP. The total flavonoid contents were 380.44 (fresh)-1043.04mg/100g (oven) in case of LPP and 296.38 (fresh)-850.54mg/100g (oven) in case of OPP. The gallic acid contents were 2.39 (fresh)-14.02mg/100g (oven) in LPP. The (+)-catechin contents were 1.10 (fresh)-49.57mg/100g (oven) for LPP and 0.82 (fresh)-7.63mg/100g (infrared) in case of OPP. The oleic acid content was 22.99 (infrared)-58.85% (fresh) in LPP-oil and 28.59 (microwave)-61.65% (fresh) in OPP-oil. The linoleic acid contents were 13.76 (fresh)-36.90% (oven) in LPP-oil and 14.14 (fresh)-37.08% (infrared) in case of OPP-oil. The drying techniques showed profound but variable effects on radical scavenging activity, total phenolics, flavonoid, carotenoids, phenolic compounds and fatty acid composition of both LPP and OPP and oven-drying (60°C) was the most effective in improving these bioactive constituents.

Kinetic Modeling of Hydrodistillation of Essential Oil Production from Orange (Citrus sinensis) Peels on Pilot Scale

Present study involves to the pilot scale hydrodistillation process for production of essential oil of orange peels. The production of orange peels essential oil and the effect of several factors such as time, temperature and the ratio of solid/solvent on yield and quality were studied. In this work, we used fresh orange peels of C. sinensis (orange). The quantitative and qualitative analyses of the essential oils of orange peels were performed by GC/MS and sensory analysis. The maximum yield of orange peels essential oil was 1.2384 % (fresh matter) at distillation conditions (ground fresh material, the material-water ratio of 1:2, time of 105 min from the first drop, the temperature of 132 ºC). Kinetic studies of hydrodistillation process showed that the extraction of orange peels essential oil follows first order kinetic (R2 &gt; 0.95). Limonene is the dominant component of the orange peels essential oil that was identified by chromatography-mass spectrometry (94.22 %). The results of test indicated the orange peels essential oil has good qualities which were suitable to the National Standards of Vietnam.

Investigation of physicochemical and antioxidant properties of gelatin edible film mixed with blood orange (Citrus sinensis) peel extract

The present study aims at developing Grey triggerfish skin gelatin films containing phenolic extracts from blood orange (Citrus sinensis) peel, as an alternative for the existing synthetic packaging films. The effect of drying pretreatment on the phenolic compounds’ profile and antioxidant and antibacterial activities of the extracts was investigated. Physicochemical, thermal and mechanical properties of gelatin films incorporated with orange peel extract, at different concentrations and plasticized with glycerol were investigated. Films were also tested for their antioxidant capacity, monitored through the β-carotene bleaching, DPPH radical-scavenging and reducing power activities. Results showed that the fresh orange peel extract (FOPE) was more effective against all bacteria tested and exhibited higher antioxidant effect than the thermally-dried orange peel extract (DOPE). In addition, the LC-ESI-MS analysis showed that the quinic acid was the major compound among the total poly-phenols followed by rutin, trans-ferulic acid, naringenin and 4,5-di-O-caffeoylquinate. After its addition, FOPE modified the mechanical and thermal properties of gelatin films, which showed more deformable texture than the control gelatin film. This effect may be caused by the interactions between phenolic compounds of the extract and gelatin chains, as assessed by the Fourier Transform infrared (FTIR) analysis. The FOPE-added films presented higher antioxidant properties than the control. Furthermore, release kinetics of FOPE through gelatin film showed controlled quasi-Fickian diffusion. The overall results emphasized the potential use of phenolic compounds from blood orange by-products to produce bioactive films intended for food packaging.

Studying safe storage time of orange peel (Citrus reticulata) using high-throughput sequencing and conventional pure culture.

Aspergillus is a fungal genus widely studied all over the world because some species are known allergens and opportunistic human pathogens. The dynamic growth of Aspergillus is a prerequisite for establishing safe storage time of orange peel. In this paper, high‐throughput sequencing technique was used for the first time to analyze the diversity and structure of fungi in the same batch of samples at different periods of time, and 20 batches of fresh orange peel and 56 batches of dried peel were verified. Results shown that the orange peel gradually began to grow Aspergillus fungal after storing for 240 days, and the abundance became maximum at 270 days and then decreased. These results suggest the safe storage time should be from January to August. And orange peel should be dried in August to prevent rapid propagation or metabolic toxicity production of Aspergillus fungi.

Potentialities of using liquefied gases as alternative solvents to substitute hexane for the extraction of aromas from fresh and dry natural products

Abstract The potential of liquefied gases, n-butane, dimethyl ether, and HFO-1234ze as effective and green alternative solvents to substitute hexane has been evaluated for the extraction of aromatic compounds from dry lavender flowers (Lavandula angustifolia Mill.) and fresh orange peels (Citrus sinensis (L.) Osbeck). The performance of these liquefied gases as solvents has been evaluated in terms of yield, olfactory perception, and composition of the extract and also in terms of energy used, green and economic impacts, and regulatory issues. First, a predictive evaluation of the solvation performance of each solvent was carried out using simulations with the conductor-like screening model for real solvent. Then solid–liquid extractions were performed using liquefied gases at a laboratory scale to determine the extraction yield, the chemical composition, and the olfactory perception of each extract. Finally, the applicability of liquefied gas extractions in an industrial process was assessed, taking into account the potential impact on process, quality, safety, regulation, and environment.

UTILIZATION OF ORANGE WASTES FOR PRODUCTION OF VALUE ADDED PRODUCTS

it is well known that orange is the most commonly and popular fruit grown not only in Egypt but allover the world. 75% of the total production of orange are consumed at the fresh form meanwhile 25% are utilized in production of different manufactured forms such as juices, concentrates, and jam. It is also established that the wastes remained after manufacture are 10-15% of the total production. Those wastes in case of being left without any utilization are considered to be very bad source for pollution, insects, and rats especially when they were inside the factories without removal. The wastes include seeds, fibers, and peels. Thus, it was logic and naturally to study the possibility of utilization of those wastes in producing new products. Thus, this study aims to investigate the possibility of utilization of those wastes in producing important products particularly. They were found to possess significant nutrients. In the current research, osmotic dehydration of orange peel using sucrose solution at mild temperature (35oC) was investigated. Sucrose solution (40, 50 and 60% w/w) were employed for osmotic dehydration process. Responses of weight reduction (WR), solid gain (SG), water loss (WL), color (L*, a* and b*) and texture (hardness) and sensory analysis were evaluated. It was found that sucrose concentration significantly (p < 0.05) affected the mass transfer terms during osmosis process. Moisture continent was decreased from 33.64 % in fresh peel to be 16.25% on osmotic dried peels. The obtained results revealed an increase in yellowness (b*), decrease in lightness (L*) and redness (a*) as the sucrose concentration increased. Furthermore, osmotic ally dehydrated samples wereconsiderably softer than untreated samples. Also increasing of sucrose concentration and dehydration time gave softer tissue of dehydrated product compared with the fresh orange peel. Keywords: Orange peel, Osmotic dehydration, color

PERBANDINGAN METODE MICROWAVE HYDRODISTILLATION (MH) DAN MICROWAVE HYDRODIFFUSION AND GRAVITY (MHG) UNTUK MENGEKSTRAK MINYAK ATSIRI DARI KULIT JERUK

One source of essential oil that has long been popular is a citrus fruit (Citrus aurantium). Results waste citrus peel around 500,000 tonnes per year. So the prospects for the utilization of waste orange peel are big enough to extract the essential oil. However, conventional extraction methods have drawbacks in terms of product quality, so to find solutions to these shortcomings, it is necessary to use the extraction method by Microwave Hydrodiffusion and Gravity (MHG). This method combines the use of microwave heating and physical phenomena (hydrodiffusi and earth gravity) at atmospheric pressure, without addition of organic solvents or water. In this study used fresh orange peel material 400 and 500 grams, two variable microwave power of 100 and 300 Watt and the extraction time for 15, 30, 45 and 60 minutes. To know the processing time and the microwave power effective method of MHG, oil composition was analyzed by GCMS to determine the amount of the fraction of oxygenated compounds. The larger of installed microwave power, the higher of operating temperature, so the %yield increases in a shorter time. From the comparison of energy consumed, the MHG method is give 30% more energy efficient than the Microwave Hydrodistillation (MHD) method. The use of microwaves does not change the physical properties of oil. The oil produced from the MHG method has a good quality because it has specific gravity and refractive index values that meet the EOA quality standard and has a greater oxygenated compounds content than the MHD method